SU658187A1 - Method of electrochemical oxidation of copper - Google Patents

Description

The proposed method is characterized in that, with the aim of increasing the uniformity and electrical insulation properties of the coating, the process is carried out at 110-140 ° C in a solution of the composition, g / l: Hydroxide metal 500-1000 Oxidizer 5-20 Alkali metal fluoride or ammonium 20-70 Alkali metal phosphate or ammonium 30-100 In this case, the coating is subjected to heat treatment in an atmosphere of air at 200-300 ° C. The proposed method is carried out as follows. Pre-defatted samples of copper and its alloys are immersed in an alkaline solution of the above composition and kept for no current for 1-2 minutes. The anodization process is carried out at 100-140 ° C, anodic direct current density of 10-20 A / dm for 15-180 seconds. A semi-dimensional coating (irregularity of the coating does not exceed 15–20 ° / o), a semi-gloss black coating with a thickness of 3–5 µm, strongly adhering to the substrate, with a specific electrical resistance of 510–5–10 ohm-cm, is formed on the surface. Conducting the subsequent thermal treatment of products in air at an atmosphere of 1 ° at 200-300 ° C for 5-120 minutes provides an increase in electrical resistivity up to 910-8-10 Ωcm. In tab. 1 shows the compositions of the solution; in tab. 2 - Anodizing conditions and experimental data. Carrying out the process at an alkali metal hydroxide concentration of 750 g / l and a temperature of 60-80 ° C provides a film with a specific electrical resistance of no more than (0.2-1.6) 10 Ohm, see An increase in the temperature of the electrolyte SOAC (at a higher temperature of lachinac boiling) at an alkali metal hydroxide concentration of 100–250 g / l is obtained, and Llenka has a specific electrical resistance of no more than (0.5–2.2} 10 O (. Only a combination of elevated concentrations of alkali metal hydroxide and elevated temperatures at certain values of the current density and the duration of the n {process ensures a positive effect. Deviation from these modes is accompanied by the formation of loose (erased basics), non-uniform (non-coherent) coatings with low resistance. The invention can be used in electrical engineering in the manufacture of cable products, in particular, to produce electrical insulating surfaces on current carrying superconducting elements with copper stabilizing cladding, for example, NT-50 , BT-60, HLI-50, Table

10A

500

750 1000

1O

20

70

50 500

thirty

11roa (anodizing, min

Lnotsna current flow rate, L / cm

o Solution temperature, С

Topschin; coating, micron

Heat treatment temperature, C

Continue to use} heat treatment, min

Upepnoe epektrosoprotivenie. Om-cm

before heat treatment (4-8) 10 (0.7-2) 10 (0.5-1) 10

after heat treatment (0.5-1) 1O (4-8) 10 (2-5) 1O

Coverage unevenness,%

Claims (3)

Claims I. Method of electrochemical oxidation of copper in an alkaline solution at a current density of 10-20 A / dm, characterized in that, in order to improve the uniformity and electrical insulation properties of the coating, the process is carried out at 110-140 ° C in a solution composition, g / l: Alkali metal hydroxide 500-1000 Oxidizing agent5-20 Alkali metal fluoride or ammonium 20-70 Alkali metal or ammonium phosphate 30-100 T a b p and c 0.25 one 20 15 14O 12O 4.5 5.5 25O 15 200 120 18 20 2. A method according to claim, characterized in that the coating is subjected to thermal treatment in an atmosphere of air at 200-300 ° C. Sources and KIT information taken into account during the examination 1. Timonova M. A. Corrosi and protection of magnesium alloys. M., “Mechanical Engineering, 1964, p. 197. 2. Griliches S. Ya. Oxidation and phosphatization of metals. L., “Mechanical Engineering, 1971, p. 83-84. 3.Patent of France No. 2064465, cl. From 23 b 11/00. 1971.