Toughening Effects through Optimizing Cell Structure and Deformation Behaviors of Al–Mg Foams

As widely used protective materials,the application of Al foams is still limited by their low intrinsic mechanical properties caused by the brittleness of struts.The introduction of Mg is recently demonstrated effective to improve the mechanical performance of Al foams;however,the mechanism of Mg modification is still not clear.In this work,Al-Mg foams are developed through a powder metallurgy process with excellent compression performance and high energy absorption capacity.The effects of Mg modification on the cell structure,toughness,and deformation behavior are investigated systematically.As a result,the small cell size of~1.8 mm and the high sphericity of 0.92 are achieved with 5% of Mg addition,delivering high compression stress of 8.5±0.43 MPa and energy absorption capacity of 6.9±0.36 MJ/m^(3),simultaneously.The synergistic mechanism for the improved mechanical performance is also demonstrated to be the combination of stress transfer and plastic deformation behavior of cells.The results provide a new strategy to develop high-performance foam materials by improving toughness and further promote the practical application.