High-Strength Tetragonal Zirconia/Alumina Ceramic Composites Containing Strontium Hexaaluminate

Using powders prepared by a sol–gel hydrolysis process, we have prepared three-phase ceramic composite materials consisting of alpha-alumina, strontium hexaaluminate, and a solid solution based on tetragonal zirconia stabilized with yttrium [3Y-TZP], cerium [12Ce-TZP], or ytterbium cations [3Yb-TZP]. The cations stabilizing tetragonal zirconia are shown to influence the microstructure of the materials. Having a finer grained microstructure, the [Yb-TZP] matrix composites possess higher strength (bending strength of up to 850 MPa and KIc of up to 11.3 MPa m1/2).