Effects of yttrium and strontium additions on as-cast microstructure of Mg-14Li-1Al alloys  

Y和Sr的添加对Mg-14Li-1Al合金铸态组织的影响(英文)

作　　者：李瑞红[1,2] 潘复生[1,2] 蒋斌[1,2] 殷恒梅[1,2] 刘婷婷[1,2] 

机构地区：[1]重庆大学国家镁合金工程技术研究中心,重庆400044 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第4期778-783,共6页中国有色金属学报（英文版）

基　　金：Project(50725413)supported by the National Natural Science Foundation of China;Project(2010CSTC-BJLKR)supported by Chongqing Science and Technology Commission, China;Project(CDJXS10132203)supported by the Fundamental Research Funds for the Central Universities,China

摘　　要：Mg-14Li-1Al （LA141）, LA141-0.3Y, LA141-0.3Sr, and LA141-0.3Y-0.3Sr alloys were prepared in an induction furnace in the argon atmosphere. The microstructures of these alloys were investigated through scanning electron microscope （SEM）, X-ray diffractometer （XRD） and energy dispersive spectrometer （EDS）. The results show that yttrium and/or strontium additions produce a strong grain refining effect in LA141 alloy. The mean grain sizes of the alloys with addition of Y and/or Sr are reduced remarkably from 600 to 500, 260, 230 μm, respectively. Al 2 Y, Al 4 Sr and Mg 17 Sr 2 phases with different morphologies are verified and exist inside the grain or at the grain boundaries, thus possibly act as heterogeneous nucleation sites and pin up grain boundaries, which restrain the grain growth.在氩气保护气氛下,熔炼Mg-14Li-1Al(LA141),LA141-0.3Y、LA141-0.3Sr和LA141-0.3Y-0.3Sr合金。通过扫描电镜(SEM)、X射线衍射(XRD)和能谱分析研究这几种合金的组织。结果表明:单独添加Y或Sr或复合添加Y和Sr,对LA141的组织细化有明显的效果;添加Y,Sr,和复合添加Y和Sr的LA141合金的晶粒尺寸从原始尺寸600μm分别减小到500、260和230μm;不同形貌的Al2Y,Al4Sr和Mg17Sr2相存在于晶粒内部或晶界处,提供了异质形核质点、阻碍了晶界的滑移,从而抑制了晶粒的长大。

关 键 词：Mg-14Li-1Al alloy microstructure grain refinement second phase 

分 类 号：TG292[金属学及工艺—铸造]