A method for producing an aluminum alloy extrusion includes: conducting extrusion processing using a casted billet of an aluminum alloy containing 6.0 to 7.0% by mass of Zn, 1.5 to 2.0% by mass of Mg, 0.20 to 1.50% by mass of Cu, 0.10 to 0.25% by mass of Zr, 0.005 to 0.05% by mass of Ti, 0.15 to 0.35% by mass of Mn, 0.25% by mass or less of Sr, content of Mn and Zr and Sr being 0.10 to 0.50% by mass, with the balance being Al and inevitable impurities to obtain an aluminum alloy extrusion; cooling the extrusion to 100° C. or less at a cooling rate of 50 to 750° C./min immediately after the extrusion processing; and then conducting an aging treatment which is performed in one-stage or two-stage and a heat treatment which is performed at higher temperature for a shorter time than the aging treatment.

A method for producing an aluminum alloy extrusion includes: conducting extrusion processing using a casted billet of an aluminum alloy containing 6.0 to 7.0% by mass of Zn, 1.5 to 2.0% by mass of Mg, 0.20 to 1.50% by mass of Cu, 0.10 to 0.25% by mass of Zr, 0.005 to 0.05% by mass of Ti, 0.15 to 0.35% by mass of Mn, 0.25% by mass or less of Sr, content of Mn and Zr and Sr being 0.10 to 0.50% by mass, with the balance being Al and inevitable impurities to obtain an aluminum alloy extrusion; cooling the extrusion to 100° C. or less at a cooling rate of 50 to 750° C./min immediately after the extrusion processing; and then conducting an aging treatment which is performed in one-stage or two-stage and a heat treatment which is performed at higher temperature for a shorter time than the aging treatment.

There are provided a heat exchanger having a flat tube and a fin bonded together, without causing melting of a coating material covering the fin, and a method of manufacturing thereof. A heat exchanger includes: a flat tube having a flat cross-sectional shape and covered with an anticorrosive layer; and a fin bonded to the flat tube with a bonding agent on a first surface of the anticorrosive layer interposed therebetween, and covered with a coating material, the first surface of the anticorrosive layer having been roughened, and the bonding agent being fixed to the roughened first surface.

There are provided a heat exchanger having a flat tube and a fin bonded together, without causing melting of a coating material covering the fin, and a method of manufacturing thereof. A heat exchanger includes: a flat tube having a flat cross-sectional shape and covered with an anticorrosive layer; and a fin bonded to the flat tube with a bonding agent on a first surface of the anticorrosive layer interposed therebetween, and covered with a coating material, the first surface of the anticorrosive layer having been roughened, and the bonding agent being fixed to the roughened first surface.

Described are processes for shaping age hardenable aluminum alloys, such as 2XXX, 6XXX and 7XXX aluminum alloys in T4 temper, or articles made of such alloys, including aluminum alloy sheets. The processes involve heating the sheet or article before and/or concurrently with a forming step. In some examples, the sheet is heated to a specified temperature in the range of about 100-600° C. at a specified heating rate within the range of about 3-600° C./s, for example about 3-90° C./s. Such a combination of temperature and heating rate results in an advantageous combination of sheet properties.

Described are processes for shaping age hardenable aluminum alloys, such as 2XXX, 6XXX and 7XXX aluminum alloys in T4 temper, or articles made of such alloys, including aluminum alloy sheets. The processes involve heating the sheet or article before and/or concurrently with a forming step. In some examples, the sheet is heated to a specified temperature in the range of about 100-600° C. at a specified heating rate within the range of about 3-600° C./s, for example about 3-90° C./s. Such a combination of temperature and heating rate results in an advantageous combination of sheet properties.

A coated steel substrate has a steel substrate having a surface. A coating layer is atop the surface. The coating layer includes: aluminum activated by indium; and a ceramic binder. The coating also may comprise of multiple layers with different properties to facilitate the galvanic protection capability.

A coated steel substrate has a steel substrate having a surface. A coating layer is atop the surface. The coating layer includes: aluminum activated by indium; and a ceramic binder. The coating also may comprise of multiple layers with different properties to facilitate the galvanic protection capability.

The present invention discloses a method for ultra-low temperature forming an ultra-thin curved part of a high-strength aluminum alloy. The method includes the following steps: step 1: selecting a cladding with a suitable thickness according to a wrinkle limit of a sheet; step 2: stacking the sheet and the cladding, then putting into a die, and closing a blank holder; step 3: filling a cavity of a female die with an ultra-low temperature medium to cool the sheet to below −160° C.; step 4: applying a set blank holding force by the blank holder, and enabling a male die to go down to form a thin-walled curved part; and step 5: opening the die and taking out the formed thin-walled curved part. The present invention utilizes the favorable formability of the high-strength aluminum alloy at the ultra-low temperature and the instability resistance of the thick sheet.

The present invention discloses a method for ultra-low temperature forming an ultra-thin curved part of a high-strength aluminum alloy. The method includes the following steps: step 1: selecting a cladding with a suitable thickness according to a wrinkle limit of a sheet; step 2: stacking the sheet and the cladding, then putting into a die, and closing a blank holder; step 3: filling a cavity of a female die with an ultra-low temperature medium to cool the sheet to below −160° C.; step 4: applying a set blank holding force by the blank holder, and enabling a male die to go down to form a thin-walled curved part; and step 5: opening the die and taking out the formed thin-walled curved part. The present invention utilizes the favorable formability of the high-strength aluminum alloy at the ultra-low temperature and the instability resistance of the thick sheet.