SURFACE-COATED CUTTING MEMBER

摘要

A surface-coated cutting member includes a substrate, a metal layer vapor-deposited on a surface of the substrate and a hard coating vapor-deposited on the metal layer. The substrate is made of hard material selected from the group consisting of tungsten carbide-based cemented carbide, titanium carbo-nitride based cermet and high speed steel. The metal layer is made of metal selected from Group IVa of the Periodic Table and has an average thickness of 0.1 to 1 mu m. The hard coating has an average thickness of 1 to 9 mu m, and includes an inner layer of an average thickness of 0.2 to 4 mu m vapor-deposited on the metal layer, an intermediate layer of an average thickness of 0.2 to 4 mu m vapor-deposited on the inner layer and an outer layer of an average thickness of 0.2 to 3 mu m vapor-deposited on the intermediate layer. The inner layer is made of carbide or carbo-nitride of metal selected from Group IVa of the Periodic Table, and the intermediate layer is made of carbo-nitride of metal selected from Group IVa of the Periodic Table. The outer layer is made of nitride of metal selected from Group IVa of the Periodic Table.