Coated CBN polycrystalline superabrasive tools

Abstract

A polycrystalline cubic boron nitride (cBN) cutting tool contains less than 70 volume-% cBN and is coated with a layer of hard refractory material. Appropriate hard refractory coating materials possess characteristics, which include that such material: (a) forms a stable chemical bond (e.g., a nitride or boride) with cBN, (b) is inert to ferrous metals, (c) will not promote back-conversion of cBN, and (d) will form a continuous coating on cBN under conditions which are not detrimental to cBN. Materials that exhibit such characteristics broadly include, for example, a boride, carbide, nitride, or silicide of a metal. Representative of such materials are, for example, the borides of Ti, Zr, V, Ta, Cr; the carbides of Zr, V; the nitrides of Cr, Ta, Si, Al; and the suicides of Mo.

Dependencies are inferred from the claim text.