Athermal defect recovery in high entropy alloys: Real-time evidence from in-situ TEM

Conventional annealing of high-entropy alloys relies on elevated temperatures to promote defect recovery and microstructural refinement, but such treatments are slow, composition-dependent, and often lead to uncontrolled grain growth. In this study, we explore electron wind force (EWF) as a low temperature, athermal route to rapid defect mitigation in a CuCoNiFeCr system. Using in-situ transmission electron microscopy, we directly tracked the same microstructural region while increasing EWF magnitude. Our observations revealed a progressive reduction in defect density. Short duration (40 µs), low frequency (2 Hz), low-current (0.1 A) pulses mitigated most of the mobile defects in 5 min. Increasing current amplitude drove extensive defect migration, with limited grain growth. Ex-situ annealing of bulk HEA corroborated these findings, showing a ∼26.8 % decrease in electrical resistance and a ∼12.5 % reduction in hardness, consistent with dislocation annihilation and structural relaxation. Similar recovery trends observed in aluminum confirm the generality of the approach.