Fabrication of Al–Zn/α-Al2O3 nanocomposite by mechanical alloying

In this study fabrication and characterization of alumina particles reinforced aluminum-based metal matrix nanocomposite by mechanical alloying were investigated. Aluminum and zinc oxide powders mixture milled by a planetary ball mill in order to produce Al–13.8 wt.% Zn/5 vol.% Al2O3 nanocomposite. The structural evaluation milled and annealed powders studied by X-ray diffraction, SEM observation and hardness measurement. The aluminum crystallite size estimated with broadening of XRD peaks by Williamson–Hall formula. The results showed that milling of aluminum and zinc oxide for 60 h led to displacement reaction of the zinc oxide and aluminum to produce Zn and Al2O3 phases. The milled powder had a microstructure consisting of nanosized Al2O3 particles in an Al–Zn solid solution with a nanoscale grain size of 40 nm. Microhardness of this nanocomposite was found to be about 190 HV.