Development of Columnar, Vertically-cracked, and Crack-free Microstructures via the Solution Precursor & Suspension Plasma Spray Processes

Progressive Surface, Inc has developed yttria stabilized zircionia (YSZ) coatings via the solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) processes with the 100HE plasma torch.  The coatings produced have been of different types, with microstructures characterized as columnar, columnar-cracked, vertically-cracked, and crack-free.  The columnar microstructures were sprayed at atmospheric pressures, and the vertically-cracked microstructures were obtained with less demanding processing conditions than those required for achieving a DVC coating by the APS process.  Thus, SPS and SPPS exhibit the potential to simplify the production of current thermal barrier coating (TBC) microstructures, to provide new coating structures, and to tailor microstructures for the next generation of TBCs.  Additionally, the 100HE plasma torch has been found to be effective at meeting the unique demands of these emerging plasma spray processes.