Patent ID: 6998173

Claim:
A coated cutting insert comprising: a substantially fully dense substrate made by sintering a compacted mass of starting powders in an atmosphere containing a nitrogen partial pressure, and the starting powders including the following components: a binder selected from one or more of cobalt, nickel, iron and their alloys wherein the binder is present between about 3 weight percent and about 12 weight percent, up to about 95 weight percent tungsten, up to about 7 weight percent carbon, and up to about 13 weight percent of one or more of the following components: titanium, tantalum, niobium, hafnium, zirconium, and vanadium; the substrate having a rake surface and a flank surface, a cutting edge being at the intersection of the rake and flank surfaces; the substrate having a zone of non-stratified binder enrichment of a generally uniform depth beginning adjacent to and extending inwardly from the cutting edge and at least one of the rake surface and the flank surface toward a bulk region; the zone of binder enrichment having a first nitrogen content, and the bulk region of the substrate having a second nitrogen content, and the first nitrogen content being greater than the second nitrogen content; and a coating on the cutting edge and at least a portion of one or both of the rake surface and the flank surface of the substrate.