I
    EPA460/3-74-023-a
    NOVEMBER 1974
       PROCESS DEMONSTRATION
              AND COST ANALYSIS
         OF  A MASS PRODUCTION
              FORGING TECHNIQUE
                 FOR AUTOMOTIVE
                  TURBINE WHEELS
                           - PHASE I
         U.S. ENVIRONMENTAL PROTECTION AGENCY
            Office of Air and Waste Management
         Office of Mobile Source Air Pollution Control
         Alternative Automotive Power Systems Division
               Ann Arbor, Michigan 48105

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                                             EPA-460/3-74-023-a

      PROCESS  DEMONSTRATION
           AND COST  ANALYSIS
        OF A  MASS  PRODUCTION
           FORGING  TECHNIQUE
FOR AUTOMOTIVE TURBINE  WHEELS -
                     PHASE I
                          by

             M. M. Allen, D. J. Hill, and B. H. Walker

                   Pratt & Whitney Aircraft
                    Florida R&D Center
                      P. O. Box 2691
                West Palm Beach, Florida 33402



                   Contract No. 68-01-0477
                  Project Officer: P. L. Stone
                 Lewis Research Center, NASA
                Project Coordinator: R. B. Schulz
             Office of Air and Waste Management, EPA
                       Prepared for

          U. S. ENVIRONMENTAL PROTECTION AGENCY
               Office of Air and Waste Management
           Office of Mobile Source Air Pollution Control
           Alternative Automotive Power Systems Division
                  Ann Arbor, Michigan 48105

                      November 1974
                                     1670
  ''..,' A' ..,'.1 -,- a r;; . --t, F.oom

Chicago, IL

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This report  is issued by the Environmental Protection Agency  to report
technical data of interest  to a limited  number of readers.  Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - as supplies permit - from the  Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or,  for a fee, from  the
National Technical Information Service, 5285 Port  Royal Road, Springfield,
Virginia 22161.
This report was  furnished to the U. S. Environmental Protection Agency
by Pratt & Whitney Aircraft, in fulfillment of Contract No. 68-01-0477,
which was administered by the Lewis Research Center, NASA, under an
EPA-NASA interagency agreement.  This report  has been reviewed  and
approved for publication by the Environmental Protection Agency.  Approval
does not signify that  the contents necessarily reflect  the views and policies
of the agency.  The material presented in this report may be based on an
extrapolation of the "State-of-the-art."  Each assumption must be carefully
analyzed by the reader to assure that it is acceptable for his purpose.
Results  and  conclusions should be viewed correspondingly.  Mention of
trade names or commercial products does not constitute endorsement or
recommendation for use.
                  Publication No.  EPA-460/3-74-023-a
                                   11

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                                    TECHNICAL REPORT DATA
                             (Please read Instructions on the reverse before completing)
 1. REPORT NO.
  EPA-460/3-74-023-a
                               2.
                                                             3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
  Process Demonstration and Cost Analysis of A Mass
  Production Forging Technique for Automotive Turbine
  Wheels - Phase I
                                                             5. REPORT DATE
                                                               November 1974
              6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)

  M.  M. Allen, D. J. Hill, B.  H. Walker
              8. PERFORMING ORGANIZATION REPORT NO.

                FR-6690
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Pratt & Whitney Aircraft
  Florida Research and Development Center
  P.O.  Box 2691
  West  Palm Beach, Florida 33402
              10. PROGRAM ELEMENT NO.
                1 AB 017
              11. CONTRACT/GRANT NO.

                68-01-0477
 12. SPONSORING AGENCY NAME AND ADDRESS
  U.S. Environmental Protection Agency
  Office of Mobile Source Air Pollution Control
  Alternative Automative Power Systems Development Division
  Ann Arbor, Michigan  48105	
                                                             13. TYPE OF REPORT AND PERIOD COVERED
                Final Report
              14. SPONSORING AGENCY CODE
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT
      Low cost fabrication of integrally-bladed automotive turbine wheels utilizing the
      GATORIZING forging process was demonstrated.  Basic forging parameters
      were developed for the nickel-base alloy IN 100.  Several wheels were produced
      and post forging heat-treating studies were conducted to develop an optimum com-
      bination of stress-rupture and LCF properties.  Target goals for these properties
      were higher than those achieved in this initial study.  The capabilities and limita-
      tions of the forging process are defined along with an estimate of turbine wheel
      cost in large production quantities.
 7.
                                 KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.IDENTIFIERS/OPEN ENDED TERMS
                            c. COSATI Field/Group
          Gas turbine engine
          Automative engine
          Turbine wheel
          Forging technique
 8. DISTRIBUTION STATEMENT

  Release Unlimited
19. SECURITY CLASS (ThisReport)
    Unclassified
                                                                           21. NO. OF PAGES
                                               20. SECURITY CLASS (Thispage)
                                                    Unclassified
                                                                           22. PRICE
EPA Form 2220-1 (9-73)
                                              iii

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                                                       Pratt & Whitney Rircraft
                                                                        FR-6690
                                FOREWORD
      This report is submitted in accordance with the requirements of Con-
tract  EPA 68-01-0477.  It is the Phase I Final Engineering Report and covers
all the work performed under the contract from 26 April 1973 to 26 July 1974.
      Mr. Marvin M.  Allen, Senior Project Metallurgist,  is the program
manager. Messrs. Bryant H.  Walker, Senior Materials Test Engineer,  and
David J.  Hill,  Metallurgist, are the responsible engineers.  This report carries
the internal  designation PWA  FR-6690.
      The EPA Project Officer for this contract is Phillip  L. Stone, Materials
and Structures Division, NASA-Lewis Research Center. Mr. Stone is working
with EPA under a special technical assistance  agreement between NASA and
EPA.   The EPA Project Coordinator for this contract is Robert B.  Schulz,
Office of Air and Waste Management.
                                    IV

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                                                       Pratt & Whitney Rircraft
                                                                         FR-6690
                                ABSTRACT
      Low cost fabrication of integrally-bladed automotive turbine wheels
utilizing the GATORIZING forging process was demonstrated.  Basic forging
parameters were developed for the nickel-base alloy IN 100.  Several wheels
were produced and post forging heat-treating studies were conducted to develop
an optimum combination of stress-rupture and LCF properties.  Target goals
for these properties were higher than those  achieved in this initial study.  The
capabilities and limitations of the forging process are defined along with an
estimate of turbine  wheel  costs in  large production quantities.

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                                                    Pratt & Whitney fiircraft
                                                                    FR-6690

                              CONTENTS
SECTION                                                         PAGE
          ILLUSTRATIONS	        vii
          SUMMARY	         1
I         INTRODUCTION	         2
H         PROGRAM ELEMENTS AND DISCUSSION	         4
          A.    Task 1 - Basic Process Demonstration	         4
          B.    Task 2 - Process Parameter Evaluation	        15
          C.    Task 3 - Generation of Design Data	        35
          D.    Task 4 - Definition of Manufacturing Process ....        46
          E.    Task 5 - Manufacturing Cost Study	        56
IE        SUMMARY OF RESULTS	        62
IV        RECOMMENDATIONS	        63
                                  VI

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                                                      Pratt & Whitney fi ire raft
                                                                       FR-6690
                             ILLUSTRATIONS
FIGURE                                                             PAGE
1          Phase I - Feasibility Demonstration and Cost Analysis;
           Task 1 - Basic Process Demonstration	         5
           IN 100 Mult Ready for Canning Prior to
           Second Extrusion	
           IN 100 Canned Extrusion Billet,  152.4 MM (6 In.)
           Diameter by 438. 2 MM (17 1/4 In.) Long	
           IN 100 Extrusion - 62.23 MM (2.45 In.) Cut in Tow
           Pieces for Shipping	
5          Typical Microstructure of Double-Extruded IN 100
           Billet Stock	         8
6          Cross Section of Phase I Disk Preform	        10
7          Tooling for Phase I - Task 1 Preform	        10
8          Finish Machined Preform Tooling	        11
9          Task I Wheel Preform	        12
10         Diagram for Test  Specimens Machined from
           Preform and Wheel	        13
11         Task 1 Preform Microstructure Baseline Heat Treat ...        15
12         Phase I - Feasibility Demonstration and Cost Analysis;
           Task 2 - Process  Parameter Evaluation	        16
13         Blade Gradient Study	        20
14         Room Temperature Tensile Properties vs Forging
           Temperature	        24
15         760C (1400F) Tensile Properties vs Forging
           Temperature	        25
16         Tooling for Phase I - Task II Bladed Wheel	        26
17         Blade Insert Concept Used for Finish Die Design	        26
18         Finish Machined Bladed Wheel Tooling Preform	        27
19         Initial Bladed Wheel Forging	        28
20         Modified Blade Cross-Section	        28
21         Fully Bladed Wheel Forging	        29
22         Task II Alternate Heat Treatment Evaluation -
           Electron Photomicrographs	        34
23         Tensile Properties vs Heat Treatment	        36
24         Stress Rupture Capability vs Heat Treatment	        37
25         927C (1700F) LCF  Capability vs Heat Treatment	        38
                                   vn

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                                                      Pratt & Whitney fiircraft
                                                                      FR-6690

                       ILLUSTRATIONS (Continued)
FIGURE                                                            PAGE
26         Phase I - Feasibility Demonstration and Cost Analysis;
           Task 3 - Generation of Design Data	        39
27         Tensile Properties vs Solution Temperature Preform
           Data 1038C (1900F) Forge Temperature	        40
28         Stress Rupture Capability vs Solution Temperature ....        41
29         Automotive Turbine Wheel Design Data Tensile
           Properties of Wrought IN 100	        52
30         EPA Automotive Turbine Wheel Design Data LCF
           927C (1700F)  IN 100	        53
31         EPA Automotive Turbine Wheel Design Data IN 100
           Larson-Miller  Plot of 1. 0% Creep  Life	        54
32         EPA Automotive Turbine Wheel Design Data IN 100
           Larson-Miller  Plot of Stress Rupture  Life	     55
33         Trade-Off Curve:  LCF and Rupture vs Grain Size	        56
34         Plant Layout EPA Rotor Production 191, 000 sq ft	        57
                                   viii

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                                                        Pratt & Whitney Pircraft
                                                                         FR-6690
                                 SUMMARY
      This report describes the work performed under Phase I of a two-phase
program.  The objective of the overall program is to develop a low-cost forging
technique for the production of integrally-bladed automotive gas turbine wheels.
The Pratt & Whitney Aircraft GATORIZING forging technique is being used.
      Phase I consisted of a process definition, process demonstration, mechanical
properties determination,  and a manufacturing cost estimate per unit based on a
production rate of 1, 000, 000 wheels per year.  The wheel selected as a model
was the compressor-turbine wheel for the EPA/Chrysler Baseline Gas  Turbine
Engine.  This wheel is 14.0 cm (5. 5 in.) in diameter tip-to-tip. The material
selected was the Ni-base alloy IN100.
      In Phase I, the basic forging parameters for producing integrally-bladed
turbine wheels were developed and several wheels were successfully produced.
The optimum forging strain rate was determined to be 0. 25  cm/cm/min
(0.1 in./in. /min), with a preform forging temperature of 1038C (1900F) and
final wheel forging temperature of 1093C (2000F).   The heat treatment selected
to achieve an optimum combination of stress-rupture and low cycle fatigue
(LCF) properties was a double solution  at 1177C  (2150F) and 1066C (1950F)
followed  by precipitation at 871C (1600F) and 982C (1800F),  and aging at
649C (1200F) and 760C (1400F).  Design data was obtained from wheels heat
treated as described above.  These data indicated that neither the stress rupture
nor the low cycle fatigue properties met the target values of a 100 hr, 955C
(1750F)  stress-rupture strength of 121  MN/m2 (17.5 ksi),  and 5000 LCF cycles
to failure at 927C (1700F) and a 0. 5% strain range.  The typical properties
were, however,  close to the target values (100 MN/m2, 14.5 ksi and 3200 cycles,
respectively) and were considered as good a combination of properties as could
be achieved within the limits of the investigation using GATORIZED IN 100.
      Design data curves and turbine wheel manufacturing flow sheets were
prepared and are included in this  report along with a description of the capa-
bilities and limitations of the forging process.  The estimated cost per finished
wheel was about $50 in quantities of 1, 000, 000 per year.

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                                                        Pratt & Whitney fiircraft
                                                                         FR-6690
                                 SECTION I
                              INTRODUCTION
      In 1970, the Environmental Protection Agency (EPA) initiated a research
program with United Aircraft Research Laboratories (UARL) to conduct a study
of several selected automotive gas turbine engine concepts that appeared to have
the best possibility of meeting the U.S. Government's automotive engine exhaust
emission standards for 1976.  The study1 included  estimating the probable manu-
facturing cost of several versions of gas turbine engines in quantities of 100, 000
and 1, 000, 000 units annually and comparing the cost of the candidate engines to
current piston engines.
      The major unknown in estimating the cost of the gas turbine engine was
the manufacturing cost of the turbine wheel.  It was assumed that, at the
1, 000, 000 unit annual rate, high-ductility, close-tolerance forging techniques
would be used to produce the turbine wheels to nearly finished dimensions from
the relatively expensive materials specified.  Several proprietary versions of
these basic techniques have been developed by United Aircraft for current military
aircraft engine programs. The basic United Aircraft-patented process, developed
and reduced to practice at the Florida Research and Development Center (FRDC)
of Pratt & Whitney Aircraft (P&WA),  is referred to as the GATORIZING forging
process.
      This process differs from previous hot isothermal forging  methods in  that
the temperature and forging rate are controlled either to produce a condition of
superplasticity in the material being forged, or to maintain a condition of super-
plasticity in material previously placed in that condition by special processing
techniques.   This condition is essentially one wherein a material, over a specific
temperature  and strain rate, flows at a very low stress and  exhibits extreme
ductility.  Exploiting the superplastic state of the material allows forging of com-
plex, contoured shaped wheels to extremely close tolerances,  which substantially
reduces the input weight of the material required and also reduces machining costs.
In addition, smaller,  less costly forging equipment than that required for conven-
tional nickel  base superalloy or titanium alloy forging can be used.
 United Aircraft Research Laboratories Report K-971017-4, "Manufacturing
 Cost Study of Selected Gas Turbine Automotive Engine Concepts," dated
 August 1971.

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                                                        Pratt & Whitney fiircraft
                                                                         FR-6690

      The forged product produced by the GATORIZING process has two distinct
 advantages over a cast wheel.  The enhanced ductility, toughness  and cyclic
 capability inherent in a wrought product will contribute to the reliability and
 durability of the small turbine engine wheels.   Another advantage  of a forging
 is the greater consistency of part quality  and freedom from internal defects.
      In November 1972,  EPA contracted with  Chrysler Corporation for the
 development of an experimental gas turbine engine which would meet the 1976
 Federal Emissions Standards, have good  fuel economy, and would be competi-
 tive in performance,  reliability and potential manufacturing cost with the con-
 ventional piston-engine-powered,  standard size American  automobile (EPA
 Contract No. 68-01-0459).
      In support of the above program,  EPA contracted with Pratt & Whitney
 Aircraft, Florida Research and Development Center, to demonstrate the feasi-
 bility of low-cost production of integrally-bladed automotive turbine wheels.
'This contract is being conducted as a two-phase program.   The first phase,
 described herein, consisted of several  major task areas:  basic process demon-
 stration, process parameter evaluation, generation of design data, definition
 of the manufacturing sequence,  and a manufacturing cost estimate for IN 100
 Chrysler-type compressor-turbine wheels.  IN 100 was selected for several
 reasons: Pratt & Whitney Aircraft has a  great amount of past experience
 forging the alloy; and it had the  potential of  meeting the Chrysler stress-rupture
 and low cycle fatigue  life targets.  Phase n of  the contract has recently been
 initiated. In Phase II, the forging technique will be further refined and a
 material will be selected and characterized so  as to meet the latest EPA/
 Chrysler Upgraded Engine Requirements.

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                                                       Pratt & Whitney Pircraft
                                                                        FR-6690
                               SECTION II
                  PROGRAM ELEMENTS AND DISCUSSION
A.    TASK 1 - BASIC PROCESS DEMONSTRATION
      Task 1 involved the selection of the processing parameters for the raw
material, the initial GATORIZING parameters,  and the selection of the baseline
heat treatment.  These parameters were based on extensive experience with
IN 100.  The raw material was procured, the preform dies were designed and
manufactured, and the initial preform was forged and evaluated.  Task 1 is
shown schematically in figure 1.
1.    Raw Material Procurement  and Evaluation
      IN 100 material, vacuum-induction melted and vacuum-arc remelted from
virgin metals, was provided by Allvac Metals.  The material was supplied from
Allvac heat No. E-073, and the chemistries were within the acceptable range.
The material was machined and canned in stainless  steel for subsequent extru-
sion.  Cameron Iron Works extruded the material at 1066C (1950F) through a
205.7 mm (8.1 in.) orifice,  resulting in a reduction ratio of 6. 8:1.  The extruded
material was then remachined to a 139. 7 mm (5. 5 in.) diameter mult, figure 2,
and recanned in stainless steel, as shown in figure 3.  This mult was re-extruded
at RMI at 1066C through a 62.23  mm (2.45 in.) diameter orifice.  The extrusion
breakthrough pressure was 805.3  MN/m2 (58.4 ksi) and the run pressure was
722.6 MN/m^  (52.4 ksi).  The as-extruded material is  shown  in figure 4.  The
material structure, as-extruded,  was 95 to 98% recrystallized fine grains,  ASTM
11.5 to  16, with some isolated unrecrystallized areas.  Representative photomicro-
graphs are shown in figure 5.  Standard tensile specimens were machined, and
superplasticity tests  were run. The test results, shown in table I,  verified that
the material was in a superplastic condition.
2.    Preform Die Design and Fabrication
      The dies used for the program were manufactured from TZM molybdenum.
This material was selected because of its excellent thermal conductivity, elevated
temperature strength, and wear resistance.   It  is very important that temperature
uniformity be achieved from the center to the edge of the die stack in the GATORIZING
process; experience has shown that temperature gradients are minimal in the radial
direction in TZM molybdenum die stacks up to 76.2 cm (30. 0 in.) in diameter.

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                   VISUAL INSPECTION
               TENSILE
            RT, 760C (1400F)
                                                  SELECT BASELINE
                                                   PARAMETERS
                                                    DESIGN AND
                                                  FABRICATE DIES
                                                FORGE ONE PREFORM
                                                     BASELINE
                                                 HEAT TREATMENT
                                                CUT-UP EVALUATION
    LCF
927C (1700F)
                                         NDI EVALUATION
                                          (ZYGLO, SONIC)
CREEP-RUPTURE
 927C(1700F)
MACROSTRUCTURE
      AND
MICROSTRUCTURE
Figure 1.  Phase I - Feasibility Demonstration and Cost Analysis; Task 1 - Basic Process Demonstration     FD 72646A
                                                                                                                      O

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                                                Pratt & Whitney Oircraft
Figure 2.  IN 100 Mult Ready for Canning Prior to
          Second Extrusion
 FC 29014

 Figure 3.  IN 100 Canned Extrusion Billet,
           152.4 MM (6 In.) Diameter by
           438.2 MM (17 1/4 In.) Long
FAL 28671

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                                                                                                  FE 131243
Figure 4.  IN100 Extrusion - 62.23 mm (2.45 in.) Cut in Two Pieces for Shipping
FD 74444
                                                                                                                        T
                                                                                                                        rV
                                                                                                                        D
                                                                                                                        o

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00
                                      FAM 81111
                     EDGE TRANSVERSE
                                                                                      FAM 81110
                                                                    CENTER TRANSVERSE


                    EDGE LONGFTUDINAL
Figure 5.  Typical Microstructure of Double-Extruded INIOO Billet Stock
                                                                                      FAM 81109
                                                                    CENTER LONGITUDINAL
                                                                                                     FD 74445
BO
|
r-T
0>
p
o

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                                                        Pratt & Whitney fiircraft
                                                                          FR-6690
        Table I.  IN100 Double Extruded Superplasticity Test Results
Specification Flow Stress, Elongation, Reduction of
No. Temperature N/m2 x 106 psi % Area, %
1
2
1079C (1975F)
1079C (1975 F)
67.7
58.7
9820
8510
445
295
99.7
99.7
      Most of P&WA's experience with the GATORIZING forging process has
been with this die material.  Conventional machining and  electrical discharge
machining (EDM) techniques have been well established.  The design of the dies
to forge the preform and bladed wheel was based on our experience with die and
insert designs, lubricants,  and metal flow characteristics.
      A two-step forging sequence was selected to GATORIZE the wheels.  The
first step produced a nonbladed oversized preform, which had a two-fold pur-
pose: (1) to ensure proper metal distribution for forging  the bladed wheel;
and (2) to further enhance the forgeability of the material. The second forging
step was for the purpose of reducing the disk area to final dimensions  and filling
the blade die insert cavities.
      The preform configuration  (figure 6) and preform dies were designed and
the tooling fabricated.  A cross-sectional view of the preform tooling is shown
in figure 7 and photographs  of the actual tooling are shown in figure 8.
3.    Preform Forging and  Evaluation
      One forging mult, 44.45 mm (1.75  in.) in diameter by 85.85 mm (3.38 in.),
was machined from the extruded stock.  The baseline forging and heat treatment
parameters  had been established by prior experience with wrought IN 100.  The
mult was coated with a boron nitride lubricant and GATORIZED at 1038C (1900F)
to the preform configuration.  The forging completely filled the tooling with a
50% reduction flow stress of 23.4 N/m2 (3400 psi) and exhibited an excellent
surface finish.  The strain rate averaged  0.25 cm/cm/min (0.10 in./in./min).
      The preform was subsequently dimensionally checked,  visually and die
penetrant inspected for laps and other surface defects,  and inspected for internal
defects by X-ray and ultrasonic inspection techniques.  The preform was within
allowable dimensional tolerances and had  no surface or internal defects.  The
as-forged preform exhibited a uniform, fully recrystallized fine grained struc-
ture (ASTM  14. 5 to 16. 5).   The forging mult, forged preform,  and representa-
tive microstructure are shown  in figure 9.
                                     9

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                                                       Pratt & Whitney fiircraft
0.076 cm
(0.030 in.) R
                         10.617 cm (4.180 in.) DIA
                               5.588 cm
                           "(2.200 in.) DIA~"





1.930 cm
(0.760 in.)
(R
0.203 cm
(0.080 in.)
t
wi~r<

EF)
f
3.38
-(1.334
I

                         11.201 cm  (4.410 in.) DIA-
   Figure 6.  Cross Section of Phase I Disk Preform
1.458 cm
(0.574 in.)
FD 71221A
              TOP KNOCK OUT
      BOTTOM DIE
                                                        TOP DIE
                                                         PREFORM
                                                          CAVITY
                                    I BOTTOM KNOCK OUT

    Figure 7.  Tooling for Phase I - Task 1 Preform         FD 72643
                                   10

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                                        Pratt & Whitney Rircraft
10.16 em
(4.00 in.)
                  10.16 em
                   (4.00 in.)
10.16 em
(4.00 in,)
                    \  ^fl^.   20.1
                                                    32 em
                                                  (8.00 in.)
Figues 8.  Ftaiih Maehtntd
                        Tooling
                                              FI 13077IA
                                              FI 130773A
                                              FD 7580SA
                    11

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                                            Pratt & Whitney Rircraft
                  BILLET
                                FORGING
                                              FAE 131443
 MAG: 100X
                TYPICAL MICROSTRUCTURE
                                                FD 75604A
     Figure 9.  Task I Wheel Preform
      The selected baseline heat treatment was one which would give the high
strength and LCF life typically required in a turbine disk alloy. At the time,
it was anticipated that it might be necessary to preferentially heat treat the
blades to establish the elevated temperature stress rupture capability.  The
baseline heat treatment was as follows:
Solution:
Precipitation:

Age:
                            1121C (2050F)/2 hr/OQ (oil quench)
                            871C (1600F)/40 min/AC (air cool)
                            982C (1800F)/45 min/AC
                            649C (1200F)/24 hr/AC
                            760C (1400F)/4 hr/AC
                                    12

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                                                      Pratt & Whitney fiircraft

      The preform was heat treated to the baseline heat treatment and test
specimens were subsequently machined from the preform according to the
diagram of figure 10.  This cut-up procedure was essentially the same for all
subsequent preform and bladed wheel evaluations.
                             CREEP RUPTURE
                                  LCF
                       V-NOTCH
                       RUPTURE
CREEP RUPTURE
\
\
      Figure 10.  Diagram for Test Specimens Machined
                 from Preform and Wheel
                      FD 79231A
      Task 1 mechanical property tests conducted included room temperature
and 760C (1400F) tensile tests; 927C (1700F) creep rupture tests at 103.4 MN/m2
(15 ksi); 68. 9 MN/m2 (10 ksi),  and 34. 5 MN/m2 (5 ksi); 871C (1600F) creep
rupture tests at 68.9 MN/m2 (10 ksi); notch rupture tests  at 927C and
103.4 MN/m2;  and 927C LCF tests at 1. 0% and 2. 0% total strain range.  Time
to 1% creep and time to rupture were  recorded on the creep  rupture tests.  The
results of the tests are tabulated in table II.
      The heat  treated preform exhibited a uniform fine grain microstructure
with an ASTM grain size predominantly 10. 5 to 13. 5  with occasional 9. 5.
Electron microscopic review showed the structure to be typical of that afforded
by the baseline heat treatment. Representative photomicrographs at 100X and
1000X are shown in figure 11.  The question of preferential heat treatment of
the blades was  resolved in Task 2.
                                   13

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Table II.  Results of Task 1 Evaluations
Heat Treatment:
Preform S/N:
Forge Temperature:
Baseline
2-4
1038C (1900F)
              TENSILE
Test
C
RT
760
760
Temperature,
F
RT
1400
1400
Test Temperature,
C
927
927
927
927
871
927
927

Test
C
927
927
F
1700
1700
1700
1700
1600
1700
1700

Temperature,
F
1700
1700
0.2% Yield
MN/m2 ksi
Ultimate Elongation,
MN/m2 ksi %
1132.9 164.2 1421.3 206.0 11.3
1059.1 153.5 1135.0 164.5 12.0
1063.2 154.1 1139.1 165.1 11.3
CREEP RUPTURE
Stress Level
Mj^/m2 ksi
103.4
103.4
68.9
34.5
68.9
103.4
103.4





15
15
10
5
10
15
15

Total Strain,
%
2.0
1.0
Rupture
hr
1.6
1.8
4.8
14.6
35.7


STRAIN




Life, Elongation,
Red. of Area, Time to 1
Red. of Area,
11.1
16.4
10.4
. 0% V/N Rupture,
% % Creep, hr hr
100.8
101.0
133.0
108.8
68.0


CONTROL LCF
Mean Strain,
%
1.0
0.5
70.0 0.1
68.2 0.1
84.7 0.2
92.0 1.0
83.6 2.2
 



Total Cycles
28
335
__




3. 1
3.9


Remarks
Failed
Failed
                                                                               3
                                                                               Co
                                                                               0>
                                                                             q
                                                                             S W
                                                                             o :$

-------
                                                 Pratt & Whitney Oircraft
                              CM
MAG: 100X
                                          MAG: 1000X
                                                      FD 84120
     Figure 11.  Task 1 Preform Microstructure Baseline
                 Heat Treat
B.   TASK 2 - PROCESS PARAMETER EVALUATION
     Task 2 was designed to evaluate critical processing parameters, forging
temperatures, forging strain rate, and heat treatment.  Task 2 is shown
schematically in figure 12.  One of two preforms initially forged was used for
gradient bars and heat treat samples to evaluate the microstructural response
to thermal treatment.  The second preform was heat treated to baseline param-
eters and  evaluated in an identical fashion as the Task 1 part to further establish
baseline properties.  Subsequently six additional parts were forged to assess the
effect of forging temperatures, strain rates,  and heat treat variables  on the final
part. Only one parameter was varied at a time, the others being baseline.  The
forging temperature,  forging strain rate, and heat treatment which yielded the
best part consistent with mass production economics was applied  to the Task 3
design data generation.
1.   Preform Forging
     The eight forging multiples were machined from the extruded stock and
boron nitride coated.  Four of these mults were forged into the preform con-
figuration per Task 1  baseline parameters  (i. e., 1038C, 1900F  and 0. 25 cm/cm/min,
0.10 in. /in. /min). Three mults were forged at alternate forging temperatures of
1010 C  (1850 F), 1066C  (1950 F),  and 1093C  (2000 F).  One mult was  forged at
1038 C  (1900 F) at  an accelerated strain rate of 0.38 cm/cm/min (0. 15 in./in./min).
                                    15

-------
                                               FORGE TWO ADDITIONAL
                                                 TASK I  PREFORMS
                                                                                    1
                                                                               HEAT TREAT
                                                                             (SAME AS TASK  I)
                         CUT-UP FOR
                    GRADIENT BAR STUDY
                                                                                    I
                                  VISUAL AND NDI
                                   EVALUATION
                                                                          MECHANICAL PROPERTY
                                                                       AND STRUCTURAL EVALUATION
                                                                             (SAME AS TASK I)
                                                                                    J
                                                SELECT ALTERNATE
                                              PROCESSING PARAMETERS
                    J_
      THREE ADDITIONAL
     FORGE  TEMPERATURES
         T2, T3 AND T4
                     L
ONE ADDITIONAL
 STRAIN RATE
                                                 1
TWO ADDITIONAL HEAT TREATMENTS
  AS DETERMINED FROM GRADIENT
  BAR EVALUATION S2A2 AND S3A3
                                                        _L
                                              FORGE 6 TASK 2 WHEELS
                                             MECHANICAL PROPERTY AND
                                             STRUCTURAL EVALUATION
                                                 (SAME AS TASK I)
                                                SELECT PROCESSING
                                                   PARAMETERS
Figure 12.  Phase I - Feasibility Demonstration and Cost Analysis; Task 2 - Process Parameter Evaluation   FD 72647A
                                                                          CD
                                                                          <
                                                                          5
                                                                          o

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                                                       Pratt & Whitney fiircraft


All eight were visually inspected, dimensionally checked, and found to be satis-
factory.  These preforms were used in the Task 2 evaluations as  summarized in
table III.
2.   Additional Baseline Property Evaluation
     Two of the four preforms forged at the baseline parameters (S/N 2-10
and 2-11) and the preform forged at the  alternate strain rate  (S/N 2-9) were held
for subsequent  reforging into the bladed wheel configuration.   The third baseline
preform (S/N 2-5) was given the baseline heat treatment,  inspected by nondestruc-
tive inspection  techniques, and evaluated using the same procedure as the Task 1
preform.  The  results  are tabulated in table IV,  and are equivalent to the Task 1
baseline properties.
3.   Structural Response to Heat Treatment
     Gradient  bars were cut from the fourth baseline preform (S/N 2-6) to
establish the structural response to heat treatment.  These slices were held at
various solution temperatures up to 1232C (2250F).  Significant grain growth
occurred at temperatures above 1149C  (2100F).  Typical microstructures from
this study are shown in figure 13.  The gradient  bar study showed as expected
that a notable variation in grain size was achievable in the material by varying
the solution heat treatment temperature.  The heat treatments for the Task 2
alternate heat treatment study and the Task 3 blade heat treatments were selected
based on the results of this study.
4.    Effect of  Varying Forging Temperature
      The final form dies were not yet completed, so it was decided to evaluate
the effects  of forge temperature on the preforms,  rather than delay the  program.
Therefore, the three preforms forged at the alternate forge temperatures (S/N 2-3,
2-8, and 2-7) were heat treated to the baseline heat treat  and evaluated  per the
Task 1 procedures.  The data from the evaluations are tabulated in table V.
                                    17

-------
Table III.  Summary of Task 2 Evaluations
S/N
           Forge Temperature,
          Preform     Wheel
        C     (F)    C      (
   Heat Treatment
                                                                        Program Use
                                                       ASTM Grain Size
                                                   Predominate  Occasional
2-5
2-3
1038
1010
1900 -
1850 -
Baseline:
1121C (20i
50F)
Solution,
Baseline
Forge Te
Data
:mperature
10.
! 10.
5 -
5 -
13.5
13.5
9.5
10.0
    2-8     1066   1950   -


    2-7     1093   2000   -


    2-6     1038   1900   -

    2-9     1038   1900   1093   2000


   2-10    1038   1900   1093   2000
2-11    1038   1900   1093  2000
                                      Oil Quench
                                    871C (1600F) Air Cool
                                    982C (1800F) Air Cool

                                    649C (1200F) Air Cool
                                    760C (1400F) Air Cool

                                    Various
                                    Baseline
1177C (2150F) Solution,
 Air Cool + 1121C (2050F)
Solution, Air Cool + Base-
 line Precipitation and Age

1177C (2150F) Solution,
 Air Cool + 1066C (1950F)
Solution, Air Cool + Base-
 line Precipitation and Age
                                                                  Study

                                                                 Forge Temperature
                                                                  Study

                                                                 Forge Temperature
                                                                  Study

                                                                 Gradient Bar Study
                                                                 Alternate Strain
                                                                  Rate Study

                                                                 Alternate Heat
                                                                  Treat Study
                             Alternate Heat
                               Treat Study
                                                     11.5 - 13.5
                                                     9. 5 - 12.5
                                                     11.5 - 13.5
                                                      3.0 - 4.0
                                                                                             4.0 - 6.0
                                                                     13.5
                                                                                                        7.0-10.0
                                                                                                        7.0 - 8.0
                                                                                03
                                                                                D
                                                                                0>
                                                                                O
                                                                              8

-------
Table IV.  Results of Task 2 Baseline Evaluation
Heat Treatment:
Preform S/N:
Forge Temperature:
Baseline
2-5
1038C (1900F)
                 TENSILE
Test
C
RT
760
760

 Test
C
871
871
871
871
871
871
Temperature,
F
RT
1400
1400

Temperature,
1700
1700
1700
1700
1700
1700
0. 2% Yield
M|
                                                                              o 3

-------
                                                            Pratt & Whitney Pircraft
                    1149C  FAM 81096
                    (2100F)
               1 163 C
               (2125F)
                                                 1190C  FAM 81084
                                                 (2175F)
      1204 C  FAM 81oa6
     (2200 F)
MAGNIFICATION: 100X
 1218C  FAM 81092
(2225 F)
 Figure  13.   Blade Gradient Study
      1232C  FAM 81095
      (2250 F)
ETCHANT: KALLING'S

      FD 74447
                                     20

-------
Table V. Results of Task 2 Alternate Forge Temperature Evaluation
Heat Treatment: Baseline
Preform S/N: 2-3, 2-7, 2-8
Forge Temperature: 1010C (1850 F)
1093C (2000F)
1066C (1950F)
TENSILE
Test
C
RT
RT
RT
RT
760
760
760
760
760
760
Temperature,
F
RT
RT
RT
RT
1400
1400
1400
1400
1400
1400
0. 2% Yield
S/N
2-3
2-7
2-8
2-8
2-3
2-3
2-7
2-7
2-8
2-8
MN/m2
1159.1
1106.7
1116.3
1108.7
1070.8
1054. 9
1057.0
1067.4
1062.5
1034.2
ksi
168.0
160.4
161.9
160.8
155.2
152.9
153.2
154.7
154.1
150.0
Ultimate
M^/m2
1331.6
1486.8
1572.0
1509.9
1121.9
1115.0
1131.5
1155.7
1130.0
1111.4

ksi
193.0
215.5
228.0
219.0
162.6
161.6
164.0
167.5
163.9
161.2
Elongation
%
9.3
12.7
24.6
14.7
12.0
13.3
3.3
10.0
14.7
13.3
Red. of Area,
%
12.1
15.9
28.0
16.9
14.5
18.3
4.3
9.5
17.2
12.4
                                                                                               BO
                                                                                               D

                                                                                               CD
                                                                                            to
                                                                                            o

-------
Table V.  Results of Task 2 Alternate Forge Temperature Evaluation (Continued)
CREEP RUPTURE
Test Temperature,
C F
871
871
927
927
927
927
927
927
927
927
927
927
927
to 927
*> 927
927
927
927
927
927
927
927

1600
1600
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700

S/N
2-3
2-7
2-3
2-3
2-7
2-7
2-3
2-3
2-7
2-7
2-3
2-7
2-3
2-7
2-8
2-8
2-8
2-8
2-8
2-8
2-8
2-8

Test Temperature,
C F


927
927
1700
1700
Stress Level Rupture Life, Elongation, Red. of Area Time to 1. 0% V/N Rupture,
MN/m2 ksi hr % % Creep, hr hr
68.9
68.9
103.4
103.4
103.4
103.4
103.4
103.4
103.4
103.4
68.9
68.9
34.5
34.5
103.4
103.4
103.4
103.4
68.9
68.9
34.5
34.5

S/N
2-7
2-7
10
10
15
15
15
15
15
15
15
15
10
10
5
5
15
15
15
15
10
10
5
5




25.2
64.7
0.6
1.3
3.0
3.5


_
-
2.6
5.2
12.5
27.3
1.6
2.1

-
4.9
4.6
15.7
23.9
STRAIN
Total Strain,
%
2.0
2.0
159.0
88.7
142.0
115.0
41.9
104.8
-
-
-
-
83.0
90.1
192.5
232.9
57.9
69.4
-
-
100.2
100.3
139.0
269.0
CONTROL LCF
Mean Strain,
%
1.0
1.0
87.8
81.2
68.2
70.3
62.0
68.0
-
-
-
-
86.0
82.0
92.8
91.5
68.4
72.8
-
-
85.6
84.8
89.5
91.6




1.3
5.8
<0. 1
<0. 1
0.2
<0. 1
-
-
-
-
0.1
0.3
0.5
1.6
0.15
0.18
-
-
<0.3
0.2
0.8
1.6

Total Cycles
21
13
_


-
-

2.6
2.2
6.9
5.7



-
-

4.9
4.0
-




Remarks
Failed
Failed
                                                                                                      TJ
                                                                                                      03
                                                                                                    I
                                                                                                    05
                                                                                                    O
0>
5
o
3

-------
                                                        Pratt & Whitney fiircraft


      The forging temperature study showed that mechanical properties did not
vary significantly with forging temperatures over the 1038C (1900F) to 1093C
(2000F) range investigated.  Room temperature tensile properties are shown in
figure 14.  There appeared to be a degradation in room temperature ultimate
tensile strength with the 1010C  (1850F) forging temperature.  The reasons for
the variation in tensile ductility  have not been explained at this time.   Elevated
temperature ultimate and yield strength were  insensitive to forging temperature
over the entire range investigated as shown in figure 15.  Again a degree of in-
consistency in ductility was noted.  The low cycle fatigue (LCF) test specimens
from the preforms forged at  1010C and 1098C (S/N 2-3 and 2-8) were incor-
rectly machined and could not be tested.  The LCF life of the preform forged at
1093C (2000F) was similar  to the LCF properties of the baseline forgings.
However, all of these initial  tests were conducted at an excessively high, and
unrealistic strain range.  Subsequent LCF testing was done at a lower and more
appropriate strain level of 0. 5%. This lower  strain range was selected based
on the results of an analytical analysis of the wheel using stresses  and tempera-
ture gradients supplied by the Baseline Engine Contractor.
5.    Bladed Wheel Die Design and Manufacture
      The final integrally bladed wheel tooling was designed per Chrysler
drawing No. 2443630,  with the exception of the pockets located in both sides of
the disk rim.  The pockets were excluded for  the Phase I feasibility demonstra-
tion for two reasons:  (1) it was  felt that the primary goal of this initial program
was to demonstrate the feasibility of economically GATORIZING an integrally
bladed wheel of the type used in automotive gas turbines,  and (2) it is highly
probable that the final wheel  design can be modified to exclude pockets, because
of the improved  structural uniformity and higher levels of mechanical properties,
especially LCF, associated with the wrought product.
      A cross section of the  tooling for the final bladed wheel design is shown
in figure 16. The cavities for the 53 blades are formed by simple  split inserts.
This  concept is shown by the 5X model in figure 17.  The finished machined
tooling is shown in figure 18.
                                    23

-------
                                          WHEEL PREFORM DATA  BASELINE HEAT TREATMENT
ibl/
CM
E 1070
S
S 1741
a 
z
UJ
IT
to 1103
96B
^u
' 200
I
I-
U 180
UJ
oc
CO
160
140

c
c

i
3
3 J

5 ]

] [

G

1 r
J L
                     O  ULTIMATE STRENGTH
D - 0.2% YIELD STRENGTH
to
A
- % ELONGATION
s?
Z
g
<
o
0
UJ
Figure 14.
13
14
13
12
11
10
9
98
180
Room r.









L


A




\

L



2C 1010C 1038C 1066C 1093
0F 1850F 1900F 1950F 200C
FORGE TEMPERATURE
Femperature Tensile Properties vs Forging Temperature FD 79
Pratt & Whitney Pircraft
<
m
o u- co
^1 . o q_ M

-------
                                       WHEEL PREFORM DATA    BASELINE HEAT TREATMENT
to
CJ1
1172
CM
.E
5
I
1-
0
 1034
I-
965
Figure 15.
170
i
i-
(3
Z
LU
 150
CO
140
16
14
59 12
Z
0 10
1-
0 8
O
4
2
98
180
760C
e
E

s c
^ r
? \
[
? [

] C
O
] 
~i
J
O - ULTIMATE STRENGTH (~) . o.2% YIELD STRENGTH A - % ELONGATION


A
A AzruiiMia .
A A





2




5




\




Z
TJ
^ !
2C 1010C 1038C 1066C 1093C ^
0F 1850F 1900F 1950C 2000F =
FORGE TEMPERATURE ^
(1400F) Tensile Properties vs Forging Temperature FD 79234A 5
0
3

-------
                                                Pratt & Whitney Rircraft
                          r^-^-\/~
TOP KNOCKOUT PIN

           TOP DIE
        BOTTOM DIE
                                     -BOTTOM KNOCKOUT
                                       SYSTEM
Figure 16.  Tooling for Phase I - Task II Bladed Wheel  FD 74448B
Figure 17.  Blade Insert Concept Used for Finish
           Die Design
                FE 129863A
                              26

-------
                                                         Pratt & Whitney fiircraft
      Figure 18.  Finish Machined Bladed Wheel Tooling       FC 29992
                  Preform                                    FD 79228A
6.    Wheel Forging
      The remaining three Task 2 preforms were machined to clean up the out-
side diameter and assure concentricity in the final form die.   The preforms
were coated with the boron nitride lubricant. Because the Task 2 forging tem-
perature study indicated that forging temperature had no significant  effect on
mechanical properties, a forging temperature of 1093C (2000F) was selected
to assure optimum forgeability.  The baseline strain rate was used for the initial
trials.  The first bladed wheel forging trial  (S/N 2-10) resulted in the partially
bladed wheel shown in figure 19. The lack of blade fill  was attributed to the
degree of taper in the  airfoil thickness  (root to tip).  The  blade cavities were
opened up 0. 25 mm to 0. 51 mm (0. 01 to 0. 02 in.) to minimize the frictional
forces.   In addition, there were problems removing the inserts at room tem-
perature due to the large difference in coefficient of thermal  expansion between
IN 100 and the TZM molybdenum dies.  Because tooling  was not available (re-
quired tooling will be available in Phase II) to remove the inserts while at the
forging temperature a portion of the twist was taken out of the airfoil to facilitate
insert removal at room temperature.  The resulting modified blade cross sections
are shown in figure 20.  The first forging attempt with the modified blade inserts
(S/N 2-14) resulted in a fully bladed wheel as shown in figure 21.  The S/N 2-11
preform  was then also successfully forged.
                                     27

-------
                                                  Pratt & Whitney Oircraft
Figure 19.  Initial Bladed Wheel Forging
FE 137261
FD 79237A
           TIP
        MIDSPAN
          ROOT
                              	CURRENT DESIGN
                              	 MODIFIED TOOLING
Figure 20.  Modified Blade Cross-Section
FD 79246
                              28

-------
                                                        Pratt & Whitney Rircraft
     Figure 21.  Fully Bladed Wheel Forging
KFE 135874
FD 79238A
      The bladed wheel forging trials established initial relationships between
blade shape and forgeability.  The successful forging of the blades after slight
enlargement of the die insert cavities was  attributed to the reduction of die sur-
face friction relative to the flow stress over the increased cross-sectional area.
It is expected that further refinement of the blade shape can be made to further
characterize blade shape and forgeability relationships.
7.    Effect of Varying Forging Strain Rate
      The S/N  2-9 wheel was successfully forged at the accelerated strain rate
from the preform forged at the same accelerated strain rate.  This wheel was
given the baseline heat treatment, cut up and evaluated per Task 1 parameters.
The mechanical property test results are given in table VI.  The properties
were typical of the baseline forgings.  The grain size was ASTM 11. 5 to
ASTM 13. 5 which was also typical of the baseline forgings.  Thus it was deter-
mined that varying the forging strain rate  over the range studied, 0.25 to
0.38 cm/cm/min (0.10 to  0.15 in./in./min), did not adversely affect mechanical
properties or structure.  The baseline strain rate did provide slightly better
forgeability and was therefore specified for the mass production processing
parameters.
                                     29

-------
                                 Table VI.  Results of Task 2 Alternate Strain Rate Evaluation
co
o


Test
C
RT
760
760



Temperature,
F
RT
1400
1400

Test Temperature,
C F
927
927
927
927
1700
1700
1700
1700
Heat Treatment:
Wheel S/N:
Forge Temperature:

0.2% Yield
M^/m2 ksi
1090.8 158.2
1038.4 150.6
999.1 144.9

Stress Level Rupture
M^/m2 ksi hr
103.4 15 1.5
103.4 15 1.4
103.4 15
103.4 15
Baseline
2-9
1038C/1093C (1900F/2000F)
TENSILE
Ultimate Elongation,
Mj^/m2 ksi %
1389.3 201.5 11.3
1103.8 160.1 4.0
1069.4 155.1 7.3
CREEP RUPTURE
Life, Elongation, Red. of Area 1.0% Creep
% % hr
89.5 68.8 0.1
66.2 57.0 0.1


Red. of Area
12.4
8.4
11.4

V/N Rupture,
hr
4.4
4.5
STRAIN CONTROL LCF
Test
C
927
927
Temperature,
F
1700
1700
Total Strain,
0.5
0.5
Mean Strain,
% Total Cycles
0.25 3168
0.25 2884
Remarks
Failed
Failed
                                                                                                                                TJ

                                                                                                                                5
                                                                                                                                3
                                                                                                                                Co
                                                                                                                                CD
                                                                                                                              1  o
                                                                                                                              O5

                                                                                                                              Oi

-------
                                                       Pratt & Whitney Oircraft


8.    Mechanical Property Response to Alternate Heat Treatments
      The Task 2 alternate heat treatment study was aimed at establishing a
single wheel heat treatment which would achieve a compromise structure com-
bining the high tensile strengths typical of fine grain structure with the good
rupture life of large grained material, while maintaining an adequate LCF life.
Two heat treatments were determined from the gradient studies with this aim
in mind.  The two remaining wheel forgings (S/N 2-10 and 2-11) were each given
one of these two heat treatments:
      Solution:    (1) 1177C (2150F)/2 hr/AC +  1121C (2050F)/2 hr/AC
                 (2) 1177C (2150F)/2 hr/AC +  1066C (1950F)/2 hr/AC
      Both heat treatments included the following precipitation and age cycles:
           871C (1600F)/40  min + 982C  (1800F)/45 min +
           649C (1200F)/24  hr + 760C (1400F)/4 hr
      All cycles were air cooled.
      These Task 2 wheels were cut up and evaluated.  The grain size of the
wheel given the 1177C (2150F)/1121C (2050F) double solution (S/N 2-10) was
predominantly ASTM 3-4, with occasional ASTM  7-10.  The S/N 2-11 wheel
which was solutioned at 1177C (2150F)/1066C (1950F) had a slightly smaller
grain size of predominantly ASTM 4-6, with occasional ASTM 7-8.  The mechanical
property test data are presented in table VII.
      It was felt that the differences in the mechanical properties could not be
adequately explained on the basis of grain size alone, so an Electron Microscopic
(EM) examination was conducted on material from both rotors.  The EM review
showed differences  in the secondary phases, probably due to the different double
solution cycles.  Representative electron photomicrographs are shown in fig-
ure 22.  Further study is needed to characterize  the relation of these phases to
the  heat treatments, and how they affect mechanical properties.
                                    31

-------
Table VII.  Results of Task 2 Mechanical Property Response to Heat Treat Evaluation
                            Heat Treatment:
                            Wheel S/N:
                            Forge Temperature:

                                  TENSILE
2-10 & 2-11
1038C (1900F)
Test
C
RT
RT
760
760
760
760

to Test
N C
927
927
927
927
927
927
927
927
Temperature,
F
RT
RT
1400
1400
1400
1400

Temperature,
F
1700
1700
1700
1700
1700
1700
1700
1700
S/N
2-10
2-11
2-10
2-10
2-11
2-11

0.2% Yield
M^/m2 ksi
979.1
999.0
932.9
937.7
978.4
980.4

Stress Level,
S/N MN/m2 ksi
2-10
2-10
2-11
2-11
2-11
2-11
2-10
2-11
103.4 15
103.4 15
103.4 15
103.4 15
103.4 15
103.4 15
103.4 15
103.4 15
142.0
144.9
135.3
136.0
141.9
142.2
CREEP
Ultimate,
M^/m^ ksi
1094.9 158.8
1327.2 192.5
1115.6 161.8
1111.4 161.2
1143.1 165.8
1043.2 151.3
RUPTURE
Rupture Life, Elongation,
hr %
360.9
480.2
198.2
116.5
336.2
330.3
-
-
4.9
7.0
3.7
6.3
Discontinued**
Discontinued**
-
-
Elongation,
%
4.7
12.0
6.7
5.3
8.0
1.3

Red. of Area,
%
2.8
2.4
3.6
6.0


-
-
Red. of Area,
%
8.5
17.6
8.4
7.4
9.0
4.4

1. 0% Creep, V/N Rupture,
hr hr
164.8
236.0
93.5
34.3


159.7 Disconl
185. 1 Disconl
                                                                                                    TJ
                                                                                                    3
                                                                                                    3
                                                                                                    0>
                                                                                                  hrj D


                                                                                                  * 3
                                                                                                  X 03

-------
             Table VII.  Results of Task 2 Mechanical Property Response to Heat Treat Evaluation (Continued)

                                                STRAIN CONTROL LCF

   Test Temperature,                    Total Strain,        Mean Strain
    C         F           S/N              %                 %               Total Cycles	Remarks
927
927
927
927
1700
1700
1700
1700
2-10
2-10
2-11
2-11
0.5
0.5
0.5
0.47
0.25
0.25
0.25
0.235
2769
3109
5768
9313
Failed
Failed
Failed
Failed
   *S/N 2-10     1177C (2150F) Solution,
                 Air Cool + 1121C (2050F)
                 Solution, Air Cool + Baseline
                 Precipitation and Age

co   S/N 2-11     1177C (2150F) Solution,
00                Air Cool + 1066C (1950F)
                 Solution, Air Cool + Baseline
                 Precipitation and Age

  **Equipment breakdown
                                                                                                                          3>"

                                                                                                                          CD
                                                                                                                       05
                                                                                                                       (0
                                                                                                                       o

-------
                                                              Pratt & Whitney Oircraft
       1177C/1121C (2150F/2050F)
               SOLUTION
                 1177C/1066C (2150F/1950F)
                         SOLUTION
MAG: 3000X
B678-5
                                              MAG: 3000X
                                                                               B677-28
                                          CM
MAG: 10.000X
B678-6
MAG: 10,OOOX
                                                                                B678-12
           Figure 22.  Task II Alternate Heat Treatment
                      Evaluation - Electron Photomicrographs
                                FD 84121
                                          34

-------
                                                        Pratt & Whitney Rircraft


      The mechanical property data points from these wheel forgings are
presented in figures 23, 24, and 25,  along with data points from the base-
line evaluations and the Task 3 blade property characterization.   The curves
are preform data from figure 28.  These figures show that, while  sacrificing
tensile strength (compared to baseline), one of the alternate heat treatments
(1177C,  2150F/1066C, 1950F) resulted in the highest LCF capability and
maintained close  to the desired level of stress rupture strength.  This heat
treatment was, therefore,  selected for use in part 2 of  Task 3.
C.    TASK 3 - GENERATION OF DESIGN DATA
      Task 3 was twofold  as shown schematically in figure 26.  The first part
involved  selecting and evaluating heat treatments designed to enhance the high
temperature rupture properties of the blades. This part was conducted con-
currently with Task 2.  The second part was the establishment of complete
design curves  for the short time, long time  and  cyclic properties of the wheel.
A summary of the Task 3 evaluations is given in table VIII.
1.    Blade Property Characterization
      As mentioned previously, it was initially planned  to preferentially heat
treat the blades of the finished wheel to enhance the rupture properties.  In an
effort to  determine  a structure for the blades that would result in a good balance
of stress rupture life and ductility, solution heat treatment temperatures of
1163C and 1177C (2125F and 2150F) were selected from the gradient study.
These solution temperatures result in structures which are most likely to have
optimum 927C -  982C (1700F - 1800F)  capabilities.  The grain  structures
resulting from the 1163C and 1177C (2125F  and 2150F) solution are a compro-
mise between the fine grains in the material given the baseline heat treatment
(figure 11) and the excessively large grains  resulting from solution heat treatment
temperatures above 1177C (figure 13).  The fine grains generally have poor
creep and rupture lives, while extremely  coarse grained structures normally
exhibit poor rupture ductility and reduced low-cycle fatigue properties.
                                    35

-------
                                                Pratt & Whitney fiircraft
                      BLADED WHEEL DATA
        1038C (1900F)/1093C (2000F) FORGE TEMPERATURE
Ibl/ .&)
1379 200
1241 180
1103 160
CM 965 140
-I
z JS
i t-
H 827 0 120
(5 Z
Z LU
LU GC
cc *~
H ">
/>
689 100
552 80
414 60
276 40
138 20
n
o
V
 &
 :
V
Q  BASELINE:
1121C (2050F) OIL QUENCH
A A 1163C (2125F) AIR COOL +
1121C (2050F) OIL QUENCH
Q  1177C (2150F) AIR COOL +
1121C (Z050F) OIL QUENCH
^7 Tf 1177C (2150F) AIR COOL +
1121C (2050F) AIR COOL
<^> ^ 1177C (2150F) AIR COOL +
1066C (1950F) AIR COOL
NOTE:
ALL HhAI I nbA 1 IvlbIM 1 b rLUb
BASELINE PRECIPITATION AND
AGE CYCLES
^
QALJ W ULTIMATE STRENGTH
0AH V^ -2% YIELD STRENGTH
D
1


A
^
z
ROOM 760C
TEMP 1400F
927C 982C
1700F 1800F
                      FORGE TEMPERATURE
Figure 23.  Tensile Properties vs Heat Treatment
FD 79245A
                             36

-------
            100
                                                        BLADED WHEEL DATA
                                         1038C (19000F)/1093C(2000F) FORGE TEMPERATURE
co
      GO
      V)
cc
00
             10
                                                                 HEAT TREATMENT
                                                                    O -  BASELINE: 1121C (2050F)
                                                                          OIL QUENCH
                                                                    A -  1177C (2150F) AIR COOL +
                                                                          1121C (2050F) AIR COOL
                                                                    \~\ -  1177C (2150F) AIR COOL +
                                                                          1066C (1950F) AIR COOL
                                                                    A -  1163C (2125F) AIR COOL >-
                                                                          1121C (2050F) OIL QUENCH
                                                                                                        DESIGN POINT
                                                                          NOTE: TYPICAL CURVES FROM PREFORM DATA,
                                                                                  FIGURE 28. ALL HEAT TREATMENTS
                                                                                 PLUS BASELINE PRECIPITATION AND
                                                                                 AGE CYCLES
                                                                                                                        TJ
                                                                                                                        3
              42
                    43
44
  45           46           47
PARAMETER = T(20 + LOG t ) x 10 3
                                                                                           48
                                                                                                 49
   Figure 24.  Stress Rupture Capability vs Heat Treatment
50
                                                                                                         FD 79241A
                                                                                       D
                                                                                       05
                                                                                       <
                                                                                       5
                                                                                       n
                                                                                       o

-------
w
00
                                       BLADED WHEEL DATA CONSTANT STRAIN TESTING
                                                    (STRAIN RANGE 0.5%)
                                                    CYCLES TO FAILURE

                                                          1,000
                                                                5,000
10,000
                                           I    I
                           BASELINE:
                           1121C (2050F)
                           OIL QUENCH
                           1163C (2125F), AIR COOL
                         + 1121C (2050F) OIL QUENCH
  1177C (2150F), AIR COOL
+ 1121C (2050F) OIL QUENCH
                           1177C (2150F) AIR COOL
                         + 1121C (2050F) AIR COOL
                           1177C (2150F) AIR COOL
                         + 1066C (1950F) AIR COOL
                           DESIGN POINT
                                               NOTE: ALL HEAT TREATMENTS PLUS
                                                      BASELINE PRECIPITATION AND
                                                      AGE CYCLES
                                               00
                                      o
                                                                                o    o
                                              00
                                                                    o
 o
    Figure 25.  927C (1700F) LCF Capability vs Heat Treatment
                                                                                     FD 79242A
QJ
3
Co
                                                                                                                             (D
                       o
                       5

-------
                    A.  BLADE PROPERTY CHARACTERIZATION
                                                       B.  DISK PROPERTY CHARACTERIZATION
                             FORGE TWO FLAT
                                 PANCAKES
                                                                 FORGE 5 TASK 2
                                                            WHEELS USING PARAMETERS
                                                              SELECTED FROM TASK 2
                            HEAT TREAT (OPTIMIZE
                          927C(1700F) 982C(1800F)
                               CAPABILITIES)
09
to
                                                                                          HEAT TREAT
                                                                                         VISUAL AND NDI
                                                                                          EVALUATION
                           MECHANICAL PROPERTY
                        AND STRUCTURAL EVALUATION
         TENSILE
    RT, 927C(1700F),
      982C(1800F)
                                                                GENERATE DESIGN
                                                                      DATA
CREEP-RUPTURE
 871C(1600F),
 982C(1800F)
LCF
MACROSTRUCTURE
      AND
MICROSTRUCTURE
                             TENSILE
1.0% CREEP
                                                     STRESS RUPTURE
LCF
3
3
Co
   Figure 26.  Phase I - Feasibility Demonstration and Cost Analysis; Task 3 - Generation of Design Data
                                                                                    FD 72645A
                                                                                                                          o
                                                                                                                          3

-------
  1517


  1379


  1241


CN 1103
.E
z
5
I 965
Z
LU
oc
rfk
o
827
        689
        552
        414
        276
              z
              UJ
              IT
              C/S
              LLJ
                  220
                  200
                  180
                  160
                  140
             120
             100
                   80
             60
             40
\
\
1


}2 POINTS
a
m
A H 3 POINTS

- OAD  ULTIMATE STI
AB  0.2% YIELD SI
)  BASELINE HE/
1121C (2050
PRECIPITATIO
^A - 1163C (2125
QJB ' ' ' 1 1^> (2lbO
f
LENGTH
"RENGTH
^T TREAT
F) SOLUTION + BASELINE
N AND AGE
F) SOLUTION + BASELINE
F) SOLUTION + BASELINE

[







r

i
                                          ROOM
                                          TEMP
                                                             760C
                                                             1400F
                                                                                  927C
                                                                                  1700F
                                                            TEST TEMPERATURE
   Figure 27.  Tensile Properties vs Solution Temperature Preform Data 1038C (1900 F) Forge Temperature
 982C
1800F
                                                                                                          FD 79239A
T
r+
0)


O

-------
                                                PREFORM DATA
100
     CO
     CO
     ill
     cc
*>    fc
 10
           o
  OCX
                                                            o
                                                            A
                                                            D
                                                   I            I             I
                                                   SOLUTION TEMPERATURE
                                                   BASELINE - 1121C (2050F) +
                                                     BASELINE PRECIPITATION AND AGE
                                                   1163C (2125F)  + BASELINE
                                                   1177C (2150F)  + BASELINE
                                                       QD
                                                       NOTE:
                                                        POINTS DESIGNATE MULTIPLE
                                                        DATA POINTS
   42
43
                                      44
                                               45           46           47

                                               PARAMETER = T(20 + LOG t) x ID'3

Figure 28.  Stress Rupture Capability vs Solution Temperature
                                                                              48
49
50
                                                                                                   FD 79240A
                                                                                                                  3
                                                                                                                  fio
                                                                                                   3
                                                                                                   (D
                                                                                                   <
                                                                                                   TJ
                                                                                                   o
                                                                                                   3

-------
                                  Table VIII.  Summary of Task 3 Evaluations
S/N
   Forge Temperature
 Preform       Wheel
 C      F     C     
   Heat Treatment
   Program Use
   ASTM Grain Size
Predominate   Occasional
2-2A    1038   1900
2-2B    1038   1900   -
2-6B    1038   1900
2-12A   1038   1900   1093   2000
2-12B   1038   1900   1093   2000
2-13
2-15
2-16
2-17
2-18
1038   1900   1093   2000
1163C (2125F) Solution,
 Air Cool + Baseline
1177C (2150F) Solution,
 Air Cool + Baseline

1177C (2150F) Solution,
 Air Cool + Baseline

1163C (2125F) Solution,
 Air Cool + Baseline
1177C (2150F) Solution,
 Air Cool + Baseline

1177C (2150F) Solution,
 Air Cool + 1066C (1950F)
Solution, Air Cool + Baseline
 Precipitation and Age
Blade Property
 Characteriz ation

Blade Property
 Characterization

Blade Property
 Characterization

Blade Property
 Characteriz ation

Blade Property
 Characterization

Disk Property
 Characterization
                                                                                4. 0 - 6.0 and
                                                                                8.0 - 13.5
                                                                                3.0 - 4.0
                                                                                2.0 - 4.0
                                                                                3.0-4.0
                                                                                4.0-6.0
4.0 - 6.0
                6.0 - 8.0
                5.0 = 10.0
                6.0 - 10.0
                6.0 - 8.0
6.0 - 8.0

-------
                                                        Pratt & Whitney Pircraft


      It was anticipated that the wheel would require a protective high tempera-
ture coating on the blades and platforms for erosion/corrosion resistance.  The
application of the coating requires a 760C (1400F) pack coating application cycle
followed by a high temperature diffusion cycle.  A coating study determined that
the coating diffusion cycle was compatible with and therefore could be achieved
during the 1121C (2050F)  solution treatment portion of the baseline heat treat-
ment.  The 760C (1400F)  pack coating application cycle was therefore the only
additional operation required.
      The coating application cycle 760C  (1400F) was not included in the heat
treatment of wheels or preforms for mechanical property testing since it is
followed by a high temperature solution cycle which would negate any structural
effects from the lower temperature cycle. In conducting the coating study,  it
was found that there were no adverse effects on the coating from the oil quench
used in the baseline heat treatment.  Thus the coating of wheels could easily be
included in any of the heat treatments studied in the program.
      Two forging mults were machined from the extruded stock.  These were
boron nitride coated and forged into the preform configuration at the baseline
parameters.  One preform (S/N 2-12) was subsequently forged into a bladed
wheel at 1093C (2000F).  Both the preform (S/N 2-2) and the bladed wheel were
cut in half.  One half from each part was  given the  1163C (2125F) solution cycle
for 2 hours, and the other half of each disk was given the 1177C (2150F) solu-
tion for 2 hours. A segment of S/N 2-6 was also used in this evaluation.  All
pieces were air cooled.  The disk halves  subsequently received the baseline
heat treat and were cut up for mechanical property testing.
      Evaluation of these disk halves  included room temperature, 927C and
982C (1700F and 1800F) tensile properties,  871C and 982C  (1600F and 1800F)
creep rupture properties, 927C (1700F)  low cycle fatigue properties, and a micro-
structural evaluation.  The mechanical property test results are listed in table DC,
and the preform data are plotted in figures 27 and 28.  Baseline preform data are
also shown.  For comparison with the Task 1 and 2 results, Task 3 wheel results
are also included in figures 23, 24, and 25, as mentioned previously.   The micro-
structural evaluation showed a grain size  of predominantly duplexed ASTM 3-6
and ASTM 8-13. 5 from the 1163C (2125F) solution and predominantly ASTM 3-6
from the 1177C (2150F) solution.
                                    43

-------
Table IX.  Results of Task 3 Blade Property Characterization Evaluation
            Heat Treatment:
            Preform S/N:
            Forge Temperature:
            Wheel S/N:
            Forge Temperature:
2-2A & B, 2-6B
1038C (1900F)
2-12A & B
1038C/1093C (1900F/2000F)
                             TENSILE
Test
C
RT
RT
760
760
760
760
927
927
982
982
Temperature,
F
RT
RT
1400
1400
1400
1400
1700
1700
1800
1800
0.2% Yield,
S/N
2-2A
2-2B
2-6A
2-6A
2-6B
2-6B
2-6B
2-12B
2-6B
2-12B
MN/m^
1047.3
1020.4
946.6
966.0
923.2
898.4
535.7
464.7
358.5
276.5
ksi
151.
148.
137.
140.
133.
130.
77.
67.
52.
40.

9
0
3
1
9
3
7
4
0
1











CREEP

Test
C
871
871
871
871
871
871
982
982
982
982

Temperature,
F
1600
1600
1600
1600
1600
1600
1800
1800
1800
1800


Stress Level,


Rupture
S/N MN/m2 ksi
2-2B 224
2-2A 224
2-12A 224
2-6B 138
2-2A 345
2-6B 345
2-2A 103
2-2B 103
2-6B 68
2-12A 103
32.
32.
32.
20
50
50
.4 15
.4 15
.9 10
.4 15
5
5
5







hr
165.
22.
14.
657.
-
-
3.
42.
86.
2.

Ultimate,
Mj^/m2 ksi
1336.9 193.9
1221.8 177.2
1097.6 159.5
1116.9 162.0
1114.9 161.7
1083.9 157.2
633.6 91.9
584.7 84.8
429.2 62.2
410.2 59.5
RUPTURE

Life, Elongation,

3
1
5
8


0
7
8
2
7o
2.5
7.4
6.5
Discontinued**
-
-
14.1
5.9
9.6
16.8
Elongation,
%
11.3
10.0
18.0
9.3
24.0
5.3
4.7
3.3
2.7
2.7


Red. of Area
%
4.8
7.2
8.3
-
-
-
24.1
3.6
18.1
15.0
Red.












Time to
1.0% Creep
hr
49.0
5.5
4.4
643.5
-
-
0.4
13.7
23.5
0.2
of
%
13.
11.
19.
11.
21.
6.
7.
6.
3.
2.














Area,

6
6
4
0
2
5
4
7
3
2


V/N Rupture,
hr
-



3.7
21.2
-



                                                                                              0)
                                                                                              D
                                                                                              0)
                                                                                            ^ 
                                                                                            7 O
                                                                                             s
                                                                                            to -*
                                                                                            o '-f

-------
                Table IX.  Results of Task 3 Blade Property Characterization Evaluation (Continued)

Test Temperature,
C F
927 1700
927 1700
927 1700

S/N
2-12A
2-12B
2-12B
STRAIN
Total Strain,
%
0.5
0.5
0.5
CONTROL LCF
Mean Strain,
%
0.25
0.25
0.25

Total Cycles
2382
5069
3859

Remarks
Failed
Failed
Failed
 *S/N 2-2A, 2-12A
1163C (2125F) Solution,
Air Cool + Baseline
  S/N 2-2B, 2-6B,  2-12B  1177C (2150F) Solution,
                          Air Cool + Baseline

**Equipment Failure
                                                                                                                      TJ
                                                                                                                      CD
                                                                                                                      0>
                                                                                                                   s
                                                                                                                   o

-------
                                                        Pratt & Whitney Pircraft
2.    Disk Property Characterization
      Processing parameters selected from Task 2 which provided optimum
wheel properties were used for forging five preforms and subsequently five
wheels.  The preform forging temperature was 1038C (1900F), the wheel forging
temperature was 1093C (2000F), and the strain rate was 0.25  cm/cm/min
(0.1 in./in./min).  These wheels were heat treated to the Task 2 alternate heat
treat utilizing the 1177C (2150F) + 1066C  (1950F) double  solution cycles.
      The five wheels were visually inspected and evaluated by nondestructive
inspection techniques.  All were  within dimensional tolerances and no internal or
external defects were detected.  The wheels were cut up and machined into test
specimens.  A variety of testing  parameters were used to establish design curves.
The testing parameters and test results are listed in table X.  The design curves
are presented in figures 29,  30,  31, 32, and 33.  These curves  are discussed
in Task 4.
D.    TASK 4 -  DEFINITION OF  MANUFACTURING PROCESS
      The Task 4 manufacturing process definition consists of detailed process
sheets for the manufacture  of the finished wheel and a. description of the capa-
bilities and limitations of the forging process.
1.    Manufacturing Flow Sheet
      Table XI is a detailed list of the operations required in the processing
sequence designed for the mass production of GATORIZED automotive gas
turbine wheels.
2.    Capabilities and Limitations of Forging Process
      The GATORIZING forging process has the capability to forge complex,
contoured shaped parts to extremely close tolerances (0.051 mm (0.002 in.))
with no surface cracking. Parts  can be forged to near finished  shape with very
minimal machining  to obtain  finish dimensions.  Finish machining will only be
required to deburr, tip blades to  length, turn bearing surfaces,  and remove
metal for balancing.
                                    46

-------
Table X. Results of Task 3 Disk Property Characterization Evaluation
        Heat Treatment:
        Wheel S/N:
        Forge Temperature:
1177C (2150F) Solution, Air Cool +
1066C (1950F) Solution, Air Cool +
Baseline Precipitation and Age
2-13, 2-15, 2-16, 2-17 and 2-18
1038C/1093C (1900F/2000F)

TENSILE
Test Temperature,
C F
RT
316
316
316
649
649
649
760
871
871
871
982
982
982
RT
600
600
600
1200
1200
1200
1400
1600
1600
1600
1800
1800
1800
S/N
2-16
2-15
2-16
2-17
2-13
2-15
2-18
2-15
2-13
2-17
2-18
2-16
2-17
2-18
0.2% Yield
M^/m2 ksi
989.4
958.4
954.9
981.1
996.3
998.4
1000.4
960.4
646.0
618.5
626.0
315.8
299.9
314.4
143.5
139.0
138.5
142.3
144.5
144.8
145.1
139.3
93.7
89.7
90.8
45.7
43.5
45.6
Ultimate,
MN/m2 ksi
1279.0
1202.4
1245.2
1244.5
1168.7
1226.6
1273.5
1105.2
715.0
763.9
765.3
405.4
346.1
402.7
185.5
174.4
180.6
180.5
169.5
177.9
184.7
160.3
103.8
110.8
111.0
58.8
50.2
58.4
Elongation,
%
10.7
8.0
10.7
11.3
5.3
7.3
13.3
6.7
2.7
6.7
3.3
3.3
2.7
3.3
Red. of Area,
%
13.8
11.4
14.4
14.7
10.5
12.6
15.3
8.9
5.9
8.5
5.4
2.2
4.4
1.6
                                                                                               0)
                                                                                               3
                                                                                               BO
                                                                                               0>
                                                                '
                                                                Oi
                                                                05
                                                                
                                                                                               o

-------
Table X.  Results of Task 3 Disk Property Characterization Evaluation (Continued)
CREEP RUPTURE
Test Temperature,
C F
760
760
760
760
760
871
871
871
871
 871
00 927
927
927
927
871
871
871
760
760
871
871
927
927
982
982
1400
1400
1400
1400
1400
1600
1600
1600
1600
1600
1700
1700
1700
1700
1800
1800
1800
1400
1400
1600
1600
1700
1700
1800
1800
S/N
2-15
2-16
2-17
2-13
2-18
2-13
2-17
2-18
2-16
2-18
2-16
2-17
2-15
2-18
2-17
2-15
2-16
2-15
2-16
2-18
2-13
2-18
2-17
2-16
2-17
Stress Level,
Mj^/m^ ksi
344.7
488.2
488.2
551.6
551.6
344.7
448.2
448.2
551.6
551.6
206.8
206.8
103.4
103.4
68.9
103.4
103.4
551.6
551.6
448.2
448.2
344.7
344.7
103.4
103.4
50
65
65
80
80
50
65
65
80
80
30
30
15
15
10
15
15
80
80
65
65
50
50
15
15
Rupture Life,
hr
321.4 Disc.
334.7
301.0
76.2
84.1
5.4
1.4
0.9
0.2
0.2
8.9
7.3
74.3
225.1
67.8
10.3
25.3
-
-
-
-
-
-
-
-
Elongation,
	
5.64
5.2
11.1
12.4
5.2
3.8
2.4
4.8
3.9
1.8
3.5
7.0
7.2
20.9
9.3
7.4
-
-
-
-
-
-
-
-
Time to
Red. of Area, 1. 0% Creep,
% hr
_
6.9
8.7
11.2
12.1
3.3
6.8
3.2
3.6
4.4
3.6
3.6
17.6
6.5
17.6
9.2
8.0
-
-
-
-
-
-
-
-
-
160.2
117.4
26.1
29.1
2.4
0.5
0.5
<0. 1
<0. 1
3.8
2.6
15.1
84.2
16.4
2.9
7.6
-
-
-
-
-
-
-
-
V/N Rupture,
hr
_
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
231
144.3
4.6
3.3
1.1
1.3
85.2
91.9
                                                                                                        TJ
                                                                                                        3

                                                                                                        Co
                                                                                                        05

                                                                                                     m
                                                                                                     <>
                                                                                                     O

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Table X.  Results of Task 3 Disk Property Characterization Evaluation (Continued)
STRAIN CONTROL LCF
Test Temperature,
C
927
927
927
927
927
927
927
927
927
927
F
1700
1700
1700
1700
1700
1700
1700
1700
1700
1700
S/N
2-13
2-13
2-15
2-15
2-16
2-16
2-17
2-17
2-18
2-18
Total Strain,
%
0.5
0.3
0.7
0.5
0.5
0.7
0.4
0.5
0.4
0.7
Mean Strain,
%
0.25
0.15
0.35
0.25
0.25
0.35
0.20
0.25
0.20
0.35
Total Cycles
3,537
52,255
861
1,595
4,865
951
38,391
2,315
82,645
496
Remarks
Failed
DNF
Failed
Failed
Failed
Failed
Failed
Failed
DNF
Failed
                                                                                                       TJ

                                                                                                       s
                                                                                                       3
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g
<=>
                                                                                                        q
                                                                                                        3

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                                                Pratt & Whitney fiircraft
                                                                 FR-6690
             Table XI.  Manufacturing Flow Sheet
Operation               Description
    5          Cast Master Melt Ingots
   10          Prepare Ingot for Remelting
   15          Produce Remelt Ingot
   20          Prep Ingot for Canning
   25          Can Ingot
   30          Extrude Ingot to 6. 35 cm (2. 5 in.) Dia.
   35          Remove Can from  Extrusion
   40          Inspect Extrusion
   45          Store for Manufacturing
   50          Cut Extrusion into Multiples
   55          Degrease  Mults
   60          Lubricate with Boron Nitride
   65          Preheat Mult
   70          Load into  Preform Press
   75          Gatorize Preform  Disk
   80          Eject Preform and Cool
   85          Trim Flash and Turn OD Concentric to Hub
   90          Degrease  Preform
   95          Lubricate with Boron Nitride
  100          Assemble Ring of Inserts and Preform Disk
                 Package
  105          Preheat Package
  110          Load Package into Press
  115          Gatorize Final Form Wheel
  120          Eject Package and Cool to Room Temperature
  125          Disassemble  Package
  130          Inspect, Relubricate,  and Return Inserts to
                 Load Station
  135          Barrel Finish Wheel
  140          Solution Heat Treat Wheel
  145          Plunge Grind Blade Tips to Correct Dia.
  150          Apply Aluminide Coating
  155          Stabilization and Age Heat Treat Wheel
  160          Dimensional Check with Sigma Test
  165          Finish Machine Wheel Hubs
  170          Deburr and Polish Wheel
  175          Final Inspect
  180          Degrease
  185          Identify and Store
  190          Ship Parts
                             50

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                                                         Pratt & Whitney aircraft
                                                                          FR-6690

      The primary limitation on the shape of parts which can be forged is the
 development of laps during forging.  Lapping is a condition that results from
 metal flow from two directions after the outside diameter of the forging is in
 contact with the die walls.  Lapping may be prevented by using a two-step forging
 with ID entrance angles as low as 2 deg,  if required.  The only limitations are
 that during  the first forging step, lapping be prevented, and during the second
 forging step the surface area of the forging is  always increasing.  A decreasing
 surface area would create a lap.
      The advantages of a two-step forging operation are a savings in material
 input weight and a savings in the cost of machining away the excess metal.  The
 advantages  of a one-step operation are in the elimination of the need for a second
 set of forging dies and the saving of one forging operation on every part.  The
 lubrication  requirements are  less severe on a two-step forging operation  in that
 the preform can be lubricated prior to the final forging operation.
      Certain special considerations have to be made in designing the airfoil
 for successful forging of integrally bladed wheels.   Airfoil cross-sectional
 areas should have the following characteristics to enhance forging:
      1.     Near constant to constant airfoil thickness
      2.     Minimum chord taper
      3.     Maximum permissible  leading and trailing edge radii
      4.     Minimum airfoil twist
      5.     Airfoil solidity ratio not more than 4 blades/2. 54 cm (1. 00 in.)
            of disk rim.
 3.    Design Data Sheets
      The design data sheets were generated in the Task 3 disk property char-
 acterization.  Typical tensile  vs temperature data and 927C (1700F) low  cycle
fatigue life data are shown in figures 29 and 30 respectively.  Typical creep
 and stress rupture data are shown on the Larson-Miller plots of figures 31
 and 32.  Figure 33 is a trade-off curve demonstrating graphically how a change
in grain size affects rupture and LCF lives.  These curves all represent typical
properties and are based on the limited testing that was done during Phase I.
                                    51

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        1379
        1241
        1103
    cs    965


     Z
Ol
to
     0
     V)

     LU
         827
         689
         414
         276
         138
              200
              180
              160
              140
          X
          I-
          0
          z
          LU
          cc

          V)

          LU
          -J

          v>
120
O
0
                   80
               60
               20
                                 0.2% YIELD STRENGTH
                                                              LEGEND

                                                                 TYPICAL
                                                                                  ULTIMATE STRENGTH
                                                               POINTS
                            400      800      1200

                                   TEMPERATURE - F
                                     1600      2000   0
                                                                             400
                                                                                  800      1200

                                                                                 TEMPERATURE - F
                                                                                      1600
                             204      427      649

                                   TEMPERATURE - C
                                                   871
                                              1093
204      427       649

       TEMPERATURE  - C
                                                                                                        871
1093
Figure 29.  Automotive Turbine Wheel Design Data Tensile Properties of Wrought INIOO
                                                                                                              FD
                                                                                                           TJ
                                                                                                           3
tney
                                                                                                           o
                                                                                                           3
                                                                                                           a

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                                                Pratt & Whitney fiircraft
                          LIFE  CYCLES

Figure 30.  EPA Automotive Turbine Wheel Design
           Data LCF 927C (1700F) IN100
FD 84123
                             53

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     1000
      100
   O
   x
01
       10
   1000
    100
             V)
             CO
             Ul
             cc
                                                                             7
                                                                         899C
                                                                         1650F
                                                                       1   7
                                                                      871C
                                                                     1600F
    7
732C
1350F
  r?i7
760F    788C
1400F   1450F
    71
816C
1500F
                                                                                                             982C
                                                                                                             1800F
                                                                                                 982C(1800F) 3 POINTS
                                                                                                 927C(1700F) 4 POINTS
                                                                                                 871C (1600F) 3 POINTS
                                                                                                 760C (1400F) 4 POINTS

                                                                                                   /
                   45
                46
                                                 50     51     52     53     54     55

                                                   LARSON-MILLER PARAMETER, C = 23.0

Figure 31.  EPA Automotive Turbine Wheel Design Data INIOO Larson-Miller Plot of 1. 0% Creep Life
                                                                                                                  FD 84124
                                                                                                     Co

                                                                                                     |

                                                                                                     r+

                                                                                                     0>
                                                                                                                                 O

-------
    1000
  co 100
  cc
  D
  O
  I
  LU
01
      10
  1000
   100
co
CO
111
cc

CO
                                                                                                       7	1
                                                                                                   954C    982C
                                                                                                   1750F   1800F
                                                                         1
                                                                      899C
                                                                     1650F
    7
732C
1350F
  n    i
760F    788C
1400F   1450F
927C
1700F
                                                                                               982C (1800F) 3 POINTS
                                                                                               927C (1700F) 4 POINTS
                                                                                               871C (1600F) 5 POINTS
                                                                                               760C (1400F) 4 POINTS

                                                                                                 z
                                                                                                   V NOTCH FAILURES
                                                                  52     53     54     55      56      57      58
      45     46      47      48     49     50
                                                      LARSON-MILLER PARAMETER, C = 23.0
                                                                                                       59     60
    Figure 32.  EPA Automotive Turbine Wheel Design Data INIOO Larson-Miller Plot of Stress Rupture Life     FD 84125
                                                                                                                                 3
                                                                                                                                 Co
                                                                                                                     I
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-------
                                                        Pratt & Whitney Rircraft
                20-
             V)
             V)
             at
             cc
             D
             o.
             CO
             111
             cc
                W-t
                 5-
Q 100 hr STRESS
    RUPTURE STRENGTH
r] 3000 LCF CYCLES
    (TYPICAL VALUES)
^ 5000 LCF CYCLES
  (CURVE EXTRAPOLATED
    BY SIMILAR SLOPE)
                                                        -0.6
                       -O.BUJ
                           o
                           z
                           cc
                       -0.41
                           cc
                                                        -0.30
                                                        -0.2
                                                        -0.1
                      8-10           4-6
                              ASTM GRAIN SIZE
                  2-4
      Figure 33.  Trade-Off Curve:  LCF and Rupture vs
                 Grain Size
                            FD 84127
      The use of these curves for actual design would be dependent on design
philosophy.  For example, in a growth limited application (yield or creep), a
design might be based on typical properties in that the part grows  based on the
average properties.   On the other hand, a burst or rupture limited criteria
would probably dictate the use of a minimum  curve, which minimum would
depend on the desired confidence level.
E.    TASK 5 - MANUFACTURING COST STUDY
1.    Background
      For the purposes of this study,  a projected manufacturing process,  and
a complete facility, shown in figure 34,  suitable for volume production of auto-
motive turbine wheels was developed based on the manufacturing flow sheet
generated in Task 4.  This process includes  the physical manufacturing cost
elements and all other significant cost elements necessary to project a mean-
ingful unit cost for automotive turbine wheels.
                                    56

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01
            EMPLOYEE


            PARKING


            ISO CARS)
                         I-	
                         I- --- J
                          TRUCK


                          DOCKS
                        ]_	H
                          	.^

                          HIPPING
                                           D n n 03 tJd DsD DRiD D D D


                                           B-nnnnnnnnnn:
      ELECTRONIC

        GAGING LJ  LI
                                     GRIT BLAST
                                            ABRASIVE SAWS
                           AND

                         *

                          RECEIVING


                          OPFICES
                              ION PRESS




                          OVERHEAD CONVEYORS



                               BARREL FINISHERS
                           ~~1  FTT n n ra^iSDODffi&mFn^r
                           1'  M-1 U UF LJLU u DODDDOOi!vr'aw"
                              ASSYSASSY LATHE GmNDER BARREL VERT Q Q Q 0 0 Q D 0 LJ R  PI  H^
                                              BROACH  BENCHES   [J  M
                                                         LATHES
                                                        n n
                                        PREFORM GATOR PRESSES
                                                       DECREASE
                                                                 CONTINUOUS FURNACE HEAT TREAT ' A"
                                                                    FINAL FORM GATOR PRESSES
                                                                                    MACHINE MAINTENANCE
                                                                      ELECTRICAL

                                                                        SHOP
                             f"^	FINAL FORM GATOR PRESSES            PLUNGE

                        n   ^ 'n   n   n   D   n   D   n1 T&.
SMALL


TOOL

CRIB
                         CENTRAL


                         OPFICES
D   n
nnnnnnnnn
nnnnnnnan
nnnnnnnnn
nnnnnnnnn
nnnnnnnnn
nnnnnnnnn_
nnnnnnnnnn
                                                                                          a
                                     nnnnnnnnnn
                  n   n   n
                  n   n   n   a
                  n   n   n   a
                  n   n   n   a
                  n   n   n   n 
                  n   n
                      n
                                                                                                 CONDIT

                                                                                                  ION ING
                                         n   n
                             n   n   n   n  n
                                             n
                                             n
                                                            n   n
                                                            n   n
                                                            n   n
         BATCH


        FURNACES

         MANUAL

         LOAD

         AND

         UNLOAD





         'C' THRU
                                                                                                G"
                                                                                             ELECTRONIC
                                                                                              GAGING
         CONTROL CONSOLES

     n   en  m   en

       SPECIAL HORZONTAL LATHES
        CONTROL CONSOLES

cn  CD   cu   mi
                                                                             en   CD
                                                                             OVERHEAD CONVEYOR
            n
I	1   I	1 BOROMATICS I	1
       nnn
                                                                                      en
                                        n  a  a  n  a  n
                                                                                                     EMPLOYEE

                                                                                                     PARKING

                                                                                                     (35 CARS)
   Figure 34.  Plant Layout EPA Rotor Production 191, 000 sq ft
                                                                        FD 84126
                                                                                    TI

                                                                                    3
                                                                                    3
                                                                         CD


                                                                         D

                                                                         o

-------
                                                        Pratt & Whitney fiircrafi

      For purposes of comparison, this cost study was patterned after that
conducted by Williams Research Corporation for the EPA under Contract EPA-
460/9-73-001.  With one exception, Williams' assumptions were used to estab-
lish a baseline for this cost study.  This exception is that the wheel produced in
the "P&WA" facility is complete with gas path coating and  ready for final assembly
and balancing, whereas, the wheel produced in the Williams' facility is a raw
casting requiring finish machining and coating before assembly.
2.    Manufacturing Assumptions
      The following assumptions were made to generate the manufacturing facility
and cost to produce automotive turbine wheels:
      1.     The manufacturing facility will be a complete production
            operation in that raw materials  are received in the form of
            alloy constituents  to make up the master melts,  and finished
            wheels ready for assembly are shipped out.
      2.     The facility is designed to eliminate labor where possible by
            use of automated production techniques.
      3.     The production facility will operate 249 days, two 8-hour shifts,
            5 days per week.  Additional upkeep is planned for furnace over-
            haul and system maintenance.
      4.     Capital depreciation on all facilities except the building were
            carried over 8 years.  The building was carried over 40 years.
      5.     Labor floor/floor prime was estimated assuming all opera-
            tions are automated where possible.
      6.     Tooling life was estimated to be 25 thousand forging cycles
            with 25 resinks and insert tooling to have a 100 forging cycle
            life.
      7.     Performance variation of 1. 333 was used for determination
            of manpower requirements.
                                     58

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                                                         Pratt & Wh itney fi ire raft


      8.    General and administrative costs were set to be 10%; same
           as Williams Research Corp. report.
      9.    Corporate profit was set at 25%; same as Williams Research
           Corp.  report.
3.    General Process Description
      In the effort to produce wrought turbine wheels at low cost, the proposed
manufacturing process utilizes current technology casting methods, conventional
superalloy extrusion, P&WA's patented forging technique (known as GATORIZING),
and typical high volume,  automated production.
      Melting is carried out in two steps; the first, to alloy master heat ingots,
and the second, to produce remelt ingots.  The material is  then conditioned to
a superplastic state by extruding the remelt ingots.  The wheels  are then forged
to final dimensions utilizing the GATORIZING process to maintain the material
in a superplastic  condition.  The desired mechanical properties of the wheels
are then  restored utilizing production heat treat techniques.
      The finishing operations, such as cleaning, deburring, blade tipping,
lathe turning the hubs and applying blade coatings, use either current or modi-
fications of current production practices.
4.    Cost Summary
      The cost summary was developed analyzing all cost elements that would
normally be associated with a manufacturing operation of this type.
      The major cost centers  within this study were:
      1.    Materials
      2.    Manpower
      3.    Capitalization.
      The first cost center considered raw material production,  extrusion cans,
forging die material,  expendable tools, scrap factors, freight and other pertinent
items to  this category.
      Manpower was established by analyzing the manufacturing operation for
direct labor, indirect supporting labor,  and indirect salaried requirements.  A
plant manpower description broken down on a per shift basis is shown in table XII.
Table XIII is a summary of general and administrative costs incurred in the opera-
tion of this facility.
                                     59

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                                                        Pratt & Whitney Pircraft

      The final cost center considered a complete manufacturing facility including
operation equipment,  building, grounds, support equipment,  etc.  A summary of
the major facilities cost is listed in table XIV.
      From these three major cost centers overhead rates were established.
The general and administrative fees and profit were computed to establish a
final selling price of $51.77 per turbine wheel.  A condensed cost summary  is
given in table XV.
       Table XII.  Manpower Requirement Summary Automotive Turbine
                  Wheel Manufacturing Facility
Description
Direct Hourly
Indirect Hourly
Indirect Salary
G&A Personnel
Totals
Shift
123
73
12
38
16
139
71
10
16
2 1
99 1
Total
144
22
54
19
239
             Table XIII.  Summary of General and Administrative
                         Estimated Cost



Item
A
B
C
D
E
F
Description
Salaries & Benefits (Insurance, Pensions, etc.)
IR&D Monies
Expenses (Insurance, Office Supplies,
Utilities, etc.)
Total
Table XIV. Estimated Cost Summary of
Description
Ingot Production and Extrusion Facilities
Wheel Production Facilities
Tool Build and Maintenance Facility
Equipment Maintenance Facilities
Support Facilities
Building and Grounds
Total
Total
$ 348,000
2,632,000
855,000
$3,835,000
Facilities
Est. Cost Total
$ 4,792,000
13,286,000
1,889,000
940,000
2,177,000
6,845,000
$29,929,000
                                     60

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                                                      Pratt & Whitney Rircraft
                                                                      FR-6690
II
                        Table XV.  Cost Summary
                  (GATORIZED Automotive Turbine Wheel)
I Raw
A.
B.
C.
D.
E.

F.
G.
H.
Material
Metal per pound (as converted ingot)
Die Material (per pound of wheel)
Freight and Expendable Tools (per pound of wheel)
Initial Die Material (3 sets)
Scrap Cost @ 5%
Subtotal
15% Contingency
Cost per pound of wheel
Cost per rotor @ 2. 7 lb/ wheel

$ 5.76
2.29
0.47
0.60
0.30
$ 9.42
$ 1.41
$10.83
$29.25
Labor & Overhead
     A.    Direct Labor/Wheel
     B.    Overhead/Wheel

           1.    Depreciation
           2.    Wages,  fringes and
                 benefits, Indirect
           3.    Fringes and benefits for
                 direct labor
           4.    Indirect expenses
           5.    TOTAL

     C.    Labor Plus Overhead/Wheel

HI   Totals

     A.    Raw Materials/Wheel
     B.    Labor plus Overhead/Wheel
$3.05
$1.17
$ .52
$2.86-

Overhead
is 508%
                                          Subtotal
     C.    Plus G&A and Profit
                                                       $ 1.50
                                    Total Cost Per Wheel
                                                       $ 7.60

                                                       $ 9.10
                                                       $29.25
                                                         9.10

                                                       $38.35

                                                        13.42

                                                       $51.77
                                  61

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                                                        Pratt & Whitney Rircraft
                                                                         FR-6690
                                SECTION III
                          SUMMARY OF  RESULTS
      This study provides adequate evidence that volume production of automotive
turbine wheels utilizing the GATORIZING process is within the current state-of-
the-art.  Integrally bladed turbine wheels were successfully forged and it was
demonstrated that control of the LCF-stress-rupture life tradeoff can be
achieved with heat treat variations.
      The selling price of a mass-produced turbine wheel, based upon a material/
labor ratio of 75%/25% and an overhead of 508% at the projected study level of
one million parts per year could be less than $55. 00.  The capitalization of a
complete facility to manufacture 1, 000, 000 turbine wheels per year would cost
$29, 930, 000.  The impact of alternate production rates of 100, 000 and 10, 000, 000
rotors per year will be studied in more detail in  Phase II of this contract.
                                    62

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                                                        Pratt & Whitney fiircraft
                                                                         FR-6690
                                SECTION IV
                           RECOMMENDATIONS
      Based on the findings of Phase I, it is recommended that Phase II consist
primarily of:  a detailed design analysis  to produce a turbine wheel design more
compatible with the forging technique and still compatible with the performance
characteristics of the Chrysler Baseline Gas Turbine Engine; and the production
of several integrally-bladed turbine wheels for engine verification and other
qualification testing.  After initial wheel forgings of IN 100 are produced, a
second Ni-base alloy, modified IN 792, will be introduced into the program.
The modified IN 792 is reported to have superior hot corrosion resistance and
mechanical properties consistent with the Upgraded  Engine Requirements.
                                    63

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