SU985158A1 - Electrolyte for deposition of ni-fe-p a alloy coatings - Google Patents

Description

(54) ELECTROLYTE FOR DEPOSITION OF COATINGS BY NICKEL-IRON-PHOSPHOR ALLOY

The invention relates to electroplating, in particular to the deposition of coatings of nickel-iron-phosphorus alloy, which can be used in microelectronics, computer technology, as well as in the automotive and tractor industry.

An electrolyte for deposition of alloy coatings / Nickel-iron-phosphorus, containing nickel and iron sulfates, boric acid, ammonium chloride and sodium hypophosphorite Q. is known.

The closest to the proposed one is vol. Etc an electrolyte for the deposition of magnetic envelopes by a nickel-iron-phosphorus alloy (iron, 1-3% phosphorus) containing sulfate and nickel chloride, ferrous sulfate, hypophos. sodium fat, saccharin, precursory and citric acids and lauryl sulfate nat.ri 2.

However, this electrolyte is not sufficiently effective in the deposition of protective coatings.

The purpose of the invention is to increase the physicomechanical properties and corrosion resistance of coatings.

This goal is achieved by the fact that the electrolyte containing nickel sulfate and chloride, ferrous sulfate, O sodium hypophosphite, saccharin, boric and citric acids, additionally contains glycine or sodium acetate in the following ratio of components, g / l:

Nickel sulfate O-kS

Nickel chloride 30-5

Ferrous sulfate10-30

Sodium hypophosphite 8-12

Boric acid25-5

Lemon acid. 20-30

Glycine or sodium acetate 5-10

Saccharin1-2

The deposition is recommended to be carried out on copper or steel substrates at SO-B C and a current density of 2-7 A / dm: Spree Moderate stirring) using nickel anodes. In order to better adhere the coatings to the substrate, before the precipitation, the parts are cathodically degreased in a solution that contains, g / l: trisodium phosphate 25-30, sodium carbonate 25-30 and liquid glass.

The acidity of the electrolyte, 33, 5) is established by a 20% solution of sulfuric acid.

The scattering capacity of the proposed electrolyte, measured in a flat cell with a collapsible cathode, is 30. The corrections of electrolyte for all components, as well as pH, ensure reliable operation for a long time. The invention is illustrated by several examples presented in Table . 1. As can be seen from the data table. 1, in order to introduce phosphorus into the alloy in sufficiently large quantities, the electrolyte must contain glycine or sodium acetate in combination with citric acid in equal proportions. If one of these components is used, the desired .eff. the effect is not reached (example 4). In tab. 2 shows the phytochemical properties and corrosion resistance of the coatings obtained in the electrolyte according to the invention and the electrolyte without glycine or sodium acetate. Corrosion tests were carried out by a potentiostatic method in an ACC solution (5% sodium chloride solution + acetic acid, 24 for 2 hours). As tests have shown, the stationary potential of the coatings in the ACC solution relative to NVE is (-9.0.) - (-105) V for the alloy foil, for the steel-coating system (thickness 30 µm) - (-195) -C210) mV, while for coatings produced in an electrolyte without glycine (sodium acetate), the stationary potential

is -130 and -320 mV, respectively.

As can be seen from the table. 2, the internal stress of precipitation obtained from the proposed electrolyte is much less than the internal stress obtained from an electrolyte without glycine (sodium acetate). The microhardness of the proposed alloy is higher than the microhardness of the alloy obtained from a known electrolyte, and heat treatment significantly increases the microhardness significantly (2 times) of the alloy obtained from a known electrolyte. The alloy obtained according to the invention also possesses better protective properties, which is characterized by a more positive value of the stationary strength of both the alloy foil and the steel-coating system at the same thickness, i.e. satisfactory protective ability is provided with a smaller coating thickness. From the electrolyte according to the invention, it is possible to obtain an alloy with a sufficiently high content of both phosphorus and iron with a limited concentration of the latter in solution. Due to the above, obtaining the proposed alloy results in a sufficient saving of the scarce nickel metal, along with increased microhardness of heat-treated coatings and lower internal stresses, which is explained by the inclusion of phosphorus in the alloy in rather large quantities. In addition, the proposed electrolyte is characterized by high buffer properties. The alloy production rate, characterized by the permissible current density, is also high (2-7 A / dm) compared with the known electrolyte (0.21, 2 A / dm). Since the total concentration of nickel salts in this electrolyte is lower, the concentration of the known electrolyte is 60-90 g / l versus 22b g / l, this makes it possible to consider the invention more than economically advantageous. The savings from replacing the chemical method with the electrochemical one is 29,160 rubles. in year.

985158 Electrolyte for deposition of nickel-iron-phosphorus alloy coatings containing nickel sulphate and chloride, ferrous sulphate, sodium hypophosphite, harin, boric and L1 monoic acid, characterized in that additionally contains glycine or sodium acetate at the following ratio of components, g / l Nickel sulfate 30 + 5 Nickel chloride -30-A5 Ferrous sulfate 10-30 Sodium hypophosphite 8-12

8 Continued table. 2 Glycine or sodium acetate fj-10 Saccharin1-2 Sources of information taken into account during examination 1.Ilyushenko LF Electrolytically deposited magnetic films. Minsk, Science and Technology, 1972, p. 168.-. 2. Taranets V. Jl-Flerov V.N. Effect of citric acid additive on the process of electrodeposition of nickel-iron-phosphorus alloys, - Journal of Applied Chemistry, 1975 t., No. 12, p. 2764-2765.

Claims (1)

Claim Electrolyte 'for depositing coatings with a nickel-iron-phosphorus alloy containing co-containing nickel sulfate and chloride, ₂₀ ferrous sulfate, sodium hypophosphite, saccharin, boric and citric acids, characterized in that, in order to increase physicomechanical properties and corrosion resistance 25 coatings, it additionally contains glycine or sodium acetate in the following ratio of components, g / l: Boric acid 25-45 Citric acid 20-30 Glycine or sodium acetate 5-10 Saccharin 1-2 Nickel sulfate 30-45 Nickel chloride 30-45 Iron sulfate 10-30 Sodium hypophosphite 8-12