Smelting process for high strength and ductility die-cast A356 aluminum alloy

Abstract

The invention belongs to the technical field of smelting of aluminum alloy and particularly relates to a smelting process for high strength and ductility die-cast A356 aluminum alloy. The smelting process for the high strength and ductility die-cast A356 aluminum alloy comprises the steps of raw material melting, deslagging and refining, wherein molten aluminum liquid is treated through a combinedrefining modificator obtained by mixing mixed rare earth, Al-Zn intermediate alloy and Al-Ag intermediate alloy in Al-Ti-B, Al-Ti-C, Al-Sr and Al-Zr; the additive amount of the mixed rare earth is 0.01-0.03wt% of the total amount of the molten aluminum alloy liquid, the additive amount of the Al-Zn intermediate alloy is 0.012-0.02wt% of the total amount of the molten aluminum alloy liquid, and the additive amount of the Al-Ag intermediate alloy is 0.04-0.09wt% of the total amount of the molten aluminum alloy liquid. According to the smelting process, the molten aluminum liquid is treated by adding the combined refining modificator, and a traditional air suction reaction caused by Al-Sr modification is avoided while a long-time modification effect is maintained; and besides, by the adoption of a combined refiner provided by the invention, a special-shaped core is formed in melt more efficiently, the solidification efficiency and solidification quality of the aluminum alloy are improved, and the obtained A356 aluminum alloy has the technical characteristic of high strength and ductility.

Description

technical field [0001] The invention belongs to the technical field of smelting aluminum alloys, and in particular relates to a smelting process of high-strength and tough die-casting A356 aluminum alloys. Background technique [0002] A356 aluminum alloy is an aluminum-based high-silicon alloy. Simply put, A356 aluminum alloy is an Al-Si binary alloy with magnesium added to form a strengthening phase Mg2Si. The aging strengthening ability of the alloy can be significantly improved by heat treatment, and the alloy can be improved. mechanical properties. The current automotive wheel hub aluminum often uses the requirements of the American standard A356.2 to specify its requirements for alloy ingots. [0003] For cars, the most effective way to save fuel consumption is to reduce the weight of the car, and the use of lightweight materials is the most important way, because aluminum alloy materials have light weight, high strength, good formability, moderate price, high recover...

AI Technical Summary

Problems solved by technology

However, the impact toughness of existing cast aluminum alloys is low, and they generally cannot withstand large impact loads. When a car collides or is driven violently, the aluminum alloy material cannot withstand large impact loads and serious deformation will cause the lives of passengers. Property safety poses a serious threat; in addition, considering the cost factor, aluminum alloy materials must be mixed with a certain amount of returned charge during the casting process, and the returned charge is doped with refiners, modifiers and aluminum chips. It has a serious impact on the mechanical properties of the finished product. Therefore, the use of a suitable melting process has an important impact on obtaining high-strength and tough die-casting aluminum alloys.

[0004] In the smelting and casting process of aluminum alloy, grain refinement is an essential process. The grain refiner used is inseparable from the Al-Ti-based master alloy. Al-Ti-B master alloy is an efficient crystal grain of aluminum alloy The grain refiner is still the best grain refiner so far, and the more popular grain refiner is used, but there are some problems in this type of refiner, such as TiB2 is easy to accumulate, and it is easy to combine with the oxide film or the salt in the melt. Solvent-like combination causes inclusions, resulting in pinhole defects in aluminum products. Although Al-Ti-C is the aluminum alloy grain refiner that people are most keen to develop at present, its production and manufacturing are relatively difficult, especially C is difficult to dissolve. Into the matrix, its manufacturing cost is higher