Effects of CeO2 Addition on Slip - Cast Yttria Tetragonal Zirconia Polycrystals Toughened Alumina (ZTA)

Abstract

Addition of CeO2 into ZTA and its effects on microstructure and mechanical properties were investigated. CeO2 was detected with significant amounts only above 10 wt%. Viscosity was measured for slurry preparartions and characterization of mechanical properties of ZTA. Additions of CeO2 of more than 10 wt% surpassed the solubility limit and formed Ce2Zr3O10. Ce2Zr3O10 increased the tetragonality factor, prevented excessive grain growth through a pinning effect, which is attributed to the segregation of Ce2Zr3O10 to the grain boundaries and showed a peak in fracture toughness with a value of 9.3 MPam1/2 with 10 wt% additions of CeO2. Further additions of CeO2 reduced ZTA’s mechanical strength. Maximum value of Hv was 17700 MPa with 10 wt% CeO2. Porosities have been attributed as the underlying reason as to why theoretical density were always higher than measured densities.