RU2101395C1 - Electrolyte for depositing copper-cobalt alloy - Google Patents

Abstract

FIELD: electrolytic processes. SUBSTANCE: electrolyte contains copper and cobalt salts, Trilon B, ammonium acetate, and organic additive - leveller at specified proportion of components which makes possible obtaining bright and half-brilliant coatings with high corrosion resistance. EFFECT: improved quality if coatings. 1 tbl

Description

 The invention relates to electroplating, in particular to electrolytic deposition of a copper-cobalt alloy.

 Known electrolyte for the deposition of a copper-cobalt alloy containing cobalt chloride, copper sulfate, sodium pyrophosphate and ammonium citrate.

The scattering capacity of this electrolyte, measured in the Field cell, is 48-53% and the corrosion rate of the coatings obtained in a 0.1 n sulfuric acid solution is 0.20-0.24 g / m ² h.

The proposed electrolyte differs from the known one in that, in addition to copper and cobalt salts, it contains Trilon B (ethylenediaminetetraacetic acid disodium salt), ammonium acetic acid and, as an organic additive, equalizer A (methyldiethylaminomethyl acrylphenol polyglycol ether benzosulfate) in the following ratio of components, g / l:
Cobalt sulfate 100-120
Copper sulfate 20-30
Trilon B 40-50
Ammonium acetate 20-30
Equalizer A 2.5-3.5
The aim of the invention is to increase the dispersing ability of the electrolyte and the corrosion resistance of the resulting coatings.

 An additional introduction of ammonium acetate promotes an increase in the electrical conductivity of the solution and its buffering properties, and also improves the uniformity of the distribution of metal at the cathode.

Trilon B binds copper and cobalt ions into very strong trilonate complex compounds (lg beta _{Cu EDTA} 18.80 and lg beta _{Co EDTA} 16.31), which inhibits the hydrolysis of salts and improves the stability of the electrolyte.

 The surfactant nonionic substance equalizer A, adsorbed on the cathode, inhibits the recovery of metal ions, while improving the wettability of the surface of the precipitation.

 The electrolyte is prepared by dissolving copper salts of cobalt and Trilon B salts in separate portions of water. Part of Trilon B (taking into account the concentrations) is added to the copper sulfate solution, and the other half of Trilon B solution is added to the cobalt salt solution. The mixture of solutions is left for 10-15 minutes for complete complexation, and then slowly (with stirring) a solution of copper complexon is added to the cobalt complexone solution.

The electrodeposition of the coatings is carried out at a cathodic current density of 0.4-4.0 A / dm ² , a temperature of 20-25 ^o C, pH 0.8-3.1 with stirring using a platinum anode.

 Specific examples of the use of electrolyte and some properties of the coatings are given in the table.

 The dissipating ability of the proposed electrolyte by increasing the polarization of the cathode when Trilon B and equalizer A are introduced into its composition increases by 17-19% compared with the known electrolyte.

 The corrosion rate of alloys obtained from the proposed electrolyte is 37.5-40% lower than coatings deposited from a known electrolyte.

Using the proposed electrolyte makes it possible to obtain light, semi-brilliant, fine crystalline, dense coatings. Precipitation withstands bending at an angle of 90 ^o without kink and does not exfoliate from the base after heating at 250 ^o C for 1 h and subsequent sharp cooling.

Claims (1)

An electrolyte for the deposition of a copper-cobalt alloy containing copper and cobalt sulfate salts, a complexon and an organic acid, characterized in that it additionally contains ammonium acetate, and as a complexon and an organic additive, respectively, trilon B and a leveling agent A, methyldiethylaminomethylmethacrylphenol benzosulfate polyglycol ether components in the following ratio g / l:
Cobalt Sulfate 100 200
Copper sulfate 20 30
Ammonium acetate 20 30
Trilon B 40 50
Equalizer A 2.5 3.5r

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