Polycrystalline cubic boron nitride compacts - which contain titanium nitride, titanium carbo:nitride, or titanium boro:nitride, and can be used for turning very hard steels etc.

摘要

A mixt. is made contg. BN, and 0.1-30wt.% of materials (I) which are difficult to melt and have a particle size of 50-1000 angstroms; and the mixt. is subjected to high pressure and temp. to obtain the required prod. Materials (I) are pref. monocrystalline nitrides of the transition metals, with particle size 100-1000 angstroms. Material (I) is esp. TiN; or TiCxNy, where x is 0.1-0.9 and y is 0.9-1; or TiBxNy, where x is 0.05-0.3 and y is 0.95-0.7. In all cases, the initial mixt. may also contain 0.1-5% aluminium. The initial mixt. pref. includes BN with a graphitic-, wurzite-, and/or cubic-structure. For example, cutting tools can be made with superior properties to those exhibited by conventional materials.