| 摘要 |
A polycrystalline diamond material comprises a first phase 12 of bonded together diamond crystals and a second phase 14 of a reaction product between a binder/catalyst material used to facilitate diamond bonding and a material that reacts with the binder/catalyst material. The reaction product occurs at interstitial regions between diamond crystals and has a coefficient of thermal expansion that is closer to that of the bonded diamond crystals that the CTE for the binder/catalyst material alone. The binder/catalyst may be a group VIII element such as cobalt and the reacting material may be silicon, silicon carbide, aluminium, boron, beryllium, molybdenum, niobium, tantalum, titanium, vanadium or zirconium. The PCD material can be attached to a carbide, nitride, carbonitride or cermet substrate and can be used to make cutting inserts and shear cutters in subterranean drill bits. |
