Abstract: A tool for friction stir welding includes a tool part, a shank part and a cap part. The tool part and the shank part have a hexagonal frustum-shaped concave section and a hexagonal frustum-shaped convex section to enable movement of the tool part with respect to the shank part in a direction parallel to an axis of rotation while movement of the tool part with respect to the shank part in a direction around the axis of rotation is restricted, by the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section of the tool part and the shank part are fitted to each other. After the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section are fitted to each other, by the tool part and the shank part being covered by the cap part, the tool part is fixed to the shank part.

Abstract: A carbon atmosphere thermometer 10a has: a thermocouple having thermocouple wires 16, 18, a thermocouple temperature measuring junction 14, and an insulating tube 12; a first protection tube 20 surrounding the thermocouple, while at least partially spaced apart from the thermocouple wires 16, 18 and others of the thermocouple; and a second protection tube 22 surrounding the first protection tube 20, while at least partially spaced apart from the first protection tube 20. For this reason, it becomes feasible to protect the thermocouple from the external environment, while preventing the thermocouple from reacting with the first protection tube 20. Furthermore, it becomes feasible to protect the thermocouple and the first protection tube 20 from the external environment, while preventing the first protection tube 20 from reacting with the second protection tube 22.

Abstract: A method for purifying nanoparticles by which a large amount of nanoparticles can be obtained in a safe manner and in a short time as compared to a conventional method for purifying nanoparticles. A method for purifying nanoparticles by which nanoparticles are purified from a dispersion liquid in which nanoparticles are dispersed in a solvent A used in synthesis of the nanoparticles, the method including: a mixing step of mixing the dispersion liquid, a solvent B that is miscible with the solvent A, and a solvent C that forms two phases together with the solvent B; a concentrating step of concentrating the nanoparticles in a phase of the solvent C; a washing step of forming a third phase containing the nanoparticles in the phase of the solvent C; and a purifying step of extracting the third phase and removing the solvent C from the third phase.

Abstract: A tool for friction stir welding includes a tool part, a shank part and a cap part. The tool part and the shank part have a hexagonal frustum-shaped concave section and a hexagonal frustum-shaped convex section to enable movement of the tool part with respect to the shank part in a direction parallel to an axis of rotation while movement of the tool part with respect to the shank part in a direction around the axis of rotation is restricted, by the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section of the tool part and the shank part are fitted to each other. After the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section are fitted to each other, by the tool part and the shank part being covered by the cap part, the tool part is fixed to the shank part.

Abstract: A tool for friction stir welding includes a tool part, a shank part and a cap part. The tool part and the shank part have a hexagonal frustum-shaped concave section and a hexagonal frustum-shaped convex section to enable movement of the tool part with respect to the shank part in a direction parallel to an axis of rotation while movement of the tool part with respect to the shank part in a direction around the axis of rotation is restricted, by the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section of the tool part and the shank part are fitted to each other. After the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section are fitted to each other, by the tool part and the shank part being covered by the cap part, the tool part is fixed to the shank part.

Abstract: A platinum wire in which crystal grain growth is slowed in order to prevent damage caused by creep without dispersing a metal oxide, and occurrence of slip at crystal grain boundaries is slowed. A platinum thermocouple wire that is used in a negative electrode of a platinum-based thermocouple and has a nitrogen mass concentration of 10 to 100 ppm, and when structure observation of the cross section of the wire in a longitudinal direction is performed, a structure is observed in which there is a plurality of crystal grains, which have an aspect ratio {(length of major axis)/(length of minor axis perpendicular to major axis)} of 5 or more and elongate in the longitudinal direction of the wire, in a wire thickness direction.

Abstract: Method of producing a target having a small average crystal grain size of gold or platinum and having a uniform crystal grain size in an in-plane direction of a target surface and a thickness direction of the target in order to further stabilize film deposition characteristics during sputtering.

Abstract: A thermocouple that can stably perform direct temperature measurement under a high temperature environment (1500° C. or higher but 2300° C. or lower) and a manufacturing method for the same. A thermocouple according to a first embodiment is a thermocouple including at least a protective tube and element wires, the protective tube and the element wires are insulated from one another by an insulator, and the insulator is either one or both of a powder and a compact, and is composed of at least one of a zirconium oxide, a hafnium oxide, or a composite oxide of zirconium and hafnium.

Abstract: A tool for friction stir welding includes a tool part, a shank part and a cap part. The tool part and the shank part have a hexagonal frustum-shaped concave section and a hexagonal frustum-shaped convex section to enable movement of the tool part with respect to the shank part in a direction parallel to an axis of rotation while movement of the tool part with respect to the shank part in a direction around the axis of rotation is restricted, by the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section of the tool part and the shank part are fitted to each other. After the hexagonal frustum-shaped concave section and the hexagonal frustum-shaped convex section are fitted to each other, by the tool part and the shank part being covered by the cap part, the tool part is fixed to the shank part.

Abstract: A carbon atmosphere thermometer 10a has: a thermocouple having thermocouple wires 16, 18, a thermocouple temperature measuring junction 14, and an insulating tube 12; a first protection tube 20 surrounding the thermocouple, while at least partially spaced apart from the thermocouple wires 16, 18 and others of the thermocouple; and a second protection tube 22 surrounding the first protection tube 20, while at least partially spaced apart from the first protection tube 20. For this reason, it becomes feasible to protect the thermocouple from the external environment, while preventing the thermocouple from reacting with the first protection tube 20. Furthermore, it becomes feasible to protect the thermocouple and the first protection tube 20 from the external environment, while preventing the first protection tube 20 from reacting with the second protection tube 22.

Abstract: An object of the present invention is to provide a process for recovering ruthenium at a sufficient recovery rate from a solid in which a ruthenium compound is supported on a carrier. The present invention relates to a process for recovering ruthenium, comprising the following steps (1) to (3): (1) bringing a solid in which a ruthenium compound is supported on a carrier, into contact with a reducing gas, to thereby reduce the ruthenium compound; (2) cooling the solid obtained in the step (1) to 250° C. or lower under an atmosphere of a non-oxidizing gas; and (3) mixing the solid obtained in the step (2) with an oxidizing solution, to thereby dissolve ruthenium in the solution.

Abstract: A metal material processing method includes arranging two metal materials to face each other in a processing portion and inserting a distal end of a rod-shaped rotary tool into the processing portion while rotating the rotary tool, the two metal materials are processed. The distal end of the rotary tool has a probe protruding in a central portion and a shoulder in a peripheral portion, and the probe and the shoulder are constituted by different materials in at least surface portions that are in contact with the metal materials.

Abstract: In a metal material processing method, two metal materials are arranged to face each other in a processing portion, and a distal end of a rod-shaped rotary tool is inserted into the processing portion while rotating the rotary tool, thereby the two metal materials are processed. The distal end of the rotary tool has a probe protruding in a central portion and a shoulder in a peripheral portion. The probe and the shoulder are constituted by different materials in at least surface portions that are in contact with the metal materials.

Abstract: Metallic materials having a melting point of at least 2000° C. are caused to abut against each other in a welding part. The rear face side of the welding part is covered by a backing member having a thermal conductivity of 30 W/mK or lower, and then a columnar probe of a rotary tool comprising an Ir alloy is inserted into the front face side of the welding part to weld the metallic materials together. On the front face side of the welding part, inactive gas is supplied into a shield cover. The rotary tool is moved along a longitudinal direction of the welding part while rotating the rotary tool, whereby the metallic materials are welded together. By using the rotary tool comprising an Ir alloy, the refractory metals can be welded to each other by means of friction stir welding.

Abstract: Metallic materials having a melting point of at least 2000° C. are caused to abut against each other in a welding part. The rear face side of the welding part is covered by a backing member having a thermal conductivity of 30 W/mK or lower, and then a columnar probe of a rotary tool comprising an Ir alloy is inserted into the front face side of the welding part to weld the metallic materials together. On the front face side of the welding part, inactive gas is supplied into a shield cover. The rotary tool is moved along a longitudinal direction of the welding part while rotating the rotary tool, whereby the metallic materials are welded together. By using the rotary tool comprising an Ir alloy, the refractory metals can be welded to each other by means of friction stir welding.

Abstract: It is an object of the invention to reduce mixing of an impurity from a friction stir welding tool, reduce abrasion of the tool, and prevent the tool from being easily broken even though an object to be worked formed by a metal or an alloy having a high melting point of 1350° C. or more is friction-stir-welded. The friction stir welding tool according to the invention can friction-stir-weld a metal or alloy having a high melting point of 1350° C. or more as an object to be worked. At least a portion brought into contact with the object to be worked has a composition containing iridium, containing rhenium, ruthenium, molybdenum, tungsten, niobium, tantalum, rhodium, or two or more of them, and containing zirconium, hafnium, lanthanum, cerium, samarium, gadolinium, scandium, yttrium, or two or more of them, and has a Micro Vickers Hardness of 300 Hv or more.

Abstract: An object of the present invention is to provide a process for recovering ruthenium at a sufficient recovery rate from a solid in which a ruthenium compound is supported on a carrier. The present invention relates to a process for recovering ruthenium, comprising the following steps (1) to (3): (1) bringing a solid in which a ruthenium compound is supported on a carrier, into contact with a reducing gas, to thereby reduce the ruthenium compound; (2) cooling the solid obtained in the step (1) to 250° C. or lower under an atmosphere of a non-oxidizing gas; and (3) mixing the solid obtained in the step (2) with an oxidizing solution, to thereby dissolve ruthenium in the solution.

Abstract: It is an object of the invention to reduce mixing of an impurity from a friction stir welding tool, reduce abrasion of the tool, and prevent the tool from being easily broken even though an object to be worked formed by a metal or an alloy having a high melting point of 1350° C. or more is friction-stir-welded. The friction stir welding tool according to the invention can friction-stir-weld a metal or alloy having a high melting point of 1350° C. or more as an object to be worked. At least a portion brought into contact with the object to be worked has a composition containing iridium, containing rhenium, ruthenium, molybdenum, tungsten, niobium, tantalum, rhodium, or two or more of them, and containing zirconium, hafnium, lanthanum, cerium, samarium, gadolinium, scandium, yttrium, or two or more of them, and has a Micro Vickers Hardness of 300 Hv or more.

Abstract: Refractory superalloys consist essentially of a primary constituent selected from the group consisting of iridium, rhodium, and a mixture thereof, and one or more additive elements selected from the group consisting of niobium, tantalum, hafnium, zirconium, uranium, vanadium, titanium and aluminum, and the superalloys having a microstructure containing an FCC-type crystalline structure phase and an L1.sub.2 -type crystalline structure phase are precipitated. Preferably the amount of additive element(s) is 2 to 22 atom %.