Microstructural evolution of a silicon carbide-carbon coated nanostructured ferritic alloy composite during in-situ Kr ion irradiation at 300°C 450°C

This work focuses on irradiation behaviors of a novel silicon carbide and carbon coated nanostructured ferritic alloy (SiC-C@NFA) composite for potential applications as a cladding and structural material for next generation nuclear reactors. The SiC-C@NFA samples were irradiated with 1 MeV Kr ions up to 10 dpa at 300 and 450 degrees C. Microstructures and defect evolution were studied in-situ at the IVEM-Tandem facility at Argonne National Laboratory. The effects of ion irradiation on various phases such as alpha-ferrite matrix, (Fe,Cr)(7)C-3, and (Ti, W)C precipitates were evaluated. The alpha-ferrite matrix showed a continuous increase in dislocation density along with spatial ordering of dislocation loops (or loop strings) at >5 dpa. The size of the dislocation loops at 450 degrees C was larger than that at 300 degrees C. The nucleation and growth of new (Ti, W)C precipitates in alpha-ferrite grains were enhanced with the ion dose at 450 degrees C. This study provides new insight into the irradiation resistance of the SiC-C@NFA system. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.