SUPERHARD ALLOY AND COATED SUPERHARD ALLOY

摘要

The present invention provides a superhard alloy having excellent impact resistance and wear resistance. The superhard alloy is characterized by comprising a WC phase, a carbonitride phase comprising at least one carbonitride selected from the group consisting of both carbonitrides of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W and solid solutions between these, and a binder phase comprising, as a main component, at least one element selected from the group consisting of Co, Ni, and Fe, the amounts of the WC phase, the carbonitride phase, and the binder phase being 55-94.8 vol.%, 1-30 vol.%, and 4.2-22.2 vol.%, respectively, of the whole superhard alloy, the sum of the WC phase, the carbonitride phase, and the binder phase being 100 vol.%. The superhard alloy is further characterized in that the WC phase has an average grain diameter of 0.05-0.8 µm and the carbonitride phase has an average grain diameter of 0.03-1.1 µm, and that the ratio of the density DB of the superhard alloy determined by a gas replacement method to the density DP of a powder obtained by pulverizing the superhard alloy to a size sufficient to enable the powder to pass through a sieve having an opening size of 75 µm, DB/DP, is 0.95 or higher.