Deposition characteristics of CeO2-Gd2O3 co-stabilized zirconia (CGZ) coating prepared by solution precursor plasma spray

A 16 mol% CeO2-4 mol% Gd2O3 co-stabilized zirconia (CGZ) ceramic top coat for thermal barrier coating (TBC) was obtained by solution precursor plasma spray (SPPS). This work describes the influence of the spray parameters, such as spray distance, atomizing pressure, and solution flow rate on microstructures of the CGZ coating. Single scan experiments were performed to better understand the formation and microstructure of splat. Scanning electron microscopy (SEM) show the atomizing pressure and spray distance have a strong influence on splat and characteristics of coating. The atomization pressure of 1.3 bar and spray distance of 35 mm are conducive to obtain larger sized splat and dense coating. The melting state of the coating became worse with increasing solution flow rate. Precursor decomposition is an exothermic reaction, which occurs mainly in the temperature range of 200–600 °C, analysed by thermogravimetry (TG)/differential scanning calorimetry (DSC). The phase compositions of the coatings were investigated by X-ray diffraction (XRD) and Raman spectra, which confirmed that the coatings were composed of t and c-ZrO2, with minor m-ZrO2 under certain processing parameters.