A combined friction stir processing and ball milling route for fabrication Al5083-Al₂O₃ nanocomposite

In this research, friction stir processing (FSP) was used to manufacture Al5083 nano composites reinforced with Al₂O₃ nanoparticles and mixture of Al5083/Al₂O₃ nanocomposite. The aim was to investigate the effect of separate addition of Al₂O₃ nanoparticles and a pre-homogenized mixture of Al5083-Al₂O₃ on the microstructural and mechanical behavior of FSP nano composites. Microstructural studies revealed a homogeneous dispersion of Al₂O₃ nanoparticles within Al matrix during FSP. However, the dispersion of Al₂O₃ nanoparticles in Al–Al/Al₂O₃ nanocomposite sample was much more significant than Al-Al₂O₃ sample indicating the proficiency of ball milling. Well-dispersed Al₂O₃ nanoparticles was contributed to a significant improvement in the hardness and tensile properties of both FSPed nano composites. Due to the more homogeneous dispersion of Al₂O₃ nano particles within Al5083 matrix, Al–Al/Al₂O₃ nanocomposite showed higher ductility and strength when compared to the Al-Al₂O₃ nanocomposite. In Al–Al/Al₂O₃, the improvement of tensile strength was obtained in parallel to an increase in the ductility. (paper)