High-toughness cast magnesium-rare earth alloy capable of being subjected to rapid high-temperature solution treatment and preparation method of high-toughness cast magnesium-rare earth alloy

Abstract

The invention discloses a high-toughness cast magnesium-rare earth alloy capable of being subjected to rapid high-temperature solution treatment and a preparation method of the high-toughness cast magnesium-rare earth alloy. The magnesium alloy comprises the following components in percentage by mass: 5.6-10.8% of Gd, 2.2-3.2% of Y, 0.1-0.4% of Zn, 0.1-0.4% of La, 0.3-0.7% of Zr, less than 0.2 wt.% of impurity elements Si, Fe, Cu and Ni, and the balance of Mg. The preparation method comprises the working procedures of material drying, magnesium melting, alloy element adding, refining, casting forming, heat treatment and the like. Through La element microalloying and subsequent heat treatment process optimization, the high-toughness cast magnesium-rare earth alloy capable of being subjected to rapid high-temperature solid solution treatment is obtained, the high-temperature solid solution time can be remarkably shortened, the solid solution treatment efficiency can be improved, and meanwhile it is guaranteed that the alloy has high strength and plasticity. The invention also provides a material basis for the implementation of the online continuous solution treatment process of the high-toughness cast magnesium-rare earth alloy.

Description

technical field [0001] The invention relates to a high-strength and toughness cast magnesium rare earth alloy capable of rapid high-temperature solid solution treatment and a preparation method thereof, belonging to the technical field of metal structural materials. Background technique [0002] As the lightest metal structural material, magnesium alloy has the advantages of high specific strength, specific stiffness, and good shock absorption, and is widely used in aerospace, transportation, 3C fields, etc. The high-temperature solution treatment + low-temperature aging treatment process is a typical heat treatment process for high-strength cast magnesium alloys, referred to as T6 treatment. For example, the high-strength cast magnesium rare-earth alloy EZ30Z (Mg-Nd-Zn-Zr-Ca) disclosed in the patent of "High-strength cast magnesium alloy containing rare earth and its preparation method" (patent number: CN200510030457.8), its conventional heat treatment process is: (525~540...

AI Technical Summary

Problems solved by technology

Although Mg-Gd cast magnesium alloys have high strength, they have low plasticity at room temperature, which makes it difficult to meet the high plasticity requirements in the aerospace field: for example, the standard tensile strength of VW103Z cast magnesium rare earth alloy is 300MPa, and the yield strength is 200MPa. The elongation is only 2.0%; the standard tensile strength of VQ132Z cast magnesium rare earth alloy is 350MPa, the yield strength is 240MPa, and the elongation is only 1.0%.

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