Effect of Laser Peening on the Residual Stress Distribution and Wettability Characteristics of Ti-6Al-4V Alloy for Biomedical Applications

Abstract

In the present study, the effect of Laser Shock Peening without Coating (LPwC) on the surface and subsurface characteristics (i.e. residual stress, hardness in-depth direction, surface roughness, XRD and contact angle studies) of a Ti-6Al-4V alloy in the solution treated (ST) condition is considered. ST was carried out at 925ºC for 1 h, followed by air cooling. LPwC was performed using an Nd:YAG with 1064 nm wavelength, at three different power densities of 3, 6 and 9 GWcm-2 with fixed overlapping of 70%. The effect of LPwC was analysed using near-surface micrographs, residual stress distribution, surface roughness, X-ray diffraction, microhardness and surface contact angle studies. From the obtained results, it was concluded that the sample peened at 6 GW cm-2 was most suited for biomedical applications.