Laser machining of silicon carbide: Experimental analysis and multiobjective optimization

Abstract

This work investigates the feasibility of laser engraving of silicon carbide by adopting a Q-Switched fiber laser. To study the effect of the laser parameters on the laser-material interaction, a 33 full factorial plan was developed and tested. During the tests, the following laser parameters were varied: scanning speed, pulse frequency, which affects the pulse power, and the number of repetitions, i.e., the number of times the laser beam passes on the same line. After the tests, digital microscopy was used to measure the depth of the engraved pocket, and a 3D laser profilometer was used to acquire the pocket surface and morphology and to calculate the main roughness parameters. The analysis of variance (ANOVA) was carried out in order to detect how the process parameters affect laser machining. The Response Surface Methodology (RSM) was additionally performed to obtain the regression model and finally, the Multi-Response Optimization (MRO) was implemented to identify the optimal process conditions. The results show that it is possible to machine pockets with low roughness (Ra <1 μm) at high material removal rates (MRR> 0.1 mg/s).