On The Effects Of Shot Peen.on The Fatigue Strgth.and The Resid.stresses Of Parts Made Of Ti A16 V4

Author:  Kussmaul, Guth, Stuttgart
Source:  Conf Proc: ICSP-3, (p.335-340)
Doc ID:  1987060
Year of Publication:  1987
Abstract:  
In recent years shot peening has become an excellent procedure for forming sophisticated components in aircraft construction. Based on comprehensive experience, which has been acquired by changing the shape of aluminum parts and by surface hardening of titanium the additional forming of milled parts made of Ti A16 V4 was taken up in a research programme. The only procedure which up to now has turned out to be acceptable for that material was the forming of titanium parts in the creep regime at 700 Deg C. But this requires expensive equipment. Due to the high yield to ultimate strength ratio and the brittle oc-phase cold forming is not accepted. As far as shot peening is concerned a research project was launched to find out whether the mechanical properties of titanium deteriate, particularly with respect to fatigue strength. Moreover, attention had to be drawn to the negative influence of residual stresses which on one hand could reduce the loading capacity of a component in operation and on the other hand favour crack initiation on the surface.