In this paper, yttria-stabilized zirconia (YSZ) was coated on Fecrralloy as thermal barrier coatings (TBC) using electrophoretic deposition (EPD) by various non-aqueous solvents. The solvents in the suspensions were varied in order to optimize kind of solvent and experimental conditions to achieve smooth and crack-free YSZ coatings. The effects of EPD parameters variations including solvents, sedimentation height, zeta potential, particle size, pH, deposition weight have been studied. Moreover, SEM and micro-hardness tests have been used to evaluate hardness and morphology of the samples. In comparison of the coatings created by various solvents, it was found that the use of acetyl-acetone with 0.4 g/l I2 produces a uniform, smooth and crack free surfaces. Also the use of this solvent led to stable state, narrow particle size distributions and higher zeta potential in suspension in compare with the other solvents. The experimental results revealed that stability of suspensions were required for obtaining high quality coatings, and particle coagulation could result in coatings with low green density and poor sinterability. It was also found that deposition yield in stable suspensions was higher. According to the results obtained from the statistical analysis by depositions time, it was found that the deposition rate decreases by an increase in deposition time.

Keywords: Electrophoretic deposition, YSZ film, Non-aqueous solvents, Suspension stability