Coated cutting tool

摘要

The present invention relates to a cutting tool comprising a substrate of cemented carbide, cermet, ceramics, cubic boron nitride or high speed steel on which at least on the functioning parts of the surface thereof a thin, adherent, hard and wear resistant coating is applied, wherein said coating comprises a laminated multilayer of alternating PVD or PECVD metal oxide layers, Me 1 X+Me 2 X+Me 1 X+Me 2 X..., where the metal atoms Me 1 and Me 2 are one or more of Ti, Nb, V, Mo, Zr, Cr, Al, Hf, Ta, Y and Si, and where at least one of Me 1 X and Me 2 X is a metal oxide+metal oxide nano-composite layer composed of two components, component A and component B, with different composition and different structure, which components consist of a single phase oxide of one metal element or a solid solution of two or more metal oxides, wherein the layers Me 1 X and Me 2 X are different in composition or structure or both and have individual layer thicknesses larger than 0.4 nm but smaller than 50 nm, said laminated multilayer layer has a total thickness of between 0.2 and 20 µm and has a compositional gradient, with regards the concentration of one or more of the metal atom(s), in the direction from the outer surface of the coating towards the substrate, the gradient being such that the difference in between the average concentration of the outermost portion of the multilayer and the average concentration of the innermost portion of the multilayer is at least 5 at-% in absolute units.