ARTIFICIAL DIAMOND-COATED HARD SINTERED TOOL MEMBER HAVING HIGH ADHESIVE STRENGTH

摘要

PURPOSE:To enhance the adhesive strength of an artificial diamond-coating layer formed by deposition by limiting the material of a tool member as a substrate and forming a fine-grained artificial diamond layer having a specified thickness and grain size as a middle layer. CONSTITUTION:A fine-grained artificial diamond layer having 0.01-1mum average thickness and 0.005-0.07mum average grain size as a middle layer is formed on the surface of a hard sintered alloy substrate made of a tungsten carbide-based sintered hard alloy or titanium carbide-based cermet. The substrate is then coated with an artificial diamond-coating layer as a surface layer with the middle layer inbetween. The coating layer has 1-10mum average thickness and 0.13mum ordinary average grain size and can be deposited with a device using a thermoelectron emitting material and adopting high-frequency plasma discharge or microwave plasma discharge.