Burak Malik Kaya, Selçuk Temiz, Umut Saraç
This review provides a comprehensive analysis of nanostructured metals, high-entropy alloys (HEAs), and bulk metallic glasses (BMGs), focusing on structure–property relationships across atomic, defect, and microstructural scales. This review elucidates the fundamental processing routes and governing mechanisms responsible for structural evolution across nanostructured metallic systems. Furthermore, recent evidence re-evaluating sluggish diffusion in HEAs and mechanisms ensuring structural stabilization are critically examined. Differences in atomic diffusion kinetics across the three material classes are systematically delineated. Finally, an AI-assisted framework and multi-objective design roadmap are presented for future intelligent metallic systems in aerospace, green energy, and biomedical applications.