Simulation and Experimental Study of C/SiC Composites by Laser-ultrasonic Hybrid Micromachining

High strength, high stiffness, low density, low thermal expansion coefficient, etc., are all characteristics of C/SiC composites, but fiber extraction, matrix cracks and burrs are prone to occur during processing which make it difficult for the parts to meet the requirements of high precision and quality. Laser-ultrasonic hybrid micromachining (L-UHM) is a recent research hotspot and has been shown to have a positive impact on the machining quality of ceramic matrix composites. The research focuses on L-UHM’s effects on the processing of C/SiC composites at various fiber orientations. Through the analysis of the temperature field simulation of laser parameters on the effect of heat affected zone (HAZ), and conventional machining (CM) and L-UHM orthogonal micromachining models were established to investigate how two alternative fiber direction cutting circumstances affect the failure mode of C/SiC composites. The findings indicate that compared with CM, LUHM significantly improves the surface quality both in the vertical longitudinal fiber direction and the parallel fiber direction. When $\mathrm{P}=60\mathrm{W}/\mathrm{m}\mathrm{m}^{2}$ and $\mathrm{A}=6\mu \mathrm{m}$, respectively, the surface roughness is reduced by 29.9 % and 35.3 %, respectively.