Preparation of Zirconia Toughened Aluminum Nano-ceramic as Dental Prosthethic Material

Objective: Processing parameters in preparation of Zirconia Toughened Aluminum (ZTA) nano-ceramic, such as additive agents, dry pressing force and sintering temperature, were investigated for the optimal properties of prepared dental ceramics. Methods: With addition of additive agents of TiO2, MgO and SiO2, Al2O3-ZrO2 nano-ceramic powders were dry pressed (5KN-9KN) and sintered (1200ºC or 1450ºC, 2h). The density and Vickers hardness of the prepared composite were measured as a function of the dry pressing force. The morphology of the cross-sectioned samples was observed by using scanning electron microscope to study the effects of different additive agents. Results: It was found that the values of both density and Vickers hardness increased with a higher dry pressing force. Good maturation of ceramic grains, i.e. higher crystallization, could be achieved at 1450ºC. The grains of the sample containing 1.05wt% MgO grew perfectly and were distributed uniformly. At the same sintering temperature, the sample containing TiO2 was well developed. Conclusions: The higher dry pressed force led to good initial density and high Vickers hardness. The use of additive agents (MgO, TiO2, SiO2) significantly reduced the sintering temperature and enhanced strength could be obtained. The optimal content of MgO addition is 1.05wt%.