Products and process for making multigrain abrasive compacts

A process as in claim wherein the fine granules of cubic boron nitride or diamond are of a diameter within the range of 0.1 to 1000 micron.

A process for preparing a multigrain abrasive compact having controlled breakdown characteristics which comprises selecting fine granules of cubic boron nitride or diamond of a diameter within the range of 0.1 to 200 micron, applying at least two layers of active coating material selected from titanium, zirconium, hafnium, tungsten, vanadium, niobium, tantalum, chromium, molybdenum, silicon, or a carbide, bromide, nitride or oxide thereof, at a total thickness in the range of 0.1 to 1.0 micron, wherein the outer layer is a sinterable material selected from nickel, copper, cobalt, or a carbide, nitride or boride of titanium, tantalum, molybdenum, zirconium, hafnium, vanadium, chromium, tungsten, silicon, or niobium;

• sintering the coated granules at a temperature about 1000.degree. C. at a pressure about 2000 psi for a period less than 5 minutes to provide a multigrain abrasive compact.

A multigrain abrasive compact which comprises cubic boron nitride or diamond granules bonded together in a sintered matrix derived from a coating on the granules which comprises one or more layers of active coating material chemically bonded to the underlying surface of the granules.

A multigrain abrasive compact which comprises cubic boron nitride granules bonded together in a sintered matrix derived from a titanium carbide coating on the granules applied by chemical vapor deposition.

A multigrain abrasive compact which comprises diamond powder produced together in chemical vapor deposition which is bonded by a sintered matrix derived from a coating on the powder applied by chemical vapor deposition, wherein the coating comprises a carbide, boride or nitride of titanium, tantalum, molybdenum, zirconium, hafnium, vanadium, chromium, niobium, tungsten, or silicon.

A process for the preparation of a multigrain, polycrystalline abrasive compact, which comprises:

• applying to fine polycrystalline granules of cubic boron nitride or diamond at least one layer of an active coating material which chemically bonds to the underlying surface, wherein the outer layer of active coating material is sinterable, and
• sintering the coated granules to provide a multigrain, polycrystalline abrasive compact mass.

A multigrain, polycrystalline abrasive compact mass which comprises polycrystalline cubic boron nitride or diamond abrasive granules bonded together in a sintered matrix derived form a coating on the granules which comprises one or more layers of active coating material chemically bonded to the polycrystalline abrasive granules.