A new spray technology for producing hard-coatings, using an electro-thermal chemical (ETC) gun is presented. The powder particles of the coating material are accelerated by conventional solid or liquid propellant combustion products. A pulsed-plasma jet, provided by a confined capillary discharge, ignites the propellant and controls the combustion process. The powder particles are accelerated to velocities calculated to be over 1000 m/s. A high throughput and high powder consumption efficiency is obtained due to the very high carrier gas density and velocity. The plasma jet enables control of the gas temperature, and consequently influences the powder temperature. The technology capabilities have been demonstrated using several material systems such as sintered carbides to obtain coatings on stainless steel and other substrates. In order to evaluate the coating device performance, the coatings obtained were characterized chemically and physically, and a physical model describing the complex processes taking place within the gun was developed. The model is able to predict the main propelling gas and particle parameters, in particular, their acceleration and heating processes.
|Number of pages||7|
|Journal||International Journal of Refractory Metals and Hard Materials|
|State||Published - May 1999|
|Event||Proceedings of the 1998 Science of hard Materials - 66th International Conference on the Science of hard Materials (ICSHMS6) - Lanzarote, Spain|
Duration: 9 Mar 1998 → 14 Mar 1998