Abstract: There is provided a heat exchanger and a fin material for the heat exchanger that can suppress occurrence of hollow corrosion in a fin and hold cooling performance for a long period of time under a high corrosion environment. The heat exchanger includes an aluminum tube through which a working fluid circulates and an aluminum fin which is bonded to the tube. The fin has a region B around a grain boundary, and a region A around the region B. In the region B, 5.0×104 pieces/mm2 less of Al—Fe—Mn—Si based intermetallic compound, each of which has equivalent circle diameters of 0.1 to 2.5 ?m, are present. In the region A, 5.0×104 pieces/mm2 to 1.0×107 pieces/mm2 of Al—Fe—Mn—Si based intermetallic compound, each of which has equivalent circle diameters of 0.1 to 2.5 ?m, are present.

Abstract: An aluminum alloy plate for a magnetic disc substrate according to the present disclosure includes, in mass %, Mg: 3.0 to 8.0%, Cu: 0.002 to 0.150%, Zn: 0.05 to 0.60%, Fe: 0.001 to 0.060%, Si: 0.001 to 0.060%, Be: 0.00001 to 0.00200%, Cr: 0.200% or less, Mn: 0.500% or less, and Cl: 0.00300% or less, with the balance being Al and inevitable impurities, and an abundance of a Cr oxide having a maximum diameter of 3 to 10 ?m observed in a metal structure is 1 or less per single side of a disc.

Abstract: An aluminum alloy substrate for a magnetic disk, wherein the sum of the circumferences of second phase particles having the longest diameter of 4 ?m or more and 30 ?m or less in the metal microstructure is 10 mm/mm2 or more.

Abstract: Disclosed are an aluminum alloy substrate for a magnetic disc, which includes an aluminum alloy consisting of Mg:4.5-10.0 mass % (hereinafter referred to as %), Be: 0.00001-0.00200%,Cu: 0.003-0.150%, Zn: 0.05-0.60%, Cr: 0.010-0.300%, Si: 0.060% or less, and Fe: 0.060% or less, with a balance being Al and an unavoidable impurity, an amount of an Mg-based oxide being 50 ppm or less, (IBe/Ibulk)×(CBe)?0.1000% where (IBe) is a maximum optical emission intensity of Be in a surface depth direction using a glow discharge optical emission spectrometer (GDS) prior to performing a plating pretreatment, (Ibulk) is a mean optical emission intensity of Be in an interior of a base material of the aluminum alloy prior to performing a plating pretreatment, and (CBe) is an amount of the Be, and a method of manufacturing the magnetic disc aluminum alloy substrate.

Abstract: The present invention provides: an aluminum alloy substrate for magnetic discs with excellent plating surface smoothness; a manufacturing method therefor; and a magnetic disc using said aluminum alloy substrate for magnetic discs. The present invention is an aluminum alloy substrate for magnetic discs, a manufacturing method therefor, and a magnetic disc using said aluminum alloy substrate for magnetic discs, the aluminum alloy substrate being characterized in being obtained from an aluminum alloy containing Mg: 2.0-8.0 mass % (“%” below), Be: 0.00001-0.00200%, Cu: 0.003-0.150%, Zn: 0.05-0.60%, Cr: 0.010-0.300%, Si: 0.060% or less, Fe: 0.060% or less, the balance being obtained from Al and unavoidable impurities.

Abstract: An aluminum alloy substrate for a magnetic disk includes 0.5 mass % or more and 24.0 mass % or less of Si, 0.01 mass % or more and 3.00 mass % or less of Fe, and the balance of Al and unavoidable impurities. The aluminum alloy substrate for a magnetic disk includes a smooth plated surface and has high rigidity.

Abstract: The disclosed method relates to manufacturing a heat exchanger which causes no brazing defects, and a heat exchanger manufactured by the method. The method relates to manufacturing a heat exchanger having an aluminum alloy tube defining a cooling-medium flowing passage and a copper alloy tube defining a water flowing passage, wherein a heat exchange is carried out between a cooling medium flowing through the cooling-medium flowing passage and water flowing through the water flowing passage. The aluminum alloy tube and the copper alloy tube are brazed to each other at a temperature of less than 548° C.

Abstract: An aluminum alloy plate for a magnetic disk substrate with a flat and smooth ground surface, a production method by which the aluminum alloy plate can be produced at low cost and a magnetic disk are shown. An aluminum alloy plate for a magnetic disk substrate which comprises an aluminum alloy containing Mg: 3.0 to 8.0 mass % (hereinafter %), Cu: 0.005 to 0.150%, Zn: 0.05 to 0.60%, Cr: 0.010 to 0.300%, Fe: 0.001 to 0.030%, Si: 0.001 to 0.030%, (Ti+V+Zr): 0.0010 to 0.0100%, B: 0.0001 to 0.0010% with a balance being Al and inevitable impurities, wherein the density of a Ti—V—B—Zr-based inclusion having a maximum diameter exceeding 5 ?m is 0 piece/6000 mm2 and the density of a Ti—V—B—Zr-based inclusion having a maximum diameter of 3 to 5 ?m is 1 piece/6000 mm2 or less; a production method thereof; and a method for producing a magnetic disk.

Abstract: An aluminum alloy plate for a magnetic disk substrate with a flat and smooth ground surface, a production method by which the aluminum alloy plate can be produced at low cost and a magnetic disk are shown. An aluminum alloy plate for a magnetic disk substrate which comprises an aluminum alloy containing Mg: 3.0 to 8.0 mass % (hereinafter %), Cu: 0.005 to 0.150%, Zn: 0.05 to 0.60%, Cr: 0.010 to 0.300%, Fe: 0.001 to 0.030%, Si: 0.001 to 0.030%, (Ti+V+Zr): 0.0010 to 0.0100%, B: 0.0001 to 0.0010% with a balance being Al and inevitable impurities, wherein the density of a Ti—V—B—Zr-based inclusion having a maximum diameter exceeding 5 ?m is 0 piece/6000 mm2 and the density of a Ti—V—B—Zr-based inclusion having a maximum diameter of 3 to 5 ?m is 1 piece/6000 mm2 or less; a production method thereof; and a method for producing a magnetic disk.

Abstract: There is provided a heat exchanger and a fin material for the heat exchanger that can suppress occurrence of hollow corrosion in a fin and hold cooling performance for a long period of time under a high corrosion environment. The heat exchanger includes an aluminum tube through which a working fluid circulates and an aluminum fin which is bonded to the tube. The fin has a region B around a grain boundary, and a region A around the region B. In the region B, 5.0×104 pieces/mm2 less of Al—Fe—Mn—Si based intermetallic compound, each of which has equivalent circle diameters of 0.1 to 2.5 ?m, are present. In the region A, 5.0×104 pieces/mm2 to 1.0×10? pieces/mm2 of Al—Fe—Mn—Si based intermetallic compound, each of which has equivalent circle diameters of 0.1 to 2.5 ?m, are present.

Abstract: A bonded body made of an aluminum alloy and a copper alloy and obtained by employing the aluminum alloy as one member to be bonded and the copper alloy as the other member to be bonded, the one bonded member and the other bonded member being bonded to each other through metallic connection, wherein the one bonded member is made of comprising an aluminum alloy containing Cu: 3.0 mass % to 8.0 mass % and Si: 0.1 mass % to 10 mass % with balance being Al and unavoidable inevitable impurities, and satisfying the chemical formula: C+2.4×S?7.8 where C (mass %) is a Cu concentration and S (mass %) is a Si composition concentration is satisfied, and the other bonded member comprises a copper alloy having a higher solidus temperature than the one bonded member. A bonding method for the bonded body is provided.

Abstract: The disclosed method relates to manufacturing a heat exchanger which causes no brazing defects, and a heat exchanger manufactured by the method. The method relates to manufacturing a heat exchanger having an aluminum alloy tube defining a cooling-medium flowing passage and a copper alloy tube defining a water flowing passage, wherein a heat exchange is carried out between a cooling medium flowing through the cooling-medium flowing passage and water flowing through the water flowing passage. The aluminum alloy tube and the copper alloy tube are brazed to each other at a temperature of less than 548° C.

Abstract: An aluminum alloy sheet for a lithographic printing plate which has excellent ink stain resistance, with a local defect in a photosensitive layer after long-term storage being hard to occur, and excellent the pit uniformity after a roughening and a manufacturing method thereof are provided. An aluminum alloy sheet for a lithographic printing plate containing a predetermined content of Fe, Si, Cu and Ti as well as one type or more selected from B and C, and composed of remaining Al and inevitable impurities, in which a concentration of an aluminum carbide present in the aluminum alloy sheet is not more than 8 ppm, an area occupancy of aggregation substances present on the aluminum alloy sheet surface after the roughening treatment with respect to an arbitrary circle with a radius 5 ?m in the aluminum alloy sheet surface is less than 10%. In a case where the area occupancy is not less than 10%, the aggregation substances are present at a rate of 1 to 2 pieces/50 cm2.