Influence of heat treatment on microstructure and mechanical properties of as-cast Mg–8Li–3Al–2Zn–xY alloy with duplex structure
Influence of heat treatment on microstructure and mechanical properties of as-cast Mg–8Li–3Al–2Zn–xY alloy with duplex structure
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DOI：
10.1016/j.msea.2016.05.085
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发表时间：
2016-07
期刊：
影响因子：
6.4
通讯作者：
Jiong Zhao;L. Zhongquan;Wencai Liu;Jie Zhang;Liang Zhang;T. Ying;Guohua Wu
中科院分区：
文献类型：
--
作者：
Jiong Zhao;L. Zhongquan;Wencai Liu;Jie Zhang;Liang Zhang;T. Ying;Guohua Wu
本文首先研究了铸态Mg-8Li-3Al-2ZN-0.5Y合金在300℃~450℃固溶处理过程中的组织演变和力学性能，并分析了Y含量(0.5wt%~1.5wt%)对固溶处理后的合金时效软化的影响。结果表明，铸态Mg-8Li-3Al-2ZN-0.5Y合金主要由α-Mg、β-Li、Al2Y和AlLi相组成。随着铸态Mg-8Li-3Al-2ZN-0.5Y合金固溶温度从300℃升高到450℃，AlLi相逐渐分解，Al和Li原子逐渐溶解到基体中。试验合金的硬度、屈服强度和极限抗拉强度显著提高，但塑性相对降低。同时，室温时效处理后的Mg-8Li-3Al-2ZN-0.5Y合金在初始时效阶段有时效硬化现象，Y的加入有利于提高合金的热稳定性。此外，还系统地研究了所研究合金的断裂行为和强化机制。
In this study, the microstructure evolution and mechanical properties of as-cast Mg–8Li–3Al–2Zn–0.5Y alloy during solid solution treatment from 300 °C to 450 °C were firstly investigated, and then the effect of Y content (from 0.5 wt% to 1.5 wt%) on the age softening of solid solution treated Mg–8Li–3Al–2Zn alloy was also analyzed. The results show that the as-cast Mg–8Li–3Al–2Zn–0.5Y alloy mainly consists ofα-Mg,β-Li, Al2Y and AlLi phases. With the increase of solid solution temperature from 300 °C to 450 °C for as-cast Mg–8Li–3Al–2Zn–0.5Y alloy, the AlLi phase is decomposed and the atoms of Al and Li dissolve into the matrix gradually. The hardness, yield strength and ultimate tensile strength of the tested alloy are increased dramatically; however, the ductility is relatively decreased. Meanwhile, the room temperature aging treated Mg–8Li–3Al–2Zn–0.5Y has age hardening during initial time, and the addition of Y is helpful to the thermal stability of Mg–8Li–3Al–2Zn alloy. In addition, the fracture behavior and strengthening mechanism of the studied alloys were also investigated systematically.