Processing-structure-property landscape in dilute zirconium alloys for nuclear energy applications

The need for sustainable energy has become paramount in today's context, owing to the alarming rise in global greenhouse gas emissions and the consequent adverse impact on climate change. Among these energy resources, nuclear energy holds a special place in fulfilling global commitments and thus warrants a special interest. Zirconium alloys are the preferred in-core structural materials in water-cooled reactors, the most widely used reactor configuration. Nevertheless, further research is needed to improve the understanding of how structural materials influence the long-term and reliable performance of nuclear reactors. Material performance and in-reactor degradation mechanisms are largely governed by various metallurgical factors that can be engineered during thermo-mechanical processing (TMP). The structural evolution at each TMP step governs that of the following steps, so that the final microstructure and properties are a cumulative outcome of the processing steps. Despite the criticality, the interlinkage among processing, microstructure, texture, and properties has not been comprehensively reviewed and remains scattered in the literature. This article provides an in-depth, state-of-the-art review of the interlinkages between processing, microstructure, and properties in zirconium alloys, elucidating the foundation of physical metallurgy, the critical role of TMP in microstructure and texture control, and the impact of microstructure and texture on the key properties of zirconium alloys. In summary, by focusing on the complex interdependence of processing, microstructure, and properties in zirconium alloys, this review emphasises their importance in advancing nuclear reactor technology and highlights emerging opportunities for innovation. Future research integrating novel alloy compositions, advanced characterisation techniques, and predictive modelling will be essential for improving the durability, safety, and reliability of zirconium-based structural materials, thereby supporting a more sustainable nuclear energy ecosystem.