Effect of Y-TZP addition on the microstructure and properties of titania-based composites

Abstract

To maintain the bioactivity and improve the mechanical properties of titania, both pure titania ceramics and titania-yttria-stabilized tetragonal zirconia (Y-TZP) composites with 5, 10, and 15 vol% Y-TZP were prepared via a sol-gel precipitation method. A titania precursor (titanium butoxide) was mixed with a submicron-sized Y-TZP powder, followed by hydrolysis-condensation reactions, green compact forming, and sintering in air at 1200 degrees Celsius to 1350 degrees Celsius. It was found that the addition of Y-TZP resulted in reduced rutile titania grain size from 13 um to 3 um. The Y-TZP tetragonal phase also resulted in improved mechanical properties of the titania-Y-TZP composites. For instance, the titania-15vol%Y-TZP composite had a hardness value of 983 kg/mm2, a bending strength of 160 MPa, and a fracture toughness of 3.79 MPa.m0.5. While the addition of Y-TZP increased the mechanical properties, it also decreased the bioactivity of the composites.