Coated tungsten carbide-based cemented carbide blade member

摘要

A surface-coated tungsten carbide-based cemented carbide blade member including a tungsten carbide-based cemented carbide substrate, and a hard coating of an average layer thickness of 3 to 30 mu m formed thereon is disclosed. The hard coating includes a first layer deposited on the substrate, a second layer deposited on the first layer, and a third layer deposited on the second layer. The first layer has a granular crystal structure, while the second layer has an elongated crystal structure. Among the constituents forming the substrate, at least tungsten and cobalt are diffused into the grain boundaries of the first and second layers.