Composition Optimization of Zirconia Toughened Alumina for Dental Ceramics

摘要

The aim of this study was to optimize sintering aids and processing parameters for zirconia toughened alumina (ZTA) nano-ceramics with optimal properties as dental ceramics. Additive agents (TiO_2, MgO, SiO_2), dry pressing forces and sintering temperatures are very important for preparation of structural ceramics. In the present study, density and Vickers hardness measurement, SEM,.and XRD analysis were employed to investigate the effects of these on the final products. The relevant results showed that higher pressing force led to an increase in the density and Vickers hardness of the sintered ceramics. Among the four groups of sintered nano-ceramics with different ratios of alumina and zirconia, and combinations of additive agents, the best densification was achieved in the sample from Group 2# containing 1.05wt% MgO after sintered at 1450°C, as indicated by SEM observation. XRD analysis confirmed the formation of MgAl_2O_4 as an intermediate compound. The existence of TiO_2 in the additive agents was in favor of the acquisition of high densification. The measured values for the density and Vickers hardness indicated that the sintered ZTA nano-ceramics would be a potential material for dental prosthetic applications.