| 摘要 |
<p>An abrasive compact comprising 40 to 90 volume percent of cubic boron nitride (CBN) crystals bonded by 60 to 10 volume percent of a bonding matrix comprised mainly of an intimate mixture of an aluminium nitride component and a metallic diboride component. The metallic diboride component comprises one or more of the metallic diborides MB2, wherein M represents metal atoms chosen from the group of titanium, zirconium, hafnium, niobium and tantalum atoms occurring as atoms of one or more elements in said group, or a solid solution of aluminium diboride in one or more of those diborides. The compact may be produced by a method which comprises intimately mixing particulate CBN crystals with a bonding agent in the proportion 95 to 60 volume percent of CBN and 5 to 40 volume percent of bonding agent, the bonding agent containing the metal atoms in the atomic proportions Al50M50 to Al90M10, subjecting the mixture of CBN crystals and bonding agent to temperatures in the range 900 °C to 1800 °C and pressures in the range 5 to 70 kilobars, and maintaining the temperature and pressure conditions for a period of at least about 30 seconds, sufficient to cause most of the bonding agent to form the bonding matrix.</p> |
