Microstructures and mechanical properties of Mg–13Gd–5Er–1Zn–0.3Zr alloy
Microstructures and mechanical properties of Mg–13Gd–5Er–1Zn–0.3Zr alloy
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DOI：
10.1016/j.matdes.2014.01.058
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发表时间：
2014-06
影响因子：
8.4
通讯作者：
X. Zhang;Zhaohui Wang;W. Du;Ke Liu;Shu-bo Li
中科院分区：
文献类型：
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作者：
X. Zhang;Zhaohui Wang;W. Du;Ke Liu;Shu-bo Li
采用光学显微镜（OM）、扫描电镜（SEM）、X射线衍射（XRD）、能谱仪（EDS）和透射电镜（TEM）研究了Mg-13 Gd-5Er-1 Zn-0. 3 Zr合金的显微组织和力学性能。结果表明，Mg晶体的基面层错（SF）与（Mg，Zn）5（Gd，Er）相的析出同时存在。在733 K均匀化处理过程中，部分（Mg，Zn）5（Gd，Er）沉淀物溶解于基体中。此外，在733 K均匀化处理过程中，从基面层错中析出了一种新的层状14 H长周期堆垛有序（LPSO）结构。时效处理后，挤压态晶粒中析出不稳定的β′相。14 H-LPSO结构和β′相的共同存在使合金的力学性能得到了很大的提高。拉伸屈服强度和极限拉伸强度分别为338.8 MPa和410.9 MPa。
Microstructure and mechanical properties of the Mg–13Gd–5Er–1Zn–0.3Zr alloy were investigated by optimal microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS) and transmission electron microscopy (TEM) in the present investigation. The results suggested that the basal plane stacking faults (SF) of Mg crystal was present together with the precipitation of the (Mg,Zn)5(Gd,Er) phase. The parts of the (Mg,Zn)5(Gd,Er) precipitate were dissolved into the matrix during homogenization treatment at 733 K. In addition, a new kind of lamellar-shaped 14H long-period stacking-ordered (LPSO) structure was precipitated from the stacking faults of basal plane during homogenization treatment at 733 K. However, the unstable β′ phase was precipitated in the extruded grains after ageing treatment. The presence of both the 14H-LPSO structure and the β′ precipitate resulted in a great enhancement in mechanical properties. The values of the tensile yield strength and ultimate tensile strength were 338.8 MPa and 410.9 MPa, respectively.