Sensor Issues and Requirements for Developing Real-Time Control for Plasma Spray Deposition

• Published in: Journal of thermal spray technology Vol. 19; no. 4; pp. 723 - 735
• Main Authors: Wroblewski, D., Reimann, G., Tuttle, M., Radgowski, D., Cannamela, M., Basu, S. N., Gevelber, M.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.06.2010; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coating; Construction; Corrosion and Coatings; Exact sciences and technology; Flux; Light intensity; Machines; Manufacturing; Materials Science; Metals. Metallurgy; Peer Reviewed; Processes; Production techniques; Real time; Sensors; Sprayers; Sprays; Surface treatment; Surfaces and Interfaces; Thin Films; Tribology; Yttria stabilized zirconia; diagnostics and control; coatings for gas turbine components; ceramic oxide layers; Plasma; Oxide layer; Hot spraying; Coatings; Spray coating; Surface treatment; Oxidation; Gas turbine; Plasma spraying; Application; Ceramic materials
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1007/s11666-010-9490-3

This paper discusses the requirements of sensors that could be used both for advanced real-time control as well as manual torch operator control of plasma spray processes, and reviews the critical issues associated with design and implementation of such sensors. The focus is on yttria-stabilized zirconia for thermal barrier coatings. The overarching requirement is that the sensor must capture the subset of particles that contributes most to coating properties and that the resulting measurements of these critical subdistributions must be aggregated in a manner that correlates best to the coating buildup. For deposition rate control, the focus of this work, experiments show that the mass flux of molten particles correlates better with coating thickness than bulk-average temperature or light intensity. However, measurement of molten mass flux for control requires sensors that are capable of sensing particle states at high rates from across a large portion of the full plume.