Abstract
The natural instability of the are in direct current (DC) plasma torches used in spray processing is one of the most important causes for variations in heating of sprayed particles, leading to inconsistencies in the final coating quality. A relatively simple diagnostic system has been set up to monitor the plasma jet instability, as well as some important process characteristics. Effects of the operating parameters and the anode condition on properties of plasma jets, particle properties, and coatings have been measured. These results show that the inconsistency caused by the jet instability influences the plasma spray process in several ways. The coating porosity and the deposition efficiency can be correlated to an average jet length obtained from a series of high speed images. Selected frequency peaks in the power spectrum of the acoustic signal are correlated with the average jet length, and these results are used to derive a simple control scheme, which adopts a fuzzy look-up model indicating the condition of the anode. Increasing the are current is the most effective way to counteract the negative effects of anode erosion.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
