Home – Home – Jornals – Chemistry for Sustainable Development 2019 number 3

MgO•nAl₂O₃ powder (n = 1, 1.25, 1.5, 1.75, 2.0, 2.5) was prepared by the bimetal alkoxide hydrolysis method. The effects of changes of aluminium content on material phase, particle size, morphology, infrared transmittance, and ceramic densification were studied. The results show that the MgO•nAl₂O₃ (n ≤ 2) powder forms a pure phase of magnesium-aluminium spinel at 1200 °C. When n is 2.5, the characteristic peak of Al₂O₃ appears. The particle size of powder gradually increases with an increase of n value. There were significant differences in the densification of powders with a various of magnesium/aluminium ratio. The density of samples varies greatly with the sintering temperature. When the sintering temperature is between 1200 and 1400 °C, there are no obvious changes. The density is found to be 3.45 g/cm3 at the sintering temperature of 1400 °C. When n is of 1.25 and 1.5, the sample density increases with an increase of sintering temperature, reaching 3.46 g/cm³ at 1550 °C. The powder with ball milling has a better sintering performance, the density of the MgO•1.5Al₂O₃ powder with ball milling is 3.448 g/cm³ at the sintering temperature of 1600 °C, which is 2.5 % higher than that of the non-ball-milled sample at the same temperature.