Abstract: SiC_f/SiC composites are promising materials for advanced aeroengine hot end components, due to their low density, high specific strength, high temperature resistance, and corrosion resistance characteristics. However, their high-performance service and wide application are limited by the machining challenges brought on by the heterogeneity and high-brittle properties. To solve this problem, the laser-induced ablation assisted belt grinding method is proposed, the material removal behavior and damage mechanism are investigated; besides, the effect of machining parameters on the grinding force, grinding temperature, and surface roughness is systematically analyzed. The results indicate that laser beam oxidizes the surface materials of SiC_f/SiC composite to produce SiO₂ particles that can be easily removed during grinding. Compared with traditional grinding, laser-induced ablation assisted belt grinding reduces the macro brittle fracture of SiC fibers, and generates grinding chips with similar shape and size. Furthermore, an increase of laser scanning spacing leads to an increase in the grinding force, grinding temperature and surface roughness. Finally, under the machining conditions of 130 μm laser scanning spacing, 100 mm/min abrasive belt feed rate, and 2 100 r/min grinding speed, SiC_f/SiC composites are mainly removed in the form of micro-fracture, and the surface morphology of the fibers and matrix is crushing and ploughing, ultimately producing a large-area flat and crack free surface, and the surface quality is therefore the best.

Key words: ceramic composite materials, laser ablation, belt grinding, laser-assisted grinding, brittle fracture damage