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.

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.

An aluminum-based composite material includes a plurality of coarse crystalline grains (3) of pure aluminum, and a plurality of fine crystalline grains (4) each having an aluminum matrix (1), and a dispersion material (2) dispersed inside the aluminum matrix and formed by reacting a portion or all of an additive with aluminum in the aluminum matrix. The fine crystalline grains exist among the coarse crystalline grains, and the fine crystalline grains have crystalline grain diameters smaller than crystalline grain diameters of the coarse crystalline grains.

A sintered cemented carbide includes a high entropy carbide or a spinodal decomposed product thereof; and a metallic binder containing at least one of Co, CoRu, Ni, CoNi, CoCr, CoNiCr, CoRe, CoNiRe, CoNiRu, or a high entropy alloy, wherein the high entropy carbide is a single-phase solid solution carbide comprising four to ten metallic elements, and the spinodal decomposed product thereof includes two chemically distinct phases having a same crystal structure. A sintered cemented carbide also includes a carbide including at least one of WC, TiC, ZrC, HfC, NbC, TaC, or Cr.sub.3C.sub.2; and a metallic binder including a high entropy alloy. The high entropy alloy is an alloy of four to ten alloy elements selected from Al, Be, Fe, Co, Cr, Ni, Cu, W, V, Zr, Ti, Mn, Hf, Nb, Mo, Ru, Re, Ge, Sn, C, B, or Si.

A cutting element includes a metallic carbide body, a first layer of polycrystalline diamond material, and at least one transition layer between the metallic carbide body and the first layer. The polycrystalline diamond material includes a plurality of interconnected diamond grains, first metal carbide particles, and a first binder material in interstitial regions between the interconnected first diamond grains, wherein the first metal carbide particles form a matrix in which the second diamond grains are dispersed and wherein the first metal carbide particles are present in the outer transition layer in an amount ranging from about 15 to 35 volume percent. The at least one transition layer includes a composite of diamond grains, second metal carbide particles, and a second binder material.

cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.

A sintered cemented carbide includes a high entropy carbide or a spinodal decomposed product thereof; and a metallic binder containing at least one of Co, CoRu, Ni, CoNi, CoCr, CoNiCr, CoRe, CoNiRe, CoNiRu, or a high entropy alloy, wherein the high entropy carbide is a single-phase solid solution carbide comprising four to ten metallic elements, and the spinodal decomposed product thereof includes two chemically distinct phases having a same crystal structure. A sintered cemented carbide also includes a carbide including at least one of WC, TiC, ZrC, HfC, NbC, TaC, or Cr.sub.3C.sub.2; and a metallic binder including a high entropy alloy. The high entropy alloy is an alloy of four to ten alloy elements selected from Al, Be, Fe, Co, Cr, Ni, Cu, W, V, Zr, Ti, Mn, Hf, Nb, Mo, Ru, Re, Ge, Sn, C, B, or Si.

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.

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 cubic boron nitride sintered material comprising cubic boron nitride grains and a binder, in which a content of the cubic boron nitride grains is no less than 30% by volume and no more than 80% by volume, the binder includes at least one selected from a second group consisting of a material made of a single element selected from a first group consisting of a group 4 element, a group 5 element and a group 6 element of the periodic table, aluminum, silicon, iron, cobalt and nickel, and an alloy and an intermetallic compound each composed of no less than two elements selected from the first group, and a content of a void in the cubic boron nitride sintered material is no less than 0.001% by volume and no more than 0.20% by volume.