High velocity pulsed plasma thermal spray

• Published in: Journal of thermal spray technology Vol. 11; no. 1; pp. 119 - 128
• Main Authors: WITHERSPOON, F. D, MASSEY, D. W, KINCAID, R. W, WHICHARD, G. C, MOZHI, T. A
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.03.2002; Springer Nature B.V
• Subjects: Acceleration; Applied sciences; Coatings; Cross-disciplinary physics: materials science; rheology; Devices; Diagnostic systems; Durability; Exact sciences and technology; Imaging; Materials science; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Particles (particulate matter); Physics; Plasma applications; Powder metals; Spray coating techniques; Sprayed coatings; Sprayers; Sprays; Stainless steel; Substrates; Tungsten carbide; Vacuum applications; Velocity; Thin films; Spray coatings; HVOF spraying; Hot spraying; Plasma arc spraying; Experimental study; Pulsed beam
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1361/105996302770349050

The quality and durability of coatings produced by many thermal spray techniques could be improved by increasing the velocity with which coating particles impact the substrate. Additionally, better control of the chemical and thermal environment seen by the particles during flight is crucial to the quality of the coating. A high velocity thermal spray device is under development through a Ballistic Missile Defense Organization Small Business Innovation Research (SBIR) project, which provides significantly higher impact velocity for accelerated particles than is currently available with existing thermal spray devices. This device utilizes a pulsed plasma as the accelerative medium for powders introduced into the barrel. Recent experiments using a particle imaging diagnostic system showed that the device can accelerate stainless steel and WC-Co powders to velocities ranging from 1500 to 2200 m/s. These high velocities are accomplished without the use of combustible gases and without the need of a vacuum chamber, while maintaining an inert atmosphere for the particles during acceleration. The high velocities corresponded well to modeling predictions, and these same models suggest that velocities as high as 3000 m/s or higher are possible.