Revealing the deformation mechanisms for room-temperature compressive superplasticity in nanocrystalline magnesium
Revealing the deformation mechanisms for room-temperature compressive superplasticity in nanocrystalline magnesium
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DOI：
10.1016/j.mtla.2020.100731
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发表时间：
2020-06-01
期刊：
影响因子：
3.4
通讯作者：
Schoenung, Julie M.
中科院分区：
文献类型：
--
作者：
Wang, Xin;Jiang, Lin;Schoenung, Julie M.
通过对工业纯Mg粉末颗粒进行低温研磨然后进行放电等离子烧结处理的块体纳米晶（NC）Mg在室温下表现出>120%的压缩应变。在10（-4）到10（-1）s（-1）应变速率范围内的压缩试验显示出类似于0.17的应变速率敏感性（m）。显微组织观察表明，晶界迁移伴随着超大塑性变形，沿着变形动力学、变形织构和位错结构分析表明，NC Mg优异的压缩塑性主要来源于晶界介导的变形机制和基底滑移主导的位错滑移。
Bulk nanocrystalline (NC) Mg processed by cryomilling of commercially pure Mg powder particles followed by spark plasma sintering exhibits a compressive strain >120% at room temperature. Compressive tests at strain rates ranging from 10(-4) to 10(-1) s(-1) reveal a strain rate sensitivity (m) of similar to 0.17. Microstructural investigation reveals grain boundary migration accompanied with the ultra-large plastic deformation, which, along with the analysis of the deformation kinetics, deformation texture and dislocation structure, suggests that the excellent compressive plasticity in NC Mg mainly originates from grain boundary meditated deformation mechanisms and basal slip-dominated dislocation glide.