Method of forming a surface coating having high surface hardness on a metal, alloy or ceramic substrate

Abstract

The present invention provides a method of forming a surface coating having a micro-Vickers hardness of about 1600 kgf/mm2 or more on a substrate made of metal, alloy or ceramic. The method comprises subjecting the substrate to a reactive plasma process which uses a target material consisting of tungsten or its alloy, a sputtering gas consisting of argon, and at least one reactive gas selected firm the group consisting of carbon dioxide and carbon monoxide, to form a tungsten oxycarbide coating on the surface of the substrate, wherein the reactive plasma process is performed additionally using at least one noble gas selected from the group consisting of helium, neon, krypton and radon, as an auxiliary gas, while maintaining the substrate at a temperature in the range of about 550 to 680 K. The method of the present invention can form a tungsten oxycarbide coating having a desirably enhanced surface hardness equivalent to that of a chromium or molybdenum oxycarbide coating on the surface of a metal, alloy or ceramics substrate without degrading the original properties of the substrate.

Dependencies are inferred from the claim text.