Irradiation-Induced Defects and Functional Regulation in Metallic Materials: A Review

Irradiation has long been regarded as a major source of degradation in metallic materials because energetic particles continuously generate irradiation-induced defects that lead to hardening, embrittlement, swelling and creep. Beyond its detrimental effects, irradiation has long been employed to modify material microstructures and properties. More recently, increasing attention has been directed toward understanding and deliberately controlling irradiation-induced defect evolution to regulate material properties within a broader defect-engineering framework. This review systematically summarizes the fundamental damage mechanisms induced by irradiation in metallic materials, with particular emphasis on irradiation hardening, embrittlement, swelling and creep. Subsequently, advances in the functional utilization of irradiation-induced defects are reviewed from three perspectives: structural modification and mechanical property enhancement, irradiation-regulated magnetic properties, and surface and interface functionalization. Representative studies demonstrate that irradiation can effectively induce nanocrystallization, refine microstructures, regulate magnetic anisotropy and Curie temperature, and improve corrosion resistance, wear resistance and biocompatibility through controllable defect engineering. Finally, the remaining challenges associated with defect controllability, quantitative structure–property relationships and engineering implementation are discussed, together with future opportunities enabled by advanced characterization, multiscale modeling and intelligent materials design. This review highlights the dual role of irradiation as both a source of material degradation and a versatile tool for microstructural and functional regulation, providing useful guidance for the development of next-generation structural and functional metallic materials for applications in nuclear energy, aerospace, biomedical engineering and advanced manufacturing.