Fabrication of composite structural material with ADC12 porous aluminum and dense steel by friction stir welding route

Porous metal is the multifunctional material with both light weight and high energy absorption properties. In this study, a composite structural material, which consists of ADC12 porous aluminum and dense steel plates, was fabricated using friction stir welding (FSW). ADC12 porous aluminum was fabricated by ADC12 aluminum alloy die castings containing large amount of gases without using blowing agent. It is expected that both fabricating precursor of ADC12 porous aluminum and bonding the precursor to steel can be conducted simultaneously by FSW. Composite material having a porosity of approximately 60% can be obtained at a holding temperature of 948 K and a holding time of 8 min. Fe-Al based intermetallic compound (IMC) layer with the thickness of approximately 20 m was observed at the interface. It was shown that IMC layer was formed at the foaming (heating) process by diffusion-limited process.