Methods of forming a polycrystalline diamond compact for use in an earth-boring tool include forming a body of polycrystalline diamond material including a first material disposed in interstitial spaces between inter-bonded diamond crystals in the body, removing the first material from interstitial spaces in a portion of the body, selecting a second material promoting a higher rate of degradation of the polycrystalline diamond compact than the first material under similar elevated temperature conditions and providing the second material in interstitial spaces in the portion of the body. Methods of drilling include engaging at least one cutter with a formation and wearing a second region of polycrystalline diamond material comprising a second material faster than the first region of polycrystalline diamond material comprising a first material. Polycrystalline diamond compacts and earth-boring tools including such compacts.

A cutting element for an earth-boring drill bit may include a thermally stable cutting table comprising a polycrystalline diamond material. The polycrystalline diamond material may consist essentially of a matrix of diamond particles bonded to one another and a silicon, silicon carbide, or silicon and silicon carbide material located within interstitial spaces among interbonded diamond particles of the matrix of diamond particles. The cutting table may be at least substantially free of Group VIII metal or alloy catalyst material. The cutting element may further include a substrate and an adhesion material between and bonded to the cutting table and the substrate. The adhesion material may include diamond particles bonded to one another and to the cutting table and the substrate after formation of the preformed cutting table.

A multi-layer polycrystalline superabrasive PCD or PCBN blank for attachment to a working tool is disclosed. The blank comprises an abrasive layer of PCD or PCBN and a substrate layer of cobalt containing cemented tungsten carbide. In between the abrasive and substrate layers is a metal mesh stabilizer layer sintered by HPHT to the abrasive and substrate layers. The apertures of the mesh layer contain PCD or PCBN which, along with the mesh are sintered to the support and substrate layers and cobalt present in the substrate layer is infiltrated through the mesh layer into the abrasive layer as a binder. The metal mesh layer provides stability to the abrasive and substrate layers which have different stress and thermal expansion properties.

Methods of forming composite particles include forming a source material over a plurality of nucleation cores and forming a catalyst material over the source material. Compositions of matter include a plurality of composite particles, each particle of the plurality comprising a plurality of nucleation cores, a source material disposed over the nucleation cores, and a catalyst material disposed over the source material. Methods of forming earth-boring tools include forming a plurality of composite particles, combining the plurality of composite particles with a plurality of grains of hard material, and catalyzing the formation of inter-granular bonds between the composite particles and the grains of hard material to faun a polycrystalline material. The plurality of in situ nucleated grains of hard material and the plurality of grains of hard material may be interspersed and inter-bonded.

A tool and a method of making the tool are disclosed. The tool includes a superabrasive compact, for example, a volume of silicon carbide diamond bonded composite, directly bonded to a tungsten carbide body during sintering. The green body may have a recess with a complementary shape to the superabrasive compact, whereby after inserting at least a part of the superabrasive compact within the recess and sintering, the tungsten carbide body and the recess shrink to form an interference fit therebetween.

An apparatus (10) for machining a workpiece (12) comprises at least two machining elements (14a, 14b) and a rotating belt (16) for moving the machining elements (14a, 14b) relative to a workpiece (12) to be machined. The machining elements (14a, 14b) each comprise a main body (20a, 20b) and a first connecting element (22a, 22b) connected to the main body (20a, 20b), which first connecting element is connectable to a second connecting element (24a, 24b) complementary to the first connecting element (22a, 22b) and connected to the belt (16). The first connecting element (22a, 22b) comprises a rotary body (26a, 26b). The second connecting element (24a, 24b) has a connection area (28a, 28b) for connection with the rotary body (26a, 26b). When the rotary body (26a, 26b) is rotated in a first rotary direction (R1) the rotary body (26a, 26b) is connected to the connection area (28a, 28b). When the rotary body (26a, 26b) is rotated in a second rotary direction (R2) opposed to the first rotary direction (R1) the rotary body (26a, 26b) is separated from the connection area (28a, 28b). The rotary body (26a, 26b) is arranged relative to the main body (20a, 20b) and connected to the latter in such a manner that during machining of the workpiece (12) a resulting force is exerted on the rotary body (26a, 26b) via the main body (20a, 20b), which force provides a torque for a rotation of the rotary body (26a, 26b) in the first rotary direction (R1).

An apparatus (10) for machining a workpiece (12) comprises at least two machining elements (14a, 14b) and a rotating belt (16) for moving the machining elements (14a, 14b) relative to a workpiece (12) to be machined. The machining elements (14a, 14b) each comprise a main body (20a, 20b) and a first connecting element (22a, 22b) connected to the main body (20a, 20b), which first connecting element is connectable to a second connecting element (24a, 24b) complementary to the first connecting element (22a, 22b) and connected to the belt (16). The first connecting element (22a, 22b) comprises a rotary body (26a, 26b). The second connecting element (24a, 24b) has a connection area (28a, 28b) for connection with the rotary body (26a, 26b). When the rotary body (26a, 26b) is rotated in a first rotary direction (R1) the rotary body (26a, 26b) is connected to the connection area (28a, 28b). When the rotary body (26a, 26b) is rotated in a second rotary direction (R2) opposed to the first rotary direction (R1) the rotary body (26a, 26b) is separated from the connection area (28a, 28b). The rotary body (26a, 26b) is arranged relative to the main body (20a, 20b) and connected to the latter in such a manner that during machining of the workpiece (12) a resulting force is exerted on the rotary body (26a, 26b) via the main body (20a, 20b), which force provides a torque for a rotation of the rotary body (26a, 26b) in the first rotary direction (R1).

Cutting elements for use with earth-boring tools include a cutting table having at least two sections where a boundary between the at least two sections is at least partially defined by a discontinuity formed in the cutting table. Earth-boring tools including a tool body and a plurality of cutting elements carried by the tool body. The cutting elements include a cutting table secured to a substrate. The cutting table includes a plurality of adjacent sections, each having a discrete cutting edge where at least one section is configured to be selectively detached from the substrate in order to substantially expose a cutting edge of an adjacent section. Methods for fabricating cutting elements for use with an earth-boring tool including forming a cutting table comprising a plurality of adjacent sections.

Embodiments of the invention relate to methods of making articles having portions of polycrystalline diamond bonded to a surface of a substrate and polycrystalline diamond compacts made using the same. In an embodiment, a molding technique is disclosed for forming cutting tools comprising polycrystalline diamond portions bonded to the outer surface of a substrate.

Polycrystalline compacts include a polycrystalline material comprising a plurality of inter-bonded grains of hard material, and a metallic material disposed in interstitial spaces between the inter-bonded grains of hard material. At least a portion of the metallic material comprises a metal alloy that includes two or more elements. A first element of the two or more elements comprises at least one of cobalt, iron, and nickel. A second element of the two or more elements comprises at least one of dysprosium, yttrium, terbium, gadolinium, germanium, samarium, neodymium, and praseodymium. The metal alloys may comprise eutectic or near-eutectic compositions, and may have relatively low melting points. Cutting elements and earth-boring tools include such polycrystalline compacts. Methods include the formation of such polycrystalline compacts, cutting elements, and earth-boring tools.