Effects of Ge and Ag additions on quench sensitivity and mechanical properties of an Al-Zn-Mg-Cu alloy

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• 作者：Lianghua Lin^a ; ^b ; Zhiyi Liu^a ; ^b ; ^{liuzhiyi@csu.edu.cn} ; Song Bai^a ; ^b ; Yaru Zhou^a ; ^b ; Wenjuan Liu^a ; ^b ; Qing Lv^a ; ^b
• 关键词：Aluminum alloy ; Quench sensitivity ; Germanium ; Silver
• 刊名：Materials Science and Engineering: A
• 出版年：2017
• 出版时间：13 January 2017
• 年：2017
• 卷：682
• 期：Complete
• 页码：640-647
• 全文大小：2064 K
• 卷排序：682

文摘

The effects of Ge and Ag additions on quench sensitivity and mechanical properties of an Al–Zn–Mg–Cu alloy are investigated using tensile testing, hardness testing, differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Results show that a small addition of Ge significantly reduces quench sensitivity but decreases the ductility of Al–Zn–Mg–Cu alloy. In the Ge-added alloy, some large Mg2Ge particles at grain boundaries are observed, which causes a decrease in the alloy ductility. When Ag is added to Al–Zn–Mg–Cu-Ge alloy, a combination of low quench sensitivity and improved ductility is obtained. It is also found that Ag promotes more uniform decomposition of supersaturated solid solution during aging. As a result, the density of η′ precipitates increases both in the vicinity of grain boundaries and in grain interiors.