Abstract

Significant progress has been made in the application of low plasticity burnishing (LPB) technology to military engine components, leading to orders of magnitude improvement in damage tolerance. Improved damage tolerance can facilitate inspection, reduce inspection frequency, and improve engine operating margins, all leading to improved military readiness at significantly reduced total costs. Basic understanding of the effects of the different LPB process parameters has evolved, and finite element based compressive residual stress distribution design methodologies have been developed. By incorporating accurate measurement of residual stresses to verify and validate processing, this combined technology leads to a total solution approach to solve damage problems in engine components. An example of the total solution approach to develop LPB processing of a first stage Ti-6Al-4V compressor vane to improve the foreign object damage tolerance from 0.002in.to0.025in. is presented. The LPB process, tooling, and control systems are described, including recent developments in real-time process monitoring for quality control. Performed on computer numerical control (CNC) machine tools, LPB processing is easily adapted to overhaul and manufacturing shop operations with quality assurance procedures meeting military and industry standards, facilitating transition to military depots and manufacturing facilities.

References

1.
Propulsion Directorate
, 2000, “
High Cycle Fatigue (HCF) Program 1999 Annual Report
,” Paper No. AFRL-PR-WP-TR-2000-2004.
2.
Gabb
,
T.
,
Telesman
,
J.
,
Kantos
,
P.
, and
Prevey
,
P.
, 2002, “
Surface Enhancement of Metallic Materials
,”
Advanced Materials and Processes
,
Peg
Hunt
, ed.,
ASM
,
Materials Park, OH
, pp.
69
72
.
3.
“Longer Life With Low Plasticity Burnishing,” 2001,
Manufacturing Engineering
,
B.
Hogan
, ed.,
SME
, pp.
34
38
.
4.
1998, U.S. Patent No. 5,826,453;
2002, U.S. Patent No. 6,415,486.
5.
Prevéy
,
P. S. P.
,
Telesman
,
J.
,
Gabb
,
T.
, and
Kantzos
,
P.
, 2000, “
FOD Resistance and Fatigue Crack Arrest in Low Plasticity Burnished IN718
,”
Proceedings of the Fifth National High Cycle Fatigue Conference
, Paper No. IN718.
6.
Prevéy
,
P.
,
Shepard
,
M.
, and
Smith
,
P.
, 2001, “
The Effect of Low Plasticity Burnishing (LPB) on the HCF Performance and FOD Resistance of Ti-6Al-4V
,”
Proceedings of the Sixth National Turbine Engine High Cycle Fatigue (HCF) Conference
, Jacksonville, FL, Mar. 5–8.
7.
Shepard
,
M. S.
,
Prevéy
,
P. P.
, and
Jayaraman
,
N. J.
, 2003, “
Effect of Surface Treatments on Fretting Fatigue Performance of Ti-6Al-4V
,”
Proceedings of the Eigth National Turbine Engine HCF Conference
, Monterey, CA, Apr. 14–16.
8.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
, and
Shepard
,
M. S.
, 2004, “
Improved HCF Performance and FOD Tolerance of Surface Treated Ti-6-2-4–6 Compressor Blades
,”
Proceedings of the Ninth National HCF Conference
, Pinehurst, NC, Mar. 16–19.
9.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
, and
Ravindranath
,
R. R.
, 2003, “
Low Plasticity Burnishing (LPB) Treatment to Mitigate FOD and Corrosion Fatigue Damage in 17-4 PH Stainless Steel
,”
Proceedings of the Tri-Service Corrosion Conference
, Las Vegas, NV, Nov. 17–21.
10.
Jayaraman
,
N. J.
, and
Prevéy
,
P. P.
, 2003, “
Application of Low Plasticity Burnishing (LPB) to Improve the Corrosion Fatigue Performance and FOD Tolerance of Alloy 450 Stainless Steel
,”
Proceedings of the Tri-Service Corrosion Conference
, Las Vegas, NV, Nov. 17–21.
11.
Prevéy
,
P. P.
, and
Cammett
,
J. C.
, 2002, “
The Influence of Surface Enhancement by Low Plasticity Burnishing on the Corrosion Fatigue Performance of AA7075-T6
,”
Proceedings of the Fifth International Aircraft Corrosion Workshop
, Solomons, MD, Aug. 20–23.
12.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
,
Ontko
,
N. O.
,
Shepard
,
M. S.
,
Ware
,
R. W.
, and
Coate
,
J. C.
, 2004, “
Mechanical Suppression of SCC and Corrosion Fatigue Failures in 300M Steel Landing Gear
,”
Proceedings of ASIP 2004
, Memphis, TN, Nov. 29–Dec. 2.
13.
Prevéy
,
P. P.
, and
Cammett
,
J. C.
, 2002, “
Restoring Fatigue Performance of Corrosion Damaged AA7075-T6 and Fretting in 4340 Steel With Low Plasticity Burnishing
,”
Proceedings of the Sixth Joint FAA/DoD/NASA Aging Aircraft Conference
, San Francisco, CA, Sept. 16–19.
14.
Prevéy
,
P. P.
,
Hornbach
,
D. H.
,
Cammett
,
J. C.
, and
Ravindranath
,
R. R.
, 2002, “
Damage Tolerance Improvement of Ti-6-4 Fan Blades With Low Plasticity Burnishing
,”
Proceedings of the Sixth Joint FAA/DoD/NASA Aging Aircraft Conference
, San Francisco, CA, Sept. 16–19.
15.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
, and
Ravindranath
,
R. R.
, 2004, “
Incorporation of Residual Stresses in the Fatigue Performance Design of Ti-6Al-4V
,”
Proceedings of the International Conference on Fatigue Damage of Structural Materials V
, Hyannis, MA, Sept. 19–24.
16.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
, and
Ravindranath
,
R. R.
, 2005, “
Use of Residual Compression in Design to Improve Damage Tolerance in Ti-6Al-4V Aero Engine Blade Dovetails
,”
Proceedings of the Tenth Nat, HCF Conference
, New Orleans, LA, Mar. 8–11.
17.
Prevéy
,
P. P.
,
Jayaraman
,
N. J.
, and
Ravindranath
,
R. R.
, 2004, “
Introduction of Residual Stress to Enhance Fatigue Performance in the Initial Design
,”
Proceedings, Turbo Expo 2004
, Vienna, Austria, Jun. 14–17.
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