Aluminum material with high formability

Abstract

An aluminum material, which is composed of crystal grains having different crystal orientations, in which the crystal grains comprise Cube-oriented crystal grains, Brass-oriented crystal grains and Copper-oriented crystal grains with a balance of crystal grains of other orientations, and in which the proportion of the Cube-oriented crystal grains is from 0.3 to 0.7, the proportion of the Brass-oriented crystal grains is from 0.1 to 0.5, the proportion of the Copper-oriented crystal grains is 0.2 or less, and the total proportion of these orientations is from 0.4 to 1.0; and a car component using the same.

Description

TECHNICAL FIELD[0001]The present invention relates to an aluminum material. In particular, the present invention relates to an aluminum material excellent in the high degree of hem-bendability required in assembling car body panels, car parts, machine parts or the like, and excellent in sheet formability properties such as press formability for forming a body or casing.BACKGROUND ART[0002]In cars, advances are being made in the use of aluminum for body panels. A 6000-series (Al—Mg—Si base) aluminum alloy excellent in bake hardenability (property of exhibiting precipitation hardening under heating during paint-baking) that achieves high strength through painting with baking has been often used for outer panels, while a 5000-series (Al—Mg base) aluminum alloy excellent in draw formability has been used for inner panels.[0003]While the outer panel made of the 6000-series aluminum alloy is required to be excellent in bendability, namely in workability in the hem-bending usually used to ...

AI Technical Summary

Benefits of technology

[0021]Under these circumstances, the inventors of the present invention investigated the effect of distribution of crystal grain orientation on hem-bendability and sheet formability, and accomplished this invention which achieves a high level of compatibility between hem-bendability and sheet formability.

Problems solved by technology

While the outer panel made of the 6000-series aluminum alloy is required to be excellent in bendability, namely in workability in the hem-bending usually used to caulk it with an inner panel, the 6000-series (Al—Mg—Si base) aluminum alloy plate is in fact poor in hem-bendability.

A particular problem is that a panel that has been subjected to solution treatment at a high temperature for enhancing its bake-hardenability is extremely poor in hem-bendability.

However, this aluminum alloy is inferior to conventional steel sheets and 5000-series aluminum alloy sheets in press formability, and improvement in this regard is desired for unification of used materials to facilitate recycling of the car parts.

However, it has been difficult to improve both hem-bendability and formability of aluminum alloy sheet to a level equal to that of conventional steel bodies, although improvement of only hem-bendability has been possible.

Realization of a high level of sheet formability has been difficult even by a method for enhancing press formability and bendability in the relation between the tensile strength and proof stress and by controlling the crystal grain size on the surface of the aluminum alloy sheet and precipitation free zone (PFZ).

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