Fabrication of functionally graded aluminum foam using aluminum alloy die castings by friction stir processing

Functionally graded aluminum (FG) foam with varying pore structure was fabricated by utilizing friction stir processing. Die castings containing a large amount of gas were used as the starting material. The obtained FG foam had two different deformation stages and two plateau regions with a seamless bonding interface.

► For the first time functionally graded closed-cell aluminum foam was fabricated by friction stir welding.
► Deformation can be controlled at the desired location with the desired plateau stress.
► The obtained FG foam had two different deformation stages and two plateau regions with a seamless bonding interface.