Coated cemented carbide endmill having hard-material-coated-layers excellent in adhesion

Abstract

A coated cemented carbide endmill comprises a tungsten carbide based cemented carbide substrate comprising 5-20% Co as a binder phase forming component, optionally 0.1-2% of Cr and/or V as a binder phase forming component, optionally 0.1-5% of one or more of (Ti, Ta, Nb, Zr) C·N as a dispersed phase forming component, and the balance being WC as the dispersed phase forming component and inevitable impurities. The WC has a fine grained structure having an average grain size of 0.1-1.5 μm, the cemented carbide substrate has a reaction-created surface layer formed on the surface portion thereof which is formed by heating at high temperature and in which ComWnC is distributed over a thickness of 0.1-2 μm thereof, and further the substrate has coated layers composed of a Ti compound layer. Optionally, an Al2O3 layer is formed thereon with an average layer thickness of 0.5-4.5 μm, the Ti compound layer being composed of one or more layers of TiC, TiN, TiCN, TiCO, TiNO and TiCNO using MT-CVD and the Al2O3 layer is formed using MT-CVD or HT-CVD. The hard-material-coated layers of the endmill have excellent adhesion.

Dependencies are inferred from the claim text.