In this work, we investigate the relationship between an intense slip band (ISB) and the zone of large lattice rotations that forms ahead of the tip of the ISB. We develop a crystal plasticity finite element model of a discrete ISB lying within an oligocrystalline assembly and calculate the local crystalline stress and lattice rotation fields generated by the ISB. The calculations demonstrate that, first, a region of severe lattice rotations, commonly referred to as a microvolume, does not form without the ISB, and second, large amounts of accumulated slip in the ISB are required to enlarge the microvolume to sizes and rotation magnitudes observed experimentally. Ahead of the ISB tip, the quintessential plastic zone always forms, but the atypical microvolume forms when non-concentrated and spatially diffuse slip is activated by the ISB-induced stress field. This result suggests that the detrimental ISB/microvolume pair will likely appear in pairs of crystals in which transmission of the slip from the ISB is severely blocked by the grain boundary, a hypothesis that we verify with a few target cases.

在这项工作中，我们研究了强滑移带 (ISB) 与在 ISB 尖端之前形成的大晶格旋转区域之间的关系。我们开发了位于寡晶组件内的离散 ISB 的晶体塑性有限元模型，并计算了 ISB 产生的局部结晶应力和晶格旋转场。计算表明，首先，一个严重的晶格旋转区域，通常称为微体积，没有 ISB 就不会形成，其次，需要在 ISB 中积累大量的滑移来将微体积扩大到大小和旋转幅度实验观察。在 ISB 尖端之前，典型的塑性区总是形成，但是当非集中和空间扩散的滑移被 ISB 诱导的应力场激活时，就会形成非典型的微体积。该结果表明有害的 ISB/微体积对可能会出现在晶体对中，其中来自 ISB 的滑移的传输被晶界严重阻碍，我们用一些目标案例验证了这一假设。