Machinability evaluation of Titanium alloy in Laser Assisted Turning

The use of titanium and its alloys has increased in various industries recently, because of their superior properties of these alloys. Titanium alloys are generally classified as difficult to machine materials because of their thermo-mechanical properties such as high strength-to-weight ratio and low thermal conductivity. Laser Assisted Machining (LAM) improves the machinability of high strength materials in various aspects. LAM is a high temperature cutting process using a laser beam as the heat source. The laser is used as an intense heat source to increase workpiece temperature locally and decrease the strength of the machined material in front of the cutting tool. Decreasing of workpiece material strengh in material removal region resulted to improvement of material removal conditions. In this study the effectiveness of the LAM on machinability of Ti6Al4V is invetigated by compared to conventional machining in varying process parameters such as cutting speed, feed rate, laser power and material removal temperature. The machinability of the titanium alloy under varying conditions is evaluated by examining specific cutting energy, surface roughness and chip morphology. This investigation has shown that LAM reduces specific cutting energy about 30% and improvement of surface roughness as compared to conventional machining.