Patent ID: 8119262
Filing Date: 2012-02-21
Classification: C23C,Y10T

Abstract:
1. Cutting tool comprising a substrate of sintered cemented carbide or cermet, ceramic, cubic boronitride or high speed steel comprising a thin, adherent, hard and wear resistant coating, said coating comprising a laminar, multilayered structure of alternating layers of refractory compounds in non-repetitive form, X+Y+X+Y+X . . . where the alternating layers X and Y are composed of polycrystalline nitrides having a cubic structure, wherein the nitrides are metalnitrides, metalcarbides or metalcarbonitrides, the sequence of individual layer thicknesses having no repeat period but being essentially aperiodic throughout the entire multilayered structure wherein said individual X or Y layer thickness is larger than about 0.1 nm but smaller than about 100 nm, varying essentially at random, and the total thickness of said multilayered coating is from about 0.5 μm to about 20 μm, the multilayered structure having an average chemical composition of Al a Ti b Si c Cr d (C e N 1−e ) where a is greater than zero and less than about 0.5, b is greater than about 0.1 and less than about 0.9, c is greater than about 0.01 and less than about 0.17, d is equal to or greater than zero and less than about 0.06, and a+b+c+d=1, where e is equal to or greater than 0 and less than about 1, wherein said coating comprise homogeneous layers which are repeatedly alternated with multilayered structures, where the homogeneous layers comprise metalnitrides, metalcarbides or metalcarbonitrides or mixtures thereof, and where the average chemical composition of the coating is Al