High-strength aluminum-alloy material, aluminum-alloy plate and manufacturing method thereof

Abstract

The invention discloses a high-strength aluminum-alloy material. The high-strength aluminum-alloy material contains the chemical elements in percentage by mass: not lower than 1.5% and not higher than 3.0% of Mg, not lower than 0.05% and not higher than 0.2% of Si, not lower than 0.1% and not higher than 0.2% of Mn, not lower than 0.2% and not higher than 0.4% of Fe, higher than 0 and not higher than 0.03% of Cu, higher than 0 and not higher than 0.05% of Ti, either not lower than 0.05% and not higher than 0.15% of Ca or not lower than 0.05% and not higher than 0.15% of Sr and the balance of Al and other unavoidable impurities. The invention further discloses an aluminum-alloy plate manufactured from the aluminum-alloy material. The invention further discloses a manufacturing method of the aluminum-alloy plate, wherein the method comprises the steps of carrying out double-strip casting, carrying out cold rolling, carrying out online solid solution treatment and carrying out online aging pretreatment. The high-strength aluminum-alloy material and the aluminum-alloy plate, disclosed by the invention, have relatively high strength and good natural aging stability. After painting and baking, the yield strength of the high-strength aluminum-alloy material and the aluminum-alloy plate is higher than 300Mpa.

Description

technical field [0001] The invention relates to an alloy material, in particular to an aluminum alloy material. The invention also relates to an aluminum alloy plate made of the aluminum alloy material and a manufacturing method thereof. Background technique [0002] The lightweight of automotive materials is the focus of current car manufacturers. The use of aluminum alloy sheets in the manufacture of automotive structural parts is also increasing. The available materials are 2000 series, 5000 series and 7000 series alloy materials. However, the corrosion resistance of 2000-series alloy materials containing Cu is poor, the 5000-series alloy materials are prone to softening during the baking process, and the elongation of 7000-series alloy materials is insufficient, which will cause difficulties in material processing. The 6000 series Al-Mg-Si alloy materials that can be strengthened by heat treatment are gradually being widely used because of their good formability, corro...

AI Technical Summary

Problems solved by technology

[0003] However, 6000 series Al-Mg-Si alloy materials will undergo natural aging after solution treatment, and magnesium and silicon atoms will segregate at room temperature, resulting in an increase in yield strength.

Especially in the process of transportation and storage of aluminum alloy plates, the mechanical properties of the plates will be unstable as time goes by, often the yield strength and tensile strength will increase, while the elongation will decrease significantly, resulting in the aging of aluminum alloys. The plate rebounds seriously during stamping, and even cracks during edge wrapping, which seriously affects product quality

In addition, the yield strength of 6000 series Al-Mg-Si alloy materials after painting and baking under conventional casting and rolling conditions is usually lower than 300MPa, which cannot meet the needs of the automotive industry for higher strength lightweight aluminum plate structures. piece of demand

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