Electric field-assisted high-pressure strategy for diffusion bonding of Al_0.3CoCrFeNi high-entropy alloy: Synergistic experimental and molecular dynamics simulation

Direct bonding of high-entropy alloy (HEA) is essential for advanced industry applications, yet high-quality bonding remains challenging due to their inherent diffusion hysteresis. This work proposes an electric-field-assisted high-pressure diffusion bonding strategy for HEA, employing a multiscale approach that combines experiments and molecular dynamics (MD) simulations to elucidate the microstructural mechanism by which bonding pressure influences the joint microstructure, strength, and interfacial atomic diffusion. Results showed that under electric-field assistance, increased pressure enhanced the bonding quality and shear performance of the HEA joint. MD simulations further confirmed that higher pressure promotes Al-dominated interfacial atomic diffusion due to its larger atomic size and lower cohesive energy. Meanwhile, this elevated pressure induces a distinct transformation of the FCC structure toward a disordered state at the interface. This work presents a novel approach to achieving high-quality HEA diffusion bonding by elucidating the mechanisms of pressure-driven diffusion and microstructural evolution that are crucial for advanced engineering applications with enhanced performance.