Abstract

In the current study, the effect of adding nano Al2O3 to 3 mol%Y2O3 stabilized tetragonal zirconia (3Y-TZP) prepared by precipitation method on the grain size and the mechanical properties was investigated. Different amount of nano Al2O3 (1.5 wt. % , 2.5 wt.% , 3.5 wt.% and 4.5 wt.%) have been added to (3Y-TZP). X-Ray diffraction (XRD) and scanning electron microscopy (SEM) was used to characterize both the prepared powder and the full dense ceramic composite. It has been found that ,the addition of nano Al2O3 have an influence on the densification process and lead to increase in both the apparent and bulk relative densities and recorded a 96.45% and 94.46 % respectively at 4.5 wt.%. The results also shows a decrease in grain size from 0.7 μm to 0.62 μm as the amount of nano Al2O3 vary from 0 wt.% to 4.5 wt.% due to the restricted of the grain boundary mobility via the effect of particle pinning. Also, the addition of nano Al2O3 have great effect on mechanical properties .The Vicker's microhardness and the flexural strength shown an increase as the nano Al2O3 amount increase and recorded 84.1201 HV, and 368.62 MPa maximum values respectively at 4.5 wt.% nano Al2O3 .