Patent ID: 7932199

Claim:
A compact with a cubic boron nitride (cBN) portion and a non cBN portion, the compact comprising: (a) between about 71 and about 93 volume-% cBN; (b) between about 1 and less than_about 20 volume-% of aluminum oxide; (c) between about 3 and about 26 volume-% of one or more refractory metal compounds selected from the group consisting of: i. a compound having the general formula MZ (1-x) ; ii. a compound having the general formula MC (1-x) Nx; and iii. a combination or solid solutions of two or more compounds each having the general formula MZ or MZ 2 ; wherein: Z is selected from the group consisting of C, B, N and combination thereof, M is a metal from any of groups IV-VI of the periodic table, and x is a number between 0.01 and 0.99; and (d) between greater than 6 and about 20 volume-% of a source of one or more non-oxide aluminum compounds; wherein the total aluminum content in the non cBN portion of the sintered compact exceeds about 30 weight-% wherein the cBN has a grain size distribution that is at least bimodal having a coarse portion comprising about 40% to about 80% of the cBN and a fine portion comprising about 20 to about 60% of the cBN; wherein the coarse portion has an average grain size of about 5 to about 30 μm and the fine portion has an average grain size of about 0 to about 10 μm; and wherein the ratio of the average grain size of the coarse portion to the average grain size of the fine portion is about 3:1 or greater.