Y-doped Mg alloy and preparation method thereof

Abstract

The invention discloses a Y-doped Mg alloy. The Y-doped Mg alloy is composed of Mg, Zn, Zr and Y and comprises, by mass, 4.9-5.5% of Zn, 0.16-0.19% of Zr, 2.9-3.2% of Y, and the balance Mg and inevitable impurities. A preparation method of the Y-doped Mg alloy comprises the steps of (1) preparation of alloy powder, specifically, adding ethyl alcohol to Mg-Zn-Zr powder and Y powder, adding zinc stearate, conducting vacuum pumping, and conducting ball milling to obtain the alloy powder; (2) sintering, specifically, feeding the alloy powder into a vacuum hot pressing sintering furnace, and conducting vacuum pumping, heating sintering and cooling to obtain an alloy billet; and (3) hot extrusion, specifically, conducting heat preservation, feeding the alloy billet into an extrusion die for extrusion and then obtaining the Y-doped Mg alloy. According to the Y-doped Mg alloy and the preparation method thereof, the rare earth element Y is subjected to solid solution to go into a Mg base body to promote formation of an alloy double-peak crystal structure, grain refinement, generation of high-melting-point hard phases and the like. On the premise of ensuring the strength, the toughness and plastic formability of the Mg alloy are improved, and a certain reference basis is provided for actual application of the Y-doped Mg alloy.

Description

technical field [0001] The invention relates to the technical field of alloy smelting, in particular to a magnesium alloy doped with yttrium and a preparation method thereof. Background technique [0002] Only by developing and applying lightweight and high-strength materials to realize the lightweight of industrial fields, aerospace and automobile manufacturing industries can we further realize the social needs of green environmental protection, energy saving and emission reduction. The Mg-Y alloy with light weight and high strength can significantly reduce its weight when used as a structural part, but the existing Mg-Y alloys are not widely used in the industrial field because the alloy itself has some defects: [0003] (1) Powder metallurgy process and technology: Magnesium is a metal element with very active chemical properties. When the temperature reaches a certain value, it can be combined with O 2 Chemical reactions occur, and even explosions may occur, so it is ve...

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Problems solved by technology

Because the conventional powder metallurgy method is affected by its complex process, high cost or poor quality of the billet, the powder metallurgy process system is not perfect, so in order to obtain high-performance magnesium-yttrium alloys, it is necessary to optimize the powder metallurgy process of magnesium-yttrium alloys. technology for systematic research

[0004] (2) It is difficult to have both low-density and high-strength properties of magnesium alloys: the strength and ductility of Mg-Zn-Zr alloys are low, and alloying elements are generally added to increase the strength of the alloy, but this method is in While improving the strength, it is often at the expense of the excellent plasticity and toughness of the alloy

[0005] (3) The tension / compression yield symmetry of magnesium yttrium alloy is poor: general magnesium alloy is used as a structural material, and during use, high tensile yield strength and low compressive yield strength limit the general application of magnesium yttrium alloy

[0006] (4) Poor corrosion resistance of magnesium yttrium alloy: the poor corrosion resistance of magnesium yttrium alloy is due to its active chemical properties, so when used in various environments, galvanic, local, intergranular and high temperature corrosion will occur, and it will also A series of problems such as stress corrosion cracking and corrosion fatigue will occur. The existence of these corrosion problems will inevitably affect the application effect and service life of magnesium-lithium alloys, and reduce its application range.

[0007] (5) The high temperature resistance of magnesium yttrium alloy is poor: when the general magnesium yttrium alloy is used for a long time, the temperature does not exceed 150 ℃

[0008] In summary, the ternary Mg-Zn-Zr alloy still has a series of problems such as low strength, poor corrosion resistance, and poor thermal stability that have not been resolved. In addition, the Mg-Zn-Zr alloy system is not perfect. After adding Y, the alloy Material properties have been significantly improved, so it is necessary to design and develop new Mg-Zn-Zr-Y alloy materials and alloy systems

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