Abstract
Materials in the system Si-C-N feature excellent properties for wear and corrosion protection applications even at elevated temperatures and an excellent thermal shock resistance among the ceramics. As these materials have no melting point, they cannot be processed purely by conventional spraying techinques, but need to be synthesized. Plasmajet CVD processes with single and triple DC torches and HF torches with supersonic nozzles have successfully been applied to produce Si-C(-N) coatings on different steel, aluminum, titanium and copper alloys as well as on graphite. Various liquid single precursors with suitable structure have been tested and evaluated with regard to the morphology and structure of the produced coatings. The processes are compared taking into account their characteristics concerning the injection modes, gas temperature and velocity profiles. Emission spectroscopy is used to determine the mechanisms of the coating formation. Guidelines for the optimum production of Si-C(-N) coatings by Plasmajet CVD are deducted.
