Velocity and temperature distributions of alumina-titania in-flight particles in the atmospheric plasma spray process

Control of the thermal spray process generally considers the monitoring of the mean in-flight particle characteristics (i.e., mean velocity and temperature) during the coating process. The correlation with process parameters is often established without considering the modifications of characteristic distributions. The aim of this work was to demonstrate the need for these distributions. Three processing parameters (arc current, primary and secondary plasma gas flow rates) were correlated to the characteristic distributions in the case of alumina-titania in-flight particles. A high speed two color pyrometer was used to measure, at the centre of the particle flow, individual in-flight particle characteristics, which were used to build velocity and temperature distributions. Results showed a change on characteristic distributions and demonstrated a significant effect of the energetic parameters in the control of the in-flight particle characteristics. (C) 2004 Elsevier B.V. All rights reserved.