SU1284748A1 - Electrolyte for dimensional electrochemical machining of metals - Google Patents

Abstract

This invention relates to electrophysical and electrochemical methods for the treatment of metals, mainly copper and its alloys, namely, electrolytes for dimensional electrochemical machining (echo) of products made from these materials. The purpose of the invention is to increase the productivity and accuracy of processing, improve the quality of the surface being treated and eliminate sludge formation. To do this, ammonium nitric acid and sodium citric acid are introduced into the electrolyte based on a 20% aqueous solution of sodium nitric acid, which form water-soluble complexes with ions of the metal or alloy processed, which prevents the separation of the sludge in the interelectrode space and increases accuracy ECHO, increasing the coefficient and: 5 the selectivity of the anodic process. On average, an increase in ECO performance, depending on the type of metal or alloy, is 5–25%, with an increase in the selectivity coefficient by 15–25% and a decrease in the height of the surface microroughness as compared with ECM in electrolyte-pro. with the same modes 2-7 times. B. During the treatment process, the electrolyte does not slurry and, after passing 450 Kl / l of electricity, remains transparent, bluish in color. C 3 (L 00 4ib 00

Description

The invention relates to electrophysical and electrochemical methods for the treatment of metals, namely, to electrolytes for the dimensional electrochemical machining of articles made of copper and its alloys.

The aim of the invention is to increase the productivity and accuracy of processing, to improve the quality of the surface being treated and to eliminate sludge formation,

This goal is achieved by adding ammonium nitric acid and citric acid sodium, which form water-soluble complexes with ions of the metal or alloy being processed, to a known electrolyte based on an aqueous solution of sodium nitrate, which forms water-soluble complexes with the metal or alloy ions, which prevents the release of sludge in the interelectrode space and increases accuracy processing due to an increase in coefficients

PRI me R 2, Preparing an electrolyte, a solution with stirring in 5 liters of tap water, 1750 g of sodium nitric acid, 600 g of ammonium nitric acid, and 150 g of sodium citric acid, and then after complete dissolution The volume of the topping-up is adjusted to 10 liters. This solution is used for an ECM alloy of copper and 8% nickel in an experimental setup at hydrodynamic and temperature conditions, similar to example 1, and the treatment is carried out at a voltage on a 18 V cell, current density 61.8A / ci / and feed rate 1.17 mm / min, which is 23% more than with the ECHO in a known electrolyte. The coefficient of selectivity is 1.16 instead of 1.08, and the height of asperities is 0.1-0.25 μm instead of 0.5-0.7 μm. After processing in a known electrolyte.

Example 3. Prepare an electrolyte solution in 5 liters of tap water.

five

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of electrolyte selectivity. 25 2000 g sodium nitrate, 700 t

thirty

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The proposed electrolyte composition was tested in dimensional electrochemical shaping of samples from copper single crystal and from copper alloys with nickel and aluminum.

Example 1. Preparing an electrolyte, a solution in 5 liters of tap water, 1,500 g of sodium nitrate, 500 g of ammonium nitric acid, and 100 g of sodium citrate. After complete dissolution of the components by topping up with water, the volume is brought up to 10 liters and is used for the electrochemical shaping of cavities in single crystals of copper h-a experimental setup. The magnitude of the MEP is 0.1 - 0.4 mm, the flow rate of the electrolyte is 20 m / min, the temperature is 20 -. The treatment is carried out at a voltage on the cell of the installation of 14 V, a current density of 48.0 A / cm2, and a feed rate of 0.93 mm / min. In this case, the coefficient of selectivity, calculated by the ratio of the removal rates at the MEP at 0.1 and 0.15 mm, amounts to 1.19 instead of 1.08 obtained in a known electrolyte based on a 20% aqueous solution of sodium nitrate and the height of microscopic irregularities is 0.32-0.33 microns instead of 0.6-0.85 microns in a known electrolyte. After passing 450 cells / l of electricity, the electrolyte remains clear, bluish in color, and no sludge is present.

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ammonium nitric acid and 200 g of sodium citric acid, and then after complete dissolution the volume of water is added to 10 liters. This solution produces ECM products from copper alloy with 10% aluminum - piercing holes with a diameter of 6 mm. At temperature and hydrodynamic conditions analogous to example 1, with a voltage across the cell of a 10 V installation and a current density of 33 A / cm, the feed rate of EI is 0.71 mm / min instead of 0.6 mm / min using a known electrolyte. The coefficient of selectivity is 1.1 instead of 1.08, and the height of micro-roughness is 0.33 µm instead of 0.6-0.8 with an ECM in a known electrolyte. In all examples, the electrolyte, after passing 450 C / L of electricity, remains transparent and has a bluish-green appearance.

As can be seen from the above examples, the performance, the selector for the ability and, therefore, the accuracy of the ECHO in the proposed Bbmie electrolyte than in the known, the height of the microroughness is less and the slime formation is completely eliminated.

Claims (1)

Invention Formula Electrolyte for dimensional electrochemical metal processing, pre0 five 0 five ammonium nitric acid and 200 g of sodium citric acid, and then, after complete dissolution, the volume of water is added to 10 liters. This solution produces ECM products from copper alloy with 10% aluminum - piercing holes with a diameter of 6 mm. At temperature and hydrodynamic conditions, similar to example 1, with a voltage across the cell of a 10 V unit and a current density of 33 A / cm, an EI feed rate of 0.71 mm / min instead of 0.6 mm / min is obtained using a known electrolyte. The selectivity coefficient here is 1.17 instead of 1.08, and the height of the microroughness is 0.33 µm instead of 0.6-0.8 with ECM in the Known electrolyte. In all examples, the electrolyte, after passing 450 C / l of electricity, remains transparent and has a bluish-green appearance. As can be seen from the above examples, the performance, the selectivity and, therefore, the accuracy of the ECHO in the proposed Bbmie electrolyte than in the known, the height of the microroughness is less and the slime formation is completely eliminated. Invention Formula Electrolyte for dimensional electrochemical machining of metals, pre312847484 property of copper and its splits, a higher ratio of components, the basis of an aqueous solution of sodium nitrogen% by weight: but acidic, characterized by sodium nitric, in order to produce 15–20% acid durability and precision of processing, 5 Ammonium Nitrogen Surface Improvement and Acidic 5-7 sludge formation, he added- Sodium lemon-containing ammonium nitric acid1-2 Lime and sodium citric acid when barely- WaterEverything Else