The relation between ductility and stacking fault energies in Mg and Mg-Y alloys
The relation between ductility and stacking fault energies in Mg and Mg-Y alloys
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DOI：
10.1016/j.actamat.2012.02.006
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发表时间：
2012-04-01
期刊：
影响因子：
9.4
通讯作者：
Raabe, D.
中科院分区：
文献类型：
--
作者：
Sandloebes, S.;Friak, M.;Raabe, D.
利用透射电子显微镜和密度泛函理论研究了Mg-Y合金室温塑性比纯Mg提高的机制。这两种方法都显示出随着Y的加入，本征层错I-1能（I-1 SFE）显著降低。不同的竞争变形机制（基底，棱柱，锥体滑移）的相对激活的SFE的影响进行了讨论。从这个分析中，我们提出了一个关键的机制，解释了从六方密排镁的主要基础滑移到固溶体Mg-Y合金的基础加锥体滑移的转变。该机制的特征在于< c + a >位错的增强成核，其中本征层错I-1（ISF 1）充当< c + a >位错的异质源。可能的电子和几何原因的SFE的取代Y原子的修改被确定和讨论。(C)2012 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The underlying mechanisms that are responsible for the improved room-temperature ductility in Mg-Y alloys compared to pure Mg are investigated by transmission electron microscopy and density functional theory. Both methods show a significant decrease in the intrinsic stacking fault I-1 energy (I-1 SFE) with the addition of Y. The influence of the SFE on the relative activation of different competing deformation mechanisms (basal, prismatic, pyramidal slip) is discussed. From this analysis we suggest a key mechanism which explains the transition from primary basal slip in hexagonal close-packed Mg to basal plus pyramidal slip in solid solution Mg-Y alloys. This mechanism is characterized by enhanced nucleation of < c + a > dislocations where the intrinsic stacking fault I-1 (ISF1) acts as heterogeneous source for < c + a > dislocations. Possible electronic and geometric reasons for the modification of the SFE by substitutional Y atoms are identified and discussed. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.