High-Speed End Milling of Cemented Carbides Using Diamond-Coated Tools

This study aims to improve the efficiency and precision of milling WC-Co based cemented carbide (WC-Co) using the chemical vapor deposition (CVD) diamond-coated carbide tools. Five types of WC-Co materials with varying WC grain sizes and Co contents are machined at cutting speeds of 100 m/min and 400 m/min. Tool flank wear width (VB), wear morphology, cutting forces, and tool flank temperature are evaluated to clarify the effects of microstructural and compositional differences. The results show that coarse- and medium-grained materials exhibit reduced VB at the higher cutting speed of 400 m/min, while fine-grained and high-Co-content materials show increased VB under the same condition. Abrasive wear dominates at the low cutting speed of 100 m/min, whereas adhesive wear becomes prominent at the high cutting speed of 400 m/min. Based on the measured cutting forces and tool flank temperatures, the influence of WC grain size and Co content on tool wear behavior is discussed in relation to the cutting speed-dependent wear mechanisms. These findings provide useful insights for optimizing cutting conditions in high-efficiency and highprecision milling of cemented carbides.