Regulating solid-solution-type alloying and composition–structure evolution is an effective strategy for optimizing electromagnetic matching in high-entropy systems. However, precise control over composition redistribution and phase evolution remains challenging for high-entropy alloy nanoparticles (HEA NPs) synthesized under ultrafast nonequilibrium conditions. Herein, we propose a controllable electrical explosion of wire (EEW) strategy to regulate the dynamic phase transformation of AlFeCoNiCu HEA NPs. During EEW, energy deposition regulates the phase-transition sequence, vapor/plasma-phase mixing, and rapid nonequilibrium condensation of metal wires, enabling sufficient atomic/ionic diffusion and redistribution to form HEA nanocrystals with tunable crystal-phase constitution. The optimized FCC/BCC phase constitution promotes multicomponent solid-solution formation and reduces local compositional heterogeneity, while rapid EEW-induced nonequilibrium condensation freezes lattice distortion, phase interfaces, and defects. As a result, the optimized HEA NPs exhibit excellent electromagnetic wave absorption (EWA), with a minimum reflection loss of –55.71 dB and an effective absorption bandwidth of 7.30 GHz. They also show enhanced corrosion resistance, with a corrosion potential of –0.026 V. This work demonstrates that EEW offers a scalable nonequilibrium phase-engineering route for constructing high-performance HEA nanocrystals with integrated EWA and corrosion-resistant functions.
