Bioinspired tungsten-copper composites with Bouligand-type architectures mimicking fish scales

The microscopic Bouligand-type architectures of fish scales demonstrate a notable efficiency in enhancing the damage tolerance of materials; nevertheless, it is challenging to reproduce in metals. Here bioinspired tungsten-copper composites with different Bouligand-type architectures mimicking fish scales were fabricated by infiltrating a copper melt into woven contextures of tungsten fibers. These composites exhibit a synergetic enhancement in both strength and ductility at room temperature along with an improved resistance to high-temperature oxidization. The strengths were interpreted by adapting the classical laminate theory to incorporate the characteristics of Bouligand-type architectures. In particular, under load the tungsten fibers can reorient adaptively within the copper matrix by their straightening, stretching, interfacial sliding with the matrix, and the cooperative kinking deformation of fiber grids, representing a successful implementation of the optimizing mechanisms of the Bouligand-type architectures to enhance strength and toughness. This study may serve to promote the development of new high-performance tungsten-copper composites for applications, e.g., as electrical contacts or heat sinks, and offer a viable approach for constructing bioinspired architectures in metallic materials.