A. Killinger, N. Stiegler, J. Rauch, R. Gadow, Universität Stuttgart, Stuttgart, Germany
Thermal spraying of suspensions containing particles of submicron or nano size offer new possibilities in functional coating development and open up new application fields. Regarding their mechanical and physical properties, suspension sprayed coatings differ significantly from conventionally sprayed coatings, due to their refined microstructure.
Spraying nano oxide ceramic suspensions by means of hypersonic flame spraying (HVSFS) has been developed and proven to run as a stable process. Typically, dense coatings with a refined microstructure and a layer thickness typically ranging from 20 – 50 µm can be achieved. Thus, HVSFS can close the gap between conventional spray coatings and thin films.
The presentation gives an overview of the HVSFS process development, containing spray gun design, suspension preparation, substrate preparation and coating process. Examples are given for applications as tribofunctional coatings in engine applications, as electrolyte in SOFC and conducting and insulating coatings in electrical applications.
Summary: A short introduction to thermal spraying of suspensions containing particles of submicron or nano size will be given and recent developments will be briefly discussed.
Recent results in HVSFS process development will be presented, containing spray gun design, suspension preparation, appropriate substrate preparation and coating process features.
Potential industrial applications like tribofunctional coatings in engine applications, functional coatings (electrolyte) for SOFC as well as conducting and insulating coatings in electrical applications are discussed and compared to standard HVOF and APS spray coatings.
