Effect of Spraying and Suspension Parameters On the Properties of Suspension Plasma Sprayed Solid Oxide Fuel Cell Electrolytes

Plasma spraying is a deposition technique that produces good quality, fully sintered coatings at high deposition rates.  Coatings with finer microstructures and controlled porosity can be produced by modifying the plasma spray system to use a suspension of micro to nanosized powders as the feedstock.  These qualities make suspension plasma spraying an interesting, novel manufacturing technique to fabricate solid oxide fuel cell (SOFC) active layers.  In the present study, layers of fully stabilized yttria-stabilized zirconia (YSZ) that could be used as an SOFC electrolyte were deposited using an axial injection suspension plasma spray system.  The effect of spraying parameters such as plasma gas flow rate, plasma composition, and arc current, and of suspension parameters such as solid and suspension feed rates on coating parameters such as microstructure, permeation rate, and deposition efficiency was examined.   Optimal spraying and suspension conditions were developed in order to produce coatings with low porosity and high deposition efficiency.