Induction plasma spraying of samaria doped ceria as electrolyte for solid oxide fuel cells

Samaria doped ceria (SDC), used as a solid oxide fuel cell (SOFC) electrolyte, was deposited by Solution Plasma Spray (SoIPS) process. An aqueous solution of mixed nitrates was axially injected into the Radio Frequency (RF) inductively coupled plasma through an atomization probe. The atomic ratio of the SDC components in solution was (Ce0.85SM0.15)O-1.925. In order to control the initial spray droplet diameter, Malvern RT sizer atomization tests were performed. In-flight particle temperature and velocity were analyzed by DPV 2000. Coatings thickness and morphology were measured and observed by scanning electron microscopy, the substrate porosity being determined through gas permeability measurements. Results indicate that the coating's porosity and density strongly depend on the plasma spraying parameters. Gap size of the injection probe, atomization gas flow rate and the probe position have no significant effects on the coating's porosity under the spraying conditions applied in this study.