A method of modifying surfaces of diamond particles comprises forming spinodal alloy coatings over discrete diamond particles, thermally treating the spinodal alloy coatings to form modified coatings each independently exhibiting a reactive metal phase and a substantially non-reactive metal phase, and etching surfaces of the discrete diamond particles with at least one reactive metal of the reactive metal phase of the modified coatings. Diamond particles and earth-boring tools are also described.

A drill bit includes a shank having a threaded coupling formed at an upper end thereof; a bit body mounted to a lower end of the shank and having a plenum; a gage section forming an outer portion of the drill bit; a cutting face forming a lower end of the drill bit and including: a core receptacle formed at a center of the cutting face, operable to receive a core of earth, and including: a concave core cutter mounted to a bottom of the bit body; and a core port extending from the plenum through the bottom of the bit body and operable to discharge drilling fluid onto the core and core cutter; a plurality of blades protruding from a bottom of the bit body and extending from a periphery of the core receptacle to the gage section; and a plurality of leading cutters mounted along each blade.

A drill bit includes a shank having a threaded coupling formed at an upper end thereof; a bit body mounted to a lower end of the shank and having a plenum; a gage section forming an outer portion of the drill bit; a cutting face forming a lower end of the drill bit and including: a core receptacle formed at a center of the cutting face, operable to receive a core of earth, and including: a concave core cutter mounted to a bottom of the bit body; and a core port extending from the plenum through the bottom of the bit body and operable to discharge drilling fluid onto the core and core cutter; a plurality of blades protruding from a bottom of the bit body and extending from a periphery of the core receptacle to the gage section; and a plurality of leading cutters mounted along each blade.

An instrumented cutter including a polycrystalline diamond table bonded to a substrate with a sensor, for monitoring the condition of the polycrystalline compact diamond table, embedded in the substrate. Further the instrumented cutter includes a wireless transmitter equipped with a power supply to power to the wireless transmitter.

A cutting element includes a table coupled to a substrate at an interface. The table includes a working surface opposite the interface and defined by a perimeter, a table thickness measured between the interface and the working surface, and a torque transmittable depression formed in the working surface of the table a distance away from the perimeter. The torque transmittable depression extends a depth into the table and has a cross-sectional profile with a torque transmittable shape. The depth of the depression may be greater than the thickness of the table, or an optional sensor may be placed in the depression.

A cutting element includes a table coupled to a substrate at an interface. The table includes a working surface opposite the interface and defined by a perimeter, a table thickness measured between the interface and the working surface, and a torque transmittable depression formed in the working surface of the table a distance away from the perimeter. The torque transmittable depression extends a depth into the table and has a cross-sectional profile with a torque transmittable shape. The depth of the depression may be greater than the thickness of the table, or an optional sensor may be placed in the depression.

A cutting element includes a polycrystalline diamond layer having a cutting face and a diamond layer side surface, a substrate attached to the polycrystalline diamond layer, the substrate having a bottom surface and a substrate side surface, an interface between the diamond layer and the substrate, and a mask covering at least the bottom surface and the substrate side surface of the cutting element.

A cutting element includes a polycrystalline diamond layer having a cutting face and a diamond layer side surface, a substrate attached to the polycrystalline diamond layer, the substrate having a bottom surface and a substrate side surface, an interface between the diamond layer and the substrate, and a mask covering at least the bottom surface and the substrate side surface of the cutting element.

Polycrystalline diamond compacts having interstitial diamonds and methods of forming polycrystalline diamond compact shaving interstitial diamonds with a quench cycle are described herein. In one embodiment, a polycrystalline diamond compact includes a substrate and a polycrystalline diamond body attached to the substrate. The polycrystalline diamond body includes a plurality of inter-bonded diamond grains that are attached to one another in an interconnected network of diamond grains and interstitial pockets between the inter-bonded diamond grains, and a plurality of interstitial diamond grains that are positioned in the interstitial pockets. Each of the plurality of interstitial diamond grains are attached to a single diamond grain of the interconnected network of diamond grains or other interstitial diamond grains.

A metal matrix composite tool includes a body having hard composite portion that includes reinforcing particles dispersed in a binder material. At least some of the reinforcing particles comprise a monolithic particle structure including a core having irregular outer surface features integral with the core.