Effect of milling time on the microstructure of Al_2O_3-Mo Nanocomposite

In this paper, the effect of milling time in the production of Al_2O_3-Mo nanocomposites via mechanical milling is investigated. The crystallite size of Al_2O_3- 20 vol.% Mo powder mixtures grinded using a planetary ball mill are determined at different milling times using the XRD technique. The crystallite sizes of the milled powders are confirmed to be in nano-meter scale. The results show that increasing the milling time leads to a decrease in the crystallite size as well as in the unit cell volume. Furthermore, microstructural investigations using SEM imaging show uniform distribution of ultrafine second phase in the matrix. It is shown that the Al_2O_3-Mo nanocomposite is produced successfully after five hours of milling time.