Polycrystalline diamond includes a working surface and a peripheral surface extending around an outer periphery of the working surface. The polycrystalline diamond includes a first volume including an interstitial material and a second volume having a leached region that includes boron and titanium. A method of fabricating a polycrystalline diamond element includes positioning a first volume of diamond particles adjacent to a substrate, the first volume of diamond particles including a material that includes a group 13 element, and positioning a second volume of diamond particles adjacent to the first volume of diamond particles such that the first volume of diamond particles is disposed between the second volume of diamond particles and the substrate, the second volume of diamond particles having a lower concentration of material including the group 13 element than the first volume of diamond particles. Various other articles, assemblies, and methods are also disclosed.

Polycrystalline diamond may include a working surface and a peripheral surface extending around an outer periphery of the working surface. The polycrystalline diamond includes a first volume including an interstitial material and a second volume having a leached region that includes boron and titanium. A method of fabricating a polycrystalline diamond element may include positioning a first volume of diamond particles adjacent to a substrate, the first volume of diamond particles including a material that includes a group 13 element, and positioning a second volume of diamond particles adjacent to the first volume of diamond particles such that the first volume of diamond particles is disposed between the second volume of diamond particles and the substrate, the second volume of diamond particles having a lower concentration of material including the group 13 element than the first volume of diamond particles.

A sintered material contains hard particles composed of one or more selected from the group consisting of cubic boron nitride, Al.sub.2O.sub.3, AlON, SiAlON, TiC, TiCN, TiN, WC, and diamond, a metallic binder phase mainly composed of Co or Ni and containing at least one element selected from the group consisting of Co, Ni, Al, W, V, and Ti, and Al.sub.2O.sub.3 dispersed in the metallic binder phase.

Polycrystalline diamond compacts having parting compound within the interstitial volumes are disclosed herein. In one embodiment, a polycrystalline diamond compact includes a polycrystalline diamond body having a plurality of diamond grains bonded together in diamond-to-diamond bonds, interstitial volumes positioned between the adjacent diamond grains, and a parting compound positioned in at least a portion of the interstitial volumes of the polycrystalline diamond body.

A cutting tool includes a supporting body and a cBN or PCD cutting edge tip attached to the supporting body via a 5-150 ?m braze joint. The supporting body is cemented carbide having 3-25 wt % of a metallic binder, optionally up to 25 wt % of carbides or carbonitrides of one or more elements of group 4, 5, or 6, and the rest WC. The metallic binder includes at least 40 wt % Ni, and the braze joint has, in the order from the supporting body, a first layer of TiC situated next thereto, with an average thickness of 10-400 nm, a second layer, with an average thickness of 0.5-8 ?m, having in average at least 5 wt % metallic Ni, in average 25-60 wt % metallic Cu and in average 15-45 wt % metallic Ti, and a third layer, with an average thickness of 4-145 ?m, having metallic Ag and metallic Cu.

A cubic boron nitride sintered material of the present disclosure includes 35 to 100 volume % of a cubic boron nitride grain and 0 to 65 volume % of a binder, wherein: a lattice constant of the cubic boron nitride grain is 3.6140 to 3.6161 , a silicon content in the cubic boron nitride grain is 0.02 mass % or less, and the binder material includes at least one selected from a group consisting of a compound and a solid solution of the compound, the compound consisting of at least one element selected from a group consisting of a group 4 element, a group 5 element, a group 6 element in the periodic table, aluminum, silicon, iron, cobalt and nickel, and at least one element selected from a group consisting of carbon, nitrogen, boron and oxygen.

A polycrystalline diamond compact includes a polycrystalline diamond material having a plurality of grains of diamond bonded to one another by inter-granular bonds and an intermetallic gamma prime () or -carbide phase disposed within interstitial spaces between the inter-bonded diamond grains. The ordered intermetallic gamma prime () or -carbide phase includes a Group VIII metal, aluminum, and a stabilizer. An earth-boring tool includes a bit body and a polycrystalline diamond compact secured to the bit body. A method of forming polycrystalline diamond includes subjecting diamond particles in the presence of a metal material comprising a Group VIII metal and aluminum to a pressure of at least 4.5 GPa and a temperature of at least 1,000 C. to form inter-granular bonds between adjacent diamond particles, cooling the diamond particles and the metal material to a temperature below 500 C., and forming an intermetallic gamma prime () or -carbide phase adjacent the diamond particles.

A body comprising at least two components having one or more different properties and a method of producing the same are disclosed. One of the body components is in the form of particles with optional adhesive interlayers. A second of the components has a surface locally melted in a predetermined pattern and only to a predetermined depth by scanning an electron beam there across to incorporate the particles and form a metal composite film. Thereby, a predetermined volumetric concentration of the incorporated particles varies continuously from the locally melted surface so as to provide two surfaces in the body having different coefficients of thermal expansion.

A polycrystalline compact comprises a plurality of grains of hard material and a plurality of nanoparticles disposed in interstitial spaces between the plurality of grains of hard material. The nanoparticles have cores of a first material and at least one oxide material on the cores. An earth-boring tool comprises such a polycrystalline compact. A method of forming a polycrystalline compact comprises combining a plurality of hard particles with a plurality of nanoparticles to form a mixture and sintering the mixture to form a polycrystalline hard material comprising a plurality of interbonded grains of hard material. A method of forming a cutting element comprises infiltrating interstitial spaces between interbonded grains of hard material in a polycrystalline material with a plurality of nanoparticles.

Provided are a diamond composite material which is excellent in thermal conductivity, suitable as a material for a heat radiating member, and dense, the heat radiating member, and a method for producing a diamond composite material that can productively produce a diamond composite material which is excellent in wettability between diamond and metal and dense. The diamond composite material includes: a coated diamond particle including a diamond particle and a carbide layer covering a surface of the diamond particle and including an element of group 4 of the periodic table; and silver or a silver alloy binding such coated diamond particles together, with an oxygen content of 0.1 mass % or less.