High-strength heat-resistant magnesium alloy and smelting and heat treatment methods thereof

Abstract

The invention relates to the technical field of magnesium alloy material manufacturing, in particular to a high-strength heat-resistant magnesium alloy and smelting and heat treatment methods thereof.The high-strength heat-resistant magnesium alloy is prepared from a magnesium-rare earth intermediate alloy, a magnesium-zirconium intermediate alloy and a magnesium ingot, calculating in mass fraction, impurity elements are less than 0.022%, zirconium is 0.4-0.6%, rare earth elements are 8.2-10.5%, and the balance is Mg. The high-strength heat-resistant magnesium alloy has good aging precipitation strengthening and solid solution strengthening effects, has the characteristics of good casting performance and good comprehensive performance, and can meet the technical requirements of weapon systems and aircraft shell castings.

Description

technical field [0001] The invention relates to the technical field of magnesium alloy material production, in particular to a high-strength heat-resistant magnesium alloy and a melting and heat treatment method thereof. Background technique [0002] Defects such as insufficient strength, poor heat resistance and poor corrosion resistance have seriously hindered the pace of magnesium alloys replacing aluminum alloys and other materials in aerospace, military and other industries. Rare earth elements, especially Y, Nd, etc., play a significant role in improving the strength, heat resistance, and corrosion resistance of magnesium alloys, such as WE54 and WE43. [0003] Nowadays, rare earth magnesium alloys have good room temperature, high temperature mechanical properties and corrosion resistance, and have good application prospects; but the high cost of rare earth magnesium alloys seriously limits its wide application, especially in civilian applications. Moreover, heavy rar...

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Problems solved by technology

[0004] Patent No. CN201610301346.4 discloses a Mg-Gd-Y-Zr-Nd magnesium alloy, and at the same time discloses that "after melting the magnesium ingot, adding the magnesium-rare earth master alloy and the magnesium-zirconium master alloy separately, And the magnesium-rare earth master alloy is added in batches at a temperature of 780-800°C to increase the fluidity of the master alloy; combined with stirring during the addition, the alloy melt in the melting furnace can achieve convection diffusion and eddy current The combination of diffusion and atomic diffusion ensures the uniform distribution and mixing of alloy elements; combined with the addition of solvent, the solvent can be fully contacted and the effect of slag removal is improved. Another focus of this program is to provide a A smelting structure consisting of a gas supplier, a power source rotor, a cover plate, a draft tube, a melting furnace, an impeller, and a solvent supplier, wherein the gas supplier communicates with the tail of the power source through a gas supply pipe; the front end of the power source is connected to the rotor Connection; the other end of the rotor is connected to the impeller and extends into the draft tube; the gas supply pipe extends from the tail of the power source and passes through the center of the rotor to be linked with the impeller; the outlet end of the solvent supplier extends to the melting furnace The guide tube is set in the melting furnace, and the cover plate is covered on the top of the melting furnace. Although the mechanical properties of the alloy can be improved by using this scheme, the corrosion resistance of the magnesium alloy is still not satisfactory.

[0005] In addition, the current Mg-Gd-Y-Zr-Nd magnesium alloys are all smelted, cast into ingots, homogenized and annealed, then forward hot extruded with a large extruder, extruded into rods for aging Processing, and then extruding the residues of impurities and the presence of other alloy phases in the manufacturing process of magnesium alloys are prone to corrosion behaviors such as galvanic corrosion, pitting corrosion and filiform corrosion, so surface coating, laser treatment, friction stir processing, etc. are often used Technology improves the corrosion resistance of traditional cast-formed magnesium alloys, which directly leads to longer processing processes

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