High-strength die-casting aluminum alloy for pressure casting

Abstract

The invention relates to the field of alloy material, and discloses a high-strength die-casting aluminum alloy for pressure casting. The aluminum alloy is Al-Mg-Si-Mn series, and comprises 4.5-6.3 wt% of magnesium, 1.4-2.8 wt% of silicon, 0.4-1.0 wt% of manganese, no more than 0.22 wt% of iron, no more than 0.20 wt% of titanium, no more than 0.05 wt% of copper, no more than 0.0045 wt% of beryllium, no more than 0.30 wt% of unavoidable impurity, and the balance of aluminum. The die-casting aluminum alloy provided by the invention has excellent casting property and good mechanical property, and the tensile strength and the yield strength are greatly promoted; the die-casting aluminum alloy has large elongation percentage and high rigidity, and also has good corrosion resistance without solid solution heat treatment; and the high-strength die-casting aluminum alloy for pressure casting can be used for safety spare parts on passenger cars, and satisfies the requirement of light weight development for passenger cars.

Description

technical field [0001] The invention relates to the field of alloy materials, in particular to a die-cast aluminum alloy for die-casting. Background technique [0002] Die casting, referred to as die casting, is a high-speed and efficient advanced forming process. It is one of the main forming methods for complex thin-walled aluminum and magnesium alloy castings. It occupies a considerable share in the production of aluminum and magnesium alloy parts for automobiles / motorcycles. proportion. However, the aluminum and magnesium alloy castings produced by die-casting have many internal pores, and cannot be subjected to solution heat treatment or welding forming, nor can they be subjected to excessive machining. Therefore, the application of die castings in important security parts of cars / motorcycles, such as sub-frames on chassis suspensions, door pillars and other structural stress-bearing parts, is severely limited. How to give full play to the technical advantages of die-...

AI Technical Summary

Problems solved by technology

However, Fe and Al and Si in the alloy will generate needle-like FeAl 3 , Al-Fe-Si intermediate compounds, the existence of such intermediate compounds seriously weakens the mechanical properties of die castings, especially the fracture toughness

For Al-Si-Cu alloys, although the addition of Cu can increase the strength of die castings, it reduces the toughness of castings, and the addition of Cu will reduce the corrosion resistance of castings.

In addition, Al-Si-Mg alloys need solid solution strengthening and aging treatment to improve their mechanical properties. However, as mentioned above, die castings generally cannot be subjected to solution heat treatment. will cause severe deformation

Therefore, the existing Al-Si-Cu series, Al-Si-Mg series and Al-Mg series die-casting aluminum alloys are not high-strength and high-toughness die-casting aluminum alloy materials, and cannot meet the requirements of complex thin-walled, high-strength, The requirements of high toughness, impact resistance, corrosion resistance and other automotive structural stress parts cannot be applied to the security parts of cars, and cannot meet the development of lightweight cars

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