Enhanced damping capacity of graphene origami reinforced metal matrix nanocomposites

The growing demand for structural materials with superior mechanical and damping properties in dynamic applications has driven the exploration of advanced nanocomposites. In this study, we introduce a strategy to simultaneously enhance the mechanical and damping properties of metal matrix nanocomposites by embedding three-dimensional graphene origami (GOri). Molecular dynamics simulations show that GOri/Cu nanocomposites exhibit enhanced tensile mechanical properties and damping performance compared to single-crystal copper (Cu). The mechanical enhancement arises primarily from dislocation blocking at the Cu-GOri interface and the unfolding deformation of the embedded GOri. Under cyclic loading, the $Q$ factor of GOri/Cu nanocomposites is significantly lower than that of single-crystal Cu, indicating a substantial increase in energy dissipation. Detailed analysis points to interfacial friction as the dominant energy dissipation mechanism, driven by unfolding-refolding motions of the embedded GOri. Furthermore, the damping performance is shown to improve with increasing loading frequency, strain amplitude, graphene content, and ambient temperature. The degree of GOri folding plays a critical role: greater folding leads to a rougher interface, thereby enhancing interfacial energy dissipation. These findings provide valuable insights into the design of nanocomposites with improved performance for dynamic applications.