Age-Hardening Response of Replicated Microcellular Al-4.5%Cu

We study the response to age hardening of Al-4.5%Cu replicated foams with 75 and 400 pm cell sizes and with varying relative densities. The 400 mu m cell size foams have a similar behavior to the bulk alloy, whereas the 75 pm cell size foams with relative densities below 20% show no increase in strength with age hardening; this effect is interpreted as due to damage accumulation. Overall, the present study shows that, by age hardening the metal making the foam, open-celled replicated aluminium foams can be made as strong as commercial closed-celled aluminium foams, despite their inferior mesostructure.