SU1024532A1 - Electrolyte for applying self lubricating nickel- and cobalt-based coatings - Google Patents

Abstract

ELECTROLYTE FOR THE DRAWING OF SELF-LUBRICATED COATINGS ON THE BASIS OF NICKEL AND COBALT, containing salts of precipitated metals selected from the group consisting of sulfates, chlorides, sulfamates of nickel and cobalt or their mixtures, a buffer additive selected from the group that includes a boron, and a body, and a body, and a body, and a body, and a body that has a boron, and a body that has a boron, and a cobalt, nickel and cobalt, or a mixture of deposited metals, are selected from the group consisting of a nickel and cobalt sulfates, chlorides, sulfamates of nickel and cobalt, or a mixture of them lubricants, characterized in that, in order to reduce roughness and increase the density of coatings while expanding the range of operating current densities, it additionally contains a bis-quaternary salt of pyridine bases Formulas f 1 Jzcr R ™ where R H, OH; Gl H, OH R - f g - LI and b1 - SNe R H R -CHg-0-CHe-0 according to the following, the ratio of components, g / l: Salts of deposited metals275-365 Bufferne additive 20-40 Particles of solid lubricant5-200 bis - Quaternary salt of pyridine bases 0.04-0.2

Description

The invention relates to the deposition of electroplating, in particular composite, and can be used to obtain composite electrochemical coatings (CEP) based on nickel, cobalt and their alloys containing particles of solid lubricants graphite, molybdenite (MoSj) and hexagonal boron nitride (oC-BN ). The electrolyte can be used in the engineering and instrument making, automotive, aviation and other industries in the industry to protect parts of components operating under dry and boundary friction (in general conditions and in vacuum) from abrasion.

An electrolyte is known for depositing a self-lubricating nickel-graphite coating containing, g / l: nickel sulfate 300-450} nickel chloride 20-50 boric acid 20-40} wetting agent, for example sodium lauryl sulfate 0.05-1} fine graphite 2-50. The electrolyte is designed to produce uniform coatings at current densities of 3-15 only for the composition N1 - graphite f

However, xopoijee coating quality is achieved by using a very high mixing rate (preventing the formation and incorporation of nik-el hydroxide in the sediment), as well as a large distance between the cathode and the anode. In addition, when coating on special steels, iron, copper, copper alloys and other metals, the use of a sublayer of another metal, such as nickel, is required.

The closest to the technical essence of the invention is an electrolyte for applying self-applied coatings based on nickel and cobalt, containing salts of precipitated salts, such as sulfates or chlorides, a buffer additive, such as boric acid, and solid lubricant particles, such as molybdenum disulfide particles, graphite, boron nitride and others 2.

A disadvantage of the known electrolyte is that the coatings are deposited in the form of loose, non-coherent precipitates in a rather narrow range of operating current densities.

The aim of the invention is to reduce the roughness and increase the density of coatings while expanding the range of operating current densities.

This goal is achieved by the fact that an electrolyte for applying self-lubricating coatings based on nickel and cobalt, containing salts of deposited metals selected from the group including sulfates, sulfide nickel and cobalt sulforides or their mixture, buffer additive selected

from the GROUP, including boric and aminoacetic acid, and solid lubricant particles, additionally contains a Sue-Quaternary salt of pyridine bases of the general formula

where R N, HE | pji

H, OHf CH

R Hf

   -CHg -O -CH ,, R + R 2 O

with the following ratio of components ,, H / L

Salt Osausdal1nh

metals275-365

Buffer Additive 20-40

Solid particles

grease 5-200

Sue-Quaternary

pyridine salt

foundations0.04-0.2

The additive introduced into electropolit adsorbing on particles and exhibits a wetting effect reduces their agglomeration, which stabilizes the suspension and promotes the formation of early dimensional coatings with the inclusion of fine particles. Possessing also a leveling effect, the additive leads to poluneniya smooth coatings in a wide range of current density, regardless of the interelectrode distance and bath configuration (bell / stationary).

In addition, the addition of this additive to the electrolyte stabilizes the CEP deposition mode, increases the current output of the metal by 20-50% (when deposited with conductive particles) and reduces the amount of hydrogen released, which reduces the alkalization of the cathode layer and the inclusion of metal hydroxides in the sediment. impairing its quality. This eliminates the need for complex hydrodynamic regimes and high mixing speeds and allows for electrolysis at high current densities (up to 50 A / dm for conducting particles).

The electrolyte is prepared as follows.

A solid lubricant powder in the form of a creamy paste is introduced into the appropriate electrolyte to produce NiCO or Ni-CO alloy, which is obtained by dissolving the corresponding components of the copolymer in water. The paste is obtained by thoroughly mixing the powder particles with a small amount of electrolyte in which the quaternary salt of the pyridine base is dissolved. When precipitating with graphite and molybdenite, the pH of the electrolyte should be in the range of 1.5-2.2, with about-BN 1.5-4.0. The temperature of the electrolyte is 20-40 ° C. The particles are kept in suspension by mixing (mechanical or air). The coating can be carried out both in stationary baths and in bulk and submersible type bells. Rotating the bell at a speed of 10-15 rpm is sufficient to maintain 50-100 g / l of particles in suspension. The content of the dispersed phase in coatings is almost independent of the Additive Name Name, and the current density in the range of 1-50 A / dm. In this case smooth uniform coatings with a thickness of up to 40-50 microns are obtained. The number of inclusions and caps can vary from 5 to 30 vol.% Depending on the electrolyte composition, concentration of the dispersed phase and the quaternary salt of the pyridine base. For conductive particles of graphite and MoSj, the boundary values of the concentration of the suspension are 5-60 g / l, for non-conducting particles about -BN 25-200 g / l. As the quaternary salts of pyridine bases, one of the additives listed in Table 2 can be introduced. 1, Table 1 Does the structural formula

2,6-Dipyridine-N-methyl) -4-methylphenol-dichloride

An example. Several electrolyte formulations were prepared for the precipitation of nickel, cobalt and nickel-cobalt alloy with different content of the main components and additives. NiS047H20 is used as starting salts; NiCl2 SHgO; Coso vhjo; CoCl2 6H2O. Industrial solid powders of graphite (grade C-1), molybdenum disulfide (grade MVC), and boron nitride 1-10 microns in size are used as solid lubricants.

The coatings are deposited on the cathode from

R OH; R N

Clchz

steel or copper with mechanical agitation of the electrolyte.

The content of the dispersed phase is determined by the weight method for nitride

0 for boron and graphite after dissolving coatings in 10% nitric acid or for disulfide or lipden after dissolving coatings in hydrochloric acid, or spectrophotometrically using the single method, after dissolving coatings in concentrated nitric acid.

The data obtained are presented in Table 2.

For comparison, data were obtained in the absence of additions of 5c-quaternary salts of pyridine bases with

maintaining the remaining characteristics of the electrolyte and the regime unchanged. The data obtained are presented in Table. 3

Table 3

Claims (1)

ELECTROLYTE FOR APPLICATION OF SELF-LUBRICATED COATINGS BASED ON NICKEL AND COBALT, containing salts of precipitated metals selected from the group consisting of sulfates, chlorides, nickel and cobalt sulfamates or mixtures thereof, a buffer additive selected from the group comprising solid boric and amino acids and characterized in that, in order to reduce the roughness and increase the density of coatings while expanding the range of working current densities, it additionally contains a bis-quaternary salt of pyridine bases of the general formula where R ¹ = H, OH} R ^d = H, OH: R ^r = = CHj; R ^l * = H R ^w + R '= —CH _g —O — CHg — O in the following, ratio of components, g / l: Salts of precipitated metals 275-365 Buffer additive Particulate grease bi-c-Quaternary salt of pyridine bases 20-40 5-200 0.04-0.2 (11). from goppa, including boric and aminoacetic acids, and particles of solid lubricant, additionally contains Sue quaternary salt of the pyridine bases of the general formula