Abstract
Quality control of a thermal spray system manufacturing process is difficult due to the many input variables that need to be controlled. Great care must be taken to ensure that the process remains constant to obtain a consistent quality of the parts. Control is greatly complicated by the fact that measurement of particle velocities and temperatures is a noisy stochastic process. This article illustrates the application of quality control concepts to a wire flame spray process. A central feature of the real-time control system is an automatic feedback control scheme that provides fine adjustments to ensure that uncontrolled variations are accommodated. It is shown how the control vectors can be constructed from simple process maps to independently control particle velocity and temperature. This control scheme is shown to perform well in a real production environment. We also demonstrate that slight variations in the feed wire curvature can greatly influence the process. Finally, the geometry of the spray system and sensor must remain constant for the best reproducibility.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
M.J. Harry and J.R. Lawson, Six * Sigma Producibility Analysis and Process Characterization, Addison-Wesley Publishing Co., Inc., Reading, MA, 1992
K. Ramadan and P.B. Butler, Analysis of Particle Dynamics and Heat Transfer in Detonation and Thermal Spraying Systems, J. Therm. Spray Technol., 2004, 13(2), p 248–264
S.P. Mates, D. Basak, F.S. Biancaniello, S.D. Ridder, and J. Geist, Calibration of a Two-Color Imaging Pyrometer and Its Use for Particle Measurements in Controlled Air Plasma Spray Experiments, J. Therm. Spray Technol., 2002, 11(2), p 195–205
J.F. Bisson, M. Lamontagne, C. Morequ, L. Pouliot, J. Blain, and F. Nadequ, Ensemble In-Flight Particle Diagnostics Under Thermal Spray Conditions, Thermal Spray 2001: New Surfaces for a New Millemium, C.C. Berndt, K.A. Khor, and L.F. Lugscheider, Ed., May 28–30, 2001 (Singapore), ASM International, 2001, p 705–714
M. Friis and C. Persson, Control of Thermal Spray Processes by Means of Process Maps and Process Windows, J. Therm. Spray Technol., 2003, 12(1), p 44–52
T.C. Hanson, C.M. Hackett, and G.S. Settles, Independent Control of HVOF Particle Velocity and Temperature, J. Therm. Spray Technol., 2002, 11(1), p 75–85
S. Sampath, X. Jaing, A. Kulkami, J. Matejicek, D.L. Gilmore, and R.A. Neiser, Development of Process Maps for Plasma Spray: Case Study for Molybdenum, Mater. Sci. Eng., A, 2003, 348(1–2), p 54–66
M.H. Li, D. Shi, and P.D. Christofides, Diamond Jet Hybrid HVOF Thermal Spray: Gas-Phase and Particle Behavior Modeling and Feedback Control Design, Ind. Eng. Chem. Res., 2004, 43(14) p 3632–3652
C. Moreau and L. Leblanc, Optimization and Process Control for High Performance Thermal Spray Coatings, Key Eng. Mater., 2001, 197, p 27–57
J.R. Fincke, W.D. Swank, R.L. Bewley, D.C. Haggard, M. Gevelber, and D. Wroblewski, Diagnostics and Control in the Thermal Spray Process, Surf. Coat. Technol., 2001, 146–147, p 537–543
J.G. Ziegler and N.B. Nichols, Optimum Settings for Automatic Controllers, Trans. ASME, 1942, 64, p 759–768
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dykhuizen, R.C., Neiser, R.A. Process-based quality for thermal spray via feedback control. J Therm Spray Tech 15, 332–339 (2006). https://doi.org/10.1361/105996306X124310
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1361/105996306X124310