Study on the Surface Generation Mechanism during Ultra-Precision Parallel Grinding of SiC Ceramics

Silicon carbide (SiC) is a typical, difficult-to-machine material that has been widely used in the fabrication of optical elements and structural and heat-resistant materials. Parallel grinding has been frequently adopted to produce a high-quality surface finish. Surface generation is a vital issue for assessing surface quality, and extensive modeling has been developed. However, most of the models were based on a disc wheel with a cylindrical surface, whereas the surface topography generation based on an arc-shaped tool has been paid relatively little attention. In this study, a new theoretical model for surface generation in ultra-precision parallel grinding has been established by considering the arc-shaped effect, synchronous vibration of the wheel, and cutting profile interference in the tool feed direction. Finally, the ground surface generation mechanism and grinding ductility were analyzed in the grinding of SiC ceramics. The results showed that the spiral and straight-line mode vibration patterns were the main feature of the machined surface, and its continuity was mainly affected by the phase shift. Furthermore, for the in-phase shift condition, the grinding ductility was more significant than for the out-of-phase shift due to the continuously decreasing relative linear speed between the wheel and workpiece.