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 made it a valuable material in severe conditions, however, its machining is still a challenging task. A pulsed Nd:YAG laser with an average power of 1000 W coupled to an optical fiber was employed to explore the limits and the quality of different techniques for the laser cutting of Si-SiC samples with a thickness of 6 mm.
In this work, the feasibility of the single-pass technique in comparison with multi-pass laser cutting was explored for different processing parameters and using both inert assist and reactive assist gas. The experimental results were compared as a function of processing time and cut quality. The cut quality was examined by means of cross sectional inspection and compositional microanalysis to detect microcrack formation and microstructure changes.