COATED SINTER OF CUBIC-SYSTEM BORON NITRIDE

摘要

A coated sinter of cubic-system boron nitride which is optimum for use in cutting tools which are excellent in wearing resistance and heat resistance in the high-speed cutting of steel. The coated sinter comprises: a base which is a sinter comprising at least 99.5 vol.% cubic-system boron nitride; and a hard coating film having a thickness of 0.1 to 10 mu m formed on at least part of the surface of the base by physical vapor deposition. The hard coating film desirably comprises one or more compound films consisting mainly of at least one metallic element selected among Group IVa elements and aluminum and at least one element selected among carbon, nitrogen, and oxygen. The coated sinter preferably has, between the hard coating film and the base, an interlayer comprising a compound consisting mainly of boron and at least one metallic element selected among Group IVa elements.