摘要
锑和稀土均有细化Mg 9%Al 0 4%Zn合金铸态组织的作用,而且锑和稀土的同时加入,复合细化效果更显著。锑与合金中的镁元素形成短棒状的金属间化合物Mg3Sb2,稀土与合金中的铝元素形成片状金属间化合物Al11La3和Al11Ce3。各相在α Mg晶粒内和晶界均有分布。单独加入锑或稀土时对该合金的铸态室温力学性能基本没有影响,但同时添加0 8%RE和0 4%Sb时,合金的铸态室温力学性能显著提高。与Mg 9%Al 0 4%Zn合金相比,添加0 8%RE和0 4%Sb合金的铸态拉伸强度σb提高了33%,伸长率δ提高了70%。铸态Mg 9%Al 0 4%Zn 0 4%Sb 0 8%RE拉伸断口具有明显的塑性变形特征。
Antimony and rare earth were added into cast Mg9%Al04%Zn alloy .The ascast microstructure and ambient tensile properties of different cast magnesium alloys were studied. The results show that both antimony and rare earth can refine the ascast microstructures of Mg9%Al04%Zn alloy. When rare earth and antimony were added together, a much better refining effect was observed. Rare earth reacts with aluminum element in magnesium alloy and forms pieceshaped compound Al11RE. Antimony reacts with magnesium element forms rodshaped compound Mg3Sb2.These compounds distribute both in αMg dendrites and at grain boundaries. Moreover, a remarkable effect of adding antimony and rare earth alone on the cast mechanical properties of the alloy were not observed, but when 08%RE and 04%Sb were added together into Mg9%Al04%Zn alloy, the ascast mechanical properties at ambient temperature were improved dramatically. Compared with Mg9Al04Zn alloy, the ultimate tensile strength σb of the modified alloy was improved by 33 percent and the elongation rate δ was improved by 70 percent and an apparent ductile deformation feature can be observed on the fracture surface of tensile sample by using scanning electronic microscopy.
出处
《铸造》
CAS
CSCD
北大核心
2002年第11期690-694,共5页
Foundry
关键词
镁合金
显微组织
力学性能
锑
稀土
magnesium alloy
ascast microstructure
mechanical properties
antimony
rare earth
