Abstract: An aluminum alloy for casting, made of an Al—Si—Cu—Mg alloy which consists of specific amounts of Si, Cu, and Mg, in addition to specifically desired amounts of titanium, phosphorus, boron, and optional additional chemical elements sodium and strontium, with the balance of the aluminum alloy comprising aluminum and any impurities. When a content of phosphorus is defined as X mass %, the content of phosphorus, a content of Y mass % of sodium, and a content of Z mass % of strontium satisfy the following relationships: 0.45Y+0.24Z+0.003?X?0.45Y+0.24Z+0.01; 0?Y?0.01; and 0?Z?0.03. The aluminum alloy ensures surface smoothness of a cast article by specifying the phosphorus content. This minimizes a surface segregation layer, even in production of a cast article using a molten metal containing a eutectic structure modifier such as sodium.

Abstract: The present invention is an aluminum alloy for low-pressure casting, and the aluminum alloy is made of an Al—Si—Cu—Mg alloy and contains: 8.0 to 12.6 mass % of Si; 1.0 to 2.5 mass % of Cu; 0.3 to 0.8 mass % of Mg; and 0.2 mass % or less of Ti, wherein the aluminum alloy further contains X mass % of P, Y mass % of Na, and Z mass % of Sr, with the balance including Al and inevitable impurities, and wherein a content of P, a content of Na, and a content of Sr satisfy all of the following relationships: 0.45Y+0.24Z+0.003?X?0.45Y+0.24Z+0.01; 0?Y?0.01; and 0?Z?0.03. The present invention ensures surface smoothness of the casted article by specifying the P content. This minimizes a surface segregation layer even in production of a casted article using a molten metal containing a eutectic structure modifier such as Na.

Abstract: An aluminum alloy cast impeller has a stable high-temperature strength (e.g., 0.2% proof stress value of 260 MPa or more) at about 200° C. A boss part, blade parts, and a disc part have secondary dendrite arm spacings of 20 to 50 ?m, 10 to 35 ?m, and 5 to 25 ?m, respectively, and satisfy the relationship Amax>Bmax>Cmax, where Amax, Bmax, and Cmax are the maximum values of the secondary dendrite arm spacings of the boss part, the blade parts, and the disc part, respectively. During casting, Al alloy molten metal is pressure injected into a 200 to 350° C. plaster mold. A 100 to 250° C. chill occurs on a surface in contact with an impeller disc surface, so that the chill temperature (° C.)<(plaster mold temperature?50° C.).

Abstract: The present invention provides: a compressor impeller that cast from an aluminum alloy, has superior production characteristics, and exhibits stable high-temperature strength when used at temperatures around 200° C.; and a method for producing same. The compressor impeller that is cast from an Al alloy is provided with a boss section, a plurality of vane sections and a disc section; the boss section, the plurality of vane sections and the disc section excluding the end section comprise an Al alloy comprising a predetermined metal composition; and at the end section of the disc section, there are at least 10,000/mm2 of intermetallic compounds having a circle-equivalent diameter of 1-6 ?m, and there are no greater than 500/mm2 of intermetallic compounds having a circle-equivalent diameter exceeding 6 ?m.

Abstract: Disclosed is a composite superconductor comprising a superconductor and a metal member. The metal member is composed of one or more members to be joined together in such manner that the one or more members cover the superconductor, and at least one member is made of aluminum or an aluminum alloy.

Abstract: Disclosed is a composite superconductor comprising a superconductor and a metal member. The metal member is composed of one or more members to be joined together in such manner that the one or more members cover the superconductor, and at least one member is made of aluminum or an aluminum alloy.

Abstract: A method of readily detecting or differentiating rheumatoid arthritis, which has so far been diagnosed in a comprehensive manner based on various tests and clinical symptoms, and a method of readily and objectively estimating the stage of disease and the degree of dysfunction with regard to rheumatoid arthritis are provided. The detection and differentiation of rheumatoid arthritis are performed by measuring the levels of L-PGDS in a sample such as a body fluid such that the measurement value is used as an index. Further, the stage of disease or the degree of dysfunction of a rheumatoid arthritis patient is determined using the measurement value as an index.