Designing a novel gradient-structured Cu-CuCoCrFeNi contact to synergistically enhance arc erosion and wear resistance

The enhancement of arc erosion and wear resistance of copper-based contacts is critically determined by designing novel structures and optimizing second-phase strengthening systems. In this work, a novel gradient-structured Cu-CuCoCrFeNi contacts was constructed. The similar work functions and identical FCC structures of CuCoCrFeNi high-entropy alloys (HEAs) and Cu are utilized to reduce interfacial electronic mismatch, whereby bonding strength and electrical conductivity are enhanced. This unique microstructure is designed with the aid of finite-element simulations (FEM) and realized by the High-pressure Multi-Field Assisted Rapid Sintering. The synergistic effects of this structure on improving arc erosion and wear resistance were investigated through experiments, computational fluid dynamics (CFD), and FEM. Results indicate heat flux and current are effectively dissipated, mitigating local surface melting and damage. Transition and bottom layers constitute stable electrical and thermal conduction channels inside the molten pool, supplying a continuous copper source to the surface layer. The continuous HEAs skeleton on the surface restricts liquid copper flow and blocks transmission channels, thereby promoting rapid fracture of the molten bridge and significantly improving arc erosion resistance. Furthermore, through a "skeleton load bearing and film friction-reduction" mechanism, the continuous HEAs skeleton mainly carries the loads and restricts heat conduction, enabling preferential plastic deformation of the Cu matrix to generate a friction-reducing film. This process protects the matrix while effectively dissipating shear stress and retarding thermal softening.