Experimental studies on material removal mechanisms in ultrasonic assisted grinding of SiC ceramics with a defined grain distribution brazed grinding wheel

Ultrasonic assisted grinding (UAG) is one of the most suitable methods for the processing of hard and brittle materials such as silicon carbide (SiC). During UAG of SiC, the machining quality is directly determined by the material removal mechanism. However, the research on the material removal mechanism for UAG of SiC is still not sufficiently developed. To achieve better comprehension of the material removal mechanism in UAG of SiC, this study conducted both UAG and conventional grinding (CG) tests with a brazed grinding wheel with defined grain distribution. The material removal mechanism in UAG of SiC was studied by comparing the ground surface/subsurface micro-morphology, surface roughness, grinding force, and specific grinding energy between both processes. The results showed that the material removal mechanism experienced a transition from ductile removal to brittle fracture with increasing undeformed chip thickness in both UAG and CG. In addition, the ground surface roughness, grinding force, and subsurface breakage size increased with increasing undeformed chip thickness, while the specific grinding energy first decreased rapidly and then stabilised. Compared with conventional grinding, UAG always resulted in lower surface/subsurface breakage, surface roughness grinding force, and specific grinding energy under identical operating conditions.