Effect of differently oriented interlayer phases on the radiation damage of Inconel-Ni multimetallic layered composite.

Multimetallic layered composites (MMLCs) have shown an excellent potential for application under extreme environments, e.g., accident-tolerant fuel cladding, because of their low oxidation tendency and high corrosion resistance. Interfacial phases or complexions in nanocrystalline materials accelerate the annihilation of defects and enhance the radiation resistance of materials, making MMLCs with engineered interlayer phases compelling to deploy in extreme conditions. However, implementation of MMLCs in full capacity remained a challenge due to a lack of fundamental understanding of the underlying mechanisms governing the characteristics of the interface between the metallic layers. The precise role of interlayer phases in MMLCs and their interaction with defects, specifically under extreme conditions, is still unexplored. Pursuing atomistic simulations for various Inconel-Ni MMLCs model materials, we revealed accelerated defect mobility in interlayers with larger crystalline misorientation and the inverse relationship between the interface sink strength to the misorientation angle. Furthermore, we found a linear relation between interlayer misorientation angle with the density of radiation-induced defects and radiation enhanced displacements. Finally, our results indicate that radiation-induced material degradation is accelerated by the higher defect formation tendency of MMLCs with a high-angle interlayer interface. [Display omitted] • The misoriented interlayer phase makes the radiation-induced diffusion anisotropic. • Radiation-induced defect formation and diffusion increase as the misoriented angle increases. • Interphase defect sink strength is higher for the interstitials than vacancies. • Defect recombination hampers due to vacancy-interstitial imbalance at higher doses. • Radiation-induced structural degradation is more acute for structures with a high misorientation angle interface. [ABSTRACT FROM AUTHOR]