Patent ID: 8557406

Claim:
A coated polycrystalline cubic boron nitride cutting insert comprising: a polycrystalline cubic boron nitride substrate, the polycrystalline cubic boron nitride substrate having a rake surface and at least one flank surface, and a cutting edge formed at the juncture between the rake surface and the flank surface; a wear-resistant coating scheme comprising: an inner coating layer region deposited by chemical vapor deposition on at least some of the rake surface and at least some of the flank surface of the polycrystalline cubic boron nitride substrate; an alumina-containing coating layer region deposited by chemical vapor deposition on the inner coating layer region, and the alumina-containing coating layer region comprising at least one exposed alumina coating layer; and the exposed alumina coating layer exhibiting a post-blasted stress condition ranging between about 50 MPa (tensile stress) and about −2GPa (compressive stress) as measured by XRD using the Psi tilt method and the (024) reflection of alumina.