Hydrogen-enhanced local plasticity in aluminum:: An ab initio study
Hydrogen-enhanced local plasticity in aluminum:: An ab initio study
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DOI：
10.1103/physrevlett.87.095501
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发表时间：
2001-08-27
影响因子：
8.6
通讯作者：
Kaxiras, E
中科院分区：
文献类型：
--
作者：
Lu, G;Zhang, Q;Kaxiras, E
采用从头计算确定参数的Peierls-Nabarro模型研究了含H和不含H杂质Al的位错核性质。我们发现，H不仅促进了位错从裂纹尖端发射，而且显著提高了位错的迁移率，导致裂纹尖端前方材料的宏观软化和变薄。我们观察到氢原子与位错核之间有很强的结合，其结合能取决于位错的性质。这种依赖关系通过抑制位错交叉滑移和提高滑移平面度直接影响Al的力学性能。
Dislocation core properties of Al with and without H impurities are studied using the Peierls-Nabarro model with parameters determined by ab initio calculations. We find that H not only facilitates dislocation emission from the crack tip but also enhances dislocation mobility dramatically, leading to macroscopically softening and thinning of the material ahead of the crack tip. We observe strong binding between H and dislocation cores, with the binding energy depending on dislocation character. This dependence can directly affect the mechanical properties of Al by inhibiting dislocation cross-slip and developing slip planarity.