Multiscale modelling of plastic flow localization in irradiated materials
Multiscale modelling of plastic flow localization in irradiated materials
复制标题
DOI：
10.1038/35022544
复制
发表时间：
2000-08-24
期刊：
影响因子：
64.8
通讯作者：
Caturla, MJ
中科院分区：
文献类型：
--
作者：
de la Rubia, TD;Zbib, HM;Caturla, MJ
高能粒子对金属的辐照会导致其力学性能显著下降（1,2），最显著的是屈服应力增加和延展性降低，通常还伴有塑性流动局部化。这种效应限制了核电站压力容器的使用寿命（3），并限制了基于核聚变的替代能源材料的选择（4）。尽管这些现象已为人所知多年（1），但其潜在的基本机制及其与辐照场的关系尚未得到明确证明。在此，我们利用对辐照金属的三维多尺度模拟，揭示了无缺陷通道中塑性流动局部化的潜在机制。我们观察到辐照诱导的缺陷簇对位错的钉扎，随着缺陷被位错吸收而随后的脱钉，以及随着应力增加位错的交滑移。塑性流动通道的宽度受到相对的位错偶极子段和剩余缺陷簇之间相互作用的限制。
The irradiation of metals by energetic particles causes significant degradation of the mechanical properties(1,2), most notably an increased yield stress and decreased ductility, often accompanied by plastic flow localization. Such effects limit the lifetime of pressure vessels in nuclear power plants(3), and constrain the choice of materials for fusion-based alternative energy sources(4). Although these phenomena have been known for many years(1), the underlying fundamental mechanisms and their relation to the irradiation field have not been clearly demonstrated. Here we use three-dimensional multiscale simulations of irradiated metals to reveal the mechanisms underlying plastic flow localization in defect-free channels. We observe dislocation pinning by irradiation-induced clusters of defects, subsequent unpinning as defects are absorbed by the dislocations, and cross-slip of the latter as the stress is increased. The width of the plastic flow channels is limited by the interaction among opposing dislocation dipole segments and the remaining defect clusters.