Method for preparing magnesium alloy

Abstract

The invention provides a method for preparing a magnesium alloy. The method comprises the following steps of: a) performing high-energy ball milling on magnesium silicide nano powder, zinc powder, aluminum powder and magnesium powder for 1 to 2 hours to obtain mixed powder, wherein the mixed powder comprises 2.2 to 3.6 weight percent of magnesium silicide, 0.5 to 1.5 weight percent of zinc, 4.5 to 5.5 weight percent of aluminum and 90.5 to 91.9 percent of magnesium; b) pressing the mixed powder to form a blank; and c) heating the blank under the protection of inert gas at the temperature of between 420 and 450 DEG C, preserving the heat for 30 to 50 minutes, extruding after heating, performing water cooking on the extruded blank, and thus obtaining the magnesium alloy. The magnesium alloyprepared by directly adding the magnesium silicide nano powder into the raw materials and adopting the method of combining high-energy ball milling for preparing the powder and hot extruding has fineand uniform microstructure, reinforcing phase particles are uniformly distributed in the matrix structure, and the room temperature mechanical property of the magnesium alloy is improved.

Description

technical field [0001] The invention relates to the technical field of metal materials, in particular to a preparation method of a magnesium alloy. Background technique [0002] Magnesium alloy is an alloy composed of magnesium as the base and adding other elements. It is the third important metal structure material after steel and aluminum alloy. Due to the advantages of light weight, high specific strength, high specific stiffness, vibration damping, good electromagnetic shielding and radiation resistance, magnesium alloys play an important role in the fields of automobiles, electronic appliances, transportation, aerospace and national defense. role. [0003] Ordinary magnesium alloys have poor high-temperature mechanical properties. When the temperature rises, its strength decreases greatly, so it is difficult to use it at high temperature for a long time. Improving the high-temperature mechanical properties of magnesium alloys has been an important topic in magnesium a...

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Problems solved by technology

[0004] The microstructure of the Mg-Al-Si series heat-resistant magnesium alloy prepared by casting method in the prior art is coarse, and the Mg 2 The nucleation and growth process of the Si phase is difficult to control, resulting in the formation of Mg 2 The Si phase is large in size and appears in the shape of a thick Chinese character block, which leads to the unsatisfactory mechanical properties of this alloy at room temperature. The strength at room temperature is only about 240MPa, which is difficult to meet the continuous demand of modern industry for heat-resistant magnesium alloy materials.

[0005] Starting from the powder, the method of combining mechanical pulverization and powder metallurgy sintering is a common method for preparing high-performance alloy materials. Although the method of combining these two preparation technologies can control the microstructure of magnesium alloys, there are still Mg 2 The technical problem that the Si phase nucleation and growth process is not easy to control makes the generated Mg 2 The size of the Si phase is relatively large, appearing in the shape of a thick Chinese character block, and the use of powder metallurgy sintering technology will cause the oxidation of metal magnesium, so that a large amount of oxides are included in the alloy, which greatly affects the mechanical properties of the magnesium alloy

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