Suspension Plasma Spraying of Intermediate Temperature SOFC Components Using an Axial Injection DC Torch
Intermediate temperature SOFC components, such as dense, nanostructured SDC electrolytes (samarium doped ceria) and porous anode sublayers were fabricated by suspension plasma spraying using an axial feed dc plasma torch. The liquid carrier employed in this approach allowed for controlled injection of much finer particles than in conventional thermal spraying, leading to thin coatings with a refined microstructure. Dense, thin (<10(m) and non-fractured electrolytes were created. Various processing routes for SOFC half-cells, using tape-cased, plasmasprayed and suspension-sprayed anodes, were explored. Loss of integrity and non-continuous coverage of the anode constituted the principal difficulties in the subsequent electrolyte deposition. The role of suspension feedstock particle size is discussed. Amongst various schemes investigated, a processing route that employs sequential suspension plasma spraying steps for both the electrolyte and the anode, using relatively large primary particles in the feedstock, constituted the most promising approach.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
J. Oberste Berghaus et al., "Suspension Plasma Spraying of Intermediate Temperature SOFC Components Using an Axial Injection DC Torch", Materials Science Forum, Vols. 539-543, pp. 1332-1337, 2007