Influence Of A Shot Peening Treatment On The Fatigue Limit Of Ti-6a1-4v

Author:  Wagner, L. and Lutjering, G.
Source:  Conf Proc: ICSP-2, (p.201-207)
Doc ID:  1984031
Year of Publication:  1984
Abstract:  
The effect of shot peening on the fatigue limit of various microstructures of the Ti-6A1-4V alloy tested at R = -1 in inert and corrosive environments was studied. From a previous work on the influence of the shot peening parameters on the fatigue life on Ti-6A1-4V (Wagner et al, 1984) the shot peening treatment, which resulted in the most marked improvement of fatigue life in an aggressive environment, was chosen. The fatigue tests were performed using push-pull loading in vacuum and 3.5% NaC1 solution and rotating-beam specimens in laboratory air. For the push-pull tests in vacuum generally a drastic loss in the fatigue limit of shot peened specimens compared to the electrolytically polished condition was observed. On the other hand, by testing in 3.5% NaC1 solution no change or a slight improvement in fatigue limit, depending on the microstructure, was found after shot peening. In contrast to push-pull loading the fatigue limit of shot peened rotating-beam specimens tested in laboratory air was always improved compared to the electrolytically polished condition. Descriptors: Shot peening; Dislocation density; Residual stresses; Surface roughness; Cyclic stability of the residual stresses; Fatigue crack nucleation and propagation; Environmental effects.