Abstract
Yttria partially stabilized zirconia (YSZ) was atmosphere plasma sprayed on to mild steel substrates. The spray parameters were varied to determine their effects on the elastic modulus of the coating. The parameters were (i) continuous spray vs. paused spray, (ii) bond coat vs. no bond coat, and (iii) cooled vs. not-cooled. The elastic modulus was measured using laser ultrasonics and Knoop Indentation. Using indentation, the continuous/ paused spray exhibited the greatest effect with the paused spray samples having a lower elastic modulus value regardless of the condition of the other parameters. The other parameters did not reveal any statistically significant effect. The laser ultrasonics measurements showed that cooling and no-cooling had a greater effect on elastic modulus, with the other parameters having little effect. Laser ultrasonics detected parameters whose influence can be detected near the surface (in this work the cooling and no-cooling), but did not detect those parameters that influence the properties throughout the coating. Indentation detected the parameters that influence the properties throughout the coating, in this work continuous and paused spraying.
