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 polycrystalline diamond structure comprises a first region and a second region adjacent the first region, the second region being bonded to the first region by intergrowth of diamond grains. The first region comprises a plurality of alternating strata or layers, each or one or more strata or layers in the first region having a thickness in the range of around 5 to 300 microns. The polycrystalline diamond (PCD) structure has a diamond content of at most about 95 percent of the volume of the PCD material, a binder content of at least about 5 percent of the volume of the PCD material, and one or more of the layers or strata in the first region comprise and/or the second region comprises diamond grains having a mean diamond grain contiguity of greater than about 60 percent and a standard deviation of less than about 2.2 percent. There is also disclosed a method of making such a polycrystalline diamond structure.

A method for treating a super-hard structure, the method including heating the super-hard structure to a treatment temperature of at least 500 degrees centigrade and cooling the super-hard structure from the treatment temperature to a temperature of less than 200 degrees centigrade at a mean cooling rate of at least 1 degree centigrade per second and at most 100 degrees centigrade per second to provide a treated super-hard structure. A PCBN structure produced by the method may have flexural strength of at least 650 MPa.

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.

A sintered body includes diamond particles and a binder. Each of the diamond particles has a boron concentration is 0.001 mass % to 0.1 mass %. The binder has a boron concentration of 0.01 mass % to 0.5 mass %.

An object of the present invention is to provide a cubic boron nitride sintered body and a coated cubic boron nitride sintered body that can extend the tool life by having excellent wear resistance and fracture resistance. A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein in a cross-sectional structure, content ratios of the cubic boron nitride and the binder phase fall within specific ranges, the binder phase includes a Ti compound phase containing a specific compound, an Al compound phase containing a specific compound, and a W compound phase containing WC, an average grain size of the W compound phase is 0.5 m or more and 3.0 m or less, content ratios of the Ti compound phase and the Al compound phase based on a whole of the binder phase fall within specific ranges, a content ratio X1 of the W compound phase is 2.0 area % or more and 30.0 area % or less, a content ratio X2 of the W compound phase based on a whole of the binder phase in a range from an interface between the cubic boron nitride and the binder phase to a distance of 300 nm toward the binder phase side is larger than the content ratio X1.

An object of the present invention is to provide a cubic boron nitride sintered body and a coated cubic boron nitride sintered body that can extend the tool life by having excellent wear resistance and fracture resistance. A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein in a cross-sectional structure, content ratios of the cubic boron nitride and the binder phase fall within specific ranges, the binder phase includes a Ti compound phase containing a specific compound, an Al compound phase containing a specific compound, and a W compound phase containing WC, an average grain size of the W compound phase is 0.5 m or more and 3.0 m or less, content ratios of the Ti compound phase and the Al compound phase based on a whole of the binder phase fall within specific ranges, a content ratio X1 of the W compound phase is 2.0 area % or more and 30.0 area % or less, a content ratio X2 of the W compound phase based on a whole of the binder phase in a range from an interface between the cubic boron nitride and the binder phase to a distance of 300 nm toward the binder phase side is larger than the content ratio X1.

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.