SPARK COATING PROCESS AND APPARATUS

摘要

The invention relates to a process and an apparatus for spark coating some materials with special properties on various base metal pieces. The claimed process is designed to carry out coatings of 0.01...0.5 mm and 0.5...3.0 mm, respectively, on various base metal pieces () and implies the generation of sparks between the tip of an electrode () and a base metal piece (), which leads to forming a variable interstice of 0...0.5 mm, by means of which an intermittent thermal contact () is established, said contact generating sparks associated with fine drops sprayed on the base metal, rotation of the electrode () in order to avoid the accidental welding thereof on the piece (), forward motion for the uniform coating of the base metal, and oscillation of the electrode along the piece on the vertical and horizontal planes for the uniform spreading of the coating. The claimed apparatus comprises a transformer () with an apparent power of 0.160...2.0 kVA, provided with some components for limiting the short-circuit current in the secondary winding, the secondary circuit consisting of a rectifier () which supplies a capacitor () with the positive terminal connected to a spark applicator () wherein there is mounted a consumable electrode () put into rotary motion or vibration through a mechanical and electrical flexible cable () by a rotary or vibratory mechanism () controlled by a speed or frequency regulator (), while the negative terminal of the capacitor () is connected to a positioning table () whereon there is positioned the base metal piece () on which the deposition or the coating of the electrode () with the special material is further carried out.