In this work, the deformation behavior of irradiated tungsten at elevated service temperatures is examined using mechanism-based crystal plasticity finite element framework by considering multiple mechanisms, including thermal softening and irradiation hardening. The previously developed mechanism-based crystal plasticity model is first utilized to assess the yield stress of unirradiated and irradiated tungsten upon low-temperature irradiation. The engineering stress-strain response under uniaxial compression is then predicted by considering the effect of irradiation-induced defect clusters on the motion of deformation-induced dislocations, and the predicted results agree well with the experimental measurements. More importantly, the formation and evolution of plastic strain localization zones in the form of shear bands are qualitatively captured, and the maximal principal strain distribution is quantitatively linked to the dose of irradiation damage. Finally, the deformation-induced shear band as a result of plastic instability in the compressed tungsten specimen is discussed.

在这项工作中，通过考虑多种机制，包括热软化和辐照硬化，使用基于机制的晶体塑性有限元框架来检查辐照钨在高温下的变形行为。先前开发的基于机制的晶体塑性模型首先被用来评估低温辐照下未辐照和辐照钨的屈服应力。然后通过考虑辐照诱导缺陷簇对变形诱导位错运动的影响，预测了单轴压缩下的工程应力应变响应，预测结果与实验测量结果吻合良好。更重要的是，定性地捕获了剪切带形式的塑性应变局部化区的形成和演变，最大主应变分布与辐照损伤剂量定量相关。最后，讨论了压缩钨试样中塑性不稳定性导致的变形诱导剪切带。