One or more masses of bonded particles of diamond, cubic boron nitride (CBN), and wurtzite boron nitride (WBN) are sandwiched between or encapsulated by two masses of cemented carbide bonded to the particle masses. In the preferred embodiment, the particle masses are comprised of (1) at least 70% by volume of said particles, and (2) a metallic phase comprised of the cementing agent of the carbide mass. The composite compacts find utility in drill bit, mining tool and wear part applications.
A method for making such a composite compact comprises (1) placing within a reaction cell masses of abrasive particles and at least two carbide masses interleaved with the abrasive particle masses, (2) the masses are placed in the cell in such a manner to allow for the accommodation of pressure and (3) simultaneously subjecting the cell and the contents thereof to temperature and pressure conditions at which the particles are stable.
A method for abrading or cutting a workpiece with a composite compact comprises providing (1) a tubular carbide mass and a bonded mass of abrasive particles disposed in and bonded to the carbide mass in a central cavity thereof and (2) moving either the compact or workpiece relative to the other to provide the cutting or abrading action.