I read about this interesting method processing. I want to implement it on a CNC machine :)

From the book “Handbook of Technological Engineer in Mechanical Engineering” (Babichev A.P.):

Electrochemical dimensional machining is based on the phenomenon of anodic (electrochemical) dissolution of metal when current passes through an electrolyte supplied under pressure into the gap between the electrodes without direct contact between the tool and the workpiece. Therefore, another name for this method is anodic chemical treatment.

During the processing process, the tool electrode is the cathode, and the workpiece is the anode. The electrode-tool moves progressively at speed Vn. The electrolyte is fed into the interelectrode gap. Intense movement of the electrolyte ensures a stable and highly productive course of the anodic dissolution process, removal of dissolution products from the working gap and removal of heat arising during the processing process. As the metal is removed from the anode workpiece, the cathode tool is supplied.

The speed of anodic dissolution and processing accuracy are higher, the smaller the interelectrode gap. However, as the gap decreases, the process of its regulation becomes more complicated, the resistance to pumping the electrolyte increases, and breakdown can occur, causing damage to the surface being treated. Due to the increase in gas filling at small gaps, the rate of anodic dissolution decreases. Should choose

such a gap size at which the optimal metal removal rate and forming accuracy are achieved.

To obtain high technological performance of ECM, it is necessary that the electrolytes meet the following requirements: complete or partial exclusion adverse reactions, reducing the current efficiency of the anodic dissolution of the workpiece metal only in the processing zone, excluding the dissolution of unprocessed surfaces, i.e. the presence of high localizing properties, ensuring flow in all areas of the workpiece surface being processed electric current calculated value.

The most common electrolytes are neutral solutions inorganic salts chloride, nitrates and sulfates of sodium and potassium. These salts are cheap and harmless to operating personnel. Wide Application received aqueous solution sodium chloride (table salt) NaCl due to its low cost and long-term performance, which is ensured by the continuous reduction of sodium chloride in solution.

ECM installations must have filters for cleaning the electrolyte.

I am pleased with the achieved roundness of the hole. But the funnel shape is not pleasing.

Now I’ll try to pump the electrolyte through a medical needle.

Modified April 18, 2008 by desti

K.: Technology, 1989. - 191 p.
ISBN 5-335-00257-3
Download(direct link) : sputnik_galvanika.djvu Previous 1 .. 8 > .. >> Next

In electrochemical milling, a protective coating can be made of any acid-resistant paint applied using a stencil. The etching solution in this case consists of 150 g/l sodium chloride and 150 g/l nitric acid. Etching occurs at the anode at a current density of 100-150 A/dm2. Copper plates are used as cathodes. After the process is terminated, the cathodes are removed from the bath.

Electrochemical milling differs in higher accuracy compared to chemical ones.

PRE-TREATMENT OF ALUMINUM AND ITS ALLOYS

To ensure strong adhesion of the electrolytic coating to aluminum, an intermediate layer of zinc, iron or nickel is applied to the surface of the latter (Table 21).

CHEMICAL AND ELECTROCHEMICAL POLISHING

A smooth metal surface can be obtained by chemical or electrochemical (anodic) polishing (Tables 22, 23). The use of these processes makes it possible to replace mechanical polishing.

When oxidizing aluminum, to achieve a shiny surface, mechanical polishing alone is not enough; after it, chemical or electrical polishing is necessary.

21. Solutions for pre-treatment aluminum

Orthophosphoric acid Ice acetic acid Orthophosphoric acid

280-290 15-30 1-6

Acid orange * To obtain:

dye 2

pinned surface

1st treatment with intermediate process

ratu-ra. WITH

4. ORTHOPHOSPHOR!

Triethane! lamin

500-IfXX) 250-550 30-80

Triethanolamine Catalin BPV

850-900 100-150

Orthops f mercury acids Chromic acid

* PS mining products are processed by washing in the same washing machine 6A/dm2

tro chemical polishing When polishing precious metals chemical or electrochemical methods completely eliminate their losses. Electrochemical and chemical polishing can be not only a preparatory operation before electroplating, but also the final stage technological process. It is most widely used for aluminum. Electrochemical polishing is more economical than<ими-ческое.

The current density and duration of the electropolishing process are selected depending on the shape, size and material of the products.

COATING PROCESS TECHNOLOGY

SELECTION OF ELECTROLYTES AND PROCESSING MODES

The quality of the metal coating is characterized by the structure of the deposit, its thickness and uniformity of distribution on the surface of the product. The structure of the precipitate is influenced by the composition and pH of the solution, hydrogen released together with the metal, the electrolysis mode - temperature

ski polishing

M 41
with SS
Density
„|§..
Cathodes

From Slali
Carbon

I-IL
15-18
1,63-1,72
12XI8H9T, svshscho

1-5
10-100

Made of steel 12Х18Н97
H: rusting

From styles 12Х18Н9Т Aluminum and 3-5 20-50 - (aluminum) stainless

0.5-5.0 20-50 1.60-1.61 From copper or evin- Copper on it

temperature, hoc density, presence of swing, filtration, etc.

To improve the structure of the precipitate, various organic additives (glue, gelatin, saccharin, etc.) are introduced into the electrolytes, complex salts are precipitated from solutions, the temperature is increased, continuous filtration is used, etc. The released hydrogen can be absorbed by the precipitate, contributing to an increase in fragility and porosity , and the appearance of so-called pitting points. To reduce the effect of hydrogen on the quality of the deposit, parts are shaken during the process, oxidizing agents are introduced, the temperature is increased, etc. The porosity of the deposit decreases with increasing thickness.

The uniform distribution of the deposit on the surface and the surface depends on the dissipating ability of the electrolyte. Alkaline and cyanide electrolytes have the best dissipating ability, acidic electrolytes have much less, and chromium electrolytes have the worst dissipating ability.

When choosing an electrolyte, it is necessary to take into account the configuration of the products and the requirements that are imposed on them. For example, when coating products of simple shape, you can work with electrodes that are simple in composition >-

lntamn that do not require heating, ventilation, filtration; when covering products complex shape solutions of complex metal salts should be used; for coating internal and hard-to-reach surfaces - internal and additional anodes, filtration, mixing; to receive shiny coating- electrolytes with complex shine-forming and leveling additives, etc.

GENERAL SCHEME OF THE TECHNOLOGICAL PROCESS

The coating process consists of a series of sequential operations - preparatory, coating and finishing. Preparatory operations include mechanical processing [of parts, degreasing in organic solvents, chemical or electrochemical degreasing, etching and polishing. Final coating processing includes dewatering, brightening, passivation, impregnation, polishing, and brushing. After each operation

I'm writing a dissertation. I am new to Inventor. I don’t have enough time, can anyone help, please help) There is a beam welded from sheets 10 mm thick. The material of the sheets, as well as the welding material, are specified using Semantic 2015. Dependencies at the edges, because . in these areas the beam is welded to the longitudinal beams (Figure 1). Loads, then the force is introduced - 500 N. The result is somehow strange. N, the picture is the same. What could be the reason?

Let's go in order. I agree with paragraph 3 of Article 1358. It clearly follows from this paragraph that a Utility model (someone else’s patent) is considered used in a product (your product) if it uses at least one feature from an independent claim of someone else’s patent. This single feature used can only be a distinctive feature, since Article 1358 of the Civil Code deals with EVERY feature of an independent claim. “The independent claim must contain the necessary features: - to realize the purpose of the invention (utility model), - to achieve the technical result specified in the description; The set of features of the independent claim must provide the subject of the invention or utility model with patentability"

It looks like it. element damping is just from combines. Examples usually involve either rotor dynamics or FSI analysis using acoustic elements. Or should you shake the containment? Well, there are water tanks))) they can be modeled with acoustic elements. Although these are fleas, of course. g - constant structural damping assign different g to different materials. Why is Rayleigh damping not suitable? Well, except that you don’t know the required alpha and beta. an approach is used to create an FE model. The FE model can contain different objects such as combinations14 or simply materials with damping. Assembling the matrix from the FE model is the task of the program. Our task is to assemble the FE model and properly configure the program. Shoving your objects into its matrices after the program has formulated the matrix is ​​unproductive and does not correspond to the popular approach. A conversation about modal coordinates, apparently, is a conversation about a solution using the superposition method of harmonic or transient analysis. But this is not certain)

Let's go in order. I think you agree with paragraph 3 of Article 1358. Yes? It clearly follows from this paragraph that if at least one feature from the independent claim of the formula is not used, then the patent is not used in the object. Do you agree? This single unused feature can be both a distinctive feature and a restrictive one, since Article 1358 of the Civil Code refers to EVERY feature of an independent claim. That's actually all I wanted to say.

Ratcheting is not stabilization, but the accumulation of deformation from cycle to cycle. but the reverse process is also possible - stabilization and stretching of the hysteresis into a straight line. He probably even does it more often. How exactly a specific material will behave under specific conditions is another question. that's it. only in special cases. Let's say we stretch the material. and let us assume that our material is such that at a fairly large deformation the Bauschinger effect ceases to be observed. how can this be, for example... but we exceeded the yield limit twice. If the Bauschinger effect worked, then upon unloading and subsequent compression the material would begin to plastically deform immediately. And if at the tensile stage the yield strength were exceeded three times, then the material would flow in compression without yet being unloaded. This leads us to the conclusion that the yield surface is not rigid, but has the ability to deform in the region of large deformations. But adherents of isotropic hardening go further. And let's, so that the above-described crap does not happen, as the surface of fluidity shifts, we will also expand it. Then, with large stretching and subsequent unloading and compression, it is possible to select such parameters as to fit into a separate private experiment or several experiments. But by using isotropic hardening, we expand the surface not only in one direction, but also in the perpendicular one. If you look at the stress space, let’s say tension/compression - we were talking about sigma1, then perpendicular - sigma 2 or sigma3. And now this is categorically false. That is, this will not work for complex loading trajectories. Therefore, a combination with ishotropic hardening is a dead end. It does not exist in nature; it was simply easier to program it at the beginning of the development of FEM for problems with one-sided plastic deformation and a simple loading trajectory. As a bonus for those who read to the end. There is also combined hardening, by the way, but with good results.

Electrochemical metal processing processes are confidently gaining ground in all industries. With their help, you can perform operations such as drilling, turning, grinding or polishing, milling parts of complex configurations, and even removing burrs. At the same time, the essence of the processes of electrochemical dimensional processing is the anodic dissolution of the metal during electrolysis with the regular removal of generated waste. And therefore - and this is the most valuable thing - there are practically no hard-to-cut metals for electrochemical “cutting” processes.

All these advantages of electrochemical processing processes can be successfully used at home to perform many interesting and useful works. For example, with their help you can cut an elastic plate from a razor blade in 20-30 minutes, cut a complex-shaped hole in a thin sheet of metal, or carve a spiral-shaped groove on a round rod. To perform all these works, it is enough to have a rectifier AC, giving an output voltage of 6-10 volts, or a rectifier for 6-volt micromotors, 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 you need to make a recess of a complex configuration in any workpiece - for example, cut out an apartment number (diagram below) - then to do this you need to take a sheet of Whatman paper and draw on it life size outline of the recess you want to achieve. Then use a razor blade or scissors to cut and remove the drawn outline, and cut the sheet in accordance with the shape and size of the workpiece.

Glue the template-mask 1 obtained in this way using rubber glue or glue onto the surface of the workpiece 2, attach the 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 remaining surfaces without insulation. It’s a good idea to varnish or paint the mask template itself. After allowing the coating to dry, lower the workpiece into a glass with a concentrated solution of table salt, install a cathode plate 3 made of any metal opposite the mask template and connect it to the negative pole of the rectifier or current source.

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

Stamping and engraving

When it is necessary to make a hole of a complex configuration in a thin sheet of metal, the principles of electrochemical processing remain the same as for milling.

The only subtlety is that in order for the edges of the hole to be smooth, the template - mask 1 must be glued to the workpiece on 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, gluing the template onto the workpiece 2, orient it along one of its sides (diagram above). And in addition, in order to speed up processing and ensure uniform removal of metal from both sides, it is advisable to bend the cathode plate 3 in the shape of the letter “U” and place the workpiece into it.

To make parts of any profile from sheet steel - for example, from razor blades - parts of any profile are done somewhat differently. The profile of part 1 itself is cut out of paper and pasted onto workpiece 2 (diagram below).

Then the entire the opposite side steel sheet, and on the template side, varnish insulation is applied so that it does not adjoin the template. And only in one place does the applied insulation need to be brought to the template using 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 precise parts, you can cut out two templates, stick them on the workpiece on both sides and carry out processing in a U-shaped cathode. Using similar methods, you can make various inscriptions on metal, both convex and “indented”.

Threading and spiral grooves

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

As a result of electrochemical processing, a spiral thread cavity is formed between the turns of rubber on the workpiece. Now you need to sharpen or, more precisely, make conical the end of the workpiece that will serve as the input. wood with the sting of a screw. To do this, you need to 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 continued electrochemical processing some more time.

To make a twist drill at home as a template-mask 1, you need to take three rubber cords of the same cross-section and wind them onto 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 coated with varnish and, lowering the part into a glass bath, electrochemical milling of the drill grooves to the required depth. Now these grooves need to be expanded to form the so-called “back” of drill 3. To do this, two of the three cords are removed from each strip of rubber insulation, and electrochemical milling continues for some time. After this, by removing the remaining insulation and sharpening the lead, you will have an excellent twist drill.

Grinding

To grind the surfaces of cylindrical parts using the electrochemical method, in addition to traditional equipment, you need to have a small electric motor or drill.

Having previously insulated the surfaces of the part that are not to be treated with a pack, secure it on the shaft of electric motor 1, install the motor vertically on some bracket and lower the processed end of part 2 into a bath of electrolyte (diagram above). Power supply of the anode part. 2 current in this case is best “organized” by a sliding contact going to the motor shaft, and cathode 3 is made flat, equal in length to the surface being processed. Now all that remains is to turn on the electric motor and power to the bath. With the beginning of the process, the surface will begin to darken - the formation of waste. To get the correct cylindrical the surface being treated, this waste must be continuously removed. This can be conveniently done using a toothbrush with bristles shortened for rigidity, which, pressed against the part, should be moved steadily down and up. By periodically removing the part to measure the diameter, in this way it is possible to obtain a surface with a surface finish of X7ya and dimensional accuracy of the 2nd class.

Polishing

In order to polish any steel surface, prepare two wooden “bottles” 1 measuring 40X40 millimeters: one for roughing and the second for finishing polishing (diagram below).

Attach tin plates 2 bent at an angle to them, acting as a 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 so that the level of the solution lies slightly above the horizontal part of the cathode 2. Then the rough “boom” should be dipped with one of the ends into the bath solution of table salt, remove it and pour a pinch of fine abrasive powder on it. Now, turning on the current, begin polishing 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, raise the cathode plate higher and the dissolution rate will decrease. Having polished the entire surface with the first “roller”, change the electrolyte solution to a clean one, wash the part from the abrasive and, using the second “roller”, proceed to final polishing, which should be done either without any abrasive at all, or using tooth powder instead. With some training in this way, you can get mirror surface two to three times faster than mechanical polishing.

"Frost" on tinplate

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

To obtain various decorative patterns on metal, you can try using solutions of different salts or acids. So, for example, if instead of a solution of table salt you take a one percent solution of sulfuric acid, then the “developing” crystals will acquire a brown tint. If you sprinkle a tin plate with tooth powder, the “frost” pattern will become more contrasting, with a milky-gray tint. By preheating individual parts of a tin piece until the tin melts locally and quickly cooling them in water, one can obtain 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 it is simple tin can you can do a lot of beautiful things.