Effects of Cu addition on microstructure and mechanical properties of as-cast magnesium alloy ZK60  

Cu元素对ZK60铸造镁合金显微组织和力学性能的影响（英文）

作　　者：朱红梅[1,2] 罗承萍[2] 刘江文[2] 焦东玲[2] 

机构地区：[1]南华大学机械工程学院,衡阳421001 [2]华南理工大学材料科学与工程学院,广州510640

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第3期605-610,共6页中国有色金属学报（英文版）

基　　金：Project(51201088)supported by the National Natural Science Foundation of China;Project(12C0324)supported by the Research Foundation of Education Bureau of Hunan Province,China;Project(2011XQD26)supported by Doctoral Scientific Research Foundation of University of South,China;Project([2011]76)supported by the Construct Program of the Key Discipline in Hunan Province,China

摘　　要：The effects of Cu addition on the microstructure and mechanical properties of the as-cast magnesium alloy ZK60 were investigated with optical microscope, SEM, TEM, XRD, EPMA and tensile tester. The mechanism by which the mechanical properties are affected by Cu addition was discussed. The results show that Cu can effectively eliminate the intragranular solute segregations in the alloy, and the grain size of the alloy is decreased considerably with increasing the Cu amount. A ternary eutectic phase MgZnCu with a face-centered cubic structure is identified in the Cu-bearing alloys, which predominantly distributes at the grain boundary and acts as the nucleation sites of microcracks during the plastic deformation process. It is also found that the tensile properties of the alloy firstly increase by the trace addition of 0.5%-1%Cu and then decrease by a further addition up to 2.0%.利用光学显微镜、扫描电子显微镜、透射电子显微镜、X-射线衍射仪、电子探针、拉伸测试仪研究 Cu元素的添加对铸态ZK60镁合金显微组织和力学性能的影响，并讨论了添加Cu改善合金拉伸性能的机制。结果表明，Cu可有效消除ZK60镁合金中存在的晶内偏析，随着Cu含量的增加，合金的晶粒尺寸得到明显细化。在含Cu镁合金中，出现了一种具有面心立方结构的MgZnCu三元共晶相，该相主要富集在晶界处且在合金发生塑性变形时成为微裂纹源。拉伸实验表明，当 Cu 添加量为0.5%～1%时，ZK60镁合金的力学性能得到改善，当添加量达到2%时，合金的力学性能下降。

关 键 词：ZK60 magnesium alloy Cu addition MgZnCu phase grain refinement mechanical properties 

分 类 号：TG136.1[一般工业技术—材料科学与工程]