B. Rau

Processes electrochemical processing of metals are used in all industries. With their help, you can perform operations such as drilling, turning, grinding or polishing, milling parts of the most complex configurations, and even removing burrs. In this case, the essence of the processes of electrochemical sizing consists in the anodic dissolution of the metal during electrolysis with the regular removal of the resulting waste. That is why - and this is the most valuable thing - there are practically no hard-to-machine metals for the processes of electrochemical "cutting".
Everything these advantages of electrochemical processing processes can be successfully used at home for many interesting and useful work. For example, with their help, you can cut an elastic plate from a razor blade in 20-30 minutes, cut a hole of complex shape in a thin sheet of metal, carve a spiral groove on a round rod. To carry out all these works, it is enough to have an AC rectifier giving an output voltage of 6-10 volts, or a rectifier for micromotors for 6 volts, or, finally, a set of 2-3 batteries for a flashlight. Pieces of wire, metal, glue and other auxiliary materials can be found in any home workshop.

Milling.

If in some workpiece, you need to make a recess of a complex configuration - for example, cut out the apartment number - then for this you need to take a sheet of Whatman paper and draw on it in full size the contour of the recess that you want to get. Then, with a razor blade or scissors, cut and delete the drawn outline, and cut the sheet in accordance with the shape and dimensions of the workpiece. Glue the template-mask obtained in this way (1) using rubber glue or BF-88 glue on the surface of the workpiece (2), attach a wire to the workpiece from the positive pole of the rectifier or a set of batteries and apply 1-2 layers to all its surfaces without insulation any varnish or nitro paint. It's a good idea to varnish or paint the template mask itself. After letting the coating dry, lower the workpiece into a glass with a concentrated solution of sodium chloride, opposite the mask template, install a cathode plate (3) made of any metal and connect it to the negative pole of the rectifier or current source.
How As soon as the current is turned on, the process of electrochemical dissolution of the metal inside the contour of the template-mask will begin. But after a while, the intensity of the process will decrease, which can be seen from a decrease in the number of bubbles released at the cathode (3). This means that an insulating layer of process waste has formed on the treated surface. To remove them and at the same time measure the depth of the recess, the part must be removed from the glass and, trying not to damage the template-mask, clean off the loose layer of waste from the treated surface with a small hard brush. After that, periodically removing the part to control the dimensions and remove waste, the process can be continued until the depth of the excavation reaches the required value. And when the processing is finished, after removing the insulation and the mask-mask, the part must be rinsed with water and lubricated with oil to avoid corrosion.

Stamping and engraving.

When it is necessary to make a hole with a complex configuration in a thin sheet of metal; the principles of electrochemical machining remain the same as in milling. The subtlety lies only in the fact that in order for the edges of the hole to turn out to be even, the template-mask (1) must be glued to the workpiece from both sides. To do this, the contours of the mask template (1) should be cut out in a sheet of paper folded in half and, sticking the template onto the blank (2), orient it along one of its sides. And besides, in order to speed up the processing and ensure uniform metal removal on both sides, it is advisable to bend the cathode plate (3) in the shape of the letter "U" and place the workpiece to be processed in it.
For manufacturing from sheet steel - for example, from the blade of a razor blade - parts of any profile do a little differently. The profile of the part itself (1) is cut out of the paper and glued to the workpiece (2). Then the entire opposite side of the steel sheet is coated with varnish, and from the side of the template, the varnish insulation is applied so that it does not adjoin the template. And only in one place the applied insulation must be brought to the template with a narrow jumper (3) - otherwise the dissolution of non-insulated surfaces around the template may end before the outline of the part is formed. To obtain more accurate details, you can cut out two templates, stick them on the workpiece on both sides and carry out processing in a U-shaped cathode. Similar methods can be used to make various inscriptions on metal, both convex and "depressed".

Threading and spiral grooving.

One of the varieties of the milling process is the electrochemical cutting of spiral grooves and threads. This method can be useful for making at home, for example, wood screws or twist drills. When threading a screw, as a mask-template (1), you need to take a thin rubber cord with a square cross section 1x1 millimeter, wind it tightly in a spiral onto a cylindrical workpiece (2) and fasten its ends with threads (3). And then those surfaces of the workpiece that cannot be etched are insulated with varnish. As a result of electrochemical machining, a spiral thread cavity is formed on the workpiece between the rubber turns. Now you need to sharpen or, more precisely, make the end of the workpiece conical, which will serve as the sting of the screw entering the tree. To do this, remove the workpiece from the bath, remove the rubber from it and dry it. And then, having varnished its surface so that only the first 2-3 threads of the thread remain open, the workpiece is returned to the bath and the electrochemical processing continues for some time.
For for making a twist drill at home, as a mask-template (1), you need to take three rubber cords of the same section and wind them on a heat-treated cylindrical workpiece (2), but in two passes. Then the surfaces of the workpiece that are not to be processed, and for reliability, the rubber cords must be varnished and, by lowering the part into a glass bath, electrochemical milling of the drill grooves to the required depth is performed. Now these grooves need to be widened to form the so-called "back" of the drill (3). For this, two out of three cords are removed from each strip of rubber insulation, and electrochemical milling continues for some time. After that, by removing the remaining insulation and sharpening the lead-in part, you will have an excellent twist drill.

Grinding.

To to grind the surface of cylindrical parts by electrochemistry, in addition to traditional equipment, you must have a small electric motor or drill. Having previously insulated the surfaces of the part to be processed with varnish, fix it on the motor shaft (1), install the motor vertically on a bracket and lower the end of the part to be machined (2) into the electrolyte bath. In this case, the power supply of the anode part (2) with a current is best organized with a sliding contact going to the motor shaft, and the cathode (3) should be made flat, equal along the length of the treated surface. Now it remains to turn on the electric motor and power supply to the bath. With the beginning of the process, a darkening of the surface will begin - the formation of waste. To obtain the correct cylindrical shape of the treated surface, this waste must be continuously removed. It is convenient to do this with a toothbrush with a bristle shortened for rigidity, which, pressing it against the part, should be measured up and down. By periodically removing the part to measure the diameter, in this way it is possible to obtain a surface with dimensional accuracy according to the second class.

Polishing.

For In order to polish any steel surface, prepare two wooden "kolobashki" (1) measuring 40x40 mm: one for rough and one for final polishing. Fasten the sheet metal plates (2), which act as a cathode, on them so that their position can be adjusted in height. To debug the polishing process, you need to take the workpiece (3), connect it to the positive pole of the current source and place it in the electrolyte bath so that the solution level lies slightly above the horizontal part of the cathode (2). Then the rough "kolobashka" should be dipped with one of the ends into a solution of sodium chloride in the bath, removed and a pinch of fine abrasive powder should be poured onto it. Now, with the current turned on, begin to polish the part in a circular motion. In this case, it may happen that electrochemical dissolution will proceed faster than the process of removing waste with an abrasive. To eliminate this discrepancy, lift the cathode plate higher and the dissolution rate will decrease. After polishing the entire surface with the first "kolobashka", change the electrolyte solution to a clean one, wash the part from the abrasive and with the help of the second "kolobashka" proceed to fine polishing, which should be carried out either without abrasive at all, or using tooth powder instead. With some training in this way, you can get a mirror surface on the parts two to three times faster than mechanical polishing.

"Frost" on a tinplate.

Take an empty canned food can or just a piece of tinplate and connect to the wire from the positive pole of the rectifier. And to the other pole, connect any metal rod, having previously made a cotton swab at its lower end. If now this kind of "shaving brush" is dipped in a solution of table salt and then slowly start to drive it over the surface of the tin, then amazing things will happen to it. In those places where you have applied the "shaving brush" 2-3 times, sparkling crystals of "frost" appear - the crystal structure of the tin coating will be revealed. If you continue the process, then gray islands of waste will soon appear on the metal, firmly attached to the metal. And in the future, the entire surface of the tin will become spotty gray, with a characteristic bizarre pattern.
For obtaining various decorative patterns on metal, you can try to apply solutions of different salts or acids. So, for example, if instead of a solution of sodium chloride to take a one-percent solution of sulfuric acid, the "emerging" crystals will acquire a brown tint. If a tin plate is sprinkled with tooth powder, the "frost" pattern will become more contrasting, with a milky-gray tint. By preheating individual parts of the tin part to local melting of the tin and quickly cooling them in water, you can get the most intricate ornaments on metal. Such ornaments look especially good if they are covered with colored varnish on top. Try it and you will see that a lot of beautiful things can be made from a simple tin can.

Electrochemistry in a glass

Electrochemical metal working processes are used in all industries. With their help, you can perform operations such as drilling, turning, grinding or polishing, milling parts of the most complex configurations, and even removing burrs. In this case, the essence of the processes of electrochemical sizing consists in the anodic dissolution of the metal during electrolysis with the regular removal of the resulting waste. That is why - and this is the most valuable thing - there are practically no hard-to-machine metals for the processes of electrochemical "cutting".

All these advantages of electrochemical processing processes can be successfully used at home to perform many interesting and useful work. For example, with their help, you can cut an elastic plate from a razor blade in 20-30 minutes, cut a hole of complex shape in a thin sheet of metal, carve a spiral groove on a round rod (Fig. 1). To carry out all these works, it is enough to have an AC rectifier giving an output voltage of 6-10 volts, or a rectifier for micromotors for 6 volts, or, finally, a set of 2-3 batteries for a flashlight. Pieces of wire, metal, glue and other auxiliary materials can be found in any home workshop.

Milling.

If in any workpiece you need to make a recess of a complex configuration - for example, cut out the apartment number (Fig. 2) - then for this you need to take a sheet of Whatman paper and draw on it in full size the contour of the recess that you want to get. Then, with a razor blade or scissors, cut and delete the drawn outline, and cut the sheet in accordance with the shape and dimensions of the workpiece. Glue the template-mask obtained in this way (1) using rubber glue or BF-88 glue on the surface of the workpiece (2), attach a wire to the workpiece from the positive pole of the rectifier or a set of batteries and apply 1-2 layers to all its surfaces without insulation any varnish or nitro paint. It's a good idea to varnish or paint the template mask itself. After letting the coating dry, lower the workpiece into a glass with a concentrated solution of sodium chloride, opposite the template-mask, install a cathode plate (3) made of any metal and connect it to the negative pole of the rectifier or current source.

As soon as the current is switched on, the process of electrochemical dissolution of the metal inside the contour of the mask-template will begin. But after a while, the intensity of the process will decrease, which can be seen from a decrease in the number of bubbles released at the cathode (3). This means that an insulating layer of process waste has formed on the treated surface. To remove them and at the same time measure the depth of the recess, the part must be removed from the glass and, trying not to damage the template-mask, clean off the loose layer of waste from the treated surface with a small hard brush. After that, periodically removing the part to control the dimensions and remove waste, the process can be continued until the depth of the excavation reaches the required value. And when the processing is finished, after removing the insulation and the mask-mask, the part must be rinsed with water and lubricated with oil to avoid corrosion.

Stamping and engraving.

When a complex hole needs to be made in a thin sheet of metal, the principles of electrochemical machining remain the same as for milling. The subtlety lies only in the fact that in order for the edges of the hole to turn out to be even, the template-mask (1) must be glued to the workpiece from both sides. To do this, the contours of the mask-template (1) should be cut out in a sheet of paper folded in half and, sticking the template onto the blank (2), orient it along one of its sides (Fig. 3). And besides, in order to speed up the processing and ensure uniform metal removal on both sides, it is advisable to bend the cathode plate (3) in the shape of the letter "U" and place the workpiece to be processed in it.

For the manufacture of sheet steel - for example, from the blade of a razor blade - parts of any profile are acted somewhat differently. The profile of the part itself (1) is cut out of the paper and glued to the workpiece (2) (Fig. 4). Then the entire opposite side of the steel sheet is coated with varnish, and from the side of the template, the varnish insulation is applied so that it does not adjoin the template. And only in one place the applied insulation must be brought to the template with a narrow jumper (3) - otherwise the dissolution of non-insulated surfaces around the template may end before the outline of the part is formed. To obtain more accurate details, you can cut out two templates, stick them on the workpiece on both sides and carry out processing in a U-shaped cathode. Similar methods can be used to make various inscriptions on metal, both convex and "depressed".

Threading and spiral grooving.

One of the varieties of the milling process is the electrochemical cutting of helical grooves and threads. This method can be useful for making at home, for example, wood screws or twist drills. When threading a screw (Fig. 5), as a mask-template (1), you need to take a thin rubber cord with a square cross-section 1x1 millimeter, wind it tightly in a spiral onto a cylindrical workpiece (2) and fasten its ends with threads (3). And then those surfaces of the workpiece that cannot be etched are insulated with varnish. As a result of electrochemical machining, a spiral thread cavity is formed on the workpiece between the rubber turns. Now you need to sharpen or, more precisely, make the end of the workpiece conical, which will serve as the sting of the screw entering the tree. To do this, remove the workpiece from the bath, remove the rubber from it and dry it. And then, having varnished its surface so that only the first 2-3 threads of the thread remain open, the workpiece is returned to the bath and the electrochemical processing continues for some time.

To make a twist drill at home, as a mask-template (1), you need to take three rubber cords of the same section and wind them on a heat-treated cylindrical workpiece (2), but in two passes (Fig. 6). Then the surfaces of the workpiece that are not to be processed, and for reliability, the rubber cords must be varnished and, by lowering the part into a glass bath, electrochemical milling of the drill grooves to the required depth is performed. Now these grooves need to be widened to form the so-called "back" of the drill (3). For this, two out of three cords are removed from each strip of rubber insulation, and electrochemical milling continues for some time. After that, by removing the remaining insulation and sharpening the lead-in part, you will have an excellent twist drill.

The processes of electrochemical processing of metals are confidently gaining ground in all branches of industry. With their help, you can perform operations such as drilling, turning, grinding or polishing, milling parts of the most complex configurations, and even removing burrs. In this case, the essence of the processes of electrochemical sizing consists in the anodic dissolution of the metal during electrolysis with the regular removal of the resulting waste. That is why - and this is the most valuable thing - there are practically no hard-to-machine metals for the processes of electrochemical "cutting".

All these advantages of electrochemical processing processes can be successfully used at home to perform many interesting and useful work. For example, with their help, you can cut an elastic plate from a razor blade in 20-30 minutes, cut a hole of complex shape in a thin sheet of metal, carve a spiral groove on a round rod. To carry out all these works, it is enough to have an AC rectifier that gives a voltage of 6-10 volts, or a rectifier for micromotors for 6 volts, which can be purchased at children's toy stores, or, finally, a set of 2-3 batteries for a flashlight. Pieces of wire, metal, glue and other auxiliary materials can probably be found in any home workshop.

Milling

If in any blank you need to make a recess of a complex configuration - for example, cut out the apartment number (diagram below) - then for this you need to take a sheet of Whatman paper and draw on it the full-size contour of the recess that you want to get. Then, with a razor blade or scissors, cut and delete the drawn outline, and cut the sheet in accordance with the shape and dimensions of the workpiece.

Glue the template-mask 1 obtained in this way with rubber glue or glue on the surface of the workpiece 2, attach a wire from the positive pole of the rectifier or a set of batteries to the workpiece and apply 1-2 layers of any varnish or nitro paint to all its surfaces without insulation. It's a good idea to varnish or paint the mask template itself. After letting the coating dry, lower the workpiece into a glass with a concentrated solution of sodium chloride, opposite the template-mask, install a plate-cathode 3 made of any metal and connect it to the negative pole of the rectifier or current source.

As soon as the current is switched on, the process of electrochemical dissolution of the metal inside the contour of the mask-template will begin. But after a while, the intensity of the process will decrease, which can be seen from a decrease in the number of 3 bubbles released at the cathode. This means that an insulating layer of process waste has formed on the treated surface. To remove them and at the same time measure the depth of the recess, the part must be removed from the glass and, trying not to damage the template-mask, clean off the loose layer of waste from the treated surface with a small hard brush. After that, periodically removing the part to control the dimensions and remove waste, the process can be continued until the depth of the excavation reaches the required value. And when the processing is finished, after removing the insulation and the mask-mask, the part must be rinsed with water and lubricated with oil to avoid corrosion.

Stamping and engraving

When a complex hole needs to be made in a thin sheet of metal, the principles of electrochemical machining remain the same as for milling.

The subtlety lies only in the fact that in order for the edges of the hole to turn out to be even, the template - mask 1 must be glued to the workpiece from both sides. To do this, the contours of the template-mask 1 should be cut out in a sheet of paper folded in half and, sticking the template on the workpiece 2, orient it along one of its sides (diagram above). And besides, in order to speed up the processing and ensure uniform metal removal on both sides, it is advisable to bend the cathode plate 3 in the shape of the letter "U" and place the workpiece to be processed into it.

For the manufacture of sheet steel - for example, from the blade of a razor blade - parts of any profile do a little differently. The profile of part 1 itself is cut out of paper and glued to workpiece 2 (diagram below).

Then the entire opposite side of the steel sheet is coated with varnish, and from the side of the template, the varnish insulation is applied so that it does not adjoin the template. And only in one place the applied insulation needs to be brought to the template with a narrow jumper 3 - otherwise the dissolution of non-insulated surfaces around the template may end before the outline of the part is formed. To obtain more accurate details, you can cut out two templates, stick them on the workpiece on both sides and carry out processing in a U-shaped cathode. Similar methods can be used to make various inscriptions on metal, both convex and "depressed".

Threading and helical grooving

One of the varieties of the milling process is the electrochemical cutting of helical grooves and threads. This method can be useful for making at home, for example, wood screws or twist drills. When threading a screw (diagram below), as a template-mask 1, you need to take a thin rubber cord of square section 1X1 millimeter, wind it with tension in a spiral on a cylindrical workpiece 2 and fix its ends with threads 3. And then those surfaces of the workpiece that are not subject to pickling, insulate with varnish.

As a result of electrochemical machining, a spiral thread cavity is formed on the workpiece between the rubber turns. Now you need to sharpen or, more precisely, make the end of the workpiece conical, which will serve as entering. wood with a sting of a screw. To do this, remove the workpiece from the bath, remove the rubber from it and dry it. And then, having varnished its surface so that only the first 2-3 threads of the thread remain open, the workpiece is returned to the bath and the electrochemical processing continues for some time.

To make a twist drill at home, as a template-mask 1, you need to take three rubber cords of the same section and wind them on a heat-treated cylindrical workpiece 2, but in two passes (diagram above). Then the surfaces of the workpiece that are not to be processed, and for reliability, the rubber cords must be varnished and, by lowering the part into a glass bath, electrochemical milling of the drill grooves to the required depth is performed. Now these grooves need to be widened to form the so-called "back" of the drill 3. For this, two out of three cords are removed from each strip of rubber insulation, and electrochemical milling continues for some time. After that, by removing the remaining insulation and sharpening the lead-in part, you will have an excellent twist drill.

Grinding

To grind the surfaces of cylindrical parts by electrochemistry, in addition to traditional equipment, you must have a small electric motor or drill.

Having previously insulated the surfaces of the part that are not to be processed with a pack, fix it on the shaft of the electric motor 1, install the motor vertically on some bracket and lower the end of part 2 to be machined into the electrolyte bath (diagram above). Power supply of the anode part. 2 in this case, it is best to "organize" with a sliding contact going to the motor shaft, and make cathode 3 flat, equal along the length of the treated surface. Now it remains to turn on the electric motor and power supply to the bath. With the beginning of the process, a darkening of the surface will begin - the formation of waste. To obtain the correct cylindrical shape of the treated surface, this waste must be continuously removed. It is convenient to do this with a toothbrush with a bristle shortened for rigidity, which, pressing it against the part, should be measured downward and upward. By periodically removing the part to measure the diameter, in this way it is possible to obtain a surface with a processing finish of X7 and a dimensional accuracy of the 2nd class.

Polishing

In order to polish any steel surface, prepare two wooden "kolobashki" 1 measuring 40X40 millimeters: one for rough and the other for final polishing (diagram below).

Fasten on them the plates of sheet 2 bent by the angle, playing the role of the cathode, so that their position can be adjusted in height. To debug the polishing process, you need to take the workpiece 3, connect it to the positive pole of the current source and place it in a bath with electrolyte in such a way that the solution level lies slightly above the horizontal part of the cathode 2. Then the rough "buoy" should be dipped with one of the ends into the bath a solution of sodium chloride, remove and pour a pinch of fine abrasive powder on it. Now, with the current turned on, begin to polish the part in a circular motion. In this case, it may happen that electrochemical dissolution will proceed faster than the process of removing waste with an abrasive. To eliminate this discrepancy, lift the cathode plate higher and the dissolution rate will decrease. After polishing the entire surface with the first "kolobashka", change the electrolyte solution to a clean one, wash the part from the abrasive and with the help of the second "kolobashka" proceed to fine polishing, which should be carried out either without abrasive at all, or using tooth powder instead. With some training in this way, a mirror surface can be obtained on parts two to three times faster than mechanical polishing.

"Frost" on tinplate

Take an empty can of canned food or just a piece of tinplate and connect to the wire from the positive pole of the rectifier. And to the other pole, connect any metal rod, having previously made a cotton swab at its lower end. If now this kind of "shaving brush" is dipped into a solution of table salt and then slowly begin to drive it over the surface of the tin, then amazing things will happen to it. In those places where you have applied a "shaving brush" 2-3 times, sparkling crystals of "frost" appear - the crystal structure of the tin coating will be revealed. If you continue the process, then gray islands of waste will soon appear on the metal, firmly attached to the metal. And in the future, the entire surface of the tin will become spotty gray, with a characteristic bizarre pattern.

To obtain various decorative patterns on the metal, you can try to use solutions of different salts or acids. So, for example, if instead of a solution of sodium chloride to take a one-percent solution of sulfuric acid, the "emerging" crystals will acquire a brown tint. If a tin plate is sprinkled with tooth powder, the "frost" pattern will become more contrasting, with a milky-gray tint. By preheating individual parts of the tin part to local melting of the tin and quickly cooling them in water, you can get the most intricate ornaments on metal. Such ornaments look especially good if they are covered with colored varnish on top. Try it and you will see that a lot of beautiful things can be made from a simple tin can.

Electrochemical sizing is based on the local anodic dissolution of the workpiece material in an electrolyte solution with intensive movement of the electrolyte between the electrodes.

The machinability of metals and alloys by the electrochemical method depends on their chemical composition and does not depend on their mechanical properties and structural state. The advantages of the method include high surface quality with an increase in processing productivity, no thermal effect on the part, and no wear of the tool electrode. Due to this, during electrochemical processing, a layer of a changed structure is not formed and the formation of burns, cracks, residual stresses, etc. on the surface is excluded.

Feasibility of application

The use of electrochemical processing turns out to be highly effective and economically feasible in the following main cases:

1. for processing parts made of particularly hard, brittle or ductile materials (heat-resistant, hard and titanium alloys, stainless and hardened steels);
2. for processing structurally complex assemblies and parts (gas turbine blades, dies, molds, casting molds, internal channels and cavities, etc.), even from materials that can be cut;
3. to replace particularly laborious (including manual) operations (deburring, edge rounding, etc.);
4. to obtain a high quality, including polished surface without defects in the surface layer.

It is advisable to classify the known types of electrochemical processing according to two defining characteristics - the mechanism of the metal destruction process itself and the method of removing the reaction products from the working zone. Based on this, we can name three main directions in which the development and implementation of electrochemical processing methods is going on: electrochemical-hydraulic (anode-hydraulic) processing, electrochemical mechanical processing and combined processing methods.

Electrochemical-hydraulic processing

Electrochemical-hydraulic treatment (also called electrochemical treatment in a flowing electrolyte) is based on the anodic dissolution of metal and the removal of reaction products from the working area by an electrolyte flow. In this case, the speed of the electrolyte flow in the interelectrode gap is maintained in the range of 5-50 m / s (using a pump providing a pressure of 5-20 kgf / cm2, or due to the rotation of the cathode-tool, continuously wetted by the electrolyte). The operating voltage is maintained within 5-24 V (depending on the material and technological operation), the gap between the electrodes is from 0.01 to 0.5 mm; the size of the gap is regulated by automatic tracking systems. Stainless steel, brass, graphite (the latter when processing at alternating or impulse voltage) are used as the material for the manufacture of the electrode-tool.

The energy intensity of this group of processes depends on the chemical composition of the processed material and the current efficiency. For most technological operations, it is 10-15 kWh / kg. The most common at present are the following types of electrochemical-hydraulic processing.

Copy-stitching operations carried out with the translational movement of the cathode-tool, the shape of which is copied on the product simultaneously over the entire surface (Fig. 5).

These operations are used in the manufacture of turbine blades, forging dies, etc. At a metal removal rate of 0.1-0.5 mm / min, a surface finish of 6-7 is achieved; with an increase in the processing speed to 1-2 mm / min, the surface finish rises to 8-9. The highest productivity obtained when machining cavities on the MA-4423 machine is 15000 mm3 / min at a current of 5000 amperes. The feed rate of the tool in the direction of metal removal is 0.3-1.5 mm / min when processing dies, molds and blades and 5-6 mm / min when piercing holes. Surface finish 6-9; processing accuracy 0.1-0.3 mm. Processing is carried out with minimal gaps (0.1-0.15 mm); the largest gaps (5-6 mm) - while processing large surfaces.

Rice. 5. Scheme of piercing a hole by electrochemical method

Rice. 6. Machining with a rotating disc tool

Processing with a rotating disk tool (Fig. 6), which allows for profile, flat and circular external grinding with a non-abrasive tool to obtain a surface finish of 7-9 with a productivity on stainless steels up to 150-200 mm3 / min from a working area of ​​1 cm2 and 60-80 mm3 / min for hard alloys, it is used to obtain the profile of carbide threaded dies, shaped cutters, knurling rollers, making external spline grooves, cutting narrow slots, cutting blanks (cutting width 1.5-2.5 mm; surface finish 6-7) as well as for the processing of permanent magnets. Processing is carried out with gaps of 0.01-0.1 mm; processing accuracy 0.01-0.05 mm, surface finish 6-9. The feed rate, depending on the depth of processing, ranges from 1 to 40 mm / min, the voltage is 6-10 V. When machining cemented carbide, alternating or pulsed currents are used.

Rice. 7. Scheme of electrochemical deburring: 1 - tool; 2 - insulating sleeve; 3-blank (anode); 4 - removable burr

Wire complex contour cutting on a copy of products from hardened, stainless steels and other difficult-to-machine materials allows the manufacture of die matrices, templates, through and blind grooves. Productivity of processing is up to 40 mm2 / min with a surface finish of 8 - 9. The accuracy of processing in straight cutting 0.02 mm, when cutting along the contour 0.06 mm. The maximum thickness of the workpiece to be cut is 20 mm (the given data were obtained on the MA-4429 machine).

Removing burrs from gears (Fig. 7), parts of hydraulic equipment, small radio engineering products, etc.

Manufacturing of grooves in special products.

Figured processing of bodies of revolution both at the end of the product and outside and inside. The processing accuracy when using a shaped cathode is 0.05-0.1 mm.

Electrochemical mechanical treatment

Electrochemical mechanical treatment is based on the anodic dissolution of metal and the removal of reaction products from the treated surface and from the working area using an abrasive and an electrolyte flow. This type of machining includes electrochemical grinding (electro-abrasive or electro-diamond machining), electrochemical machining with a neutral abrasive (grinding, honing and polishing) and anodic abrasive machining. In electro-abrasive and electro-diamond machining, metal removal is carried out not only due to the reaction of anodic dissolution, but also by grains of abrasive or diamond.

Productivity with electro-diamond grinding of hard alloys is 1.5-2 times higher than with diamond grinding, and the wear of a diamond wheel is 1.5-2 times less (when working with wheels on a bronze bond of Ml, on bonds M5, MB1 and MO13E, the wear of a wheel approximately the same as for diamond grinding); the surface finish is the same as for diamond grinding. In electrochemical grinding, the power consumed to drive the grinding wheel decreases several times. At the same time, the temperature of the surface layer drops sharply, due to which the appearance of cracks and burns is completely excluded. This method is widely used for sharpening carbide tools.

Electrochemical machining with neutral abrasives is used for flat, cylindrical and profile grinding, honing of internal cylindrical surfaces, and superfinishing. In all cases, the productivity of these operations is four to eight times that of machining.

Combined processing methods

The combined processing methods include electroerosive and electrochemical - ultrasonic.

The electroerosive-chemical processing method is based on the simultaneous occurrence of the processes of anodic dissolution and erosional destruction of the metal and the removal of reaction products from the working area by an electrolyte flow. During piercing operations, the cathode feed rate reaches 50-60 mm / min for steel, 20-30 mm / min for high-temperature alloys and 10 mm / min for hard alloys. In this case, the wear of the cathode-tool does not exceed 2.5%; processing accuracy 0.1-0.4 mm (according to experimental data).

This method can also be used for circular, flat and profile grinding, cutting workpieces made of difficult-to-machine materials. When cutting stainless steel blanks, the productivity is 550-800 mm2 / min; tool wear reaches 4-5%; processing accuracy 0.1-0.3 mm. Machines for this processing method are currently not produced.

The electrochemical processing method is based on the destruction of the metal by its simultaneous anodic dissolution and exposure to ultrasonic vibrations. This method is used for machining carbide drawing dies.

The site outlines the basics of electroplating technology. The processes of preparation and application of electrochemical and chemical coatings, as well as methods of quality control of coatings are considered in detail. The main and auxiliary equipment of the electroplating shop is described. Provides information on the mechanization and automation of electroplating, as well as sanitation and safety.

The site can be used for vocational training of workers in production.

The use of protective, protective-decorative and special coatings allows solving many problems, among which the protection of metals from corrosion takes an important place. Corrosion of metals, that is, their destruction due to the electrochemical or chemical effects of the environment, causes enormous damage to the national economy. Annually, due to corrosion, up to 10-15% of the annual output of metal in the form of valuable parts and structures, complex instruments and machines goes out of use. In some cases, corrosion leads to accidents.

Electroplated coatings are one of the effective methods of corrosion protection, they are also widely used to give the surface of parts a number of valuable special properties: increased hardness and wear resistance, high reflectivity, improved antifriction properties, surface electrical conductivity, facilitating solderability and, finally, just to improve the external type of products.

Russian scientists are the creators of many of the most important methods of electrochemical processing of metals. So, the creation of electroforming is the merit of Academician B.S. Jacobi (1837). The most important work in the field of electroplating belongs to the Russian scientists E. Kh. Lenz and I. M. Fedorovskii. The development of electroplating after the October Revolution is inextricably linked with the names of the scientists professors N. T. Kudryavtsev, V. I. Liner, N. P. Fedot'ev and many others.

A lot of work has been done to standardize and normalize coating processes. The dramatically increasing volume of work, mechanization and automation of electroplating shops required clear regulation of processes, careful selection of electrolytes for coating, selection of the most effective methods for surface preparation of parts before deposition of galvanic coatings and final operations, as well as reliable methods of product quality control. Under these conditions, the role of a qualified electroplating worker is sharply increasing.

The main task of this site is to help students of technical schools in mastering the profession of an electroplating worker who knows modern technological processes used in advanced electroplating workshops.

Electrolytic chromium plating is an effective way to increase the wear resistance of rubbing parts, protect them from corrosion, as well as a protective and decorative finish. Chromium plating gives significant savings when restoring worn parts. The chromium plating process is widely used in the national economy. A number of research organizations, institutes, universities and machine-building enterprises are working on its improvement. More efficient electrolytes and chromium-plating modes appear, methods are developed to improve the mechanical properties of chrome-plated parts, as a result of which the scope of chromium-plating is expanding. Knowledge of the basics of modern chrome plating technology contributes to the fulfillment of the instructions of the normative and technical documentation and the creative participation of a wide range of practitioners in the further development of chrome plating.

The site has developed questions of the influence of chromium plating on the strength of parts, expanded the use of effective electrolytes and technological processes, introduced a new section on methods to improve the efficiency of chromium plating. The main sections have been revised taking into account the nporpecific achievements of chrome plating technology. The given technological instructions and designs of suspension devices are approximate, guiding the reader in the choice of chrome plating conditions and in the principles of designing suspension devices.

The continuous development of all branches of mechanical engineering and instrument making has led to a significant expansion of the field of application of electrolytic and chemical coatings.

By means of chemical deposition of metals, in combination with electroplating, metal coatings are created on a wide variety of dielectrics: plastics, ceramics, ferrites, sitall and other materials. The manufacture of parts from these materials with a metallized surface ensured the introduction of new design and technical solutions, an improvement in the quality of products and a reduction in the cost of production of equipment, machines, and consumer goods.

Parts made of plastics with metal coatings are widely used in the automotive industry, the radio engineering industry and other sectors of the national economy. The processes of metallization of polymeric materials have become especially important in the production of printed circuit boards, which are the basis of modern electronic devices and radio engineering products.

The brochure provides the necessary information about the processes of chemical-electrolytic metallization of dielectrics, and presents the basic laws of the chemical deposition of metals. The features of electrolytic coatings during plastics metallization are indicated. Considerable attention is paid to the technology of production of printed circuit boards, as well as methods of analysis of solutions used in metallization processes, and methods of their preparation and correction are given.

In an accessible and entertaining form, the site introduces physical nature in the peculiarities of ionizing radiation and radioactivity, the effect of various doses of radiation on living organisms, methods of protection and prevention of radiation hazard, the possibilities of using radioactive isotopes for the recognition and treatment of human diseases.