a fathy - Department of Mechanical Design and Production Engineering,Faculty of Engineering, Zagazig University, Egypt
a wagih - Department of Mechanical Design and Production Engineering,Faculty of Engineering, Zagazig University, Egypt
m Abd El-Hamid - Department of Mechanical Design and Production Engineering,Faculty of Engineering, Zagazig University, Egypt
a.a Hassan - Nuclear Research Center, Atomic Energy Authority Cairo, Egypt

The morphological and microstructural changes during mechanical milling of Al powder mixed with 2.5, 5 and 10 wt.% Al2O3 particles were studied. The milling was performed in a planetary ball mill forvarious times up to 20h. The produced composite powders were investigated using X-ray diffractionpattern (XRD) to elucidate the role of particle size, secondary phase content and milling time on grain size and lattice strain of Al matrix. The aluminum crystallite size estimated with broadening of XRD peaks by Williamson–Hall formula. The morphological changes were studied by SEM technique. Theresults show that the addition of hard Al2O3 particles accelerates the milling process, leading to faster work hardening rate and fracture of the aluminum matrix. Furthermore, Al becomes smaller crystallite size during ball milling of Al powder in the presence of Al2O3 particles. The results revealed that thegrain size of milled powders was about 45nm with a noticeable presence of agglomerates. Uniform distribution of nano-sized Al2O3 particles in the Al matrix could be achieved with increasing milling time.

Mechanical Milling,Al-Al2O3 Nanocomposite Powder,Morphology,Particle size