Experimental investigation and optimization of laser induced plasma micromachining using flowing water

Abstract In this study, laser induced plasma micromachining using flowing water (F-LIPMM) was performed to create micro-channels on stainless steel surface. The effects of process parameters (water speed, laser pulse energy, frequency and scanning speed) on the responses of micro-channel width, depth, material removal rate (MRR) and heat affected zone (HAZ) were investigated based on response surface methodology (RSM). The regression models for the machined width, depth, MRR and HAZ were developed, and the adequacies of the developed models were subsequently verified by analysis of variance (ANOVA) method. Finally, grid structures consisting of desired micro-channels were created with the optimum process parameters: water speed of 8 m/s, pulse energy of 10.4 μJ, frequency of 15.8 kHz and scanning speed of 2.7 mm/s. The uniform micro-channels with smooth bottoms, side-walls and small HAZ were obtained, and the results showed that the predicted responses using the developed models were comparable with the experimental results.