Ultrahard composite constructions

An ultrahard composite construction comprising:

• a plurality of first material phases formed from polycrystalline diamond;
• and
• a substantially continuous matrix second material phase that is formed from polycrystalline diamond, wherein the plurality of first material phases are dispersed within the second material phase;
• wherein the composite construction is formed by the process of:
• combining together a plurality of granules that each include a core that forms the plurality of first material phases, and a shell that encapsulates the core and forms at least a portion of the second material phase, wherein the granule core and shell comprise diamond grains, and wherein the volume fraction of diamond grains used to form the core is different from that used to form the shell;
• and
• subjecting the combined granules to high pressure/high temperature conditions to produce the composite construction.

A method of forming an ultrahard composite construction comprising the steps of:

• forming a plurality of granules each having a central core formed from a first ultrahard material or precursor components for forming the first ultrahard material;
• treating the granule core to render an outer core surface tacky;
• coating the tacky outer core surface with a second ultrahard material or precursor components for forming the second ultrahard material to surround the granule core;
• combining the coated granules together;
• and
• consolidating and sintering the combined coated granules at high pressure/high temperature conditions to form the ultrahard composite construction, wherein the coating on the granules forms at least a portion of a matrix ultrahard material phase, and the granule cores form a plurality of ultrahard material phases dispersed within the matrix phase.

A green-state composite material comprising a combined arrangement of a plurality of granules, each granule comprising:

• a granule core that is formed from a first ultrahard material or precursor components for forming the same, the granule core including a binding agent;
• a granule shell encapsulating the core and formed from a second ultrahard material or precursor components;
• wherein the granule core and shell are formed from the same type of ultrahard material or precursor components each having a different volume proportion of ultrahard material or precursor components;
• and
• wherein upon sintering, the composite material comprises a plurality of first ultrahard material regions formed by the granule cores, and a matrix second ultrahard material that is at least partially formed by the granule shells.

An ultrahard composite construction comprising:

• a plurality of first material phases formed from polycrystalline diamond;
• and
• a substantially continuous matrix second material phase that is formed from polycrystalline diamond, wherein the plurality of first material phases are dispersed within the second material phase;
• wherein the composite construction is formed by the process of:
• combining together a plurality of granules that each include a core that forms the plurality of first material phases, and a shell that surrounds the core and forms at least a portion of the second material phase, wherein the granule core and shell comprise diamond grains, and wherein the volume fraction of diamond grains used to form the core is different from that used to form the shell;
• and
• subjecting the combined granules to high pressure/high temperature conditions to produce the composite construction;
• wherein before the step of combining, forming the granule shell by treating the granule core to provide a tacky outer surface and coating the tacky outer surface with the diamond grains.

A green-state composite material comprising a combined arrangement of a plurality of granules, each granule comprising:

• a granule core that is formed from a first ultrahard material or precursor components for forming the same, the granule core including a binding agent;
• a granule shell surrounding the core and formed from a second ultrahard material or precursor components, wherein the granule shell is adhered to the core by contacting the core with an activating agent that interacts with the binding agent to make an outer surface of the core tacky;
• wherein the granule core and shell are formed from the same type of ultrahard material or precursor components each having different volume proportion of ultrahard material or precursor components;
• and
• wherein upon sintering, the composite material comprises a plurality of first ultrahard material regions formed by the granule cores, and a matrix second ultrahard material that is at least partially formed by the granules shells.