Optimization of Laser Trepanning Parameters for Mild Steel by Taguchi Response Surface Methodology (T-RSM)

Laser trepanning plays a vital role in the machining of holes as it needs to eliminate material only from a thin annular region, not the entire circle. The key benefits of trepanning are material saving and less energy consumption. In this study, responses from laser trepanning on mild steel were taken for optimization. Responses like hole-top circularity (HTC), hole-bottom circularity (HBC) and hole taper (HT) were recorded according to the variations made in the parameters such as laser power, gas pressure, speed of spot movement and pulsing frequency as per Taguchi’s L₂₇ orthogonal array. To optimize the operating parameters, Taguchi–response surface methodology (T-RSM) was applied. Three-dimensional response surface graphs and ramp function graph for desirability were plotted for the obtained results. Optimal level of parameters obtained was laser power-2716.83 W, gas pressure-7 bar, speed of spot movement-1200 mm/s, pulsing frequency-2000 Hz and trepanning hole-20 mm.