Large-scale aluminum foam plate fabricated by enhanced friction powder compaction process based on sintering and dissolution process

• A large Al foam plate was fabricated by friction stir welding technique.
• The powder mixture was sintered only by a friction stir welding.
• Fabricated foams exhibited appropriate compressive properties.

An enhanced friction powder compaction (FPC) process was proposed for fabricating a large plate of aluminum foam by the sintering and dissolution process. In this process, the rotating tool plunged into the die filled with a powder mixture of aluminum and NaCl during the FPC process was made to traverse perpendicularly to the direction of plunging as in the case of friction stir welding. In the enhanced FPC process, no external heat source, such as an electric furnace or a spark plasma sintering, was necessary for fabricating aluminum foam, except for the friction heat generated by traversing the rotating tool. It was found that a long plate of aluminum foam can be fabricated with a length equal to the tool traversing length. By X-ray computed tomography (CT) and scanning electron microscopy (SEM) observations of the pore structures of the fabricated aluminum foam, it was found that the entire sample had a pore structures that was similar to the NaCl morphology, regardless of the position along the traversing direction. The fabricated aluminum foam had a similar stress–strain curve to that of aluminum foam fabricated by spark plasma sintering and exhibited ductile fracture. This is considered to be attributed to the good bonding between aluminum particles in the entire sample. The fabricated aluminum foam exhibited almost the same plateau stress regardless of the position along the traversing direction.