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Synergistically enhancing the erosion and impact resistance of contacts poses a significant challenge for cutting-edge electrical equipment. Fortunately, mollusk shells in nature have evolved effective strategies to construct microstructures with superior erosion and impact resistance. Inspired by the structure of nacre, AgSnO2 contact material with hierarchical architectures has been designed and fabricated. The mechanistic link between microstructural evolution and dynamic erosion is studied through experiments combined with Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) simulations. Results show that the reconstructed SnO2 skeleton endowed with a highly continuous and anisotropic ‘flowering'-like structure forms a continuous interpenetrating network with Ag, optimizing the conductive pathways on the molten pool surface. Additionally, the Ag-rich regions in the deeper layers on both sides of the molten pool offers a stable ‘nutrient-supply’ for the continuous ‘flowering’ reconstruction of the skeleton, exhibiting excellent in-situ self-repairing erosion resistance. Benefiting from this synergistic strategy, this skeleton is reconstructed based on its natural structure, which further disperses the stress and deformation concentration while inhibiting interfacial debonding, thereby reducing the formation of cracks and significantly enhancing the impact resistance. This work is expected to breakthrough erosion and impact resistance in extreme condition electrical contact materials through biomimetic microstructure design.

[Display omitted] • CuO skeleton restructuring on the Ag–CuO contact erosion were studied. • CuO microstructural evolution affected the erosion resistance of Ag–CuO contact. • Molten bridges were dispersed by the newly formed CuO skeleton. • The stress and strain concentrations of contact surface were relieved due to CuO skeleton restructuring. • The proposed strategy augmented the erosion dispersion for the Ag-based contacts. Predicting the second-phase microstructure that evolve in arc erosion processes remains an important challenge in Ag–CuO contacts. In this study, phase identification and microstructure analysis were utilized to reconstruct a 3D model of an Ag–CuO contact for tracking and exploring the dynamic erosion of its microstructures. The results show that the dynamic evolution of the molten pool was strongly affected by repetitive thermal impacts. Ag flow and evaporation in the molten pool provide the driving force for CuO skeleton restructuring, which increased the tortuosity of the flow paths and extended the flow channel length. Thus, molten bridges with large quantities, short lengths, and small diameters were dispersed, thereby improving the surface erosion resistance. Furthermore, the effect of CuO on the micromechanical characteristics of the Ag–CuO contact was examined by employing local 3D models reconstructed using visual recognition technology combined with the finite element method. The findings show that CuO skeleton restructuring efficiently dispersed the local stress and strain concentrations on the molten pool, which delayed contact failure. Therefore, our work confirmed the role of CuO skeleton restructuring in dispersing molten bridges, and relieving stress and strain concentrations in Ag–CuO contacts, thereby further augmenting our understanding of erosion dispersion. [ABSTRACT FROM AUTHOR]