SONATA – Dr. Małgorzata Frelek-Kozak
Title of the project: Development of a novel Alumina-Forming ODS Alloys: A Fundamental Study of Multi Factor Degradation Mechanisms
Project period: 07.2026 – 07.2029
Budget: 1 141 200 zł
Description of the project:
The conflicts between the growing global demand for energy and the urgent need to reduce reliance on fossil fuels have driven worldwide interest in advanced nuclear energy systems. Future Generation-IV fission reactors and fusion devices will operate in exceptionally harsh conditions - very high temperatures, intense radiation and contact with aggressive coolants. Such extreme environments impose stringent performance requirements. This project focuses on a special group of advanced materials called Oxide Dispersion Strengthened (ODS) steels. These steels contain fine oxide particles distributed throughout the metal, which give them excellent resistance to high temperatures and radiation.
A key limitation of current ODS steels is insufficient corrosion resistance at elevated temperatures. One promising solution is to optimize their composition and thermal treatment. It is well known that addition of aluminum to alloy provides its ability to spontaneous formation of dense, protective, and extremely stable alumina (Al₂O₃) layer – so called Alumina Forming Alloy (AFA). However, aluminum also alters the structure and morphology of the internal oxide dispersoids (promoting Y-Al-O complex oxides), and thereby reduces their strengthening efficiency. Small additions of Zr into steel allows to overcome this trade-off. Since Y-Zr-O compounds form more easily than Y-Al-O oxides, presence of Zr allows to retain Al in solid solution for surface oxidation. In that mechanism addition of Zr improves the overall microstructural architecture. However, there are some limitation of that strategy. A key issue related to the formation of Y-Zr-O complexes is that strictly optimized heat-treatment is necessary to avoid detrimental diffusion of Zr into the alumina scale.
The proposed research aims to design, manufacture, and characterize a new class of multifunctional ODS alloys exhibiting superior mechanical properties, improved corrosion resistance, and enhanced radiation stability. Two AFA-ODS alloy variants will be produced - one with Zr and one without - advanced powder metallurgy routes, and tailored post-processing procedures. The produced alloys will be subjected to a comprehensive suite of degradation conditions mimicking realistic reactor-like conditions: including high mechanical stresses, corrosive environments, elevated temperatures, and irradiation damage - tested individually and in combination. This will allow us to push further boundaries of understanding the performance of this alloy at extreme operational conditions.
The project will provide a deep understanding of multi-factor degradation in alumina-forming ODS steels and quantify the beneficial role of Zr in stabilizing dispersoids while enabling protective alumina formation. By combining controlled alloy design with multiscale characterization and multi-factor testing, the project will elucidate how protective alumina films, oxide dispersions, and the ferritic matrix evolve under realistic reactor-like conditions. The implementation of this research will generate a valuable dataset that fills a significant gap in the field, providing essential insights for the scientific community and supporting the development of safer, more efficient, and more durable nuclear systems.
