摘要 |
A composition containing: about 45 to about 75 volume % of cubic boron nitride (CBN), where the CBN has finer and coarser particles having two different average particle sizes, the range of the average particle size of the finer particles being about 0.1 to about 2μm, the range of the average particle size of the coarser particles being about 0.3 to about 5μm, the ratio of the content of the coarser CBN particles to the finer CBN particles being 50:50 to 90:10; a secondary hard phase containing a nitride or carbonitride of a Group 4, 5 or 6 transition metal or a mixture or solid solution thereof, and a binder phase. |