Effect of CeO2 addition on the sintering behavior of pre-synthesized magnesium aluminate spinel ceramic powders

Abstract

In this work, the effects of 1 wt%, 2 wt%, and 3 wt% CeO2 as an additive on the sintering behavior of alumina-rich spinel and magnesia-rich spinel powders subjected to sintering at temperatures of 1600 °C, 1650 °C, 1700 °C, and 1750 °C were investigated. The sintering behavior of the ceramics was investigated according to dilatometry measurements, linear shrinkage, bulk density, phase analysis, and microstructure. It was demonstrated that CeO2 hindered the sintering process in alumina-rich spinel by reacting with Al2O3 exsolved from the spinel to form platelet-shaped particles of CeAl11O18 interspersed between the spinel grains. Meanwhile, the presence of CeO2 promotes the sintering process in magnesia-rich spinel by being distributed in an isolated form among the spinel grains.