Patent ID: 8409695

Claim:
A hard coating for a substrate comprising: a first layer comprising (Ti z Al 1-z )N, wherein 0.4≦z≦0.6; and a second layer having a plurality of sublayer groups, each sublayer group comprising a first sublayer of (Ti y Si 1-y )N, wherein 0.85≦y≦0.98, and a second sublayer of (Ti x Al 1-x )N, wherein 0.4≦x≦0.6; wherein neither a pure silicon phase nor a pure silicon nitride phase is present in the first sublayer, the first layer accounts for 20 to 60 percent of the overall hard coating thickness, the thickness of each sublayer group is in the range of from 3 to 20 nanometers, the first layer is more proximal to the substrate than is the second layer, and the sum of x and y is in the range of 1.38 to 1.46.