研究铸造及挤压Mg-12zn-1.5Er合金的显微组织及力学性能.结果表明:铸造Mg-12zn-1.5Er合金中的I相在挤压过程中被破碎,并且动态再结晶伴随着挤压过程发生,导致合金组织进一步细化.合金的晶粒为等轴晶,其平均晶粒尺寸为2～5μm;并且观察到大量的纳米级颗粒在动态再结晶晶粒中析出;与铸造合金相比,挤压合金的力学性能明显提高,这是因为组织细化、准晶强化及纳米级颗粒的析出强化;挤压合金的抗拉强度、屈服强度分别为359 MPa和318 MPa.%The microstructure and mechanical properties of the cast and extruded Mg-12Zn-l.5Er alloys were investigated. The I-phase observed in the cast Mg-12Zn-1.5Er alloy was broken during hot extrusion. The microstructure of the alloy was refinedue to the dynamic recrystallization, and the equiaxed grains have size in the range of 2-5 μm. Moreover, a great deal of nano-scale particles precipitate in the recrystallized grains. Compared with the cast one, the extruded alloy shows a great improvement on th mechanical properties as the result of refined microstructure, the dispersed/-phase and the fine precipitates. The ultimate tensile strength and the yield tensile strength of this extruded alloy are 359 and 318 MPa, respectively.
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