Subsurface damage inhibiting and synchronous removal behavior of Cf/SiC composites with laser-induced controllable ablation during abrasive belt grinding

Abstract

Aiming at improving the machinability of Cf/SiC composites, this study proposed laser-induced controlled ablation grinding (LICAG) method. Cf/SiC composites samples with various ablating depths were prepared through picosecond laser, which were then ground by abrasive belt. The results showed that Cf/SiC composites were sublimated in laser ablating zone, resulting in dentate grooves covered with loose SiO2 oxides products. The grinding force and temperature during LICAG could be decreased by up to 64.0% and 58.8%, respectively, compared with conventional grinding (CG). Carbon fiber fracture was reduced, SiC matrix and carbon fibers were removed almost synchronously during LICAG; therefore, the surface quality was improved. Moreover, subsurface micro cracks were found near the grinding surface but did not propagate downward along the fibers. Grinding chips of CG were primarily broken fibers and broken SiC matrix; on the contrary, those generated during LICAG were mostly regular fiber bundles connected to SiC matrix.