Reinforced magnesium-lithium alloy of long-period structure and preparation method of reinforced magnesium-lithium alloy

Abstract

The invention provides a reinforced magnesium-lithium alloy of a long-period structure and a preparation method of the reinforced magnesium-lithium alloy. The magnesium-lithium alloy is composed of, by weight percentage, 11-16% of Li, 1-5% of Y, 0.2-2% of Zn, 0-0.6% of Zr and the balance Mg and inevitable impurities, wherein the total amount of Si, Fe, Cu and Ni is less than 0.02%. The preparation method of the magnesium-lithium alloy comprises the steps of smelting under the atmospheric environment and thermal treatment in a common furnace, wherein the smelting process comprises the steps of drying materials, smelting magnesium, adding Y, adding Zn, adding Zr, adding Li, performing refining and performing casting. Double-stage solution treatment is mainly adopted in the thermal treatment process, that is, 300-400 DEG C solution treatment is conducted for 2-10 h, then 200-300 DEG C solution treatment is conducted for 2-6 h, and the cast alloy with the LPSO structural phase is obtained through phase transformation. According to the reinforced magnesium-lithium alloy and the preparation method, the Y element and the Zn element are added to the magnesium-lithium alloy, the LPSO structure phase is introduced into a magnesium-lithium alloy substrate, and the cast magnesium-lithium alloy material with the low density, high strength and good thermal resistance is prepared.

Description

technical field

[0001] The technical field of metal materials of the present invention, in particular, relates to a magnesium alloy and a preparation method thereof, in particular to a long-period structurally reinforced magnesium-lithium alloy added with Zn, Y and Zr elements and a preparation method thereof. Background technique

[0002] Magnesium-lithium alloy is currently the lightest metal structure material in engineering applications, with a density of 1.35~1.65g / cm 3 Between, significantly lower than the density of ordinary magnesium alloys (about 1.8g / cm 3 ).

[0003] Since Li has a body-centered cubic (bcc) structure, the addition of Li can make the lattice axis ratio of Mg with a hexagonal close-packed (hcp) structure ( c / a ) value becomes smaller, and as the Li content increases to a certain extent, the alloy structure transforms into a bcc structure. According to the Mg-Li binary phase diagram, when the Li content is below 5.7wt%, the alloy is α -Mg (soli...