Cellular structure and energy absorption of Al \\ Cu alloy foams fabricated via a two-step foaming method

Two-step foaming (TSF) method is one of cost-effective ways to prepare shaped, closed-cell Al alloy foams with a thick surface layer, which can provide good energy absorption property. In this study, we designed 27 groups orthogonal experiments based on Taguchi method to investigate the effects of key processing parameters on the closed cellular structure of Al\\Cu alloy foams fabricated via the TSF method. The compressive behavior and energy absorption of the fabricated foams were also evaluated and compared with samples prepared by powder metallurgy method (PM). The results showed that processing parameters such as the holding time, foaming temperature and their mutual interaction during the second foaming could affect the final cellular structure features, such as porosity content, average diameter, pore distribution uniformity and sphericity. Quantitative analysis in-dicated that a shorter holding time ( 5 min) and higher foaming temperature ( 760 degrees C) could fabricate Al\\Cu alloy foams with descent cellular structure and energy absorption capability. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).