Abstract: A heat-resistant molybdenum alloy of this invention comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less.

Abstract: A heat-resistant member comprising a molybdenum alloy that comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less. The member may be coated.

Abstract: A method of producing sodium tungstate of this invention including allowing cemented carbide scrap containing tungsten to react with a molten salt containing sodium sulfate and having added thereto a metal oxide, to thereby obtain sodium tungstate.

Abstract: A Mo—Si—B-based alloy for a heat-resistant alloy that satisfies, more than conventional, physical properties such as proof stress and hardness adapted to an increase in the melting point of 5 a welding object. The Mo—Si—B-based alloy powder is such that the full width at half maximum of (600) of Mo5SiB2 in X-ray diffraction peak data is 0.08 degrees or more and 0.7 degrees or less.

Abstract: An object of this invention is to provide a crucible for growing a sapphire single crystal, which is optimized for providing a sapphire single crystal and is reusable. A crucible for growing a sapphire single crystal of this invention includes: a base material (3) containing molybdenum as a main component and having a crucible shape; and a coating layer (5) with which only an inner periphery of the base material (3) is coated and which is formed of tungsten and inevitable impurities, in which the coating layer (5) has a surface roughness Ra of 5 ?m or more and 20 ?m or less.

Abstract: 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.

Abstract: A magnesium-based composite member is provided with a through hole through which a fastening member for attachment to a fixing target is to be inserted. A substrate is provided with a substrate hole through which the fastening member is to be inserted, and made of a composite material which is a composite of SiC and a matrix metal which is any of magnesium and a magnesium alloy. A receiving portion is attached to the substrate and made of a metal material different from the matrix metal. The receiving portion is provided with a receiving portion hole through which the fastening member is to be inserted, and at least a part of an inner circumferential surface of the through hole is formed from an inner circumferential surface of the receiving portion hole.

Abstract: Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method.

Abstract: Provided is a tungsten electrode material that can improve the life of an electrode than conventional by the use of a material in place of thorium oxide. The tungsten electrode material includes a tungsten base alloy and oxide particles dispersed in the tungsten base alloy, wherein the oxide particle is an oxide solid solution in which a Zr oxide and/or a Hf oxide and an oxide of at least one or more kinds of rare earth elements selected from Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu are solid-dissolved.

Abstract: A composite member has a substrate made of a composite material having SiC combined with magnesium or a magnesium alloy, and has a warpage degree of not less than 0.01×10?3 and not more than 10×10?3, the warpage degree being defined as lmax/Dmax, where lmax being a difference between a maximum value and a minimum value of surface displacement of one surface of composite member measured along a longest side thereof, and Dmax being a length of the longest side. Thereby, a composite member capable of efficiently dissipating heat to an installation object, a heat-dissipating member using the composite member, and a semiconductor device having the heat-dissipating member are provided.

Abstract: Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method.

Abstract: A method of producing sodium tungstate of this invention including allowing cemented carbide scrap containing tungsten to react with a molten salt containing sodium sulfate and having added thereto a metal oxide, to thereby obtain sodium tungstate.

Abstract: There is provided a metal laminated structure comprising a first metal layer, a second metal layer and a third metal layer, the first metal layer being disposed on one surface of the second metal layer, the third metal layer being disposed on the other surface of the second metal layer, the first metal layer including at least one of tungsten and molybdenum, the second metal layer including copper, the third metal layer including at least one of tungsten and molybdenum, and a method for producing the metal laminated structure.

Abstract: An object of this invention is to provide a crucible for growing a sapphire single crystal, which is optimized for providing a sapphire single crystal and is reusable. A crucible for growing a sapphire single crystal of this invention includes: a base material (3) containing molybdenum as a main component and having a crucible shape; and a coating layer (5) with which only an inner periphery of the base material (3) is coated and which is formed of tungsten and inevitable impurities, in which the coating layer (5) has a surface roughness Ra of 5 ?m or more and 20 ?m or less.

Abstract: One object of the present invention is to provide a wire drawing die excellent in strength and wear resistance. The wire drawing die has a core formed using highly hard diamond polycrystalline body made substantially only of diamond and produced by directly converting a raw material composition including a non-diamond type carbon material into diamond and sintering the diamond at an ultra high pressure and an ultra high temperature without adding a sintering aid or a catalyst, the polycrystalline body having a mixed construction including fine-grained diamond crystals with a maximum grain size of less than or equal to 100 nm and an average grain size of less than or equal to 50 nm and plate-like or particulate coarse-grained diamond crystals with a minimum grain size of greater than or equal to 50 nm and a maximum grain size of less than or equal to 10000 nm.

Abstract: The super abrasive wheel includes a core rotating around a rotation axis and a super abrasive layer bonded to the core. The core has a first surface and a second surface located opposite to the first surface. An annular first protrusion portion protruding in the direction away from the first surface is provided at a portion of the second surface that is surrounded with the super abrasive layer. A reference surface is provided in the second surface on the inside of the first protrusion portion. The height from the reference surface to the first protrusion portion is denoted as A. A top portion having the height B from the reference surface is provided at a portion of the second surface between the first protrusion portion and the super abrasive layer. The height B is greater than the height A.

Abstract: There is provided a metal laminated structure in which a first metal layer containing tungsten is provided on a first surface of a second metal layer containing copper and a third metal layer containing tungsten is provided on a second surface of the second metal layer opposite to the first surface, and the first metal layer contains crystal grains of tungsten in a form of a columnar crystal extending in a direction perpendicular to the first surface of the second metal layer and the third metal layer contains crystal grains of tungsten in a form of a columnar crystal extending in a direction perpendicular to the second surface of the second metal layer, and a method for producing the metal laminated structure.

Abstract: A method for producing an ammonium tungstate aqueous solution includes the steps of: adding sulfuric acid to a solution containing tungstate ions; bringing the solution having the sulfuric acid added therein, into contact with an anion exchange resin; and bringing the anion exchange resin into contact with an aqueous solution containing ammonium ions.