METHOD TO PROTECT ALUMINIUM SURFACE AGAINST CORROSION

摘要

FIELD: machine building.SUBSTANCE: method to produce a protective metal coating on the surface of an article made from aluminium or its alloys involves placement of the article in a processing zone, provision of vacuum in the processing zone, cleaning of the surface by a ion beam and deposition of the metal coating with the simultaneous supply of negative displacement voltage to the article. The surface is cleaned by the beam of inert gas ions with the energy in the range 1-5 keV. The coating deposition is carried out in two stages. At first an intermediate coating layer of copper 0.5-3 mcm thick is deposited on the surface in magnetron direct current discharge burning in the inert gas environment, with a hard cathode from copper at the discharge power of 1-2.5 kW. Afterwards the copper cathode is melted at the discharge power of 3-6 kW with the cathode temperature rise up to the value providing for sufficient pressure of a copper vapour to keep the magnetron discharge, the supply of inert gas is stopped and a basic coating layer of copper 2-10 mcm thick is deposited in the magnetron discharge burning in the copper vapour. The coating layers are deposited on the article at the negative displacement voltage up to 300 V and the surface temperature of 100-300° C.EFFECT: protection of articles made from aluminium and its alloys against corrosion in water solutions of alkalis.1 dwg, 1 ex