“…Uniform Al foam can exhibit various properties depending on its base material and pore structure (i.e., porosity and pore size) (Gibson, 2000). In recent years, to improve the performance of Al foam, functionally graded (FG) aluminum foams, which consist of foam layers with different material compositions and pore structures, have been developed (Brothers and Dunand, 2008, Hangai et al, 2012a, Hassani et al, 2012, Shinagawa, 2008, Suzuki and Kitazono, 2008. One of the major fabrication processes of uniform and FG Al foams is the precursor foaming process Seeliger, 2012, Banhart, 2013).…”