Transmission electron microscopy investigation and interpretation of the morphology and interfacial structure of the ɛ′‐Mg54Ag17 precipitates in an Mg–Sn–Mn–Ag–Zn alloy
Transmission electron microscopy investigation and interpretation of the morphology and interfacial structure of the ɛ′‐Mg54Ag17 precipitates in an Mg–Sn–Mn–Ag–Zn alloy
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DOI：
10.1107/s1600576714018913
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发表时间：
2014-10
影响因子：
6.1
通讯作者：
Xuefei Huang;Zhang-Zhi Shi;Wen-Zheng Zhang
中科院分区：
文献类型：
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作者：
Xuefei Huang;Zhang-Zhi Shi;Wen-Zheng Zhang
用透射电镜研究了峰时效Mg-Sn-Mn-Ag-Zn合金中析出物的形貌和界面结构。一个典型的' -Mg54Ag17相具有(0001)α习惯面和3对侧面，其中2对侧面取向不合理。每个优选界面的方向垂直于连接两个相邻的不同相衍射点的矢量（Δg）。利用约束重合点格（CCSL）模型，根据界面上的匹配程度来解释界面取向。利用二次CCSL （II-CCSL）模型和二次o晶格模型预测了不合理面中详细的阶梯结构和侧面的位错构型。计算得到的阶地/壁架和位错构型与高分辨率透射显微镜观察结果吻合较好。
The morphology and interfacial structure of the ∊′-Mg54Ag17 precipitates in a peak-aged Mg–Sn–Mn–Ag–Zn alloy have been investigated using transmission electron microscopy. A typical ∊′-Mg54Ag17 precipitate exhibits a (0001)α habit plane and three pairs of side facets, with two major pairs of facets being in irrational orientations. The orientation of each preferred interface is normal to a vector connecting two adjacent diffraction spots from different phases (Δg). Using the constrained coincidence site lattice (CCSL) model, the interface orientations have been interpreted according to the degree of matching on the interfaces. The detailed stepped structures in the irrational facets and dislocation configurations in the side facets have been predicted using the secondary CCSL (II-CCSL) and the secondary O-lattice model. Both the calculated terrace/ledge and dislocation configurations in side facets are in good agreement with the high-resolution transmission microscopy observations.