METHOD FOR PROVIDING OF PROTECTIVE COATINGS ON METAL OR ALLOY SURFACE Russian patent published in 2005 - IPC

FIELD: mechanical engineering, radoelectronics, chemical industry, medicine, aviation, in particular, electrochemical processing of metal and alloy surface for forming thereon of corrosion, heat- and wear-resistant coatings for imparting dielectric and decorative properties thereto.

SUBSTANCE: method involves providing microarc oxidation by means of apparatus comprising electrode and porous shield, through which liquid electrolyte is fed and voltage is supplied to zone between surface portion to be processed and porous shield having variable section thickness, said electrolyte being fed with predetermined flow rate at increasing voltage of up to 190 V; performing oxidation process by moving said device over surface to be processed. Apparatus is furnished with system for sucking electrolyte with air from surface to be processed. Oxidation current density to electrolyte flow rate ratio is in accordance with dependence: 12>I/Q_electr.>8, where I is oxidation current density, cA/m²; Q is electrolyte flow rate, kg/s. Method allows volume of electrolyte consumed to be reduced by 1.5 times due to preventing electrolyte from spreading over surface under process and from pouring of electrolyte onto floor.

EFFECT: wider capabilities of method, reduced consumption of electrolyte, provision for localization of active microarc discharge zone and stabilizing of kinetic layer of chemical conversion facilitating in producing of homogeneous coating having improved quality, and also increased protective and decorative effect of resultant coating.