Polishing mechanism analysis of silicon carbide ceramics combined ultrasonic vibration and hydroxyl

Silicon carbide (SiC) ceramic is widely used in optical aerospace components due to high-temperature stability and specific stiffness. Considering low polishing efficiency and quality from its extreme hardness, an ultrasonic-chemical assisted polishing (UCAP) approach was developed for SiC using hydroxyl/diamond hybrid slurries to investigate its polishing characteristics and mechanisms. The removal rate increased significantly with the increase of hydroxyl content, abrasive content and size, but with more severe surface deterioration. The softened oxidation of hydroxyl, homogenized distribution, stronger impact and intrusion of abrasives induced by ultrasonic synergistically achieved a 16.8% improvement in removal rate and a 28.1% enhancement of surface roughness relative to conventional diamond slurry, indicating that UCAP provides guidance for multi-field assisted polishing of ceramics.