Influence of Abrasive Grain Protrusion on High-Quality Machining of Cemented Carbide Using PCD Ball End Mills

In this study, cemented carbide was machined to a high quality using polycrystalline diamond (PCD) ball end mills characterized by various surface textures. The effect of the surface texture of the tools on the machining characteristics was studied using two types of PCD tools featuring abrasive diamond grains at various protrusion heights. In addition, a single crystal diamond tool with the same shape as that of the PCD tool was fabricated, and the experiment was repeated to study the differences in machining characteristics. The polished PCD tool yielded a high-quality machined surface with an average surface roughness of 1 nm. The polished PCD tool yielded superior sample surface roughness compared to the PCD tool for feed rates of 10–500 mm/min. The use of a polished PCD tool enables the efficient elimination of material through plastic flow, leading to the attainment of a high-quality machined surface while preventing the adhesion of materials on the tool surface. A single crystal diamond tool can also be used for machining cemented carbide within a feed rate range of 10–200 mm/min; however, its performance is inferior to that of a polished PCD tool. Experiments confirmed that the polished PCD tool was the most effective among the tested tools for the precision machining of cemented carbide.