摘要
The microstructure and mechanical properties of the cast and extruded Mg-12Zn-1.5Er 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 refined due 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 the mechanical properties as the result of refined microstructure, the dispersed I-phase and the fine precipitates. The ultimate tensile strength and the yield tensile strength of this extruded alloy are 359 and 318 MPa, respectively.
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25μm;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359MPa和318MPa。
基金
Project(2007CB613706)supported by the National Basic Research Program of China
Project(PHR200906101)supported by Innovation Project for Talents of the Beijing Municipal Education Commission,China
Project(00900054R7001)supported by Innovation Project forTeam of the Beijing Municipal Education Commission,China
