Mn元素在Mg-Zn-Mn合金中演变形式和作用的研究  

The Evolution and Effect of Mn Element in Mg-Zn-Mn Alloy

作　　者：张丁非[1,2] 石国梁[1] 赵霞兵[1] 齐福刚[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]国家镁合金材料工程技术研究中心,重庆400044

出　　处：《材料导报》2011年第18期1-5,10,共6页Materials Reports

基　　金：国家973重大基础研究项目(2007CB613700);国家杰出青年科学基金(50725413);科技部国际合作项目(2010DFR50010;2008DFR50040);重庆市科委项目(CSTC2009AB4008;2010CSTC-HDLS);中央高校基本科研业务费资助(CDJXS10132202)

摘　　要：利用透射电子显微镜(TEM)研究了Mg-6%(质量分数,下同)Zn-1%Mn(ZM61)镁合金中Mn在不同状态下的存在形式和作用。结果表明,铸态组织中大多数Mn固溶于基体中;均匀化处理以后,组织中析出少量细小的α-Mn颗粒;挤压和固溶时大部分Mn以形状规则的α-Mn颗粒的形式析出,主要有3种形态,即规则多边形(以六边形为主)、球状和棒状。通过高分辨透射电子显微分析发现,α-Mn颗粒与α-Mg基体之间存在共格界面关系((1010)α-Mg//(301)α-Mn,[1216]α-Mg//[12 3]α-Mn)。研究还发现α-Mn颗粒可以作为时效过程中MgZn2相的异质形核核心,但依附α-Mn颗粒形核的MgZn2相都较粗大。根据二维晶格错配度"Bramifit模型"计算得出,当α-Mn颗粒与MgZn2之间存在位向关系((200)α-Mn//(1010)MgZn2,[012]α-Mn//[1213]MgZn2)时,二者之间的晶格错配度仅为2.14%,且高分辨显微分析也发现α-Mn颗粒(200)面与MgZn2的(1010)呈共格关系。The form and effect of Mn in Mg-6wt%Zn-1wt%Mn（ZM61） alloy were investigated by transmission electron microscopy（TEM）. The results show that most Mn soluted in matrix in as-cast microstructure; a small amount of fine Mn dispersoids were formed during homogenization treatment; the majority of Mn precipitated as regular shape Mn dispersiods after solution treatment, the main shape of these Mn particles are regular polygon, spherical and rod-like; the form of Mn existence in as-aged samples is similar with those solution treated samples. High resolution transmission microscopy observation and fast fourier transform analysis revealed that there are cohenrent interface relationship between α-Mn and a-Mg, it is （10T0）.-Mg//（301）α-Mn, [-T216-]α-Mg//[12 3]α-Mn. According to the classical two-dimensional lattice mismatch model ＂Bramifit＂ it can be calculated that the lattice misfit between orMn and MgZnz is only 2. 14%, when their orientation relationship is （200）α-Mn//（10T0）MgZn2, [012-]α-Mn//[-1213]MgZn. Therefore, α- Mn particles can act as heterogeneous nucleas for MgZn2 phase during aging, but the MgZne particles are always coarser than those that dont＇t nueleate on α-Mn particles.

关 键 词：Mg-6%Zn-1%Mn α-Mn颗粒界面关系 晶格错配度 异质形核 

分 类 号：TG146.2[一般工业技术—材料科学与工程]