Bioinspired multi-scale heterogeneous layered structure enhances strength and ductility of copper matrix composites

In composites with specific structures, rational regulation of the structure and distribution of reinforcing phases is shown to enhance both strength and ductility. Typical structures such as network, layered, and columnar structures have proven to be effective in improving the strength and ductility of the composites. However, issues such as narrow size ranges, uneven distribution, and weak interfacial bonding of the reinforcements have resulted in the performance of the composite not being fully exploited. Here, we present a bioinspired multi-scale heterogeneous layered composite (MHLC) that achieves an optimal balance between strength and ductility. This heterogeneous layered structure is composed of alternately stacking Cu-Ti layers and GNPs/Cu layers, where the Cu-Ti layer contains uniformly distributed plate-like β-Cu4Ti intermetallic compounds, and the GNPs/Cu layer contains layered graphene nanoplatelets (GNPs). Additionally, the size, distribution, and shape of the reinforcements can be adjusted through heat treatment and cold rolling, thereby achieving a balance between strength and ductility. Molecular dynamics simulation and finite element simulation were conducted to investigate the structural evolution of β-Cu4Ti and the influence of the reinforcements on tensile properties, respectively. Our results provide important references for exploring the potential of multi-scale heterogeneous layered structures in enhancing the strength and ductility of the composites.