Optimizing Nanostructured Yttria-Stabilized Zirconia Electrophoretic Coatings on MCrAlY Bond-Coated Inconel 738LC Superalloy

In this research study, to apply uniform and homogenous nanostructured yttriastabilized zirconia (YSZ) coatings on the Inconel 738LC with MCrAlY bond-coat, the effect of electrophoretic parameters was evaluated. Two different suspensions of 3YSZ nanoparticles were prepared in acetylacetone and acetone separately, using an iodine dispersant. The electrophoretic deposition was conducted by applying voltages of 20 V, 50 V and 80 V for 3 min on MCrAlY coated Inconel 738LC. The coatings were sintered for 120 min at 900°, 1000° and 1100°C temperature. The results revealed that the non-uniform coating included some cracks and cavities as the applied voltage exceeded the optimal amount. The results also depicted that the YSZ coating prepared in acetylacetone medium with 0.4 g/L iodine dispersant, voltage of 50 V, coating time of 3 min, and sintering temperature of 1000°C was a uniform and crack-free structure. Furthermore, the results showed that a continuous alumina layer was formed during oxidation. GRAPHICAL ABSTRACT