Patent ID: 7749594

Claim:
A cutting tool comprising a substrate and a wear resistant coating, said wear resistant coating is composed of one or more layers of refractory compounds of which at least one layer consists of a multilayered MX/LX/MX/LX laminar structure where the alternating layers MX and LX are carbides or nitrides with the elements M and L selected from the group consisting of Ti, Nb, Hf, V, Ta, Mo, Zr, Cr, Al, Si or W and mixtures thereof, wherein the sequence of individual layer thicknesses has no repeat period but is essentially aperiodic throughout the entire multilayered structure, and where the individual MX and LX layer thickness is larger than 0.1 nm but the sum of any 10 consecutive layers in the structure is smaller than 300 nm, and the total thickness of said multilayered structure is larger than 0.5 μm but smaller than 20 μm, deposited by PVD-technique and that the other layer(s), if any at all, comprise(s) wear resistant nitrides, carbides, oxides and/or carbonitrides wherein at least one of MX or LX are electrically isolating and wherein the multilayered structure has a content gradient in the elements M and L.