Influence Of Shot Peening On The Fatigue Behaviour Of Ti-6Ai-4V In Respect Of Multiaxial Loading

Author:  B. Oberwinkler, H. Leitner, M. Stoschka
Source:  Conf Proc: ICSP-10 Tokyo, Japan 2008
Doc ID:  2008099
Year of Publication:  2008
Abstract:  
ABSTRACT Although shot peening treatment is commonly used in engineering practise for their beneficial effect on fatigue life, only few quantitative data is available from literature in respect of multiaxial loading. This contribution presents results of a long-term research program that aims for developing quantitative design guidelines for the influences of mechanical surface treatments on the fatigue life of structural components. Rotating bending, alternating torsion and multiaxial fatigue tests were performed on the titanium alloy Ti-6Al-4V. The heat treated and machined specimens were subjected to a shot peening process according to the MIL-S-13465C and MIL-P-81985 standards. It can be observed that shot peening leads under uniaxial loading to an increase of the fatigue strength both in the finite life and lower loaded high cycle fatigue region. Under multiaxial loading the S/N-curve is not affected by shot peening, neither in the low cycle fatigue regime nor in the high cycle fatigue region. For an assessment of the fatigue failure mechanism, investigations of the surface layer were performed. KEY WORDS High Cycle Fatigue, Titanium Alloys, Shot Peening, Multiaxial Loading;