Laboratoire d'Etude des Microstructures, Onera/CNRS, 29, avenue de la division Leclerc, 92322 Châtillon, France.
Phys Rev Lett. 2015 Dec 31;115(26):265501. doi: 10.1103/PhysRevLett.115.265501. Epub 2015 Dec 23.
Dislocation climb is a ubiquitous mechanism playing a major role in the plastic deformation of crystals at high temperature. We propose a multiscale approach to model quantitatively this mechanism at mesoscopic length and time scales. First, we analyze climb at a nanoscopic scale and derive an analytical expression of the climb rate of a jogged dislocation. Next, we deduce from this expression the activation energy of the process, bringing valuable insights to experimental studies. Finally, we show how to rigorously upscale the climb rate to a mesoscopic phase-field model of dislocation climb. This upscaling procedure opens the way to large scale simulations where climb processes are quantitatively reproduced even though the mesoscopic length scale of the simulation is orders of magnitude larger than the atomic one.
位错攀移是晶体高温塑性变形中普遍存在的一种机制。我们提出了一种多尺度方法来定量模拟介观长度和时间尺度上的这种机制。首先，我们在纳米尺度上分析攀移，并得出位错跃迁就位攀移速率的解析表达式。其次，我们从这个表达式中推导出该过程的激活能，为实验研究提供了有价值的见解。最后，我们展示了如何将攀移速率严格地提升到位错攀移的介观相场模型。这种提升方法为大规模模拟开辟了道路，即使模拟的介观长度尺度比原子尺度大几个数量级，也可以定量再现攀移过程。
