Patent ID: 6858333
Filing Date: 2005-02-22
Classification: C23C,Y10T

Abstract:
1. A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes; at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride, and wherein the silicon nitride has the formula SiN