An improved process and apparatus for cleaning and/or coating metal surfaces using electro-plasma technology

摘要

A process for cleaning an electrically conducting surface (3) by arranging for the surface to form the cathode of an electrolytic cell in which the anode (1) is maintained at a DC voltage in excess of 30V and an electrical arc discharge (electro-plasma) is established at the surface of the workpiece by suitable adjustment of the operating parameters, characterized in that the working gap between the anode and the cathode is filled with an electrically conductive medium consisting of a foam (9) comprising a gas/vapor phase and a liquid phase. The process can be adapted for simultaneously coating the metal surface by including ions of the species required to form the coating in the electrically conductive medium. Apparatus for carrying out the process is also disclosed and, in particular, an anode assembly (1) which comprises a perforated anode plate (2) which is in communication with a chamber (4) adapted to receive a flow of a liquid electrolyte, means to supply the liquid electrolyte to the chamber, and means (7) to convert the liquid electrolyte received in the chamber into a foam.