Manufacturing method of polycrystalline cubic boron nitride

The invention relates to the technical field of manufacturing of superhard materials, particularly a manufacturing method of polycrystalline cubic boron nitride, which comprises the following steps: a. manufacturing of adhesive: taking 4-6 parts by weight of aluminum powder, 6-8 parts by weight of titanium nitride, 7-11 parts by weight of titanium diboride and 8-30 parts by weight of titanium carbide, and mixing to prepare the adhesive, wherein the purity of the aluminum powder is 99.9%, the particle size of the aluminum powder is less than 5 micrometers, the oxygen content is lower than 0.05%, the purity of the titanium nitride, titanium diboride and titanium carbide is higher than 99.9%, and the particle size is 2-6 micrometers; and b. manufacturing of raw materials: taking 60-7 parts by weight of adhesive in the step a and 40-93 parts by weight of cubic boron nitride micropowder, mixing uniformly by ball milling, removing impurities and the like, wherein the purity of the cubic boron nitride micropowder is 99.9%, and the particle size is 2-5 micrometers. The polycrystalline cubic boron nitride produced by the method is electrically conductive, and has the advantages of high hardness and high wear resistance.