Effects of Zirconia Shot Peening on High Cycle Fatigue Properties of Ti-6Al-4V Alloy

摘要

Cantilever type rotating bending fatigue tests were conducted in order to investigate the effects of shot peening treatment on the fatigue properties of a Ti-6Al-4V titanium alloy. Shot peening was performed with three types of fine zirconia shot grids with different diameters and material grades. The fatigue lives of shot peened specimens fractured from the inside with a fish eye on the fracture surface were longer than those of non-peened specimens fractured from the surface. To discuss the fatigue properties, the fracture surfaces were observed and the peening effects such as surface roughness, hardness and residual stress were examined. From the observation of fish eye patterns on the fracture surfaces, it was clear that the residual stress influenced the fatigue properties of Ti-6Al-4V greatly.