Blown Arc Plasma Source for the Elaboration of Finely Structured Coatings

Abstract

New emerging technologies using blown arc plasma sources allow elaborating finely structured coatings which find many applications fields. Among them, Suspension Plasma Spraying consists in injecting within a dc plasma jet a liquid jet containing submicron solid particles which are plasma-sprayed to form coatings. This new technology has renewed the interest devoted to the understanding and the development of blown arc plasma sources. This paper focuses on a non-exhaustive description of standard (subsonic) dc plasma torches involving blown arcs related to the Suspension Plasma Spraying (SPS). The emphasis is put on important features for SPS, i.e. on the influence of operating parameters on plasma properties, the understanding of the origin of electric arc instabilities and their influence on suspension injection, and at last, the coating characteristics.

Editorial: [Thermal Plasma Sources]

“…For example, water-stabilized arc sources allow the generation of very high enthalpy and velocity plasmas [6] depending on the arc stabilization process. In direct current (dc) arc plasma torches [7] or in low-voltage circuit breakers [8], research is directed towards understanding the transient behaviour of the electric arc. Modelling of such processes implies a three-dimensional treatment of the fluid flow and electromagnetic equations.…”

“…Finally, we note that the special issue gives examples of the main excitation methods for plasma sources. These are the directcurrent transferred arcs used in circuit breakers [8] (and also in arc welding and arc furnaces, for example), the direct-current non-transferred arcs used in plasma torches of various types [6,7,9] and the inductively-coupled radio-frequency sources [8], in which electrodes are not required.…”