Non-heat-treated high-toughness die-casting aluminum-silicon alloy and preparation method thereof

Abstract

According to the non-heat-treatment high-toughness die-casting aluminum-silicon alloy and the preparation method thereof, by controlling a certain Mn / Fe proportion, the adverse effect caused by the Fe element can be effectively restrained; and by introducing a certain proportion of rare earth elements, Si in the material can be effectively refined, the rare earth elements, Al, Cu and other elements can form a high-temperature phase, and the deformation resistance of the material applied to die-casting integrated large structural parts is improved. The alloy can achieve the effects that the tensile strength is 290 Mpa, the yield strength is 140 Mpa, and the ductility is 13% under the die-casting state condition of large casting body sampling; meanwhile, the die-casting forming performance is excellent; and the used energy is clean energy and reaches the low-carbon emission standard.

Description

technical field [0001] The invention relates to the technical field of metal materials, in particular to a non-heat-treated high-toughness die-casting aluminum-silicon alloy and a preparation method thereof. Background technique [0002] With the in-depth promotion of carbon peak and carbon neutrality policies, carbon emission indicators have been continuously lowered, and recycled aluminum has the obvious advantage of low energy consumption, and has gotten rid of the aluminum industry's dependence on "prices rising with electricity". As a leading industry, it is more conducive to the healthy, stable and long-term development of the aluminum industry. The carbon emission of recycled aluminum is significantly lower than that of thermal electrolysis of primary aluminum. 1 ton of thermal electrolysis of primary aluminum emits about 12 tons of carbon dioxide, while the production of 1 ton of recycled aluminum only emits about 300Kg of carbon dioxide. The production of 1 ton of r...

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Problems solved by technology

Although traditional Al-Si alloys have good strength and good casting properties, they have poor plasticity and low elongation, and the material cannot meet the requirements of large one-piece molded die-casting parts for automobiles.

In recent years, in order to meet the needs of the automotive industry market, the development of high-toughness aluminum alloys has received more and more attention. For example, the Silafont-36 alloy (patent publication number: US 6364970B1) developed by Rheinland, Germany, which stretches at room temperature The rate is not higher than 6%. After a long time of T7 heat treatment, the tensile strength is about 210Mpa, the yield strength is 140Mpa, and the elongation is 15%, which can meet the requirements of automotive structural parts. This process has low production efficiency and complex heat treatment process. Good control, high cost of heat treatment

Another example is the non-heat treatment strengthened high-strength and high-toughness die-casting Al-Mg-Si alloy (patent publication number: CN 108754256A) developed by Shanghai Jiaotong University. The alloy has excellent mechanical properties, but the Al-Mg-Si alloy has poor casting performance and high Magnesium content is easy to oxidize and burn, aluminum liquid has high viscosity and high shrinkage rate, which will greatly erode the die-casting mold and reduce the life of the mold. It is not suitable for large body structural parts

In addition, the non-heat-treated self-strengthening aluminum-silicon alloy (patent publication number: CN 104831129A) developed by Fengyang Aiersi and Shanghai Jiaotong University has a high degree of control over impurity elements and cannot be produced with waste aluminum, which cannot meet the future carbon requirements. The demand group under the background of peak and carbon neutrality, and the elongation rate of castings under precision die casting is about 7.5%, which cannot meet the high toughness requirements for large body structural parts at this stage

For example, a high-strength and tough die-casting aluminum alloy (patent publication number: CN109881056A) developed by Shanghai Yongmaotai Auto Parts and Shanghai Jiaotong University. Although the alloy has good casting performance, the elongation of the alloy in the die-casting non-heat treatment state is only 7%. It also cannot meet the high toughness requirements of automobile structural parts; another example is a high toughness die-casting aluminum alloy (patent publication number: CN106636787A) developed by Suzhou Huichi Light Alloy. This alloy has good casting performance and strength, but the content of impurity elements The requirement is less than 0.005%, the requirement for impurity content is extremely high, and it cannot be produced by adding waste aluminum, and the elongation rate of die-casting parts in the non-heat-treated state can only reach 9.7%, which cannot meet the high toughness requirements of die-casting large-scale integrated structural parts

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