Aluminum alloy sheet

Abstract

A 7xxx-series aluminum alloy sheet produced by a common procedure is allowed to include a surface part having a texture with grown Cube orientation, and a central part having a texture with grown S orientation. Namely, the surface part and the thickness-central part in the sheet are allowed to have different textures that are optimal respectively for shock absorption and for strength. This allows the aluminum alloy sheet to have better shock absorption upon automobile collision without lowering its strength, where the shock absorption is evaluated by a VDA bend test as illustrated in FIG. 1.

Description

TECHNICAL FIELD[0001]The present invention relates to a 7xxx-series aluminum alloy sheet which is produced by common rolling, which has high strength, and which still offers excellent shock absorption.BACKGROUND ART[0002]When taking automobiles as an example of structural materials, social demands for weight reduction of automobile bodies have become higher and higher in consideration typically of global environment. To meet these demands, aluminum alloy materials are applied, instead of part of ferrous materials such as steel sheets, to panels (such as hoods, doors, and roofs, and other outer panels, and inner panels) and reinforcements such as bumper reinforcements (bumper R / F) and door beams, of the automobile bodies.[0003]However, further weight reduction of automobile bodies requires the application of aluminum alloy materials more widely even to frames, pillars, and other structural components, which particularly contribute to weight reduction among automobile components. Thes...

AI Technical Summary

Benefits of technology

[0020]The inventors of the present invention focused attention on the texture of a 7xxx-series aluminum alloy sheet after solution treatment and quenching and analyzed the relationship between the texture and the shock absorption (crushing properties) upon automobile collision, which shock absorption is evaluated by a VDA bend test. As a result, the inventors have found that the shock absorption is affected particularly by the texture of a sheet surface part (surface layer) and can be improved by allowing the sheet surface part to have a specific texture with developed Cube orientation. The inventors have also found that this sheet can maintain its strength by allowing a sheet central part (thickness-central part) to have a specific texture with developed S orientation.

[0021]Spe...

Problems solved by technology

However, rolled sheets of 7xxx-series aluminum alloys have been used in practice little, because these alloys are high alloys and are difficult to be formed into rolled sheets.

The techniques disclosed in PTL 1 and PTL 2 employ the special repeated warm rolling procedures, because common production methods using h...

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