Roll forming of porous aluminum immediately after heating and foaming using a precursor fabricated by butt-jointing of commercial purity aluminum and Al-Mg-Si alloy

Porous aluminum is a multi-functional porous material. This is a lightweight and low-density material with excellent shock absorption, thermal insulation and sound absorption properties. In this study, the precursors were fabricated by a friction stir welding process, which involved the butt-joining of A1050 aluminum and A6061 aluminum alloy precursors. We foamed the joined precursor by heating with halogen lamps. Immediately after foaming, roll forming was conducted. The X-ray CT images of the samples obtained in the experiment show that the porosity of the samples was maintained after they were roll formed. In addition, the fracture surfaces of the samples obtained via four-point bending test had a porous structure, indicating that A1050 aluminum and A6061 aluminum alloy were metallurgically joined. Furthermore, we prepared samples with the addition of iron powder to the A6061 side. The X-ray CT image of this sample showed that a mixture of the two metals can be formed, and it was confirmed that a two-layered porous aluminum can be obtained.