RSM-based optimisation of machining forces and surface roughness when laser-assisted turning Nitinol alloy

In the current investigation, the interrelation between parameter attributes, namely, laser power, cutting speed, feed rate, and depth of cut on machining forces [thrust force (Fx), feed force (Fy) and cutting force (Fz)] and surface roughness (SR) in laser-assisted turning (LAT) of Nitinol alloy using TiAlN PVD coated carbide inserts has been discussed. Experiments were performed using response surface methodology (RSM) and face centred central composite design (FCCD). Statistical techniques such as analysis of variance (ANOVA) and RSM were used to evolve regression models and to arrive at optimum parameter attributes. Results from the current research suggests that cutting speed and feed rate have superior impact on thrust force and cutting force, while feed rate and laser power are the most prominent important attributes for feed force. For SR, speed and cutting depth are the most prominent attributes. The optimum LAT parameters obtained through desirability function include power of 450 watts, cutting speed of 75 m/min, feed of 0.025 mm/rev and depth of cut of 0.5 mm with predicted machining forces of Fx = 123 N, Fy = 154 N and Fz = 102 N and surface roughness of 0.653 μm at 0.995 desirability level.