Hard coating

Abstract

The preparation refers to a hard coating with improved abrasion resistance, heat resistance, low friction and high sliding properties, improved weldability and adhesion. The hard coating consists of: a lower layer (2) with a composition of (Ti,Al)N or (Ti,Al,Mo)bi; an intermediate layer (3) formed on the lower layer (2); and a top layer (4) formed on the intermediate layer (3) with a composition of (Al,Ti,Cr,M)N. M is an atom chosen from Mo, V, and Y. The intermediate layer (3) has a main composition of (Al,Ti,Cr,M)N and has a composition between the composition of the lower layer (2) and the composition of the upper layer (4). In the intermediate layer (3), each of the atomic ratios of Al, Ti, and M changes in the direction of film thickness from the lower layer (2) to the upper layer (4). In the intermediate layer (3), the larger the atomic ratio of Cr, the closer it is to the upper layer (4) in the direction of film thickness.