稀土、锶复合添加对AM60镁合金组织和性能的影响  

Effects of Rare Earths and Strontium Composite Additions on Microstructure and Properties of AM60 Magnesium Alloy

作　　者：李双寿[1] 郑伟超[1] 汤彬[1] 曾大本[2] 

机构地区：[1]清华大学基础工业训练中心,北京100084 [2]清华大学机械工程系,北京100084

出　　处：《铸造》2007年第1期18-22,共5页Foundry

摘　　要：稀土、锶复合添加对AM60镁合金组织、力学性能和抗热裂性能的影响的研究结果表明,往AM60镁合金中添加稀土后,稀土与合金中的异质形核核心Al9Mn11相或Al(8Fe,Mn)5相反应生成Al-RE-Mn三元相,减少了合金熔体中异质形核核心的数目,从而引起了合金晶粒粗化。往AM60镁合金中复合添加稀土和锶后,锶能够消除稀土引起的晶粒粗化作用,减少晶粒粗化对合金力学性能和抗热裂性能的不利影响,从而提高合金的高温屈服强度,并消除稀土对合金抗热裂性能的恶化作用。The effects of rare earths and strontium composite additions on the microstructure, mechanical properties and hot cracking resistant property of AM60 magnesium alloy were investigated. The results show that when added into AM60 magnesium alloy, rare earths react with Al9Mn11 or Ale（ Mn, Fe ）5 phases which serve as the heterogeneous nuclei in the melt to form AI-RE-Mn ternary phases, and reduce the amount of heterogeneous nuclei in the melt, thus leading to the grain coarsening. When rare earths and strontium are compositely added into AM60 magnesium alloy, strontium can counteract the grain coarsening effect caused by rare earths addition and reduce the adverse influence of grain coarsening on the mechanical properties and hot cracking resistant property. As a consequence, it improves the yield strength at elevated temperatures and eliminates the decline of hot cracking resistant property caused by rare earths addition.

关 键 词：AM60镁合金 稀土 锶 晶粒大小 力学性能 热裂 

分 类 号：TG113[金属学及工艺—物理冶金]