Effect of oxide additives on grain growth during sintering of nanocrystalline zirconia alloys

摘要

Nanocrystalline zirconia powders alloyed with 4 wt/100 of oxides of trivalent (Y, La, Bi) and tetravalent (Ce, Th) cations wee prepared by precipitation and sintered at temperatures corresponding to their maximum shrinkage rates. Y_2O_3, GeO_2 and ThO_2 equally inhibited the grain growth during sintering. However, only Y_2O_3 was effective also in the stabilization of the tetragonal phase. The enhanced grain growth in the ZrO_2-Bi_2O_3 alloy was related to liquid phase sintering. La_2O_3 exhibited an intermediate effect on grain growth.