Effect of annealing on the mechanical properties of nano-copper reinforced open-cell aluminum foams

Hybrid metal foams can be created by reinforcing conventional open-cell aluminum (Al) foams with metals such as copper (Cu) and nickel (Ni) using electrodeposition. It has been demonstrated that hybrid foams can have an enhanced and controllable modulus, strength and energy absorption capacity. However, the low ductility of the nanocrystalline structured coating materials in hybrid foams may cause rupture and separation of the coating material and significantly reduce their energy absorption capacity. In this study, Al/Cu hybrid foams manufactured through electrodeposition were subjected to an annealing process and the effect of annealing temperature and time on their macro- and micro-level behavior under compression and tension was investigated using experimental and numerical methods. It was found that a proper amount of annealing can significantly enhance the energy absorption capacity of Al/Cu hybrid foams by increasing the coating ductility. However, excessive annealing will lead to formation of a wide zone of intermetallic compound at the Al/Cu interface and reduce the performance of Al/Cu hybrid foams.