Effects Of Trace RE Addition On Mechanical Properties And Microstructures Of Mg-2Zn-3Cu Alloys After Extruded At Low Temperature

Magnesium alloys have broad application prospect in the automobile, electronics, aerospace and rail transportation and other fields, because of its density is small, high strength, high stiffness, good damping performance and the advantages of size stability, mechanical forming and electromagnetic shielding. But because of low plasticity, low intensity, and the difficult of deforming at low temperature, which restricted the magnesium alloy widely used. So how to improve the strength and plastic, reduce the deformation processing temperature of the magnesium alloy is a hotspot in the field of study of magnesium alloys. This experiment is to explore the mechanics properties and low temperature deformation microstructures of Mg-2Zn-3Cu-RE alloy, through the heat treatment process to improve the properties of alloy. Research has achieved the following conclusion:(1). Trace RE can significantly refine solid microstructure of Mg-2Zn-3Cu alloy, and reduced difference of ingot casting hardness cross section. But the effect is different with the different kinds of rare earth. The order for refining effect is Nd>MM>Y, for improving the uniformity of microstructure is MM>Nd>Y. Mg-2Zn-3Cu-0.4Nd is the alloy with the smallest cross section hardness difference, Mg-2Zn-3Cu alloy with Y is of high hardness.(2). Mg-2Zn-3Cu alloy and trace RE alloying Mg-2Zn-3Cu alloy can achieve low temperature of80℃extrusion.Mg-2Zn-3Cu alloy can hardly be strength by the deformation at low temperature, but trace RE alloying Mg-2Zn-3Cu alloy can be strength significantly The order of strength effect is Y>Nd>MM. Zr further improve strength of the low temperature extrusion material with Y and elongation. Cu significantly enhances the strengthen effect of alloys contained RE with low temperature deformation(3).80℃extrusion state Mg-2Zn-3Cu-0.4Y and Mg-2Zn-3Cu-0.4Y-0.6Zr alloy tensile mechanical properties Respectively are:Rm=365MPa, Rp0.2=340MPa, A=12%and Rm=369MPa, Rp0.2=352MPa, A=14%; (4). The strengthening effect of low temperature extrusion state Mg-2Zn-3Cu alloy and trace RE alloying Mg-2Zn-3Cu alloy after heat treatment is not significant while elongation increased after heat treatment.80℃extrusion Mg-2Zn-3Cu-0.4Y alloy T5state mechanical properties:Rm=364MPa, Rp0.2=352, A=17%...