Al-Si-Mg cast aluminium alloy for pressure casting, and preparation method thereof

Abstract

The invention provides an Al-Si-Mg cast aluminium alloy for pressure casting and a preparation method thereof. The Al-Si-Mg cast aluminium alloy for pressure casting comprises the following components according to mass fraction: Si, Mg, Mn, Ti, B, Sb, Re, Fe, V, C, r, Zr, P, Be and the balance of Al. The Al-Si-Mg cast aluminium alloy for pressure casting has high-strength and high-toughness mechanical properties, and the mechanical property of a pressure casting test bar can reach the followings: casting state tensile strength (Sigma): 230-310 MPa, the yield strength (Sigma<0.2>): 115 to 160 MPa, and the percentage of elongation (Delta): 5.5 to 14.5. The Al-Si-Mg cast aluminium alloy for pressure casting has an excellent comprehensive mechanical property, particularly an elongation percentage, which is 1.5 times of the maximum value 3.5 percent stipulated in all material standards. Further, the Al-Si-Mg cast aluminium alloy is also excellent in welding performance and suitable for combined welding of castings.

Description

technical field [0001] The invention relates to the technical field of aluminum alloy materials, in particular to an Al-Si-Mg cast aluminum alloy for die casting and a preparation method thereof. Background technique [0002] The aluminum alloy die-casting process can produce metal parts with complex shapes, clear outlines, and thin-walled deep cavities. It has the advantages of simple process, high production efficiency, high tolerance level of castings, good surface roughness, excellent mechanical properties, and high material utilization. It has become an important part of my country's foundry industry. In the automobile industry, the demand for aluminum alloy die castings is very large, and has become an important support for automobile lightweight. [0003] Since the aluminum alloy has a strong affinity for iron, when the aluminum alloy is in contact with the iron mold during the die-casting process, physical and chemical reactions will occur, resulting in mold sticking...

AI Technical Summary

Problems solved by technology

[0012] In the alloys in the above standards, due to the high content of Fe, most of the iron exists in the alloy in the form of thick flakes or needle-like β (Al9Fe2Si2) phases, which not only reduces the fluidity of the alloy, but also increases the thermal cracking property. Severely split the matrix and reduce the mechanical properties, especially the elongation, thus greatly limiting the application field. Most of them are used on boxes, shells, and coverings that only bear simple stresses, but for complex structural parts that bear alternating stresses few apps on

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