Wear characteristics of small ball-end fine diamond grinding pins dressed by on-machine electrical discharge

Small ball-end fine diamond grinding pins dressed by on-machine electrical discharge method are promising tools for ultra-precision grinding complex structural components of hard and brittle materials. Since the electrical discharge dressing can affect the grinding pin surface morphology, it is necessary to study the wear mechanism of the metal bonded fine diamond grinding pin dressed by electrical discharge. Electrical discharge dressing experiments and fused silica grinding experiments are conducted to investigate the relationship between grinding pin wear and the dressed grinding pin surface morphology, and analyze the influence of grinding pin wear on the grinding ratio G, surface roughness, and grinding force. The metal bond recast layer, the discharge crater around the diamond grit, and the diamond graphitization are the surface morphologies of the dressed grinding pin that affect the grinding pin wear. The wear modes of the grinding pin are micro-fracture, abrasion, metal bond wear, grit pull-out. Although metal bond wear accelerates the grinding pin wear, it is prone to improve the grinding pin self-sharpening. The grinding ratio, surface roughness, and grinding force variations with the fused silica sample removal volume further verify the analysis of the dressed grinding pin wear mechanism and the self-sharpening.