Ultra-strong strength, high-toughness and anticorrosive aluminum alloy and preparation method for same

Abstract

The invention relates to an ultra-strong strength, high-toughness and anticorrosive aluminum alloy and a preparation method for the same. A trace amount of specially-reinforced rare earth elements Sm, Nd and Y are added on the basis of an Al-Zn-Mg-Cu-Zr alloy, an electromagnetic casting mode is adopted for improving the solid solubility of the alloy, homogenizing the structure and reducing segregation, and the proportion of main alloy elements is optimized to make a breakthrough in the strength of the alloy. The aluminum alloy has ultra-strong strength, higher plasticity and high anticorrosive performance; in addition, the high-abundance rare earth element such as Sm and Y serving as one of raw materials is excessively overstocked in the market, and is low in cost, so that not only can be the cost of the alloy remarkably lowered, but also the problem of application unbalance of the rare earth elements can be relieved; the strength of a material prepared from the alloy is stronger than 700MPa after the material is subjected to T77 treatment, and is remarkably stronger than that of a material prepared from a 7055 alloy, and the comprehensive performance of the material is remarkably higher than that of a material prepared from an Al-Zn-Cu-Mg aluminum alloy currently with the highest comprehensive performance.

Description

technical field [0001] The invention relates to the technical field of aluminum alloys, in particular to an ultra-high-strength, high-toughness, corrosion-resistant aluminum alloy and a manufacturing method thereof. Background technique [0002] Al-Zn-Mg-Cu-Zr series aluminum alloy belongs to ultra-high-strength deformed aluminum alloy, which has the advantages of high specific strength and specific stiffness, good corrosion resistance and thermal processing performance, and is widely used in launch vehicles, spacecraft and space stations, etc. The main structural material of spacecraft is also one of the key structural materials of weapon systems such as missiles and fighter jets, so it is widely used in aerospace and military industries. With the continuous deepening of research on ultra-high-strength deformed aluminum alloys and the continuous improvement of performance requirements, the strength requirements are getting higher and higher. [0003] For a long time, rare ...

AI Technical Summary

Problems solved by technology

Among the previously disclosed research results in this field, there is a technical solution of adding scandium to the ultra-high-strength 7055 alloy. Although this solution has a more obvious effect in improving the strength, the price of the raw material scandium is relatively expensive, and it is not suitable for large-scale industrial application.

At present, among the high-abundance rare earth elements, samarium, neodymium, and yttrium are less widely used, resulting in a large excess backlog in the market, and the price is lower than other rare earth elements. If the rare earth elements such as samarium, neodymium, and yttrium can be applied to aluminum alloys, It not only has obvious effects on improving the strength, plasticity, corrosion resistance and fracture toughness of the aluminum alloy matrix, but also alleviates the problem of unbalanced application of rare earth elements caused by the lack of application of samarium, neodymium and yttrium in the rare earth market

[0004] In addition, the current preparation process of such aluminum alloy ingots mostly adopts ordinary continuous casting technology (Direct chill casting, DCC), which leads to insufficient solid solution of alloying elements in the grain, and exists in the grain boundary or segregated in the form of eutectic compounds. Coarse second phase, in the subsequent deformation heat treatment process, only a small part remelts, and most of them still remain in the grain boundary, distributed in a chain, which seriously affects the toughness of the alloy

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