Influence of Ultrasonic Surface Rolling Process and Shot Peening on Fretting Fatigue Performance of Ti-6Al-4V

Abstract The shot-peening (SP) and ultrasonic surface rolling process (USRP) were performed on Ti–6Al-4V plate specimens. The surface hardness and residual stresses of the material were tested by vickers indenter and X-ray diffraction residual stress analyzer. The effects of different surface strengthening on its fretting fatigue properties were verified by fretting fatigue experiments. It is shown (i) that the fretting fatigue life of Ti–6Al-4V effectively improved after USRP and SP and（ii）that the surface integrity of specimens after USRP is the best, which has deeper residual compressive stress layer and more refined grain. The fretting fatigue fracture surface and wear morphology of the samples were studied and analyzed by means of microscopic observation, and the mechanism of improving fretting fatigue life by surface strengthening process was further explained