Abstract: An aluminum alloy material contains Mg: 7.0% to 10.0% (% by mass, the same applies hereinafter) and Ca: not more than 0.1%, and the aluminum alloy material contains a remainder constituted by aluminum and an inevitable impurity. The aluminum alloy material has a tensile strength of not less than 300 MPa and less than 500 MPa and an elongation of not less than 20%.

Abstract: An aluminum alloy material contains Mg: 7.0% to 10.0% (% by mass, the same applies hereinafter) and Ca: not more than 0.1%, and the aluminum alloy material contains a remainder constituted by aluminum and an inevitable impurity. The aluminum alloy material has a tensile strength of not less than 500 MPa and an elongation of not less than 3% and less than 10%.

Abstract: A method of joining heat-treatable aluminum alloy members by friction stir welding, including the steps of: a T4-treatment-performing step of performing a T4 treatment on heat-treatable aluminum alloy members so as to impart T4 temper to the heat-treatable aluminum alloy members; a joining step of joining the heat-treatable aluminum alloy members with T4 temper by friction stir welding to provide a joined product; and a reversion-treatment-performing step of performing a reversion treatment, the reversion-treatment-performing step being carried out prior to or after the joining step.

Abstract: An aluminum alloy material exhibiting excellent bendability can be produced without performing a straightening step, and can be bent without developing orange peel. The aluminum alloy material is a T4-tempered material formed of an Al—Cu—Mg—Si alloy including 1.0 to 2.5 mass % of Cu, 0.5 to 1.5 mass % of Mg, and 0.5 to 1.5 mass % of Si, with the balance being aluminum and unavoidable impurities, a matrix that forms an inner part of the aluminum alloy material having a microstructure formed by recrystallized grains having an average crystal grain size of 200 ?m or less, and the aluminum alloy material having a ratio of tensile strength/yield strength determined by a tensile test of 1.5 or more.

Abstract: A method of joining heat-treatable aluminum alloy members by friction stir welding, including the steps of: a T4-treatment-performing step of performing a T4 treatment on heat-treatable aluminum alloy members so as to impart T4 temper to the heat-treatable aluminum alloy members; a joining step of joining the heat-treatable aluminum alloy members with T4 temper by friction stir welding to provide a joined product; and a reversion-treatment-performing step of performing a reversion treatment, the reversion-treatment-performing step being carried out prior to or after the joining step.

Abstract: An aluminum alloy material exhibiting excellent bendability can be produced without performing a straightening step, and can be bent without developing orange peel. The aluminum alloy material is a T4-tempered material formed of an Al—Cu—Mg—Si alloy including 1.0 to 2.5 mass % of Cu, 0.5 to 1.5 mass% of Mg, and 0.5 to 1.5 mass % of Si, with the balance being aluminum and unavoidable impurities, a matrix that forms an inner part of the aluminum alloy material having a microstructure formed by recrystallized grains having an average crystal grain size of 200 ?m or less, and the aluminum alloy material having a ratio “tensile strength/yield strength” determined by a tensile test of 1.5 or more.

Abstract: A high-strength Al—Cu—Mg—Si aluminum alloy product obtained by extrusion is characterized in that the microstructure of the entire surface of the cross-section of the aluminum alloy product is formed of recrystallized grains, the grains have an average aspect ratio (L/t) of 5.0 or less and the orientation density of the grains in the microstructure, for which the normal direction to the {001} plane is parallel to the extrusion direction in comparison with the grains orientated to random orientations, is 50 or less. The high-strength Al—Cu—Mg—Si aluminum alloy product is characterized in that rod-shaped precipitates are arranged in the grains of the matrix in the <100> direction, the precipitates have an average length of 10 to 70 nm and a maximum length of 120 nm or less, and the number density of the precipitates in the [001] direction measured from the (001) plane is 500 or more per square micrometer.

Abstract: A frame member for use in a two-wheeled vehicle and an all-terrain vehicle that includes a plurality of Al members each made of a 7000 series Al alloy having a high strength is provided in which weld crack sensitivity is reduced and a weld joint having an excellent strength is provided. The alloy composition of the 7000 series Al alloy, which provides the Al member, containing Cu: 0.01 to 0.50%, Mg: 0.5 to 2.1%, and Zn: 4.0 to 8.5%, with the balance being Al and inevitable impurities. Further, in the production of the frame member, the plurality of Al members are integrated by welding using a filler metal containing Mg: 5.5 to 8.0%, Cr: 0.05 to 0.25%, Ti: 0.25% or less, Si: 0.4% or less, Fe: 0.4% or less, Cu: 0.1% or less, Zr: 0.05% or less and Zn: 0.25% or less, and with the balance being Al and inevitable impurities.

Abstract: A frame member for use in a two-wheeled vehicle and an all-terrain vehicle that includes a plurality of Al members each made of a 7000 series Al alloy having a high strength is provided in which weld crack sensitivity is reduced and a weld joint having an excellent strength is provided. The alloy composition of the 7000 series Al alloy, which provides the Al member, contains Cu: 0.01 to 0.50%, Mg: 0.5 to 2.1%, and Zn: 4.0 to 8.5%, the balance consisting of Al and inevitable impurities. Further, in the production of the frame member, the plurality of Al members is integrated by welding using a filler metal containing Mg: 5.5 to 8.0%, Cr: 0.05 to 0.25%, Ti: 0.25% or less, Si: 0.4% or less, Fe: 0.4% or less, Cu: 0.1% or less, Zr: 0.05% or less and Zn: 0.25% or less, and the balance consisting of Al and inevitable impurities.

Abstract: A method of joining aluminum alloy members, including the steps of: obtaining a joined body including: (a) contacting aluminum alloy members each made of a 6000 series aluminum alloy with T4 temper; and (b) performing a friction stir welding operation on a contact portion of the aluminum alloy members at which they are held in contact with each other, so as to form a stir zone at the contact portion; and performing, on the obtained joined body, an underaging treatment which is an artificial aging treatment and which is completed before hardness of the stir zone reaches maximum hardness, the underaging treatment being performed before GP zones are formed at the stir zone of the joined body.

Abstract: A heat-treated high-strength Al—Cu—Mg—Si aluminum alloy product exhibits excellent extrudability and high strength. The high-strength Al—Cu—Mg—Si aluminum alloy product obtained by extrusion is characterized in that the microstructure of the entire surface of the cross section of the aluminum alloy product is formed of recrystallized grains, the grains have an average aspect ratio (L/t) of 5.0 or less (wherein L is the average size of the grains in the extrusion direction, and t is the average thickness of the grains), and the orientation density of the grains in the microstructure, for which the normal direction to the {001} plane is parallel to the extrusion direction in comparison with the grains orientated to random orientations, is 50 or less.

Abstract: A method of joining heat-treatable aluminum alloy members by friction stir welding, including the steps of: a T4-treatment-performing step of performing a T4 treatment on heat-treatable aluminum alloy members so as to impart T4 temper to the heat-treatable aluminum alloy members; a joining step of joining the heat-treatable aluminum alloy members with T4 temper by friction stir welding to provide a joined product; and a reversion-treatment-performing step of performing a reversion treatment, the reversion-treatment-performing step being carried out prior to or after the joining step.

Abstract: A sheet of a 6000 type aluminum alloy containing Si and Mg as main alloy components and having an excellent formability sufficient to allow flat hemming, excellent resistance to denting, and good hardenability during baking a coating, which exhibits an anisotropy of Lankford values of more than 0.4 or the strength ratio for cube orientations of the texture thereof of 20 or more, and exhibits a minimum bend radius of 0.5 mm or less at 180° bending, even when the offset yield strength thereof exceeds 140 MPa through natural aging; and a method for producing the sheet of the aluminum alloy, which includes the steps of subjecting an ingot to a homogenization treatment, cooling to a temperature lower than 350° C. at a cooling rate of 100° C./hr or more, optionally to room temperature, heating again to a temperature of 300 to 500° C. and subjecting it to hot rolling, cold rolling the hot rolled product, and subjecting the cold rolled sheet to a solution treatment at a temperature of 400° C.

Abstract: A sheet of a 6000 type aluminum alloy containing Si and Mg as main alloy components and having an excellent formability sufficient to allow flat hemming, excellent resistance to denting, and good hardenability during baking a coating, which exhibits an anisotropy of Lankford values of more than 0.4 or the strength ratio for cube orientations of the texture thereof of 20 or more, and exhibits a minimum bend radius of 0.5 mm or less at 180° bending, even when the offset yield strength thereof exceeds 140 MPa through natural aging; and a method for producing the sheet of the aluminum alloy, which includes the steps of subjecting an ingot to a homogenization treatment, cooling to a temperature lower than 350° C. at a cooling rate of 100° C./hr or more, optionally to room temperature, heating again to a temperature of 300 to 500° C. and subjecting it to hot rolling, cold rolling the hot rolled product, and subjecting the cold rolled sheet to a solution treatment at a temperature of 400° C.

Abstract: A sheet of a 6000 type aluminum alloy containing Si and Mg as main alloy components and having an excellent formability sufficient to allow flat hemming, excellent resistance to denting, and good hardenability during baking a coating, which exhibits an anisotropy of Lankford values of more than 0.4 or the strength ratio for cube orientations of the texture thereof of 20 or more, and exhibits a minimum bend radius of 0.5 mm or less at 180° bending, even when the offset yield strength thereof exceeds 140 MPa through natural aging; and a method for producing the sheet of the aluminum alloy, which includes the steps of subjecting an ingot to a homogenization treatment, cooling to a temperature lower than 350° C. at a cooling rate of 100° C./hr or more, optionally to room temperature, heating again to a temperature of 300 to 500° C. and subjecting it to hot rolling, cold rolling the hot rolled product, and subjecting the cold rolled sheet to a solution treatment at a temperature of 400° C.

Abstract: A method of joining heat-treatable aluminum alloy members by friction stir welding, including the steps of: a T4-treatment-performing step of performing a T4 treatment on heat-treatable aluminum alloy members so as to impart T4 temper to the heat-treatable aluminum alloy members; a joining step of joining the heat-treatable aluminum alloy members with T4 temper by friction stir welding to provide a joined product; and a reversion-treatment-performing step of performing a reversion treatment, the reversion-treatment-performing step being carried out prior to or after the joining step.

Abstract: A method of joining aluminum alloy members, including the steps of: obtaining a joined body including: (a) contacting aluminum alloy members each made of a 6000 series aluminum alloy with T4 temper; and (b) performing a friction stir welding operation on a contact portion of the aluminum alloy members at which they are held in contact with each other, so as to form a stir zone at the contact portion; and performing, on the obtained joined body, an underaging treatment which is an artificial aging treatment and which is completed before hardness of the stir zone reaches maximum hardness, the underaging treatment being performed before GP zones are formed at the stir zone of the joined body.

Abstract: The present invention provides an aluminum alloy structural plate excelling in strength and corrosion resistance, in particular, resistance to stress corrosion cracking, and a method of manufacturing the aluminum alloy plate. This aluminum alloy structural plate includes 4.8-7% Zn, 1-3% Mg, 1-2.5% Cu, and 0.05-0.25% Zr, with the remaining portion consisting of Al and impurities, wherein the aluminum alloy structural plate has a structure in which grain boundaries with a ratio of misorientations of 3-10° is 25% or more at the plate surface. The aluminum alloy structural plate is manufactured by: homogenizing an ingot of an aluminum alloy having the above composition; hot rolling the ingot; repeatedly rolling the hot-rolled product at 400-150° C. so that the degree of rolling is 70% or more to produce a plate with a specific thickness, or repeatedly rolling the hot-rolled product at a material temperature of 400-150° C. in a state in which rolls for hot rolling are heated at 40° C.

Abstract: A sheet of a 6000 type aluminum alloy containing Si and Mg as main alloy components and having excellent formability sufficient to allow flat hemming, excellent resistance to denting, and good hardenability during baking a coating, which exhibits an anisotropy of Lankford values of more than 0.4 or the strength ratio for cube orientations of the texture thereof of 20 or more, and exhibits a minimum bend radius of 0.5 mm or less at 180° bending even when the offset yield strength thereof exceeds 140 MPa through natural aging; and a method for producing the sheet of the aluminum alloy, which comprises subjecting an ingot to a homogenization treatment, cooling to a temperature lower than 350° C. at a cooling rate of 100° C./hr or more, optionally to room temperature, heating again to a temperature of 300 to 500° C. and subjecting it to hot rolling, cold rolling the hot rolled product, and subjecting the cold rolled sheet to a solution treatment at a temperature of 400° C.

Abstract: The present invention provides an aluminum alloy structural plate excelling in strength and corrosion resistance, in particular, resistance to stress corrosion cracking, and a method of manufacturing the aluminum alloy plate. This aluminum alloy structural plate includes 4.8-7% Zn, 1-3% Mg, 1-2.5% Cu, and 0.05-0.25% Zr, with the remaining portion consisting of Al and impurities, wherein the aluminum alloy structural plate has a structure in which grain boundaries with a ratio of misorientations of 3-10° is 25% or more at the plate surface. The aluminum alloy structural plate is manufactured by: homogenizing an ingot of an aluminum alloy having the above composition; hot rolling the ingot; repeatedly rolling the hot-rolled product at 400-150° C. so that the degree of rolling is 70% or more to produce a plate with a specific thickness, or repeatedly rolling the hot-rolled product at a material temperature of 400-150° C. in a state in which rolls for hot rolling are heated at 40° C.