Abstract
This work investigates the effect of atmospheric plasma spraying (APS) parameters on in-flight particle properties, splat morphology, and coating microstructure for conventional and nano-size YSZ powders. Particle temperature and velocity were measured using a dual-slit velocimeter and individual splats and coating microstructures were examined in a scanning electron microscope. The results show that total porosity increases with decreasing arc current and increasing stand-off distance and that conventional powder coatings have higher total porosity at higher arc currents than coatings made from nanopowder. The effect of substrate temperature on splat formation was also assessed. Splat flattening and circularity increase with increasing substrate temperature, particularly for nanopowders.
