The role of Al2O3 impurities on the microstructure and properties of Y-TZP

Al2O3 is commonly present in, or introduced to, tetragonal zirconia polycry stal (TZP) ceramics as either an impurity or an additive during powder manu facture and/or subsequent processing, although its effects are not well und erstood. A study has been carried out into the effects of variously dispers ed Al2O3 at the 0-1 wt.% level on the sintering characteristics, microstruc ture, phase composition, and mechanical properties of yttria stabilised, te tragonal zirconia polycrystal (Y-TZP). The results show that these levels o f Al2O3 can enhance sintering at low temperatures, but can also cause exagg erated grain growth and reduction in sintered density for higher sintering temperatures, with corresponding changes in the mechanical properties. (C) 1999 Elsevier Science S.A. All rights reserved.