Gd对真空压铸Mg-Al合金组织性能的影响  

Effect of Gd on Microstructure and Mechanical Properties of Vacuum Die Cast Mg-Al Alloys

作　　者：吴伟[1] 代丽[1] 车欣[1] 陈立佳[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《铸造》2014年第5期449-453,共5页Foundry

基　　金：辽宁省教育厅科学技术研究项目(L2012038)

摘　　要：通过显微组织分析、X射线衍射分析、扫描电镜分析及拉伸性能测试,研究了稀土元素Gd含量对真空压铸Mg-Al镁合金组织和力学性能的影响。显微组织分析结果表明,随Gd含量的增加,合金的显微组织发生细化,β相由连续网状分布演化成断续网状分布,共晶组织数量减少,但稀土化合物相发生粗化。拉伸性能测试表明,时效处理可提高合金的拉伸性能,且随着Gd含量增加,压铸态和时效态合金的抗拉强度和屈服强度均呈现先提高后降低的趋势。拉伸断口形貌观察可见大量韧窝和解理台阶,合金表现为韧性-脆性混合断裂特征。The effect of Gd on the microstructures and mechanical properties of vacuum die cast Mg-Al alloys was investigated by means of OM, XRD, SEM and tensile test. The microstructure analysis shows that the microstructures of magnesium alloys get refined, the morphology of β phase transform from continuously netlike into discontinuous one, and the quantity of eutectic structure decreases with increasing the Gd content. However, the coarsening of RE containing compound phase occurs. The results of tensile test show that the aging treatment can enhance the tensile properties. Both tensile strength and yield strength of die cast and aged alloys increase firstly and then decrease with increasing the Gd content. The cleavage steps and dimples are observed on the tensile fracture surfaces, and the alloys exhibit the mixed brittle and ductile fracture.

关 键 词：MG-AL合金 显微组织 力学性能 稀土元素Gd 

分 类 号：TG249.2[金属学及工艺—铸造]