D. A. Hirschfeld, N. R. Spinhirne, New Mexico Institue of Mining and Technology, Socorro, NM; A. C. Hall, Sandia National Laboratories, Albuquerque, NM
Very low pressure plasma spray (VLPPS) was used for the liquid and vapor deposition of yttria-stabilized zirconia (YSZ) as a potential manufacturing method for solid oxide fuel cell (SOFC) electrolytes. Coatings created by liquid deposition had a microstructure consisting of dense splats. Vapor deposited coatings had a columnar microstructure similar to coatings deposited by electron beam physical vapor deposition EB-PVD). The columnar microstructure was dependent on substrate temperature and vapor flux continuity. Microstructures consisting of layers of splats and columns were also observed. Coating microstructure was analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrical conductivity was measured using a four-wire direct current method.
Summary: The development of columnar and mixed columnar/conventional microstructures of YSZ by VLPPS is discussed in terms of liquid and vapor deposition regimes which are controlled by spray parameters.In addition, electrical conductivity as a function of temperature of the different microstructures was examined.
