Laser-assisted machining of niobium alloy (C-103): effects of process parameters on cutting force and surface finish

In the present study, Laser-Assisted Machining was opted to obtain the machinability characteristics of Niobium alloy (C-103). The experiments were conducted by considering input variables, known as independent cutting parameters such as speed, laser power, feed, and depth of cut and the output parameters, known as responses like cutting force and surface finish of the cutting process. L9 orthogonal array was used to conduct the experiments. Taguchi technique implemented to optimize the responses. Cutting force reduces with an increase in speed and laser power and increases with an increase in feed and depth of cut. Surface roughness increases with the depth of cut and feed rate and decreases with an increase in speed and laser power. Also found, the laser has a significant effect on the responses compared to other machining parameters. Regression models for cutting force and surface roughness were developed. The effectiveness of these models was checked with regression co efficient, R-Square = 98.21%, Adjusted R-Square = 96.42%, Predicted R-Square = 92.93% for cutting force and R-Square = 92.82%, Adjusted R-Square = 89.63%, Predicted R-Square = 87.45% for surface roughness. The predicted cutting force and surface roughness for the optimal laser power of 550W, depth of cut of 0.25 mm, speed of 540 rpm and feed rate of 0.02 mm/rev (A3B1C3D1) was 24.71 N and 0.3413 µm respectively. The actual cutting force and surface roughness obtained from experiments for the same process parameters were 26.44 N and 0.375 µm respectively. The percentage of error for cutting force and surface roughness is 6.54 and 9.33 respectively which is acceptable statistically. The results obtained from laser assisted machining were also compared with conventional machining.