High-strength low-density hcp+bcc dual-structure magnesium-lithium alloy bar and preparation method thereof

Abstract

The invention discloses a high-strength low-density hcp+bcc dual-structure magnesium-lithium alloy bar. The high-strength low-density hcp+bcc dual-structure magnesium-lithium alloy bar comprises the following raw materials of, by weight, 6.1%-10.2% of Li, 4.6%-5.8% of Al, 1.5%-2.3% of Zn, 0.1%-0.6% of Y, and the balance Mg and impurity elements thereof. The impurity elements comprise Ca, Fe, Cu and Ni, the total amount is smaller than 0.2%, wherein Fe is smaller than or equal to 0.04%, and Ca is smaller than or equal to 0.03%. According to the high-strength low-density hcp+bcc dual-structure magnesium-lithium alloy bar, through reasonable matching of the types and proportional relation of the alloy elements, the trace Y element is added, and the trace Y element and the matrix Mg element form an Al2Y strengthening phase so as to improve the strength of alloy. Mg-Y intermediate alloy is added into melt, smelting is conducted, alloy cost is lowered, and industrialized production is facilitated. A semicontinuous casting process is conducted under the non-vacuum condition, on the one hand, complexity of experimental operation is lowered, on the other hand, the melt purity degree and thealloy yield are improved, and the foundation is laid for later high-strength ultralight magnesium-lithium alloy.

Description

technical field [0001] The invention relates to the field of dropped magnesium-lithium alloy rods, in particular to a high-strength low-density hcp+bcc double-structure magnesium-lithium alloy rod and a preparation method thereof. Background technique [0002] Magnesium-lithium alloy is currently the lightest alloy material on the earth, with a density of 1.35-1.65g / cm3, which is 1 / 3-1 / 2 of the density of ordinary aluminum alloys and 1 / 4-1 / 3 of the density of ordinary magnesium alloys. Magnesium-lithium alloy has many advantages such as low density, high specific strength, high specific stiffness, good resistance to high-energy particle penetration, excellent electromagnetic shielding performance, good welding performance and excellent cold forming ability, so it is widely used in In the fields of aviation, aerospace, military, communication, 3C electronic products and other fields, it is known as "green engineering material in the 21st century". In recent years, the world'...

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Problems solved by technology

In the patent application number 201110266610.2, a high-plastic magnesium-lithium alloy containing Y element and its preparation method are announced. Although the high plasticity of the alloy is guaranteed, the strength of the alloy is low, which is 145-175MPa

This will inevitably limit the application value of magnesium-lithium alloys.

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