METHOD OF FORMING OXIDE FILM COATING OF CONVERSION COBALT, PRODUCT, SOLUTION FOR CONVERSION COBALT-CONTAINING COATING, AND COATED OBJECT

摘要

FIELD: metal protection. SUBSTANCE: invention relates to forming coating on metal substrate and thereby conferring it corrosion resistance and adhesion for dyes. Method was worked out to replace preceding method in the given area where chromic acid was the basis and consists in the following. Solution for cobalt conversion is formed which includes aqueous solution containing soluble six-valent Co(II) complex, concentration of which varies over the range from 0.01 M to saturation concentration. The solution is brought in contact with substrate for a period of time sufficient for a coating to be formed through cobalt conversion. As a substrate, aluminium, its alloy, as well as galvanic Cd, Zn, and Zn-Ni coatings, and steel may be used. Aforementioned Co(III) complex has general formula Me_m[Co(R)₆]_n, where Me is Na, Li, K, Ca, Zn, Mg or Mn, m =2 or 3, n = 1 or 2, and R is carboxylate with 1-5 C atoms. Coating of invention, in particular, contains, along with cobalt oxides, alumina as a main volume component. EFFECT: improved protection of metal substrate.