Ultrahigh strength aluminum lithium alloy and preparation method thereof

Abstract

The invention discloses ultrahigh strength aluminum lithium alloy and a preparation method thereof. The ultrahigh strength aluminum lithium alloy comprises the following microelements by mass percent: 3.5 to 4.5 percent of Cu, 1.0 to 1.6 percent of Li, 0.30 to 0.70 percent of Mg, 0.2 to 0.70 percent of Ag, 0.30 to 0.80 percent of Zn, 0.20 to 0.50 percent of Mn, 0.06 to 0.16 percent of Zr, less than 0.10 percent of impurity Si, less than 0.10 percent of Fe, less than 0.05 percent of other single impurity, and the balance of Al, wherein the total amount of other impurities is less than 0.15 percent. The method comprises the steps of compounding microelements of Mg, Ag and Zn, microalloying and strengthening the microelements, performing batching according to alloy constituents, melting the raw materials, performing refining and standing on the raw material in a furnace, and casting the raw material into alloy ingots satisfying required specifications. Plates manufactured through the alloy have the advantages that the tensile strength can reach more than 580MPa, the elongation percentage is higher than 7 percent at the same time, and the plates can be applied to structural elements in fields of aerospace, nuclear industry, transportation, weapons and the like.

Description

technical field [0001] The invention relates to an ultrahigh-strength aluminum-lithium alloy and a preparation method thereof, belonging to the field of metal material engineering. Background technique [0002] The new aluminum-lithium alloy is the most ideal structural material for aerospace. With the development of application requirements and the improvement of metallurgical technology, aluminum-lithium alloys have experienced three stages of development, and the corresponding aluminum-lithium alloy products are also divided into three generations. At present, the fourth generation of aluminum-lithium alloy is being developed internationally. The basic principle for the development of aluminum-lithium alloys is to design aluminum-lithium alloys with different properties for the application requirements of different aerospace backgrounds; for example, for the aerospace industry, the design requirements for aluminum-lithium alloys are low density, high strength, high elast...

AI Technical Summary

Problems solved by technology

[0005] In traditional aluminum-lithium alloys due to Phase-induced in-plane slip leading to anisotropy in Al-Li alloys

Adding a small amount of Zr can refine the grains and inhibit the coplanar slip to a certain extent, but it cannot fundamentally improve its anisotropy

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