High-toughness casting aluminum-silicon alloy, as well as preparation method and application thereof

Abstract

The invention provides a high-toughness casting aluminum-silicon alloy, as well as a preparation method and application thereof. The aluminum-silicon alloy is prepared from the following components inpercentage by mass: 7 to 8 percent of Si, 0.4 to 0.5 percent of Mg, 0.1 to 0.2 percent of Fe, 0.1 to 0.2 percent of Ti, 0.01 to 0.02 percent of Sr, 0.03 to 0.06 percent of La, 0.02 to 0.04 percent ofCe, and the balance Al and inevitable impurity elements. The preparation method comprises the steps of smelting for preparing aluminum-silicon alloy liquid, thinning for modification, refining for degassing and purifying, casting, and carrying out solid-solution aging treatment. According to the high-toughness casting aluminum-silicon alloy, as well as the preparation method and the application thereof provided by the invention, through optimizing the contents of Si and Mg elements, and thinning and modifying alpha-Al crystalline grains, a beta-Fe iron-rich phase and an eutectic Si phase, alpha-Al branch crystals are converted into fine equiaxed grains, the elongated and flaky beta-Fe iron-rich phase and the eutectic Si phase are converted into fine granulated shapes or short rod shapes,and the damage of the elongated and flaky beta-Fe iron-rich phase and the eutectic Si phase on the strength, the plasticity and the breaking tenacity of the aluminum-silicon alloy is eliminated. The casting aluminum-silicon alloy provided by the invention has high strength, good plasticity and excellent breaking tenacity, is suitable for casting various stress structural members such as automobilelight-weight structural members.

Description

technical field [0001] The invention relates to the technical field of aluminum alloy and its preparation, in particular to a high-strength and toughness cast aluminum-silicon alloy and its preparation method and application. Background technique [0002] Aluminum alloy has the advantages of low density, high specific strength, corrosion resistance, easy processing and molding, and recyclability. It is widely used in transportation, electronic appliances, mechanical equipment, construction and other fields. With the development of lightweight automobiles, parts such as steering knuckles, airbag support arms, brake calipers, shock towers, suspension brackets, control arms, engine cylinder blocks and cylinder heads are in urgent need of "substituting aluminum for steel". The purpose of automobile lightweight. These parts are important structural parts in automobiles. In order to improve the safety and service life of automobiles, these parts also require high comprehensive me...

AI Technical Summary

Problems solved by technology

Although cast aluminum-silicon alloys have good casting fluidity and mechanical processing properties, the commonly used cast aluminum-silicon alloys still have problems of low strength, poor plasticity and insufficient fracture toughness. For example, A356 cast aluminum-silicon alloys in T6 The tensile strength in the heat treatment state is usually lower than 280MPa, the yield strength is lower than 240MPa, and the elongation is lower than 7%. The strength and plasticity cannot meet the requirements of most automotive structural parts.

[0004] Therefore, the existing cast aluminum-silicon alloy and its preparation method still need to be improved and developed.

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