FeCrAl alloys are candidates for accident tolerant fuel cladding of light water reactors. In this work, a microstructure- and temperature-dependent crystal plasticity model is employed to bridge microscale to macroscale mechanical property measurements of FeCrAl alloys. With the visco-plastic self-consistent (VPSC) polycrystal plasticity framework, a mechanism-based single crystal plasticity (MSCP) model adopts the Arrhenius type rate equation to describe the dependence of the critical resolved shear stress for dislocation slips on their temperature-dependent intrinsic frictional resistance and the microstructure-dependent irradiation hardening. The intrinsic frictional resistance associated with {110}<111> and {112}<111> slip systems were measured by in-situ micromechanical testing on unirradiated/irradiated samples at 25-500 °C. The irradiation hardening is estimated by the Bacon-Kocks-Scattergood (BKS) model with density and size of radiation-induced defects measured from microstructural characterization. Several features associated with thermo-mechanical behavior of unirradiated/irradiated polycrystalline FeCrAl alloys are captured. High density of deformation-induced dislocations and radiation-induced defects results in obvious hardening at room temperature, which is weakened at high temperature, and facilitates damage evolution during deformation. Moreover, both high temperature and radiation-induced defects, which facilitate dislocation multiplication, trigger large hardening rate. The proposed method together with application of accelerator-based ion irradiation technique is a surrogate approach to simulate neutron damage, improving the efficiency associated with evaluation of mechanical properties of FeCrAl alloys exposed to temperature, stress and radiation conditions.

FeCrAl 合金是轻水反应堆耐事故燃料包壳的候选材料。在这项工作中，采用微观结构和温度相关的晶体塑性模型将 FeCrAl 合金的微观和宏观机械性能测量联系起来。借助粘塑性自洽 (VPSC) 多晶塑性框架，基于机制的单晶塑性 (MSCP) 模型采用 Arrhenius 型速率方程来描述位错滑移的临界解析剪应力与其温度相关性的依赖性固有摩擦阻力和微观结构相关的辐照硬化。与 {110}<111> 和 {112}<111> 滑移系统相关的固有摩擦阻力是通过在 25-500 °C 下对未辐照/辐照样品进行原位微机械测试来测量的。辐照硬化是通过 Bacon-Kocks-Scattergood (BKS) 模型估算的，该模型具有从微观结构表征测量的辐射诱导缺陷的密度和尺寸。捕获了与未辐照/辐照多晶 FeCrAl 合金的热机械行为相关的几个特征。高密度的变形诱发位错和辐射诱发缺陷导致室温下硬化明显，高温下硬化减弱，并促进变形过程中的损伤演化。此外，促进位错增殖的高温和辐射引起的缺陷都会引发大的硬化率。所提出的方法与基于加速器的离子辐照技术的应用一起是模拟中子损伤的替代方法，