Compressive behavior of a rolled open-cell aluminum foam

Abstract

In this paper, we investigate compressive behavior of an open-cell 6101 aluminum foam in as-cast and as-rolled conditions. The as-cast foam with a relative density of ρ* = 7% was rolled to create two distinct as-rolled conditions with relative densities of ρ* = 29% and ρ* = 42%, respectively. The quasi-static and high strain rate compressive behavior was studied over a range of strain rates 10−4 /s ≤ ε̇ ≤ 5 × 103/s. It was found that the internal structure of as-rolled foams significantly differs from as-cast foams. Rolling causes plastic bending, stretching, and buckling of individual struts and ligaments, resulting in reduced pore size and an increase in relative density. In as-rolled condition, compressive plateau strength increased with increase in ρ*; it was up to 26 times higher as compared to the as-cast condition. In the range of strain rates considered here, strain rate sensitive compressive behavior was not observed; instead, the intrinsic strain rate sensitivity of parent material governed the compressive behavior in all conditions. Our results demonstrate the feasibility of using conventional rolling as a simple way to modify internal structure and relative density of as-cast foams, thereby enabling mechanical properties more attractive for various structural applications.