Abstract
Multi-pass friction powder sintering process was proposed for fabricating a large plate of porous aluminum by the sintering and dissolution process. In this process, sintering of a powder mixture of aluminum and NaCl was achieved only the rotating tool plunged into the die filled with the powder mixture was made to traverse as in the case of multi-pass friction stir processing. In this study, porous aluminum plates of 60 mm × 30 mm × 5 mm with porosity of 70% were successfully fabricated by multi-pass friction powder sintering process. From measurements of temperature and torque, it was found that the entire sample had almost same sintering condition during the multi-pass friction powder sintering process. From X-ray computed tomography (CT) and scanning electron microscopy (SEM) observations of the pore structures of the fabricated porous aluminum plates, it was found that the entire sample had almost same pore shape and porosity that was similar to the NaCl morphology and proportion. From compression tests of the fabricated porous aluminum plates, it was found that entire sample exhibited a similar stress-strain curve to that of the previous work regardless of the position. This is considered to be attributed to the good bonding between aluminum particles during friction powder sintering process. From these results, it was indicated that multi-pass friction powder sintering process had a potential to fabricate the porous aluminum plate that was similar to the size of the tool traversing area.
