Microstructure and yield phenomenon of an extruded Mg-Y-Cu alloy with LPSO phase
Microstructure and yield phenomenon of an extruded Mg-Y-Cu alloy with LPSO phase
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DOI：
10.1016/j.jre.2022.01.011
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发表时间：
2023-03-11
影响因子：
4.9
通讯作者：
Ding, Xiangdong
中科院分区：
文献类型：
--
作者：
Bi, Guangli;Zhang, Niuming;Ding, Xiangdong
首次报道了挤压 Mg-6.8Y-2.5Cu 合金的屈服现象，并研究了相应的微观结构。铸造合金主要由a-Mg、18R长周期叠层序(LPSO)相、共晶相(Mg20Cu4Y1)和Mg2Cu相组成。在均质化过程中，枝晶晶界处的 18R LPSO 相转变为晶粒内部的 14H LPSO 相。挤压后，均质合金晶粒尺寸显着细化至～3.69 mm，第二相明显破碎并沿挤压方向分布。挤压合金的室温拉伸测试曲线表明，随着应变速率的增加，合金的屈服强度和极限抗拉强度增加，而伸长率降低。有趣的是，随着应变率的增加，屈服平台形成并逐渐降低。屈服现象与位错倍增以及可动位错与溶质原子之间的相互作用有关。 (c) 2022 由 Elsevier B.V. 代表中国稀土学会出版。
A yield phenomenon was firstly reported in an extruded Mg-6.8Y-2.5Cu alloy and the corresponding microstructure was also investigated in this work. The cast alloy is mainly composed of a-Mg, 18R long period stacking order (LPSO) phase, eutectic phase (Mg20Cu4Y1), and Mg2Cu phase. The 18R LPSO phase at the dendritic grain boundary transforms into the 14H LPSO phase in the grain interior during ho-mogenization. After extrusion, the grain size of the homogenized alloy is remarkably refined to-3.69 mm and the second phase is significantly broken and distributed in the extrusion direction. Tensile testing curves of the extrude alloy at room temperature indicate that the yield strength and ultimate tensile strength increase while the elongation of the alloy decreases with increasing strain rate. Interestingly, a yield plateau forms and gradually decreases with increasing strain rate. The yield phenomenon is related to the dislocation multiplication and the interaction between the movable dislocations and solute atoms. (c) 2022 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.