Reducing the yield asymmetry in Mg-5Li-3Al-2Zn alloy by hot-extrusion and multi-pass rolling
Reducing the yield asymmetry in Mg-5Li-3Al-2Zn alloy by hot-extrusion and multi-pass rolling
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DOI：
10.1016/j.jma.2020.06.015
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发表时间：
2021-05-15
影响因子：
17.6
通讯作者：
Hu, Chenglu
中科院分区：
文献类型：
--
作者：
Li, Xiaoqiang;Ren, Liang;Hu, Chenglu
减少屈服不对称性对于变形镁锂合金来说是非常重要的问题。在本研究中，通过热挤压和573 K多道次轧制成功生产了Mg-5Li-3Al-2 Zn (LAZ532)合金。研究了LAZ532合金在不同轧制道次下的显微组织演变、力学性能和屈服不对称性降低。通过透射电镜观察显微组织表明，合金中存在少量超细AlMg4Zn11相和纳米Li3Al2相。随着轧制道次的增加，合金晶粒明显细化，综合力学性能显着提高。同时，它还表现出优异的拉伸和压缩屈服对称性（TYS/CYS约为1）。结果表明，弱{0001}基底层状织构、晶粒细化和Li元素的添加共同作用，可以有效提高屈服对称性。此外，根据理论分析，合金的屈服强度主要取决于LAGBs和HAGBs的强化贡献，其中HAGBs的强化效果对屈服强度的提高最大（约50%）。 (C) 2020 重庆大学。 Elsevier B.V. 代表科爱通讯有限公司提供的出版服务
Reducing the yield asymmetry is very important concern for wrought Mg-Li alloys. In this study, Mg-5Li-3Al-2 Zn (LAZ532) alloy was successfully produced by hot-extrusion followed by multi-pass rolling at 573 K. Microstructure evolution, mechanical properties and yield asymmetry reducing of LAZ532 alloys at different rolling passes were studied. By observing microstructure using transmission electron microscopy showed that a small amount of ultra-fine AlMg4Zn11 and nano Li3Al2 phases existed in the alloy. With the increasing of rolling passes, the grains of the alloys were obviously refined, and comprehensive mechanical properties were dramatically improved. Meanwhile, it also showed an excellent tension and compression yield symmetry (TYS/CYS was about 1). The results showed that the combined action of the weak {0001} basal lamellar texture, grain refinement and addition of Li element could effectively improve the yield symmetry. Furthermore, based on theoretical analysis, the yield strength in the alloys mainly depended on the strengthening contributions of LAGBs and HAGBs, and strengthening effect of HAGBs most (similar to 50%) to the yield strength improvement. (C) 2020 Chongqing University. Publishing services provided by Elsevier B.V. onbehalf of KeAi Communications Co. Ltd.