LAUSR

Abstract Grain boundaries (GBs) are considered sinks where mobile defects are attracted and annihilated thereby hampering irradiation damage accumulation. Nanocrystalline (NC) metals characteristically have greater densities of GBs relative to their coarse-grained counterparts hence they are postulated to provide enhanced resistance to irradiation damage. The use of alloying as a means to impart synergistic properties such as corrosion resistance, increased toughness, or improved conductivity is well studied, yet the cooperative effects of solute addition and grain size in the nano-regime is not well understood. In this study, a combination of in situ ion irradiation, transmission electron microscopy (TEM), and automated crystal orientation mapping (ACOM) on model Ni, NiCr, Fe, and FeCr NC thin-films are used to provide experimental evidence that grain size and irradiation induced defect morphology (defect density and size) are not directly correlated due to defect agglomeration, annihilation at sinks, and saturation, while the addition of solute impedes defect mobility, altering the final damage state.