Abstract
In this study, nano sized yttria stabilized zirconia (YSZ) suspension in organic solution was deposited by electrophoretic deposition (EPD) method as a protective layer on substrate that was previously plasma sprayed thermal barrier coating (TBCs). In order to improve the performance of TBC from degradation by melt ingression of fuel impurities. Design of experiments (DOE) by Taguchi method was used to optimize the controlled variables of EPD process. A crack free YSZ overlay coating was carried out at different variables; applied voltage (20, 40, 60) V, deposition time (3, 5, 7) min and suspension concentration (5, 10, 15) g/l using DC current. Morphological appearance and cross section of the investigated coating specimen were done using optical and field emission scanning electron microscope. Optimizing process and analysis of variances (ANOVA) were performed by “Minitab 18” software. The results indicate that best condition of coating thickness can be obtained at 40V, 5min and 10g/l when applying signal-to-noise ratio “Larger is better”.