Al and Zn strengthened Mg-Sn-RE-based high-toughness heat-resistant magnesium alloy

Abstract

The invention provides a cheap-light-rare-earth-containing Mg-Sn-RE-based high-toughness heat-resistant magnesium alloy. The chemical formula of the alloy is Mg-xSn-yRE-zM, wherein x is more than or equal to 2 weight percent and less than or equal to 8 weight percent, y is more than or equal to 0.5weight percent and less than or equal to 3 weight percent, z is more than or equal to 1 weight percent and less than or equal to 6 weight percent, RE represents La and Ce, M is one or two elements of Al and Zn, and the balance is Mg, a small amount of other elements and unavoidable impurities. The Al and the Zn have an obvious strengthening effect on the Mg-Sn-RE-based alloy, the alloy has the tensile strength of 270MPa and the elongation of about 15 percent in an as-cast state, and the steady-state creep rate of the alloy at the temperature of 175 DEG C under the pressure of 55MPa can be reduced to about 1.0*10<-7> / percent.s, which is far lower than that of an alloy junction (AJ) series heat-resistant magnesium alloy AJ52x; meanwhile, compared with the conventional rare-earth-containing heat-resistant magnesium alloy, the magnesium alloy has higher economy.

Description

technical field [0001] The invention belongs to the class of light metal magnesium alloy materials, and relates to the modification of the room-temperature performance and high-temperature performance of the magnesium alloy. Background technique [0002] Magnesium alloy, as the lightest metal structure material, will have a good application prospect in today's society where the task of energy saving and emission reduction is particularly heavy, because in aerospace, military industry, automobile and many other industries, weight reduction can reduce energy consumption. At the same time, magnesium alloy is known as the "green structural material" in the 21st century because of its light specific gravity, high specific strength and specific stiffness, strong damping, vibration and noise reduction capabilities, excellent liquid forming performance, and easy recycling. Although magnesium alloys have many advantages, there are also some disadvantages that limit their application...

AI Technical Summary

Problems solved by technology

However, according to patents CN 101476072A (a heat-resistant deformation magnesium alloy containing Ca and Sr), CN 1614064A (a high-strength creep-resistant magnesium alloy containing Ca and Si) and R. Ninomiya published in Acta metal. According to the report of Improved heat resistance of Mg-Al alloys by the Ca addition on Mater (Ca improves the creep performance of Mg-Al magnesium alloys), Mg-Al-Ca alloys are easy to form larger Mg 2 Phases of Ca and Al 2 The Ca phase deteriorates the mechanical properties of the alloy at room temperature, and the high Ca content makes it difficult to cast the alloy; there are coarse man-shaped Mg in the Mg-Al-Si alloy structure 2 The Si phase seriously endangers its mechanical properties, so that it can only be formed under the rapid cooling die-casting process; Mg-Al-Sr alloys such as AJ52 and AJ62 have high requirements for melting and pouring temperatures, and die-casting is difficult, and in ordinary gravity casting The tensile strength of the AJ52 alloy is only about 150MPa, and the elongation is only about 6%.

[0005] To sum up, the heat-resistant magnesium alloys currently developed have disadvantages such as high economic cost, demanding forming process requirements, especially unsatisfactory room temperature performance, etc., which limit the application of magnesium alloys to varying degrees.

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