Grain Boundary Structure Ordering via Electroshock Treatment Enhances Strength-Ductility Synergy

High-energy electropulsing triggers recrystallization and phase transformation via excessive Joule heating, potentially causing unwanted damage and compromising the bulk microstructure. Herein, a non-destructive, low-energy electric current strategy, termed electroshock treatment (EST), is developed to strengthen grain boundaries (GBs), the preferential site for crack initiation and propagation, while preserving the bulk microstructure. Using α-Ti as a model system, this strategy achieves a synergistic enhancement of strength and ductility by transforming the defect-rich GB structure into an ordered atomic arrangement. In situ micropillar compression tests confirm a significant increase in GB strength after EST, while molecular dynamics (MD) simulations reveal that ordered GBs, owing to their lower density of defects, raise the critical stress for dislocation emission and exhibit greater resistance to intergranular fracture. Additionally, a reduction in dislocation density after EST contributes to enhanced ductility. These findings provide a promising GB-structure-engineering pathway to reinforce polycrystalline metallic materials.