Effects of laser parameters on microgrooves morphology of SiC/SiC composites fabricated by femtosecond laser

Silicon carbide (SiC) fiber-reinforced SiC-matrix (SiC/SiC) composite has a wide range of applications in the aerospace field. However, SiC/SiC composite is typical difficult-to-machine materials due to their non-homogeneous and anisotropic properties, and traditional manufacturing processes cannot meet their processing requirements in aerospace applications. Femtosecond laser processing technology is expected to become the preferred choice to meet this demand, due to their ultrashort irradiation periods and ultrahigh intensities. In this study, the micro-grooving processing on the surface of SiC/SiC composites by femtosecond laser is investigated, and the effects of laser power, scanning speed and scanning frequency on the surface morphology of SiC/SiC composites are investigated. The results show that there are recast layers in the ablation zone and powdery substances in the processing zone during the laser ablation process of SiC/SiC composite. The width and depth of the micro-grooves increase with the increase of laser power and scanning times. When the ablation power is low and the scanning times are few, the grooves are non-uniformly distributed with sawtooth structure. When the ablation power is high and the scanning speed is low, the grooves are serrated. Properly increasing the scanning speed and scanning times can reduce the sawtooth structure and improve the surface quality of the ablated area. This proposed method can achieve good morphology of SiC/SiC and is expected to be applied to industrial processing of SiC/SiC.