Patent ID: 7790301

Claim:
A multilayer hard coating comprising at least two layers and having a periodicity of not more than 80 nm, wherein each of the at least two layers independently comprises a nitride of at least one element selected from Al, V, Si and B, or a carbonitride of at least one element selected from Al, V, Si and B; and the multilayer hard coating has an average composition satisfying either a composition (X) or a composition (Y), where the composition (X) is (Al 1-a V a )(C 1-x N x ), where 0.27≦a≦0.75, 0.3≦X≦1, and a and X independently represent an atomic ratio; and the composition (Y) is (Al 1-a-b-c V a Si b B c )(C 1-x N x ), where 0.1≦a≦0.75, 0<b+c≦0.20, 0.3≦X≦1, and a, b, c and X independently represent an atomic ratio with the proviso that b and c are not simultaneously 0 while one of b and c may be 0.