Effect of Feedstock Powders on the Microstructural and Electrical Characteristics of 8 mol% Yttria-Stabilized\ud Zirconia Plasma-Sprayed Coatings

Plasma-sprayed coatings of 8 mol% yttria-stabilized zirconia (YSZ) were fabricated using the feedstock powders obtained from co-precipitation (PPT) and spray-drying (SD) processes. Particle size and the specific mass (SM) of the feedstock powder were found to be the critical parameters that influence the microstructural and electrical properties of the coatings. While dense and larger particle-sized PPT powder resulted in a porous microstructure, dense coatings were obtained for SD powders with relatively lower SM. Electrical conductivity values of SD-coatings were found to be 30% higher than that of PPTcoatings. Electrical conductivity values of plasma-sprayed PPT-coatings improved significantly on decreasing the particles size. However, the size effect was only subtle in the case of SD coatings. PPTcoatings fabricated from smaller particle-sized powders had the necessary electrical conductivities appropriate for solid oxide fuel cell electrolyte application