Wet peening was taken on Ti-6Al-4V titanium alloy as a surface strengthening treatment. Effect of shot peening on fretting wear behavior was investigated under different conditions of partial slip

mixed slip and gross slip. The fretting wear experiment indicates that wet peening has little influence on fretting wear behavior of Ti-6Al-4V titanium alloy at condition of gross slip. However

wet peening can inhibit crack initiation occurred in accumulation of plastic deformation zone when the condition is partial slip. It is suggested that the improvement of local yield strength at surface layer by shot peening was the key reason for avoiding local fatigue damage.