Surface integrity in laser-assisted machining of Ti6Al4V

Abstract

In laser-assisted machining (LAM), the laser source is focused on the workpiece as a thermal source and locally increases the workpiece temperature and makes the material soft ahead of the cutting tool so using this method, the machining forces are reduced, which causes improving the surface quality and cutting tool life. Machinability of advanced hard materials is significantly low and conventional methods do not work effectively. Therefore, utilizing an advanced method is inevitable. The product life and performance of complex parts of the leading industry depends on surface integrity. In this work, the surface integrity features including microhardness, grain size and surface roughness (Ra) and also the maximum cutting temperature were investigated experimentally in LAM of Ti-6Al-4V. According to the results, cutting speed has inverse effect on the effectiveness of LAM process because with increasing speed (15 to 63 m/min), temperature decreases (524 °C to 359 °C) and surface roughness increases (0.57 to 0.71 μm). Enhancing depth of cut and feed has direct effect on the process temperature, grain size, microhardness and surface roughness.