SU456046A1 - Electrolyte for cobalt-tungsten alloy deposition - Google Patents

Description

one

The invention relates to the field of electroplating the coating of alloys on a metal surface and can be used to obtain heat-resistant electroplating coatings of a cobalt-tungsten alloy.

A known electrolyte for precipitating a cobalt-tungsten alloy containing a cobalt salt, sodium tungstate and ammonium sulfate. The presence of sulfuric acid and cobalt in the form of sulfate in the electrolyte makes this electrolyte unsuitable for the electroforming of parts, since precipitates are brittle, cracking in thick layers.

The proposed electrolyte is different in that

what is the quality of cobalt salts in it?

cobalt sulfamat, as well as caustic soda and

ammonium hydroxide in the following ratio of components. (in g / l)

52-58

Cobalt sulfamate

33-39

Sodium tungstate

250-300

Ammonium sulfate

10-11

Sodium hydroxide

Before creating pH

Ammonium hydroxide solution 9.0-9.5.

(25-on)

These differences contribute to reducing the fragility of precipitation and increase the productivity of the process.

At a temperature of 60 ° C "cathode current density of 3-3.5 a / dm from the electrolyte of the proposed composition were coated with an alloy of cobalt tungsten with a layer thickness of 150 mk steel samples, and also an electrilement detail with a wall thickness of 1.2 mm was made by the galvoplastic method. . The deposition time of the cobalt tungsten alloy during the manufacture of the experimental part was 50 hours. The cathode output of the cobalt-tungsten alloy in terms of current, determined with the help of a copper coolometer, is 69%. Chemical analysis of the cobalt-tungsten alloy showed that the sediment contains 34% of tungsten, the rest is cobalt.

In the study of sediment properties of a cobalt-tungsten alloy, it was found that these sediments can be separated from the substrate on which deposition was made, without the formation of cracks.

The microhardness of a freshly precipitated cobalt-tungsten alloy, measured on a PMT-3 instrument, was 514 kg / mm. The microhardness of this alloy after heat treatment in a cooling atmosphere at 700 ° C for 8 hours was 525 kg / mm. : -45B046 J Subject and scatter eNN and Electrolyte for precipitating cobalt tungsten alloy, containing a cobalt salt, sodium tungstate and ammonium sulfate, distinguishable TeiM, which, in order to reduce precipitations and increase the productivity of the process. cobalt salts cobalt sulfamate is introduced into it, as well as caustic soda but 4; ammonium hydroxide with the following ComloientoV ratio (g / l): cobalt sulfamate 52-58 sodium tungstate 33-39 ammonium sulfate 250-300 caustic sodium 10-11 ammonium hydroxide Before creating a pH (25-on) solution of 9.0-9.5.