Sr对Mg-9Li-3Al合金显微组织及高温力学性能的影响  

Influence of Sr on Microstructures and High Temperature Mechanical Properties of Mg-9Li-3Al Alloys

作　　者：周伟[1] 彭晓东[1,2] 杨艳[1] 刘华堂[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400030

出　　处：《铸造》2011年第5期489-492,共4页Foundry

基　　金：重庆市重大科技攻关项目(CSTC;2006AA4012)

摘　　要：试验研究了Sr对Mg-9Li-3Al合金挤压态显微组织和高温力学性能的影响。通过显微观察可知,元素Sr富集在晶界处以Al4Sr化合物的形式存在,并对Mg-9Li-3Al合金中α相具有良好的细化作用。在373 K温度下进行拉伸试验的结果表明,当Sr含量为2.5%时合金强度达到183.7 MPa,但伸长率有所下降。一方面由于Sr在晶界处的吸附作用使晶粒细化;另一方面Al4Sr相提高了合金的强度和耐热性能,但大量Al4Sr的存在会割裂基体,使强度降低。The microstructures and high temperature mechanical properties of Mg-9Li-3Al alloys with addition of Sr were studied.It is found that after Sr is added,the Al4Sr is formed along the grain boundary in the Mg-9Li-3Al alloys,which has refining effect on α＋β phases.Mechanical tests are carried out at 373 K.The results show that the strength of as-extruded Mg-9Li-3Al-2.5Sr alloy increases（183.7 MPa）while the elongation decreased.It is clarified that the adsorption of Sr at the grain boundary refines the grains and the Al4Sr improves the tensile properties of the alloys,but too many Al4Sr particles will worsen the properties of the alloy.

关 键 词：锶 Mg-9Li-3Al合金 高温力学性能 

分 类 号：TG113[金属学及工艺—物理冶金]