Importance of Measurement and Evaluation Procedure of Particle State in Atmospheric Plasma Spraying

Abstract

AbstractIn-flight particle state parameters (PSPs) have been shown to play a crucial role in determining the properties of atmospheric plasma-sprayed coatings. Therefore, PSPs are frequently measured before starting a coating run as part of process control. This paper shows the importance of the measurement procedure used and subsequent data processing applied for the evaluation of PSPs, with the focus on process control applications. The paper demonstrates this on the example of coating of yttria-stabilized zirconia, using a commercially available sensor system Accuraspray-G3C for measuring the ensemble particle temperatures and velocities as descriptors of the PSPs. Experimental results show a longer stabilization time of the particle jet than what is practically considered, revealing the need for an appropriate choice of the measurement procedure. Furthermore, it is demonstrated that information about PSPs can be acquired also during the coating run by periodically moving the coating gun to a stationary sensor system only for a short measurement duration. Lastly, it is shown how different data processing methods affect the evaluation of the acquired PSPs.