Ceramics-Silikáty 64, (1) 84 - 91 (2020)

MgO powders with different aggregate sizes were prepared by alcohol ball milling and were sintered at different temperatures. The morphology of the MgO aggregate, bulk density and section morphology of the sintered MgO were investigated. The results showed that there was a significant exponential correlation between the average MgO aggregate size and bulk density, the bulk density of the sintered MgO increased with a decrease in the average aggregate size. In order to obtain dense magnesia with a bulk density of more than 3.40 g·cm^-3, the average aggregate size should be reduced to less than 3 μm. The small aggregate size could produce the dense sintered MgO due to the larger contact area between the aggregates after forming. Furthermore, the sintered MgO prepared from the small aggregate size had fewer pores and microcracks after sintering, and the sintering temperature had a significant effect on increasing the grain size. In particular, the maximum grain size was more than 40 μm under 1600 °C.