Abstract

The influence of light element (C, N, O) impurities on the edge dislocation glide in fcc metals (Ni, Ag) is studied by molecular dynamics simulation. The introduction of impurity atoms is found to increase the dislocation glide threshold stress significantly, from 10 MPa in the pure metals at a temperature of 300 K to 1000–2000 MPa after the introduction of 10 at % impurity atoms. The increase in the threshold stress with the concentration of impurity atoms is shown to be caused by the Suzuki mechanism, i.e., the pinning of impurity atoms by the stacking fault between partial dislocations. The energies of binding of impurity atoms to stacking faults were determined for the metals under study. When temperature increases, the dislocation glide velocity in the pure metals decreases. After the introduction of impurity atoms, this dependence is reversed: the dislocation velocity increases gradually with temperature.

中文翻译：

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轻元素杂质对镍和银中边缘位错滑移的影响：分子动力学模拟

摘要

通过分子动力学模拟研究了轻元素（C，N，O）杂质对fcc金属（Ni，Ag）中边缘位错滑移的影响。发现引入杂质原子会显着增加位错滑移阈值应力，从纯金属在300 K的温度下的10 MPa增加到引入10 at％的杂质原子后的1000-2000 MPa。阈值应力随杂质原子浓度的增加表明是由Suzuki机理引起的，即，由于部分位错之间的堆垛层错而使杂质原子固定。对于所研究的金属，确定了杂质原子与堆垛层错的结合能。当温度升高时，纯金属中的位错滑移速度降低。引入杂质原子后，