Dislocation—Obstacle Interactions at Atomic Level in Irradiated Metals
Dislocation—Obstacle Interactions at Atomic Level in Irradiated Metals
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DOI：
10.1177/1081286508092615
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发表时间：
2009-01
影响因子：
2.6
通讯作者：
D. Bacon;Y. Osetsky
中科院分区：
文献类型：
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作者：
D. Bacon;Y. Osetsky
高能原子粒子辐照金属产生纳米级缺陷团簇，如空洞、位错环、层错四面体和辐照诱导析出物。它们是位错滑移的障碍，可以引起屈服、流动应力和塑性的实质性变化。原子尺度的计算机模拟能够提供障碍结构、施加的应力、应变率和温度如何影响这些效应的细节。描述了位错与障碍物相互作用模型的一些最新结果。重点研究了位错与体心立方金属铁中的空洞、铜的析出物和位错环的相互作用以及体心立方铜中的层错四面体。在后一种情况下，强调了表面在瞬变电镜箔反应中的重要性。结果表明，虽然一些原子过程可以用晶体缺陷的连续统理论来充分描述，但另一些则不能。
Nano-scale defect clusters, such as voids, dislocation loops, stacking-fault tetrahedra and irradiation-induced precipitates, are produced in metals by irradiation with high-energy atomic particles. They are obstacles to dislocation glide and can give rise to substantial changes in the yield and flow stresses and ductility. Atomic-scale computer simulation is able to provide detail of how these effects are influenced by obstacle structure, applied stress, strain rate and temperature. Some recent results from modelling dislocations interacting with obstacles are described. Emphasis is placed on dislocation interaction with voids, copper precipitates and dislocation loops in the BCC metal iron and stacking fault tetrahedra in FCC copper. In the latter case, the importance of surfaces in reactions in TEM foils is highlighted. It is shown that while some atomic processes can be represented adequately by the continuum theory of crystal defects, others cannot.