Atomic-scale study of nucleation of dislocations from fcc–bcc interfaces
Atomic-scale study of nucleation of dislocations from fcc–bcc interfaces
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DOI：
10.1016/j.actamat.2012.01.050
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发表时间：
2012-04
期刊：
影响因子：
9.4
通讯作者：
Ruifeng Zhang;Jian Wang;I. Beyerlein;A. Misra;T. Germann
中科院分区：
文献类型：
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作者：
Ruifeng Zhang;Jian Wang;I. Beyerlein;A. Misra;T. Germann
使用原子模拟，我们揭示了从一个低能量，原子平坦，不相干的面心立方界面与Kurdjumov-Sachs取向关系的滑移位错的成核的原子界面结构的作用。模拟了几种加载状态，系统地探讨了滑移系的选择。与传统的预期相反，优选的成核位点并不总是与预先存在的错配位错相关联，并且优选的滑移系统并不完全由施密德因子决定。在两个或多个几何上有利的系统中，激活的滑移系统取决于成核位点的结构。系统-位点组合使得成核事件后沉积在界面中的位错降低了界面能并具有相对较低的自能。这里建立的基本相关性适用于其他取向关系的界面，这些界面也是平坦的，并且具有空间不均匀的剪切阻力。
Using atomistic simulations, we reveal the role of the atomic interface structure on the nucleation of glissile dislocations from a low-energy, atomically flat, incoherent face-centered cubic–body-centered cubic interface with a Kurdjumov–Sachs orientation relationship. Several loading states are simulated to systematically probe the selection of slip systems. Contrary to conventional expectation, the preferred nucleation sites are not always associated with pre-existing misfit dislocations, and the preferred slip systems are not determined solely by the Schmid factor. Amongst the two or more systems that may be geometrically favored, the activated slip system depends on the structure of the nucleation site. The system–site combination is such that the dislocation deposited in the interface after the nucleation event lowers the interfacial energy and has a relatively low self-energy. The fundamental correlations established here apply to interfaces of other orientation relationships that are also flat and have spatially non-uniform shear resistance.