Influence Of The Shot Peening Parameters On The Surface Layer Properties And Fat. Life Of Ti-6a1-4v

Author:  Wagner, L. and Lutjering, G.
Source:  Conf Proc: ICSP-2, (p.194-200)
Doc ID:  1984038
Year of Publication:  1984
Abstract:  
The influence of the shot peening parameters (peening pressure and exposure time) on the surface layer properties (dislocation density, residual stresses, material hardness, and surface roughness) was evaluated on various microstructures of Ti-6A1-4V. Compared to the electrolytically polished condition shot peening generally decreased the fatigue life tested at R = -1 under vacuum conditions. However in an aggressive environment shot peening was found to improve the fatigue life. A pronounced overpeening effect i.e. a decrease in fatigue life with increasing peening pressure as well as exposure time was observed for those conditions of the Ti-6A1-4V alloy, which were age-hardened and exhibited cyclic softening during the shot peening process. No overpeening effect with exposure time was observed for the un-aged condition. Descriptors: Shot peening; Dislocation density; Residual stresses; Surface roughness; Cyclic hardening and softening; Cyclic stability of the residual stresses; Fatigue crack nucleation and propagation; Environmental effects