Study on Water-Jet-Guided Laser–Ultrasonic Grinding Hybrid Processing Technology for SiC_f/SiC Composite Materials

This study proposes a water-jet guidance–ultrasonic grinding hybrid process for drilling holes in ceramic matrix composites to address issues such as cracking, chipping, thermal damage, and low machining efficiency, thereby achieving high-efficiency, high-quality processing of such components. With final surface quality as the constraint, three methods—water-jet guidance, ultrasonic grinding, and the combined water-jet guidance–ultrasonic grinding—were applied to drill holes in SiC_f/SiC composite materials. The study investigated how different processes and parameters affect hole surface quality and machining efficiency. Results demonstrate that the hybrid process effectively overcomes defects inherent to single-process grinding (crazing, chipping) and laser processing (heat-affected zones, recast layers), while significantly removing surface oxides generated by water-jet-guided machining. The hole diameter deviation (<0.017 mm), hole wall surface roughness (Sa < 1.837 μm), and processing efficiency (5.25 min/hole) achieved by this composite process all outperformed those of either ultrasonic grinding or water-jet-guided processing alone. This composite process significantly enhances both processing efficiency and hole wall quality, providing a viable solution for high-quality, efficient machining of ceramic matrix composite components.