Interfacial reaction-induced intermetallic compounds (IMCs) are brittle and prone to triggering cracking, severely deteriorating the mechanical performance of composite interfaces. Overcoming IMC-induced embrittlement remains a longstanding challenge in interface design. Here, we counterintuitively leverage IMCs by inducing their nanocrystallization to achieve ultrahigh interfacial strength–ductility synergy in 18Ni350/Nb/AlNbTi₃Zr_1.5 composites. Specifically, a uniform and continuous nanostructured C14-type Fe₂Nb interfacial reactive layer (IRL) is engineered at the 18Ni350/Nb interface through the in situ nanoscale reaction. In contrast to the coarse-grained Fe₂Nb IRL characterized by pronounced brittleness, this well-developed nanocrystalline Fe₂Nb IRL exhibits superior strength and plasticity by activating grain rotation, stacking fault-mediated slip, and phase transformation-induced plasticity. These deformation mechanisms, originated from the nanostructuring and element doping of Fe₂Nb, promote stress relaxation, uniform deformation, and crack blunting during the deformation of the composite interface, thereby mitigating the brittleness of IMCs. Concurrently, the excellent thermodynamic inter-solubility of Ti, Zr, and Nb fosters robust metallic bonds without forming IMCs at the Nb/AlNbTi₃Zr_1.5 interface, which enhances compatible deformation by facilitating interfacial dislocation emission and movement, alleviating strain concentration, and preventing premature cracking during mechanical loading. Our findings reveal the significant potential of nanocrystallization engineering in overcoming the interfacial brittleness of IMCs and provide a new strategy for designing ultrahigh-strength dissimilar interfaces.

Nuclear energy is a low-carbon, safe, efficient, and sustainable clean energy. The new generation of nuclear energy systems operate in harsher environments under higher working temperatures and irradiation doses, while traditional nuclear power materials cannot meet the requirements. The development of high-performance nuclear power materials is a key factor for promoting the development of nuclear energy. Oxide dispersion strengthened (ODS) steel contains a high number density of dispersed nano-oxides and defect sinks and exhibits excellent high temperature creep performance and irradiation swelling resistance. Therefore, ODS steel has been considered as one of the most promising candidate materials for fourth-generation nuclear fission reactor cladding tubes and nuclear fusion reactor blankets. The preparation process significantly influences microstructure of ODS steel. This paper reviews the development and perspective of several preparation processes of ODS steel, including the powder metallurgy process, improved powder metallurgy process, liquid metal forming process, hybrid process, and additive forging. This paper also summarizes and analyzes the relationship between microstructures and the preparation process. After comprehensive consideration, the powder metallurgy process is still the best preparation process for ODS steel. Combining the advantages and disadvantages of the above preparation processes, the trend applied additive forging for extreme manufacturing of large ODS steel components is discussed with the goal of providing a reference for the application and development of ODS steel in nuclear energy.