Coated hard alloy blade member

摘要

A coated hard alloy blade member is disclosed which includes a substrate formed of a hard alloy of a WC-based cemented carbide or a TiCN-based cermet, and a hard coating deposited on the substrate. The hard coating includes an inner layer of TiCN having unilaterally grown crystals of an elongated shape and an outer layer of Al2O3 having a crystal form kappa or kappa + alpha wherein kappa > alpha . The resulting blade member is highly resistant to wear and fracturing, and possesses cutting ability of a higher level.