Effect of TiO2 doping on the sintering behavior of Zr-based ceramic for use as TBC

In the present work, zirconia-based ceramics incorporated with TiO2 (titania) were produced and characterized as candidate material for use as thermal barrier coating (TBC). Zirconia was stabilized in the tetragonal metastable phase from the addition of 24 wt.% of MgO (magnesia). Alternative materials, such as these, have been studied worldwide in order to prospect candidates for TBC application with improved temperature behavior. Titania was added to the matrix of ZrO2.24MgO in the proportions of 0, 7.5, 15, and 22.5 wt.%. The compacted samples were sintered for 24 h in thermal cycles at 1250 °C. Powder characteristics were evaluated by scanning electron microscopy and light scattering technique. The phase identification of raw materials and the sintered ceramics was investigated by powder X-ray diffractometry. The microstructural characterization of the sintered ceramics was performed by scanning electron microscopy and energy dispersive X-ray spectroscopy, physical indices were characterized by Archimedes’ method and the mechanical behavior evaluated by Vickers microhardness. The results indicate a direct influence of the TiO2 contents (up to 7.5 wt.%) in the improvement of the verified properties.