Single-Pass and Multi-Pass Laser Cutting of Si–SiC: Assessment of the Cut Quality and Microstructure in the Heat Affected Zone

Experimental investigations on the laser cutting of thick silicon infiltrated silicon carbide (Si–SiC) elements are presented. Si–SiC is a fully dense ceramic composite with high hardness and chemical and thermal stability, which makes it a valuable material in severe conditions. However, machining is still a challenging task. A pulsed Nd:YAG laser was employed to explore the quality of different techniques for the laser cutting of Si–SiC elements with a thickness of 6 mm. In this work, the feasibility of a single-pass technique in comparison with a multi-pass laser cutting was explored for different processing parameters and using both inert and reactive assist gas. A systematic evaluation of the cut quality was assessed by examination of the cross section of samples by optical and electron microscopy, compositional microanalysis, and Raman spectroscopy.