High-yield-strength cast aluminum alloy and preparation method thereof

Abstract

The invention provides a high-yield-strength cast aluminum alloy. The high-yield-strength cast aluminum alloy is prepared from, by mass, 6.0-6.8% of Si, 0.6-0.8% of Fe, 0.5-0.8% of Mg, 12-13% of Zn, 0.2-0.4% of Mn, 3.5-4.5% of Cu, 0.06-0.15% of Cr, 0.06-0.12% of Ti, 0.05-0.12% of Sr, 0.05-0.10% of Ni, less than 0.001% of B, less than 0.1% of impurity metal elements and the balance Al. The invention belongs to the technical field of aluminum alloys, and provides the high-yield-strength cast aluminum alloy capable of being naturally aged, so that the excellent casting property and mechanical property of the aluminum alloy are considered, and the tensile strength and the yield strength are remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to a cast aluminum alloy with high yield strength capable of natural aging and a preparation method thereof. Background technique [0002] Due to its low specific gravity and excellent performance, aluminum alloy is widely used as a lightweight material to replace steel and other materials. It is the most widely used non-ferrous metal structural material in the national economy. By adjusting the type and content of the element components contained, the aluminum alloy can have different properties such as high strength, high toughness, high thermal conductivity, corrosion resistance, and high toughness. However, due to the trade-off relationship between certain properties, some components The increase of the content can improve the corresponding performance, but it may lead to the decline of another performance at the same time, and it is impossible to achieve the...

AI Technical Summary

Problems solved by technology

Casting aluminum alloy often requires T6 treatment to obtain high yield strength, but for aluminum alloy die castings, due to the presence of tiny pores inside, T6 treatment is prone to gas expansion to form cracks or surface bubbles, resulting in the performance of castings cannot be further improved

[0005] The existing die-casting aluminum alloys are mainly Al-Si-Cu series alloys, typical grades are A380, ADC12, etc. Although these aluminum alloys have excellent casting properties, the mechanical properties of aluminum alloys, especially the yield strength and fracture strength, are difficult to meet current market demand

CN 110938767 A discloses a die-casting aluminum alloy, including aluminum element, and the die-casting aluminum alloy also contains: Zn 11-20%, Si 5.0-9.0%, Cu 1.0-3.0%, Fe 0.4 -0.8%, Ti0.1-0.4%, rare earth elements: 0.05-0.3%, Sr: 0.01-0.05%, rare earth elements include: La, Pr, Ce and Nd; by improving on the basis of Al-Si cast aluminum alloy The Zn content and the addition of mixed rare earth elements increase the strength of the aluminum alloy, but the tensile strength is still not very satisfactory.

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