Influence of magnesia on sintering stress of alumina

The sintering stress and the densification of MgO-doped Al2O3 were measured with a self-loading apparatus and a thermomechanical analyzer, respectively. The densification started at 950 °C and finished at about 1450 °C. The measured surface tensions were 0.7–0.8 N m−1 in the intermediate sintering stage but drastically decreased to 0.2 N m−1 in the final stage of sintering.