CS212927B1 - a method of producing anode materials for electrolytic deposition of two- and multi-component alloys - Google Patents

Abstract

The invention relates to a method for producing cast iron materials usable as anodes in the electrolytic deposition of two- and multi-component alloys. The essence of the solution lies in the fact that the anode material is produced by electrocrystallization from an aqueous solution containing metal ions that form the components of the produced material, these ions being supplied to the solution, bath, during the production process by anodic dissolution of pure metals and by the action of a multiple anode circuit and/or in the form of soluble salts from the action of inert anodes.

Description

The invention relates to a process for the production of alloy materials useful as anodes in the electrolytic deposition of two- and multi-component alloys.

Electrolytic deposition of alloy layers has recently been given increased attention by the electroplating industry for the advantageous properties that many alloys have compared to pure metals. Certainly, the complicated control of the electrolysis process is a limitation for the widespread distribution of, in particular, multi-component alloys. The anodes used are mostly pure metals, such as nickel, iron, cobalt and the like, and to maintain the prescribed metal concentration in the bath, a multiple anode circuit with precisely controlled currents in the individual branches must be introduced. In this way, the demands on the operation of the control elements, in addition to the increased possibility of failure occurring, of which the passivity of some of the anodes appears to pose the greatest danger to the required stationary state, will be met.

For these reasons, it is preferable to use anodes made of an alloy of the same composition as the cathodically excluded layer. These alloys are usually prepared by methods of classical metallurgy, the disadvantage of which is the considerable energy consumption and the necessity to strictly observe the specified technology in order that the composition of the produced alloy meets the requirement (eg danger of partial oxidation of some of the components). The main drawback is that the anode material prepared in this way often has a low area of activity, a low Plade potential, resulting in difficulties in conducting electrolysis, especially when some of the bath components are easily subject to anodic oxidation.

The aforementioned drawbacks are eliminated by the process for producing anode materials for the electrodeposition of two- and multi-component alloys according to the invention, characterized in that the anode material is produced by electrocrystallization from an aqueous solution containing metal ions which are constituents of the material to be produced. supplied to the solution by anodic dissolution of the pure metals using a multiple anode circuit and / or in the form of soluble salts using inert anodes.

The concentration of the components in the bath is such that the desired anode composition is achieved, as a cathode it is advantageous to use a sheet of material which is a component of the alloy to be deposited. For refilling the cathodically deposited metal into the bath, anode from the pure metals of the alloy components is used. These are connected to the individual branches of the multiple anode circuit, the ratio of Faraday currents in the individual branches being selected so as to achieve the desired composition of the deposited material, constant throughout the electrolysis.

If any of the components is not available as an anode metal material, it may be added to the electrolyte (bath) in the form of a soluble salt, and insoluble anodes may be used in the appropriate anode circuit to achieve a constant ratio of metal concentrations in solution. An example of electrical connection is shown in the figure.

After deposition of the alloy layer on the cathode at the desired thickness, the electrolysis is interrupted and the deposited layer is separated from the substrate. This operation is not necessary if the material

212 S27 selected as a pad in the amount in which it is used does not interfere. The principle of the proposed method is illustrated by three examples, but the scope of the invention is not limited or limited.

Example 1

For the production of Ni-Pe anode material with the required content of 15 wt. An electrolyte (aqueous solution) with the following composition was used:

200 g / l nickel sulphate crystal.

g / l potassium bromide 20 g / l sodium formate 20 g / l ferrous sulfate crystal.

g / l sodium sulfosalicylate g / l saccharin

0.1 g / l neokal pH β 4.2 o

The alloy was deposited on a cathode consisting of an Arema sheet of 3 dm. In the double anode circuit, nickel anodes of the NPAN type and iron anodes of Arema were used. The total current of 12 A (cathode current density 4 A / dm) was divided into individual anode circuit branches in a ratio of Fe: Ni = 1: 5. The bath temperature was 50 ° C. A chemical analysis of the deposited layer of approx. 2 mm thickness showed a true composition: 16.8 wt. Fe, 83.2 wt. Ni.

Example 2

For the production of an anode of Ni-Co material with the required content of 5 wt. cobalt bath was used with composition (aqueous solution):

250 g / l nickel sulphate crystal.

. 5 g / l cobalt sulphate crystal.

g / l boric acid 10 g / l sodium chloride

PH = 5.2 o

A pure nickel sheet of 2 dm was suspended as a cathode. The nickel anode NPAN and the platinum anode were connected in the double anode circuit. The total current of 2 A (cathode current density 1 A / dm) was split in the anode circuit in a ratio of Pt: Ni < 1: 19. _; . 10 µmol / m 2 in an amount of 18 ml / h. The bath temperature was 60 ° C. A layer of alloy having a thickness of 1 mm and a composition of 5.4 wt. % cobalt and 94.6 wt. nickel.

212 S27

Example 3

A bath (aqueous solution) having a composition of 0.01 was used to produce the anode of Fe-Ni-Co. 10 ³ mol / m ³ cobalt sulfosalicylate 0.24. 10 ³ mol / m ³ ferrous sulfosalicylate 0.56. 10 ³ mol / m ³ nickel sulfosalicylate 0.08. 10 ³ mol / m ³ potassium iodide pH = 4

A nickel sheet with an area of 2 dm was suspended as a cathode. An electrolytic cobalt anode, Arema iron anode and NPAN nickel anode were connected in the triple anode circuit. The total current of 5 A (cathode current density 2.5 A / dm) was divided in the anode circuit in the ratio Co: Ni: Fa = 1:19:22. The bath temperature was 50 ° C. Excluding a layer with a thickness of about 1 mm, the expected composition of 2.5% by weight was confirmed analytically. % cobalt, 45 wt. % nickel and 52.5 wt. irons.

Claims (1)

A method for producing anode materials for the electrodeposition of two- and multi-component alloys, characterized in that the anode material is produced by electrocrystallization from an aqueous solution containing metal ions which are constituents of the material to be produced. metals with a multiple anode circuit and / or in the form of soluble salts under the action of inert anodes.