JPS62149838A - Aluminum alloy foil excellent in formability - Google Patents

Abstract

PURPOSE:To manufacture Al alloy foil having fine crystals and excellent in strength and formability, by subjecting an Al alloy ingot containing specific amounts of Fe and Mn to homogenizing treatment, hot rolling, and then to cold rollings with interposing process annealing between the cold rolling stages. CONSTITUTION:The Al alloy ingot containing by weight, 0.7-2.0% Fe and 0.05-0.2% Mn is subjected to homogenizing treatment at 580 deg.C for 10hr. Subsequently, the above ingot is subjected to hot rolling to 6mm thickness, to primary cold rolling to 0.6mm thickness, to process annealing at 400 deg.C for 1hr, to secondary cold rolling into a foil of 0.05mm thick, and finally to final annealing at 370 deg.C for 1hr so as to be formed into the product of Al alloy foil. In this way, grains are refined by the incorporation of Fe and coarsening of grains at the time of annealing is prevented by the addition of Mn, so that Al alloy foil excellent in strength and formability can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an aluminum alloy foil that is used alone or as a laminated foil for packaging containers for food and cosmetics, electronic parts, etc., and particularly an aluminum alloy foil that has excellent formability. Regarding.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, aluminum alloy foils used for the above-mentioned purposes have generally been made of pure aluminum such as IN30 alloy, which has good rollability, or 8011 alloy.

The forming of these aluminum alloy foils into the above-mentioned packaging containers and the like has generally been carried out by deep drawing.

However, recently, the forming process has shifted from deep drawing to overhanging, which has excellent productivity, and there is also a demand for thinner aluminum foil from a cost standpoint.

However, conventional aluminum alloy foils not only have poor ductility and are difficult to form to a sufficient overhang height during overhang processing, but also have problems in terms of strength and cannot adequately meet the demands for thinner walls. could not.

On the other hand, in order to refine the crystal grains and improve activity and strength, 8079 alloy with a high Fe content is used, and CAL
Rapid annealing has been carried out using a continuous annealing furnace (continuous annealing furnace), etc. However, it is said that rapid annealing of 8079 alloy may cause coarsening of crystal grains, which may actually deteriorate ductility and formability. There was a problem like this.

The present invention was made against this background, and an object of the present invention is to provide an aluminum alloy foil that has high strength and excellent formability.

Invention of means to solve the problem, Fe; 0. 7-2. 0wt
%, Mn; 0. 05~0. The gist of the invention is an aluminum alloy foil with excellent formability, which is characterized by containing 2 wt% of aluminum and the remainder consisting of aluminum and unavoidable impurities.

In the composition of the aluminum alloy foil mentioned above, Fe is effective in refining recrystallized grains, but Fe is 0.7 wt%.
If the content is less than z, the effect will be poor, and if the content exceeds z, ovt%, the coarse compounds will increase and the ductility will decrease. The desirable content of Fe is in the range of 1.0 to 1.5 vt%.

Mn has the effect of reducing the solid solubility limit of Fe and promoting refinement of crystal grains, and is also effective in preventing coarsening of crystal grains during rapid annealing. It also contributes to improving the strength of the foil. If Mn is less than 0.05 wt%, these effects are poor, and if it exceeds 0.2 wt%, the n value (work hardening coefficient) decreases, resulting in a decrease in ductility (uniform elongation).

It is preferable that the amount of unavoidable impurities in the aluminum alloy is small, but Si should be kept at about 0.2 wt% and other elements should be kept at 0.
．． Their content is allowed up to about 0.05 wt%.

The production of the above aluminum alloy foil generally involves hot rolling the aluminum alloy ingot, cold rolling including foil rolling,
Final annealing is carried out by sequentially carrying out each essential step, but if necessary, intermediate annealing may be performed in the middle of cold rolling, that is, between the first cold rolling and the second cold rolling. Homogenization treatment is also performed before inter-rolling.

Effects of the Invention As is clear from the Examples described below, the aluminum alloy foil of the present invention with a limited composition has fine crystal grains, high strength and elongation, and even better formability.

Therefore, it is possible to make the foil even thinner in practical use,
In addition to contributing to cost reductions, improved moldability increases the range of molding that can be done with foil alone or with laminate materials, expanding the range of applications for food and cosmetic packaging containers, electronic components, etc. I can do it.

Example Next, examples of the present invention will be shown in comparison with comparative examples.

Aρ-Fe-Mn alloys having various compositions shown in Table 1 were produced into ingots by a conventional method, and then homogenized for 580'CX10 hours. Next, these ingots were made into 4mm thick
After hot rolling to a thickness of 0.6 mm, primary cold rolling was performed to a thickness of 0.6 mm, followed by intermediate annealing at 400° C. for 1 hour. Furthermore, each sample was subjected to secondary cold rolling to a thickness of 0.05 mm, and then final annealed at 370° C. for 1 hour.

[Margin below] Table 1 Each of the foil materials obtained above was examined for crystal grain size, tensile strength, and elongation, and also subjected to overhang processing to examine overhang height and evaluate formability.

The overhang height is punch diameter 50m [l, die diameter 57m]
ra, the forming height until breakage under processing conditions of 75 mm and 1 minute punch speed. The results are shown in Table 2.

As is clear from the above results in Table 2, the aluminum alloy foil of the present invention has superior strength and formability, and has finer crystal grains than the comparative example that deviates from the above conditions. .

that's all

Claims (1)

[Claims] Fe: 0.7-2.0wt%, Mn: 0.05-0.2
An aluminum alloy foil with excellent formability, characterized in that it contains aluminum and unavoidable impurities.