Grinding wheel-wafer interfacial evolution-induced transition of material removal mechanisms and its effect on SiC wafer integrity

In ultra-precision grinding of 4H-SiC wafers, the grinding wheel surface topography plays an important role in the wheel-wafer interfacial state, material removal mechanisms, and the coupled evolution of wafer surface and subsurface integrity. In this study, in-process abrasive water jet dressing was employed to regulate the wheel surface topography and consequently modify the micro-contact state at the wheel-wafer interface. Multi-scale characterizations of wheel topography, grinding responses, and wafer integrity were examined to clarify the evolution of the grinding interface and its effect on wafer quality. The results reveal a nonlinear interfacial evolution with increasing dressing scale, characterized by three states: localized passivation-instability state, dynamically stable load-bearing state, and excessive renewal-interfacial instability state. Different interfacial states showed clear correspondence with material removal behavior and wafer damage characteristics. At the dressing scale of 2 μm, the coordinated peak structure and spatial distribution of the wheel surface were associated with a more pronounced tendency toward ductile-like removal and improved wafer surface and subsurface integrity. In contrast, both insufficient and excessive dressing may destabilize the interfacial state, increase the tendency for brittle fracture-related removal, and deteriorate wafer integrity. The evolution of wheel topography may alter the local contact conditions and load distribution of composite micro-asperity units, thereby influencing abrasive-wafer interactions and the transition between ductile-like and fracture-related removal. A coupled evolutionary pathway of “wheel topography-interfacial state-material removal-wafer integrity” is established, providing a theoretical basis and physical understanding for regulating material removal behavior and optimizing the grinding wheel-wafer interface in the processing of brittle materials.