Compressive behavior of aluminum/copper hybrid foams under high strain rate loading

The accessible interconnected structure of open-cell metal foams offers the opportunity to create hybrid foam materials through electrodeposited metal coatings, which has great potential for the fabrication of functionally-graded foam systems. Nanocopper coated aluminum (Al) foam was created by reinforcing conventional open-cell Al foams with electrodeposited nanocrystalline copper (Cu). The mechanical properties of such Al/Cu hybrid foam under high strain-rate compression were investigated using a split Hopkinson pressure bar and numerical methods were used to gain a further understanding on the micro-scale failure mechanisms. It was found that the stable compressive response of open-cell Al foam can be effectively enhanced by electrodeposited nanocopper coatings. However, such enhancement is limited by the relatively high brittleness of the Al/Cu hybrid foam due to the low ductility level of the electrodeposited nano-coating material. Nonetheless, this study also shows that the overall energy absorption performance of Al/Cu hybrid foams under high strain rate loading can be significantly improved by increasing the ductility level of the electrodeposited copper coating.