| 摘要 |
PCBN material comprising at least 30 volume per cent cubic boron nitride (cBN) grains (10) bonded together by a matrix comprising aluminium nitride (20), and a plurality of regions (30) comprising boron and aluminium atoms, in which regions there are at least 15 times more boron atoms than aluminium atoms present. The regions comprise an aluminium boride phase of the inorganic chemical formula Al xBy, where x is at least 0.8 and at most 1.2, and y is at least 15, the ratio y:x being at least 15. The cubic boron nitride ceramic has been made by mixing cBN and Al grains and sintering at at least 1500 degrees Celcius and 4.5 GPa. |
