Session BB5.2

3:45 PM BB5.2
PROCESSING-PROPERTIES RELATIONSHIP OF WATER-STABILIZED PLASMA SPRAY COATINGS. R. Gansert, Hardface Alloys Inc., Santa Fe Springs, CA; H. Herman, State Univ. of New York at Stony Brook, Dept. of Materials Sci. & Eng., NY; P. Chraska, J. Ilavsky, Institute of Plasma Physics, Czech Academy of Sciences, Prague, CZECH REPUBLIC.

Water-stabilized plasma (WSP) technology enables protective coatings to be applied to components at deposition rates significantly greater than conventional plasma spray technologies. Currently, limited studies examine the relationship between fundamental aspects of processing using WSP and the resultant microstructures and properties. This study examines the WSP spray process and coatings which are formed using process diagnostics, modeling and materials characterization. Resulting microstructures are compared with microstructures obtained by other thermal spray processes. The particle velocity and temperature of molten particles are investigated, as well as, the microstructures, phase composition, porosity, density, and strength of the materials. The results show the delicate relationship between processing, microstructure and properties. The processing conditions play a major role in the formation of the splats, deposit phases, microstructures and strength. The morphology of the lamellae through the deposit thickness is substantially influenced by the processing temperatures. Subsequently, the deposit strength is dependent upon the microstructure resulting from the processing. Quench stresses, differential thermal stresses and phase transformation stresses which result from the deposition temperatures influence the strength. Industrial applications where the WSP can be applied is discussed and compared with areas of applications of other thermal spray processes.