Effect of Co-doping with Rare Earth Elements Pr and Ce on Properties of Magnesia Ceramics

In this study, the magnesia ceramics were fabricated by atmospheric pressure sintering following dry pressing, which was using light magnesium oxide purity ≥98.5% powder as primary raw material,the ZrO₂, CeO₂ and Pr₆O₁₁ as additive and polyvinyl alcohol as binding agent (10%,the same below). The sintering properties,hardness,thermal shock resistance, microstructure and phase of MgO were investigated at 1550 ℃, with a holding time of 1 to 2 hours. After the addition amount of ZrO₂ was fixed at 1%, Pr₆O₁₁ and CeO₂ were sequentially introduced to investigate the optimal doping levels of Pr₆O₁₁ and CeO₂, which were determined to be 0.5% and 5%, respectively. Subsequently, the effects of varying Pr and Ce co-doping contents on the sintering behavior and thermal shock resistance of magnesium oxide ceramic materials were examined. Co-doped MgO ceramics exhibit the highest Rockwell hardness of 86 HRB when the CeO₂ to Pr₆O₁₁ addition ratio (by mass fraction) is 3.0 ∶ 0.5, with a corresponding thermal shock resistance of 11 cycles.