Effect of in-flight particle velocity on the performance of plasma-sprayed YSZ electrolyte coating for solid oxide fuel cells

In this paper, the effect of particle velocity on the characteristics of atmospheric plasma-sprayed yttria stabilized zirconia was investigated through adjusting auxiliary helium flow rate. The temperature and velocity of in-flight particles were measured with the DPV2000 diagnostic system. The results showed that helium flow rate significantly influenced particle velocity and less distinctly influenced particle temperature. The microstructure of the coatings was characterized by scanning electron microscopy and X-ray diffraction analyzer. The ionic conductivity of the deposits through thickness direction was measured by a potentiostat/galvanostat based on three-electrode assembly approach in a temperature range of 500-1000 °C. The specific gas permeability was estimated through measuring the coating gas flow rate with a home-made experimental setup. The results showed that the gas permeability was improved by increasing the in-flight particle velocity. However, the in-flight particle velocity had little effect on the ionic conductivity of specimens.