SU833439A1 - Method of producing diamond discs - Google Patents

Description

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The invention relates to the production of diamond-containing tools and can be used in the manufacture of polishing discs for processing natural yashmazov, instrument watch stones and other highly hard {materials.

A known method for the manufacture of diamond-galvanic HHCTpyh HTOB, in which the diamond powder in an electroplating bath is periodically stirred up and, on the surface of the horizontal body of the instrument, the cathode, is fixed with a layer of electrolytic nickel p. .

However, with this method, you can fix the powder size of 50-100 microns

With a smaller graininess, a dense bulk layer of powdered powder is formed on the surface of the tool, which impedes the free movement of the metal ions of the binder, which results in deterioration of the conditions of attachment of diamond grains to the tool body. The concentration of diamond powder in the coating does not exceed 10-12%

The purpose of the invention is to obtain a concentration of diamond grains of 520 microns in size with their one-time roiling.

The goal is achieved by the fact that in the electroplating bath the distance between the cathode M4 and the anode is chosen to be (95-100)) 1 l where K is the concentration of diamond powder in the electrolyte in g / l. At the same time, the current density is chosen not higher than 1 temperature of 1820 С with one-time stirring up of diamond grains.

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Nickel and iron are taken as a binder for fastening the powder, which is obtained by layering nickel and iron layers by layer with thermal treatment at 330–350 ° C for 1-3 h.

As the material. Body of the tool take gray cast iron or corner. Ledodistuyu steel.

Experimentally established that

0 to obtain a concentration of 50-55% of diamond porosity of 5–20 µm in the diamond layer, it is necessary that during the electro-adhesive process the disk is covered with a bulk monolayer with a concentration of 60-80%.

Claims (3)

Such a layer is formed after the deposition of diamond grains in the electrolyte under this condition. If the concentration of the diamond powder in the bulk monolayer increases, a solid layer is formed on the surface of the polishing disk over 80%, the free movement of metal ions to the disk is hampered, the conditions for attachment of grains are reduced and their concentration in the diamond layer is reduced. With a decrease in the concentration of the brilliant powder in the bulk monolayer below 50%, the concentration of the fixed diamond grains is reduced by the proprC25 subdially the concentration of the bulk monolayer. An increase in the height of the electrolyte pole above the tool body — an RCM cathode or an increase in the concentration of diamond in the electrolyte leads to an increase in the concentration of diamond grains in the bulk monolayer. The choice of the bonding alloy is dictated by the adhesion strength of the fine diamond powder to the surface of the tool body and the reduction of its wear. Example. A composite electroplating coating is deposited on a steel casing with a diameter of 305 mm and contains diamond powder AFM 20/14. Electrodeposition mode: Voots electrolyte containing 1 g / l AFM 20/14, height of electrolyte column over a body l 100 mm, current density 1 A / dm t temperature, deposition time 30 min. Before switching on the current electr lit mixing with compressed air. After fixing the diamond powder, the casing is washed with water and installed in an iron bath (450 g / l, current density FeCla. A / dm, t 20 s), in which additional fixing of the diamond pig iron with iron for 40 minutes is produced. Then, the tool is heat treated for 3 hours, resulting in a homogeneous alloy of nickel and iron substitution solid solution, firmly holding the diamond powder on the surface of the tool body. The proposed method makes it possible to process natural diamonds at elevated speeds. Claim 1. A method of making diamond discs for cutting natural diamonds, in which symmean grains are mounted on a horizontally positioned instrument case, a cathode, in a galvanic bath, characterized in that in order to obtain a high concentration of diamond grains 5-20 µm in size, their roiling, the distance between the instrument case — the cathode and the anode in the electroplating bath is chosen to be (95-100) - -, where K is the concentration of diamond grains in the electrolyte in g / l. 2. A method according to claim 1, characterized in that the electroplating process is carried out at a current density not higher than 1 A / dm and at a temperature of 18-20 ° C. 3. A method according to claim 1, characterized in that layers of nickel and iron are applied successively to the diamond grains with a thermal finish. processing at a temperature of 330-350 C for 1-3 h. Sources of information taken into account during examination 1. Baikal AK and Sukiennik I.L. Diamond "galvanic coupled instrument". Kiev, Naukova Umka, 1976, p. 22-4.8.