Mesoscale modeling of irradiation damage evolution in bcc iron and vanadium: A comparative study

Voids and dislocation loops are two major types of damages in irradiated structural materials, which are mainly responsible for the degradation of material properties. Here we use the phase-field model and rate theory to simulate the microstructural evolution of voids and dislocation loops, respectively, in irradiated bcc iron and vanadium. The temperature-dependent material parameters of iron and vanadium are derived from ab initio calculations. The simulated results at different temperatures (513 K, 623 K and 722 K) and irradiation doses (1∼20 dpa) are analyzed to reveal the impact of irradiation conditions on the formation of irradiation-induced defect clusters. A comparison of the results shows larger void porosity and void/loop size in iron and higher void/loop density in vanadium. Then, a dispersed-barrier hardening model is used to correlate the mesoscale simulation results on microstructure with the yield stress change of the materials.