Surface and property characterization of laser polished Ti6Al4V

Abstract

Laser polishing is being increasingly utilized as a method of surface treatment for metal alloys, and the rapid heating and cooling in the process significantly modify the subsurface material properties. However, understanding the effect of laser polishing on the properties is still incomplete. In this study, laser polishing of titanium alloys is experimentally investigated, in which the polishing parameters are determined by the energy conservation and the surface roughness can be effectively decreased, from 7.3 to approximately 0.6 μm through the orthogonal experiments. Through thermal cycle analysis of the laser polishing based on the finite element method, the martensite formation occurs in the substrate, which leads the 25% increase of the micro-hardness. The corrosion resistance improvement of the polished surface is attributed to the reduction of surface roughness and the increase of grain size in the polished zone.