Machining is a process during which the dimensions and configuration of workpieces and parts are changed. If we talk about metal products, then special cutting tools are used for their processing, such as cutters, broaches, drills, taps, cutters, etc. All operations are performed on metal-cutting machines according to the technological map. In this article we will learn what are the methods and types of mechanical processing of metals.

Processing methods

Machining is divided into two large groups. The first includes operations that occur without removing the metal. These include forging, stamping, pressing, rolling. This is the so-called using pressure or shock. It is used to give the desired shape to the workpiece. For non-ferrous metals, forging is most often used, and for ferrous metals, stamping is most often used.

The second group includes operations during which part of the metal is removed from the workpiece. This is necessary to give it the required size. Such mechanical processing of metal is called cutting and is performed using the most common processing methods are turning, drilling, countersinking, grinding, milling, reaming, chiselling, planing and broaching.

What is the type of processing

The manufacture of a metal part from a workpiece is a laborious and rather complicated process. It includes many different operations. One of them is mechanical processing of metal. Before starting it, make up technological map and make a drawing of the finished part indicating all the required dimensions and accuracy classes. In some cases, a separate drawing is also prepared for intermediate operations.

In addition, there is roughing, semi-finishing and finishing machining of metal. For each of them, the calculation and allowances are performed. The type of metal processing as a whole depends on the surface to be treated, the accuracy class, the roughness parameters and the dimensions of the part. For example, to obtain a hole according to the H11 grade, rough drilling is used with a drill, and for a semi-clean reaming to the 3rd accuracy class, you can use a reamer or countersink. Next, we will study the methods of mechanical processing of metals in more detail.

Turning and drilling

Turning is performed on machines of the turning group with the help of cutters. The workpiece is attached to the spindle, which rotates at a given speed. And the cutter, fixed in the caliper, makes longitudinal-transverse movements. In the new CNC machines, all these parameters are entered into the computer, and the device itself performs the necessary operation. In older models, for example, 16K20, longitudinal and transverse movements are performed manually. On lathes it is possible to turn shaped, conical and cylindrical surfaces.

Drilling is an operation that is performed to obtain holes. The main working tool is a drill. As a rule, drilling does not provide high class accuracy and is either rough or semi-finishing. To obtain a hole with a quality below H8, reaming, reaming, boring and countersinking are used. In addition, after drilling, internal threading can also be performed. Such machining of metal is performed using taps and some types of cutters.

Milling and grinding

Milling is one of the most interesting ways metal processing. This operation is performed using a wide variety of cutters on milling machines. There are end, shaped, end and peripheral processing. Milling can be both rough and semi-finishing, and finishing. The smallest quality of accuracy obtained during finishing is 6. With the help of cutters, various dowels, grooves, wells, undercuts are machined, profiles are milled.

Grinding is a mechanical operation used to improve the quality of roughness, as well as to remove an excess layer of metal down to a micron. Usually, this processing is the final stage in the manufacture of parts, which means it is finishing. For cutting are used on the surface of which is located great amount grains with different shapes cutting edge. During this processing, the part is very hot. In order for the metal not to be deformed and not chipped, cutting fluids (LLC) are used. Machining of non-ferrous metals is carried out with the help of diamond tools. This makes it possible to provide best quality manufactured part.

For the convenience of studying the set new metal processing technologies, which are used in modern times, they are usually divided into types and methods.

The most commonly used method is mechanical, but its main disadvantage is a large number of processing waste. So, for example, stamping is the most economical method. But in the modern and developing world, new methods are emerging that are more economical, safer and more effective. These are the methods associated with physical properties metals and chemical reactions.

New technological methods of metal processing

Technologies of electroerosive processing method

This new technology metal processing is based on the action of a reduced electric discharge. Thanks to this processing, the most complex parts and blanks used in apparatuses and machines are created. For work, it is necessary to ensure the safety of employees, since the temperature in the places where metal is melted can reach up to 10,000 degrees Celsius. Such a temperature simply evaporates the metal and allows using technology to perform the most complex and bizarre details.

Now this technology is used in almost all industries, but is especially common in mechanical engineering and aircraft manufacturing. Small parts used in engines and turbines are produced using this equipment.

Such machines are produced by domestic factories, while the range of equipment produced is very wide: from equipment for the production of small parts to the processing of large multi-ton spare parts. You can get acquainted with it at our exhibition.

Technologies using Ultrasound

With the help of the equipment, it is possible to create ultrasonic waves and infrasonic vibrations. Both vibrations are completely harmless to human perception, but in industry they are widely used and are suitable for working with various metals - both brittle and hard. The heart of the machine is a special converter that converts electricity into high frequency vibrations. This happens due to the movement of current through the winding and the creation of an alternating magnetic field, which the converter oscillates. It is from the oscillating transducer that ultrasound comes out. Special transducers are also used that are capable of changing the amplitudes of large oscillations into small amplitudes and vice versa. A device of the required shape is attached to the end of the waveguide, usually the shape of the device coincides with the shape of the required hole.

Such machines are most often used for the manufacture of matrices and their reprocessing, as well as for memory cells made of ferrite for various microcircuits and semiconductor devices. This is not the whole range of works performed with the help of ultrasound. Welding, washing, cleaning and measurement control work is also possible. Moreover, all the work performed by the equipment on ultrasound is efficient and of high quality. You can get acquainted with ultrasonic equipment at exhibition expositions.

New technologies for electrochemical processing

In production, electrolysis is usually used. This is a reaction in which ions derived from a solute move towards the cathode and anode depending on whether they are positively or negatively charged. The products of the resulting reaction either settle on the electrodes or turn into a solution.

With the help of electrolysis, relief casts of various models are made from metal, as well as decorative coatings for products, metals are obtained from water and ores. The same new metal processing technology is used in chlorine production.

Thanks to the technology using electrolysis, it is possible to organize the production of spare parts of any shape and complexity without any special time costs. Make grooves in parts and cut existing workpieces. There are various machines that use this processing method. The main advantage of using this equipment is the ability to process any metal, as well as the non-wear of the cathode in the process of working with metal.

Metal in its various manifestations, including numerous alloys, is one of the most sought-after and widely used materials. It is from it that a lot of parts are made, as well as a huge number of other running things. But in order to obtain any product or part, it is necessary to make a lot of efforts, to study the processing processes and the properties of the material. The main types of metal processing are carried out according to different principle impact on the surface of the workpiece: thermal, chemical, artistic effects, using cutting or pressure.

Thermal action on a material is the effect of heat in order to change the necessary parameters regarding the properties and structure of a solid. Most often, the process is used in the production of a variety of machine parts, moreover, at different stages of manufacture. The main types of heat treatment of metals: annealing, hardening and tempering. Each process affects the product in its own way and is carried out under different meanings temperature regime. Additional types of influence of heat on the material are operations such as cold treatment and aging.

Technological processes for obtaining parts or blanks by means of a force effect on the surface to be treated include different types metal forming. Among these operations are some of the most popular in use. Thus, rolling occurs by compressing the workpiece between a pair of rotating rolls. Rolls can be different shapes, depending on the requirements for the part. During pressing, the material is enclosed in a closed shape, from where it is then extruded into a smaller shape. Drawing is the process of drawing a workpiece through a gradually narrowing hole. Under the influence of pressure, forging, volumetric and sheet stamping are also produced.

Features of artistic processing of metals

Creativity and craftsmanship reflect different kinds artistic processing of metals. Among them, a couple of the most ancient, studied and used by our ancestors can be noted - this is casting and. Although not much behind them in time of appearance, another method of influence, namely, chasing.

Chasing is the process of creating paintings on a metal surface. The technology itself involves applying pressure to a pre-applied relief. It is noteworthy that chasing can be done both on a cold and on a heated work surface. These conditions depend primarily on the properties of a particular material, as well as on the capabilities of the tools used in the work.

Metal machining methods

The types of mechanical processing of metals deserve special attention. In another way, mechanical action can be called a cutting method. This method is considered traditional and the most common. It is worth noting that the main subspecies of this method are various manipulations with the working material: cutting, cutting, stamping, drilling. Thanks to this particular method, it is possible to obtain from a straight sheet or chock desired part with the required size and shape. With the help of mechanical action it is possible to achieve necessary qualities material. Often a similar method is used when it is necessary to make a workpiece suitable for further technological operations.

Types of metal cutting are represented by turning, drilling, milling, planing, chiselling and grinding. Each process is different, but in general, cutting is the removal of the top layer of the working surface in the form of chips. The most commonly used methods are drilling, turning and milling. When drilling, the part is fixed in a fixed position, it is affected by a drill of a given diameter. When turning, the workpiece rotates and the cutting tools move in the specified directions. When the rotational movement of the cutting tool relative to a fixed part is used.

Chemical treatment of metals to improve the protective properties of the material

Chemical processing is practically the simplest type of material exposure. It does not require large labor costs or specialized equipment. All types of chemical processing of metals are used to give the surface a certain appearance. Also, under the influence of chemical exposure, they seek to increase the protective properties of the material - resistance to corrosion, mechanical damage.

Among these methods of chemical influence, the most popular are passivation and oxidation, although cadmium plating, chromium plating, copper plating, nickel plating, zinc plating and others are often used. All methods and processes are carried out in order to improve various indicators: strength, wear resistance, hardness, resistance. In addition, this type of processing is used to give the surface a decorative look.

For many decades, the processing of non-ferrous metals has been very popular for the manufacture of various products. Technology and modern methods production allows you to speed up the process itself, as well as improve the quality of the final product.

They have a characteristic shade and high plasticity. Their extraction is carried out from the earth's rock, where they are found in very small quantities. The processing of non-ferrous metals is costly in terms of manpower and finances, but it brings huge profits. Products made from them have unique characteristics that are not available when they are made from black materials.

All non-ferrous metals are divided into several groups according to their properties:

  • heavy (tin, zinc, lead);
  • lungs (titanium, lithium, sodium, magnesium);
  • small (antimony, arsenic, mercury, cadmium);
  • scattered (germanium, selenium, tellurium);
  • precious (platinum, gold, silver);
  • radioactive (plutonium, radium, uranium);
  • refractory (vanadium, tungsten, chromium, manganese).

The choice of the group of non-ferrous metals used in the production depends on the desired properties of the final product.

Basic properties

- ductile metal with good thermal conductivity, but low level resistance to electricity. It has a golden color with a pink tint. It is rarely used on its own, more often added to alloys. Metal is used for the manufacture of devices, machines, electrical equipment.

- the most popular alloy with copper, made by adding tin and chemical substances. The resulting raw material has strength, flexibility, ductility, it is easy to forge and it is difficult to wear.

- conducts electricity well, belongs to ductile metals. It has a silver tint and is light in weight. Fragile, but resistant to corrosion. Used in the military Food Industry and related industries.

- a rather brittle non-ferrous metal, but resistant to corrosion and ductile if heated to a temperature of 100–150 ºC. With its help, a corrosion-resistant coating is created on products, as well as various steel alloys.

When choosing a non-ferrous metal for a future part, it is necessary to take into account its properties, know all the advantages and disadvantages, and also consider alloy options. This will allow you to create the highest quality product with the specified characteristics.

Use of protective coating

To preserve the original appearance and functionality of the product, as well as to protect it from atmospheric corrosion, special coatings are applied. Processing the product with paint or primer is the simplest and most effective method protection.

To achieve a greater effect, a primer is applied to the cleaned metal in 1-2 layers. This protects against destruction and helps the paint adhere better to the product. The choice of funds depends on the type of non-ferrous metal.

Aluminum is treated with zinc-based primers or urethane paints. Brass, copper and bronze do not require additional processing. If damage occurs, polishing and applying epoxy or polyurethane varnish is carried out.

Methods for applying a protective layer

The choice of coating method depends on the type of non-ferrous metal, the financing of the enterprise and the desired characteristics of the product.

The most popular method of processing non-ferrous metals to protect against damage is considered to be galvanization. A protective layer of special composition. Its thickness is regulated depending on the temperature regime at which the part will be operated. The harsher the climate, the larger the layer.

Especially popular is the galvanic method of processing parts in the construction of houses and cars. There are several types of coverage.

- carried out using chromium and alloys based on it. The part becomes shiny, the metal after processing is resistant to action high temperatures, corrosion and wear. The method is especially popular in industrial production.

- is carried out using a current that causes the formation of a film when processing aluminum, magnesium and similar alloys. The final product is resistant to electricity, corrosion and water.

– carried out using a mixture of nickel and phosphorus (up to 12%). After coating, the parts are subjected to heat treatment, which increases the resistance to corrosion and wear.

The method of galvanic processing of parts is quite expensive, so its use for small industries is difficult.

Additional Methods

Spray plating is a budget option. The molten mixture is applied to the surface of the product using an air jet.

There is also a hot method for applying a protective layer. Parts are immersed in a bath containing molten metal.

With the diffusion method, a protective layer is created under conditions of elevated temperature. Thus, the composition penetrates into the product, which increases its resistance to external influences.

The application of another, more resistant metal to the non-ferrous metal from which the part is made is called cladding. The process involves casting, joint rolling, pressing and further forging of the product.

Modern processing technologies

There are several basic methods for processing non-ferrous metals. They are divided into several groups depending on the technology and temperature regime: hot and cold, mechanical and thermal.

The most popular of them:

  • welding (, chemical, gas, arc, electric, contact);

Metal processing originates in the prehistoric period, when ancient people learned to cast tools and arrowheads from copper. Thus began the era of metal, a fossil that remains relevant to this day. Today, new metal processing technologies make it possible to create various alloys, change technological properties, obtain complex shapes and designs.

Today, the most demanded material is iron. Based on it, many alloys are cast with different carbon content and alloying additives. In addition to steel, non-ferrous metals are widely used in industry, which are also used in a wide variety of alloys. Each alloy is characterized not only by operational properties, but also by technological ones, which determines the method of its processing:

  • casting;
  • heat treatment;
  • machining by cutting;
  • cold or hot deformation;
  • welding.

Casting is the very first method that a person began to use. The first was copper, and the smelting of iron from ore in a raw furnace began in the 12th century BC. e. Modern technologies make it possible to obtain various alloys, refine and deoxidize the metal. For example, deoxidation of copper with phosphorus makes it more ductile, and remelting in an inert atmosphere increases its electrical conductivity.

The latest advances in metallurgy have been the emergence of new alloys. New, higher-quality grades of austenitic and ferritic high-alloy stainless steel have been developed. More durable and corrosion-resistant heat-resistant, heat-resistant, acid-resistant and food steel AISI 300 and 400 series have appeared. Some alloys have been improved and titanium has been introduced into their composition as a stabilizer.

In non-ferrous metallurgy, alloys with optimal characteristics for a particular industry were also obtained. Secondary general purpose aluminum 1105, high-purity aluminum A0 for the food industry, airlines, among which the most in demand in the aviation industry are grades AB, AD31 and AD 35, resistant to sea ​​water marine aluminum 1561 and AMg5, weldable aluminum alloys alloyed with magnesium or manganese, high-temperature aluminum such as AK4. Wide range of copper-based alloys - bronze and brass also stand out characteristic features and satisfy all the needs of the national economy.

Formation of the technological characteristics of the alloy

On the modern rolled metal market, various semi-finished products from various steel and non-ferrous alloys are presented. At the same time, the same brand can be offered in a different technological state.

Heat treatment

Through heat treatment, the alloy can be brought to the most rigid and durable state, or vice versa to a more ductile state. Solid state "T" - thermally hardened, is achieved by heating to a certain temperature and subsequent rapid cooling in water or oil. Soft state "M" - thermally annealed, when after heating, cooling is slow. For aluminum, there are also thermal methods of natural and artificial aging.

For each brand, its own heat treatment modes are determined, the effects of stress on corrosion properties are studied, which also makes it possible to form technological processes.

Pressure hardening

This method was known to our ancestors. Blacksmiths increased the density of the material by forging it cold. This was called riveting a scythe or blade. Today, this process has received the name - work hardening, which is designated "H" in the marking of rolled products. Modern technologies make it possible to obtain mechanical hardening of any degree with high accuracy. For example, "H2" - half-working, "H3" - third work-hardening, etc.

The method consists in the maximum possible mechanical compression followed by partial annealing to the required technological state.

Chemical processing

Surface etching with chemicals. The method is used to change the graininess of the surface and give it a matte or shiny shade. Typically, the technique is used as a surface finish for rolled products produced by hot deformation.

Corrosion protection

In addition to coating with protective varnishes or a composite with plastic, 4 main methods are used in modern metallurgy:

  • anodizing - anodic polarization in an electrolyte solution in order to obtain an oxide film that protects against corrosion;
  • passivation - a protective passive layer appears as a result of exposure to oxidizing agents;
  • galvanic method of coating one metal with another. The process is achieved by electrolysis. In particular, the coating of steel with nickel, tin, zinc and other metals resistant to corrosion;
  • cladding - used to protect aluminum alloys that are not sufficiently resistant to corrosion. The technique consists in mechanical coating with a layer of pure aluminum (by rolling, drawing).

Bimetal technology

The method is based on the splicing of various metals through the emergence of a diffusion bond between them. Its essence lies in the need to obtain a material that has the qualities of two elements. For example, high voltage wires must be strong enough and have high electrical conductivity. For this, steel and aluminum are spliced. The steel core of the wire takes on the mechanical load, and the aluminum sheath becomes an excellent conductor. In thermometric technology, bimetals with different coefficients of thermal expansion are used.

In Russia, bimetals are also used for minting coins.

Mechanical restoration

This is an integral part of any metalworking production, which is carried out cutting tool: cutting, felling, milling, drilling, etc. In modern production, high-precision and high-performance machine tools and CNC complexes are used. At the same time, until recently, new technologies in metal processing were not available at construction sites when assembling metal structures. The mechanism for performing work at the installation site provided for the use of manual mechanical and electrical tools.

Today, special magnetic machine tools with program control have been developed. The equipment allows you to drill at a height at any angle. The device fully controls the process, eliminating inaccuracies and errors, and also allows you to drill holes of large diameter, which was previously almost impossible at height.

Pressure treatment

According to the method, pressure treatment differs into hot and cold deformation, and by type - into stamping, forging, rolling, drawing and upsetting. Mechanization and computerization of production have also been introduced here. This significantly reduces the cost of the product, while at the same time improving quality and productivity. A recent advance in the field of cold forming is cold forging. Special equipment makes it possible to produce highly artistic and at the same time functional decorative elements at minimal cost.

Welding

Among the methods that have already become traditional, one can single out electric arc, argon-arc, spot, roller and gas welding. The welding process can also be divided into manual, automatic and semi-automatic. At the same time, new methods are used for high-precision welding processes.

Thanks to the use of a focused laser, it became possible to perform welding work on small parts in radio electronics or attach carbide cutting elements to various cutters.

In the recent past, the technology was quite expensive, but with the use of modern equipment, in which the pulsed laser was replaced by a gas one, the technique became more accessible. Equipment for laser welding or cutting is also equipped with software control, and if necessary, is produced in a vacuum or inert environment

Plasma cutting

If, compared with laser cutting, plasma cutting is distinguished by a greater cut thickness, then it is many times superior in terms of efficiency. This is the most widely used method today. series production with high repeat accuracy. The technique consists in blowing an electric arc with a high-speed gas jet. There are already handheld plasma torches that are a superior alternative to flame cutting.

The latest developments in the production of complex and small parts

No matter how perfect machining is, it has its own limit on the minimum dimensions of the part being produced. Modern radio electronics uses multilayer boards containing hundreds of microcircuits, each containing thousands of microscopic details. The production of such parts may seem like magic, but it is possible.

Electroerosive processing method

The technology is based on the destruction and evaporation of microscopic layers of metal by an electric spark.

The process is performed on robotic equipment and controlled by a computer.

Ultrasonic processing method

This method is similar to the previous one, but in it the destruction of the material occurs under the influence of high-frequency mechanical vibrations. Basically, ultrasonic equipment is used for separation processes. At the same time, ultrasound is also used in other areas of metalworking - in metal cleaning, the manufacture of ferrite matrices, etc.

Nanotechnology

The method of femtosecond laser ablation remains a relevant method for obtaining nanoholes in metal. At the same time, new, less expensive and more efficient technologies are emerging. Fabrication of metallic nanomembranes by punching holes by ion etching. Holes are obtained with a diameter of 28.98 nm with a density of 23.6x10 6 per mm 2 .

In addition, scientists from the USA are developing a new, more advanced method for obtaining a metal array of nanoholes by metal evaporation using a silicon template. Today, the properties of such membranes are being studied with the prospect of application in solar cells.