Diamond coated tool, especially a machining tool of hard metal or cermet, has an inner diamond-rich carbon layer and an outer lower diamond content carbon layer of higher thermal expansion coefficient

摘要

A diamond coated tool, having an inner diamond-rich carbon layer and an outer lower diamond content carbon layer of higher thermal expansion coefficient, is new. A coated tool comprises a substrate with a deposited first carbon layer, which has a predetermined content of carbon with a diamond crystalline structure and which has a thermal expansion coefficient less than that of the substrate, and with one or more outer second carbon layers which have diamond crystalline structure carbon contents less than that of the first layer and which have thermal expansion coefficients greater than that of the first layer. An Independent claim is also included for production of the above coated tool.