Patent ID: 7939172

Claim:
A wear resistant, composite vapour deposited coating on a cutting edge of a substrate comprising: a metal-ceramic coating on the substrate comprising at least two pair of a metallic layer selected from the group consisting of titanium, chromium, vanadium, aluminum, molybdenum, niobium, tungsten, hafnium, zirconium, and alloys thereof; overlayed by a ceramic layer selected from the group consisting of nitrides, carbides, oxides, oxycarbides, oxynitrides, borides, carboborides, borocarbonitrides, silicides, borosilicides and combinations thereof, the metal-ceramic coating having a hardness of greater than about 20 gigapascals and a toughness of greater than about 0.05 H 3 /E 2 ; and at least one top coat overlaying the metal-ceramic coating, the top coat comprising an amorphous diamond-like matrix selected from the group consisting of carbon, silicon, nitrogen, hydrogen, oxygen and transition metals the top coat having nanocrystals sized from about 1 to about 100 nanometers, and having a friction coefficient of less than 0.3; wherein the top coat imposes a compressive stress of from about 0.1 to about 8 gigapascals.