Superplastic magnesium lithium alloy material with high strain rate and preparation method thereof

Abstract

The invention provides a superplastic magnesium lithium alloy material with high strain rate and a preparation method thereof. The method is as below: a) preparing the following raw materials for melting alloy according to the weight proportion: 6%-11% of Li, 0.1%-3% of Al and the balance of Mg and trace impurity elements; b) melting by using a vacuum electromagnetic induction furnace under the protection of argon; c) conducting uniformity annealing on the obtained ingot in a heat treatment furnace at 200 DEG C-350 DEG C for 6-24 h, and cooling to room temperature; and d) lathing a surface oxide layer on the ingot obtained in the step c), and then conducting a one-time extrusion with large extrusion ratio higher than 75% at 200-300 DEG C. The product of the invention is superplastic magnesium lithium alloy with low lithium content, proper amount of aluminum content and high strain rate, and the invention uses a relatively simple melting and deformation processing method for the preparation of the superplastic magnesium lithium alloy with high strain rate.

Description

technical field [0001] The invention relates to a magnesium-lithium alloy material, in particular to a magnesium-lithium alloy material with high strain rate superplasticity. The invention also relates to a preparation process of a magnesium-lithium alloy material. Background technique [0002] Magnesium-lithium alloy is currently the lightest structural metal material, not only has the advantages of traditional magnesium alloy low density, high specific strength, specific stiffness, excellent shock absorption performance and impact toughness, good cutting and electromagnetic shielding performance, and density Smaller, even reaching a density as small as plastic. It has great potential in aerospace, automobile and 3C fields. Especially with the improvement of energy-saving and environmental protection requirements in various industries, the application of magnesium-lithium alloys will be more significantly promoted. [0003] In the practical application of magnesium-lithi...

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Problems solved by technology

[0004] A search of existing literature found that most superplastic processes need to meet the requirements of relatively low strain rates, and some have complex preparation processes that are difficult to meet production requirements

Common industrial magnesium alloys, such as the superplasticity of AZ31 magnesium alloy reported by Liu Manping (Chinese Journal of Nonferrous Metals, 2002, 4, P797-801), require a strain rate that is too low, at 673K, 3 × 10 -5 the s -1 It can show an elongation rate of 314%, which is difficult for practical application

After certain processing, better superplasticity can be obtained at a higher strain rate, such as Yoshida et al. (Materials Transactions, 2002, 43, P2419-2423) reported a 6-pass equal radial Magnesium-lithium alloy at 423K, 1×10 -3 the s -1 The elongation rate of 391% is obtained under the conditions, but these processing techniques are often too complicated and difficult to achieve in actual production

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