Analysis of diamond wear morphology and segment wear evolution during the process of hard granite sawing

Diamond circular sawblade has been widely used in hard granite processing. In this study, the wear mechanism and wear evolution of the diamond segment were investigated. The wear morphologies of diamond grits were classified as emerging diamond, whole diamond, crack diamond, blunt diamond, micro-fractured diamond, macro-fractured diamond, wear flat diamond, and pull-out diamond, which is based on sufficient observation data. The main form of diamond wear is fracture. The fracture morphology of diamond grit dominates by cleavage, which is brittle transgranular fractures, and the microscopic features are fracture steps and river-like patterns. Since the {111} crystal plane has the largest interplanar spacing among all the crystal planes, cleavage fractures tend to occur on this crystal plane. Through the scratches and pitting on the diamond grit surface, it proved that the wear process is a mixed type of two-body wear and three-body wear. However, some diamond grits exhibit special fracture morphology and are without the typical characteristics of cleavage fracture. Combined with internal factors (including microstructures and internal defect) and external factors (including chip flow, thermal load and mechanical load), the mechanism of various diamond wear morphologies and segment wear phenomena observed in the sawing experiment is clarified. Finally, the evolution process of the diamond failure and segment wear are described. The research systematically revealed the mechanism of segment wear and the fracture morphology characteristics of diamond grits in the sawing granites, which can further improve the understanding of segment wear and provide theoretical guidance for segment design.