Surface Morphology of Air Plasma Sprayed Titania doped Yttria stabilized Zirconia Coatings

In this research, the influence of the projection parameters on the surface morphology of ZrO2 - 10% Y2O3 - 18% TiO2 coatings thermal sprayed by atmospheric plasma was determined. To do this, the surface morphology was characterized by Scanning Electron Microscopy for different conditions of deposition (Input Power and Spray Distance), the percentage of unmelted particles and porosity were simultaneously determined by image analysis, as well as the surface roughness of each coating. Finally, the influence of the projection parameters was established by means of a 2 2 factorial experimental design and analysis of variance, optimizing the results using a response surface methodology. The coatings presented an overlaid splats morphology with the presence of unmelted particles and a certain degree of porosity. It was found that with higher input power and shorter spray distance, a more homogeneous structure is obtained with fewer discontinuities (unmelted particles, porosity, roughness). The combined effect of the input power and the spray distance evaluated determines that the most favorable experimental combination achieves when the coating of ZrO 2 -10%Y 2 O 3 -18% TiO 2 is deposited with a power of 38 kW and a spray distance of 80 mm.