Mg-9Al-1Zn-(0-0.6)Sr镁合金铸态组织及晶粒细化研究  

An investigation of as-cast microstructure and grain refinement in Mg-9Al-1Zn-(0-0.6)Sr magnesium alloys

作　　者：吴璐[1] 潘复生[1,2] 杨明波[3] 程仁菊 汤爱涛[1] 

机构地区：[1]重庆大学国家镁合金工程技术研究中心,重庆400045 [2]重庆市科学技术研究院,重庆401123 [3]重庆理工大学材料科学与工程学院,重庆400054

出　　处：《功能材料》2014年第2期63-67,共5页Journal of Functional Materials

基　　金：科技部国际合作资助项目(2008DFR50040);国家自然科学基金资助项目(50725413);重庆科学技术委员会资助项目(CSTC,2011ggB50013,2011jjA50019,2011AC4119);重庆市教委资助项目(KJ120834);重庆大学研究生创新基金资助项目(CDJZR11130024)

摘　　要：对含Sr(0.05%~0.6%)AZ91铸态镁合金组织进行了观察,并且采用'边-边匹配'模型研究了其细化机制。结果表明,微量Sr对AZ91铸态组织有明显的晶粒细化效果,Sr含量为0.05%时细化效果最为显著。通过'边-边匹配'模型计算,得到[021]Al4Sr∥[1-1 0]Mg17Al12,(200)Al4Sr∥(332)Mg17Al12,表明微量Sr对AZ91镁合金铸态晶粒细化主要是Al4Sr相为Mg17Al12相的形成提供有效的异质形核核心,从而加速Mg17Al12相对α-Mg枝晶长大的阻碍作用。As-cast microstructure and grain refinement in the AZ9 1 magnesium alloys with different Sr contents （0,0.05%,0.1%,0.3% and 0.6wt%）were observed in this paper,and the grain refining mechanism was an-alyzed by using the calculation of “edge-to-edge”matching model.The results indicated that adding trace Sr to as-cast AZ91 alloy had obviously effects on grain refinement,thereinto with the addition of 0.05% Sr was the most remarkable.In addition,the [021]Al4Sr∥[1-1 0]Mg17 Al12 and （200）Al4Sr∥（332）Mg17 Al12 were calculated by u-sing “edge-to-edge”matching model,which can provide an evidence that the Al4 Sr phase was the effective het-erogeneous nucleant for the Mg17 Al12 phase probably.However,the mechanism of grain refinement of trace Sr effect on the as-cast microstructure of AZ9 1 magnesium alloy was the Al4 Sr phase provide heterogeneous nucle-ant for the Mg17 Al12 phase that accelerating the formation of Mg17 Al12 phase and then restricted the growth of α-Mg .

关 键 词：镁合金 AZ91 SR 晶粒细化 边-边匹配模型 

分 类 号：TG113.1[金属学及工艺—物理冶金]