Effect of sintering temperature on the microstructure and mechanical properties of ZrO2-3mol%Y2O3 sol–gel films

The microstructural evolution and mechanical properties of ZrO2-3mol%Y2O3 films were investigated as a function of the sintering temperature in the range from 100AC to 1500AC, using a battery of characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and nanoindentation. It was found that the crystallization occurs at temperatures close to 300AC. A gradual increase in the grain and crystallite sizes is observed as the sintering temperature increases up to 1000AC, and above this sintering temperature the tendency changes abruptly with a rapid increase in these values. Although Young's modulus of the coatings did not change with sintering temperature, a slight decrease was observed in the hardness values above 1000AC which is attributed to microstructure coarsening. Finally, a slight degradation of the films occurs above 1300AC, which is due to the occurrence of a process of grain spheroidization.