Effect of grain size and cobalt content on machining performance during milling tungsten carbide with PCD tool

Abstract

Tungsten carbide has been extensively utilized in the manufacturing field due to its exceptional properties. However, traditional methods such as grinding or electric discharge machining often result in a low material removal rate and inevitable surface defects, making tungsten carbide one of the most challenging materials to machine. Milling has emerged as a promising alternative for machining tungsten carbide. However, the milling of tungsten carbide has not been widely applied in the industry due to a lack of comprehensive understanding regarding the milling performance of different tungsten carbides under various conditions. In this paper, a polycrystalline diamond (PCD) tool was used in the milling of tungsten carbides to investigate the effects of tool grain size, workpiece Co content, and WC grain size on tool wear and machining surface quality. It was found that PCD tools with larger grain sizes exhibited higher wear resistance. Additionally, excessive Co content in the workpiece and large WC grain size increased tool wear and degraded the quality of the machined surface. The primary types of tool wear observed in the milling of WC-Co included adhesive wear, abrasive wear, phase change wear, and oxidation wear.