Preparation method enabling super-plastic magnesium alloy to have approximately-spherical precipitated phase

Abstract

The invention discloses a preparation method enabling a super-plastic magnesium alloy to have an approximately-spherical precipitated phase. The preparation method enabling the super-plastic magnesium alloy to have the approximately-spherical precipitated phase comprises three steps of homogenizing treatment, temperature-variable rolling grain refining and precipitated phase rounding adjustment. According to the preparation method enabling the super-plastic magnesium alloy to have the approximately-spherical precipitated phase, firstly, a magnesium alloy oversaturated solid solution is prepared through high-temperature and low-temperature staged heat treatment; secondly, dynamic recrystallization is induced through high-temperature large-reduction-rate medium-and-low-speed rolling, twin crystal refining is induced through low-temperature small-reduction-rate rapid rolling, and recrystallized grains are hindered from growing at low temperature; and the rounding heat treatment parameter is further adjusted, and a wrought magnesium alloy structure which is provided with submicron and micron matrix grains and has the approximately-spherical randomly-distributed precipitated phase is prepared. The preparation method enabling the super-plastic magnesium alloy to have the approximately-spherical precipitated phase can significantly improve the indoor-temperature strength and toughness of the magnesium alloy and is beneficial for full play of high-temperature superplasticity potential of the magnesium alloy. The preparation method enabling the super-plastic magnesium alloy to have the approximately-spherical precipitated phase breaks through the technical constraint that a traditional rolled structure cannot reach superplasticity, is particularly suitable for rolling of the magnesium alloy containing two or more kinds of high-volume-fraction mixed precipitated phases and improves the rolling efficiency.

Description

technical field [0001] The invention relates to the field of metal materials, in particular to a preparation method for making a superplastic magnesium alloy have a near-spherical precipitated phase. Background technique [0002] As the lightest metal material for engineering structures, magnesium alloy has significant advantages in light weight that cannot be replaced, which can effectively improve the fuel utilization rate of automobiles and reduce environmental pollution. In addition, magnesium alloys have excellent properties such as high specific strength, high specific stiffness, and good recycling, and are favored in the fields of aviation, aerospace, automobiles, and communications. However, the poor room temperature plastic deformation ability of commonly used magnesium alloys severely limits its application in engineering. Magnesium alloys composed of fine grains and a large number of near-spherical precipitates have superplastic deformation ability, and have beco...

AI Technical Summary

Problems solved by technology

At present, the commonly used preparation methods of superplastic magnesium alloys include: equal channel extrusion, spinning method, friction stir modification method and cumulative stack rolling, etc.; however, the above methods are mainly used to prepare small-sized samples for experiments, and it is difficult to achieve large-sized materials. Batch production, and the morphology of the precipitated phase in the prepared samples is mostly needle-like and prone to agglomeration

In addition, magnesium alloys with a high volume fraction of precipitated phases suffer from severe cracking during rolling, making it difficult to achieve industrialized rolling production.

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