Structural Evolution of Al-20% (wt) Al2O3 System during Ball Milling Stages

Production of nanostructured aluminum matrix composite powder by high energy ball milling is investigated. Scanning electron microscopy analysis as well as the tap and green density measurements were used to optimize the milling time needed for the completion of the mechanical milling process. Also, we studied the particles morphology and size distribution change with milling time and its correlation with pressability and tap density. SEM showed that distribution of alumina particles in the Al matrix reaches a full homogeneity after the steady state. This would increase the hardness of powder due to a nano-structured matrix and oxide dispersion strengthening.