Study on laser ablation quality and removal mechanism of SiCf/SiC composites by wavelength and thermal effect equation

SiC_f/SiC composites exhibit exceptional material properties, rendering them ubiquitous in aerospace, high-end automotive, and other advanced applications. However, these composites pose processing challenges due to their high hardness, brittleness, anisotropy, as well as heterogeneity. To investigate the material removal mechanisms and processing quality during picosecond laser ablation of SiC_f/SiC composites, this study conducted linear scanning ablation experiments employing picosecond pulse lasers. The experiments were followed by a detailed analysis of the surface morphology, and elemental composition of the grooves under varying laser parameters. The findings reveal that laser power, scanning speed, repetition rate, and scanning duration exert a profound influence on the postablation groove characteristics. Specifically, as laser power increases, the groove width and depth broaden, accompanied by an expansion in both the ablation area and the heat-affected zone. During laser irradiation of SiC_f/SiC composites, the chemical bonds within the matrix and fibers undergo disruption, initiating oxidation reactions, and the formation of oxides. The oxides primarily manifest as solid SiO, SiO₂, and gaseous CO and CO₂. Furthermore, this article introduces a graphical model that elucidates the material removal mechanism by using laser. Collectively, this research provides a theoretical foundation and technical guidance to achieve high performance cutting of SiC_f/SiC composites.