Effect of yttrium on the twinning and plastic deformation of AE magnesium alloy under ballistic impact
Effect of yttrium on the twinning and plastic deformation of AE magnesium alloy under ballistic impact
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DOI：
10.1016/j.msea.2014.11.025
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发表时间：
2015-01
期刊：
影响因子：
6.4
通讯作者：
H. Asgari;A. Odeshi;J. Szpunar;Lunjie Zeng;E. Olsson;Dongyang Li
中科院分区：
文献类型：
--
作者：
H. Asgari;A. Odeshi;J. Szpunar;Lunjie Zeng;E. Olsson;Dongyang Li
在这项研究中，研究了钇对弹道冲击下AE42和AE44铸造镁合金的织构形成、显微组织演变和机械响应的影响。选定的应变率为 800 和 1100 s−1，测试是使用分体式霍普金森压力棒进行的。推测在高速撞击后，钇含量较低的样品中形成了较弱的基底织构。实验结果还表明，通过增加铸造AE合金中钇的浓度，冲击合金的强度、延展性和位错密度增加，但孪晶分数降低，这表明钇对孪晶的形核和长大具有有效影响。此外，据推测，孪晶相交处位错的积累导致了样品在冲击载荷条件下的开裂和断裂。
In this research, effect of yttrium on the texture formation, microstructural evolution and mechanical response of AE42 and AE44 cast magnesium alloys were investigated under ballistic impact. The selected strain rates were 800 and 1100 s−1and the tests were conducted using Split Hopkinson Pressure Bar. It was inferred that after high velocity impact, a weaker basal texture developed in the samples with lower content of yttrium. Experimental results also showed that by increasing the concentration of yttrium in the cast AE alloys, strength, ductility and dislocation density of the impacted alloys increased but, the fraction of twinning decreased, which indicate the effective influence of yttrium on the nucleation and growth of twins. Moreover, it was inferred that accumulation of dislocations at intersections of the twins led to the cracking and fracture of the samples under shock loading conditions.