Void growth and coalescence in irradiated materials

Abstract : Irradiation with high energy particles induces crystalline defects in metallic materials. These micro-structural changes strongly modify the mechanical properties, leading in particular to significant hard-ening and strain localization at the grain scale. The effects of irradiation on the mechanisms of ductile fracture - void growth and coalescence - are assessed in this study based on model experiments. Pure copper thin tensile samples have been irradiated with protons. Micron-scale holes drilled through the thickness of these samples subjected to uniaxial loading conditions allow a detailed description of void growth and coalescence. Comparisons of experimental results to analytical and numerical results tend to indicate that, for voids of typical size on the order or higher than the grain size, accounting for irradiation macroscopic hardening is sufficient to model void growth and coalescence in irradiated materials