Abstract Energy-dispersive X-ray spectroscopy (EDS) mapping has been performed to determine the distributions of the component atoms of η-Mg(Zn,Cu)2 precipitates in an Al-Mg-Zn-Cu aluminium alloy. High-angle annular dark-field scanning transmission electron microscopy (HAADF STEM) was concomitantly employed to recognize the configurations of atomic columns. Mg and Zn maps showed their alternating atomic columns. The Cu-map revealed that the Al matrix adjacent to the interfaces of (0001)η is segregated by Cu, giving an evidence of the effect of Cu additions on the precipitation and growth of η-Mg(Zn,Cu)2 precipitates. Furthermore, the elongated-hexagonal lattice defects located inside the zig-zag stacking configurations of (2 1 ¯ 1 ¯ 0)η are related to the Zn-depleted zones, which are presumably occupied by Mg atoms.

中文翻译：

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Al-Mg-Zn-Cu 合金中 η 析出物的原子分辨率能量色散 X 射线光谱图

摘要 已经进行了能量色散 X 射线光谱 (EDS) 映射，以确定 η-Mg(Zn,Cu)2 沉淀物在 Al-Mg-Zn-Cu 铝合金中的组成原子的分布。同时采用高角度环形暗场扫描透射电子显微镜 (HAADF STEM) 来识别原子柱的配置。Mg 和 Zn 图显示了它们交替的原子列。Cu-map 显示与 (0001)η 界面相邻的 Al 基体被 Cu 隔离，这证明了 Cu 添加对 η-Mg(Zn,Cu)2 沉淀物的沉淀和生长的影响。此外，位于 (2 1 ¯ 1 ¯ 0)η 之字形堆叠结构内的细长六边形晶格缺陷与 Zn 耗尽区有关，该区可能被 Mg 原子占据。