EFFECT OF OXIDE ADDITIVES ON GRAIN-GROWTH DURING SINTERING OF NANOCRYSTALLINE ZIRCONIA ALLOYS

Nanocrystalline zirconia powders alloyed with 4 wt% of oxides of triva lent (Y, La, Bi) and tetravalent (Ce, Th) cations were prepared by pre cipitation and sintered at temperatures corresponding to their maximum shrinkage rates. Y2O3, CeO2 and ThO2 equally inhibited the grain grow th during sintering. However, only Y2O3 was effective also in the stab ilization of the tetragonal phase. The enhanced grain growth in the Zr O2-Bi2O3 alloy was related to liquid phase sintering. La2O3 exhibited an intermediate effect on grain growth. (C) 1998 Elsevier Science B.V. All rights reserved.