Preparation and application of oxidation-resistant active grinding diamond wheels for high-quality grinding of polycrystalline diamond

Diamond, as a third-generation semiconductor material, poses significant challenges for high-quality processing due to exceptional hardness and chemical stability. This paper presents an active metal-containing ceramic-bonded diamond grinding wheel specifically designed for the high-quality machining of polycrystalline diamond (PCD) substrates. By optimizing the segmented sintering process under "air-vacuum" conditions, this study mitigates issues associated with traditional sintering methods, which can lead to the oxidation of reactive metals and compromise wheel strength. Comparative studies of grinding performance reveal notable differences among wheels made from iron, cobalt, titanium, and other metals. In particular, during the machining of PCD substrates with the optimized iron-containing wheel, surface carbon atoms of PCD react with iron to form Fe 3 C. This reaction product enhances the cutting action of diamond abrasives, resulting in efficient material removal. The wheel reduces the surface roughness (Sa) of PCD substrates from 1345.3 nm to 12.3 nm, achieving a material removal rate of 2.52 μm/h. Furthermore, the machined workpiece exhibits a subsurface amorphous carbon layer measuring only 1.512 nm, with no observable subsurface damage. This study offers an effective technical solution for the high-efficiency and ultra-precision machining of PCD substrates.