Manufacture of porous aluminum using containing gases inside aluminum alloy die castings

Porous aluminum is a multifunctional material that is both lightweight and has high energy absorption. We attempted to fabricate closed-cell porous aluminum using aluminum alloy die castings, which contain a large amount of gas. This proposed die castings route has great potential for realizing high productivity, low energy consumption and low-cost manufacturing. The aim of this study is to investigate the validity of the die castings route for fabricating closed-cell porous aluminum. Also, the effect of using the friction stir processing technique to uniformly disperse the oxide, inclusions and gas in the die castings on the morphology of the pores and porosity was investigated. It was shown that porous aluminum with high sphericity and a porosity of more than 30% was realized by using the friction stir processing technique and optimizing the holding time.