Biomimetic high-entropy interface design inspired by viral capsids achieves flexible bonding in heterogeneous interfaces

Inspired by the biomimetic design of entropy-stabilized flexible connections in icosahedral virus capsids, this study presents an innovative strategy for the design of high-performance heterogeneous metal interfaces using the high-entropy effect. A high-entropy interface is developed using a gradient laser power control strategy in the laser-directed energy deposition (LDED) process, successfully constructing a 316L stainless steel/FeCoCrNiMn high-entropy alloy (HEA) heterogeneous structure. Multi-scale characterization indicated that the material was dominated by a stable FCC solid-solution structure. The gradient transition at the interface was confirmed by the spatial distribution and variation trends of the constituent elements. Electron backscatter diffraction (EBSD) analysis demonstrated complex microstructural evolution mechanisms influenced by the high-entropy effect, contributing to the strengthening of the heterogeneous metal system. Mechanical testing results showed that the flexible interface enabled the material to maintain an ultimate tensile strength of 638 MPa and an elongation of 37.5%. Furthermore, tribological testing reveals improved wear resistance, with a specific wear rate of 4.81 × 10 −5 mm 3 /N·m under a 10 N load, outperforming both 316L and HEA individually. This work not only provides a biomimetic, innovative solution to overcoming interface challenges in heterogeneous materials but also highlights the significant potential of the high-entropy effect in cross-scale interface engineering.