What is laser cutting of metal

Laser cutting of metal: what is it, pros and cons

Laser cutting in professional circles is designated as Laser Beam Cutting, or LBC for short, which inherently involves heating a particular area of ​​the product and its subsequent destruction using a laser beam.

The essence and technology of laser cutting

The laser beam is focused on a small area of ​​the product and generates enough energy on the high-density surface to process the metal. For example, to quickly melt a metal, a density of 108 watts per 1 cm2 is required, and with this indicator the following properties of a laser system can be achieved:

1. Monochromatic. In this case, the laser beam has a constant frequency and wavelength, which makes it possible to accurately focus it on a specific area using a simple lens system.
2. Directionality. The laser beam can be concentrated on a significantly small area of ​​the surface. The direction of the laser will be hundreds and thousands of times more accurate than the light beam.
3. Coherence – due to the existing resonance, a high level of power is achieved. Such fluctuations give rise to wave processes that, regardless of the time frame, will proceed consistently.

Regardless of the area and properties of the surface being processed, the properties of the laser beam and the processing process will proceed in the same way. This is achieved through the distribution of heat on the surface of the object being processed.

In the area where the laser beam is directed, the product is heated to the level of the required melting temperature - over a certain period of time, the metal heats up even more and the melting process itself proceeds deeper into it.

If necessary, you can achieve a level of boiling of the metal and fix its evaporation.

All this makes it possible to cut metal according to 2 special schemes:

1. Evaporation process.
2. Melting process.

According to the evaporation method, it is used when energy consumption is high. But this is not always economically beneficial from the point of view of economy, and the method is only suitable for processing thin sheets of steel.

Therefore, most often the processing is carried out by the melting method and to reduce energy costs the speed of the metal cutting process itself increases, a thicker layer of metal can be processed. Often specialists inject an additional gas composition into the laser cutting process itself - inert or nitrogen, oxygen.

In particular, the auxiliary gas composition itself can perform the following functions and tasks:

1. Accelerates the oxidation process of steel and reduces its reflective properties.
2. It provides additional heat due to the fact that the laser jet burns more actively due to the additional supply of gas.
3. Thanks to a more powerful jet, it carries away processing and melting products and small particles from the combustion zone.

Cutting metal with a laser has a lot of positive characteristics:

1. You can cut a steel sheet of small thickness - from 0.2 to 1 mm, and even more massive sheets, up to 20 mm, or even up to 50 mm thick.
2. During the laser cutting procedure, the beam does not come into mechanical contact with the material, and this will allow for high-quality processing of fragile and easily deformable surfaces.
3. To cut a product, you just need to make a file with a drawing, and the rest will be done by a program or computer, allowing a minimum of errors of no more than 0.1 mm.
4. Cutting thin sheets is carried out at high speed, the same applies to cutting products made of hard metal alloy.
5. There is no need to prepare a mold for casting or purchase expensive molds.
6. The cutting speed indicators are high, as is the productivity itself, the material consumption is optimal with minimal waste, which ultimately leads to a reduction in the cost of the production process.

In addition, a laser cutting machine can be called universal - it can produce almost any part, regardless of its complexity.

If we talk about the disadvantages of laser cutting, then we can highlight the following points:

1. First of all, such processing is more expensive compared to other processing methods.
2. And the thickness of the metal sheet processing itself is limited.

Installing a laser for cutting - what is it?

The modern market of laser systems offers a wide variety of models with different power levels. Conventionally, they can be divided into the following types:

1. Gas type. Presented with longitudinal/transverse supply of a gas mixture, which is used as a working fluid. In such a unit, a gas mixture is supplied through a special pipe under the action of a pump. In this case, the electrical power for pumping the gas mixture is provided by its atoms, which are in an active energy state. The most efficient components of a laser system are called carbon dioxide slit systems.
2. Solid fuel system. In such a system, a pump lamp is required - without it there is no way to transmit the required level of radiation. The working heat source in this case is a graphite or neodymium glass rod. Such systems operate in pulse mode, although if necessary they can be configured for continuous operation.
3. Gas dynamic installations. Such systems are similar to gas installations, but in them the gas mixture is heated to a temperature of 2-3 thousand degrees. It is then passed through a solo at sound speed and then cooled. This process is quite complex and expensive, therefore, due to its many operations, it is rarely used in practice.

The complete set of each machine for laser cutting of metal with a laser includes the following components:

1. A complex of special education and subsequent transmission of the gas mixture, radiation - the nozzle itself and the system for supplying a directed gas flow, rotating mirrors and a laser, a system for setting focus and optical shutters.
2. The system includes an emitter with a mirror resonator system, an active medium and a pumping and modulation system.
3. An automatic control system, plus a special range of auxiliary systems operating within the parameters of the machine itself.
4. The presence of a coordinating device system, which is necessary to move wave flows in the space of the laser beam.

Source: https://www.stroysmi.ru/metalloprokat/lazernaya-rezka-metalla-chto-eto-takoe-plyusy-i-minusy/

Where is laser cutting used?

Laser cutting technology allows you to cut materials made of plastic or metal with the highest possible precision. This is especially important in the case of metal, because in order for it to be used during work, the material must retain all its original parameters. Otherwise it will be impossible to use it.

It is important to note that laser cutting is a relatively new method of metal processing, characterized by extremely high productivity. That is why the process of manufacturing a variety of structures from metal and plastic is greatly simplified.

In the case of small-scale production, laser cutting makes production much simpler and faster. This is reflected in the final price of a product.

Needless to say, laser cutting is a commercially viable method that saves time and money.

Areas of application and advantages (pros)

If it were not for the numerous advantages of this method, it would hardly have become so popular. What are the main advantages of this method?

• Focused laser radiation is capable of providing the highest level of energy concentration, which makes it possible to achieve the separation of any type of plastic or metal, regardless of its thermophysical properties. It is also worth noting that in this way it is possible to obtain the narrowest possible cuts with a minimal thermally affected zone.
• Another extremely important advantage of the material concerns the ability to process a wide variety of materials. Moreover, laser cutting cannot have any mechanical effect on the metal. This is especially important when it comes to creating a non-standard structure that will be used during the construction of any structure. Moreover, all minor deformations that may occur directly during cutting are insignificant. That is why laser cutting is a method characterized by the highest precision.
• This method can be used both in the case of insufficiently rigid and easily deformable structures, parts or workpieces. Since laser radiation is characterized by high power, using this method it is possible to achieve enviable labor productivity, which will be combined with an unsurpassed quality level of the cut surface.
• Another advantage is of great importance for those who do laser cutting themselves. As you know, some methods are only suitable for professionals who have certain knowledge and extensive experience. In the case of laser cutting, everything is completely different. In particular, controlling the laser beam is very easy and simple. Even an untrained person who sees a laser in front of him for the first time can cope with this task. Therefore, a laser beam can work with contours of the most complex shapes. Moreover, in this way it is possible to cut out volumes of parts, as well as workpieces with the highest degree of automation of the process.
• If you compare laser cutting with any other methods of working with plastic or metal, it turns out that it simply has no equal. Traditional methods of metal processing do not have even a small part of the advantages that are characteristic of laser cutting. Needless to say, traditional processing methods cannot boast the same level of commercial benefits as laser cutting.
• It is impossible not to mention the importance of lasers in the modern manufacturing sector of the economy, which is characterized by a decrease in the level of serial production. Also, recently, the requirements for manufactured products have changed more and more often. Because of this, there has been a need to focus on various automated bending solutions, so many experts are forced to admit the fact that laser cutting has become simply irreplaceable. It has amazing comfort and flexibility.
• If we are talking about artistic or figure cutting, then you won’t be able to do without a laser. Any other methods will not achieve the required accuracy.

Among the less significant advantages, it is worth noting the following:

• The complete absence of any mechanical effects on the material being processed, which makes it possible to process even the most fragile or deformable objects.
• Using a laser, you can process a variety of types of metal, as well as plastic. We are even talking about non-ferrous metals.
• When producing a small batch of any product, it is more efficient to use laser cutting than to try to make expensive molds intended for casting. This way you can save a very large amount of money.
• Also, when using this method, you can achieve unique accuracy. We are talking about 0.001 mm per 1 sheet, whose thickness reaches 2 mm.
• To carry out automatic cutting of material, you need to prepare a drawing of the selected product, for which a simple engineering program is sufficient. After this, you need to transfer the drawing to the computer intended for installation. All this is much simpler than using other processing methods.
• It is also worth mentioning that in this way it is possible to significantly reduce the share of the human factor precisely due to production automation. This will have the best impact on the progress of production and even the quality of the products. In addition, this will lead to a reduction in labor costs.

• elements for engineering production;
• elements for racks, stands, shelves for all purposes, commercial equipment;
• elements for cases and cabinets for various purposes;
• templates, letters, stencils, signs;
• parts for decorative forged products;
• parts of modern interiors and much more.

Processed materials (maximum workpiece size 3000 x 1500 mm)

• black steel, whose thickness can reach 20 mm;
• stainless steel with a thickness of up to 12 mm;
• aluminum up to 10 mm thick.

Features of laser cutting of metal

Experts in the field of metal processing believe that it is necessary to use innovative technologies when cutting metal, as this will reduce costs and achieve much better results than using traditional methods and technologies.

What can be achieved with laser cutting

This method allows you to cut plastic and metal at extremely high speeds that are simply impossible to achieve with other methods. This can be very important if we are talking about a company that does large volume cutting. With the help of laser cutting, she will be able to satisfy the needs of a much larger number of clients, which will have a very positive impact on her level of earnings.

Also, thanks to this method, it is possible to work even with carbide materials.

We must not forget that this method is excellent for working in pulse mode.

Another result that is of interest to companies operating in the manufacturing sector concerns minimizing the thermal impact on the material.

Characteristics of the laser beam that are important during processing of plastic and metal

The laser beam is distinguished by such properties as monochromaticity, as well as coherence and directionality. It is the highest level of coherence that can give the desired resonance, which can significantly increase the radiation power. Directivity, in turn, will allow the beam to be focused on a selected area of ​​the surface, even if the area of ​​the area is negligibly small.

Monochromaticity allows you to focus the optical lens with much less operator effort.

Disadvantages of laser cutting

Laser cutting has relatively few disadvantages. In particular, this method can by no means be called universal, because for each type of material being processed there are several parameters: laser power, the use of additional gas, compliance with high safety measures and other features of the work.

It will also not be possible to cut with some types of materials. Among them there are quite popular materials used everywhere: polycarbonate, getinax, cellular polycarbonate and polypropylene, textolite and others.

Bottom line

Laser cutting is the best choice when it comes to working with metals or plastics. These materials are excellent for work, because the advantages of laser cutting will save effort, time and money.

Source: https://www.vikos-ru.ru/info/gde-primenyaetsya-lazernaya-rezka/

Laser cutting: process specifics, equipment, materials

In the construction and manufacturing industries, cutting parts using laser machines is very popular.

The mechanical impact on the material during this process is reduced to zero, and this guarantees the absence of deformation of the working surface.

Using lasers makes it possible to obtain high-quality parts while avoiding production costs associated with human factors. However, laser cutting of metal from 1 part has a number of nuances. We invite you to familiarize yourself with them.

How laser cutting works

Laser cutting of metal from 1 part can be done in different ways: using oxygen, using a mixture of gases (argon or nitrogen), using compressed air. The choice of gas for beam cutting depends on what material the part is made of, how thick the workpiece is, and whether further processing is required. For example, the use of oxygen allows you to achieve the highest possible temperatures when cutting, and argon will be indispensable when cutting titanium and zirconium.

metal laser cutting

Modern lasers are designed for cutting metal with a thickness of 0.2 mm to 40 mm. The principle of laser cutting is that the beam ensures the ignition, melting, evaporation, and blowing out of the material in the area to which it is directed with a gas jet.

Depending on the body that generates the beam, three types of sheet metal laser cutting equipment can be distinguished:

• Solid state laser machines. Equipped with a diode and a rod consisting of ruby, garnet or neodymium glass. Powerful lamps direct a charge of energy to an optical rod, which projects it onto the working surface. Focusing is carried out, among other things, thanks to mirrors and a prism. Solid-state equipment is designed for cutting copper, aluminum, aluminum alloys, and brass.
• Fiber. The beam generator is an optical fiber. Modern machines are equipped with the option of quickly adjusting the size of the focal spot, which has significantly increased the productivity of cutting parts made of copper, steel, and aluminum.
• Gas. Gases act as a generator - usually helium, carbon dioxide and nitrogen. They enter the gas discharge tube under pressure and are activated by electrical impulses. The advantage of laser cutting with gas machines is that even high-strength alloys can be used.

Control of a machine for laser cutting of parts

An automated machine for cutting metal with a laser consists of a laser itself, equipped with a power source, a control system, and a circuit that ensures the transmission of radiation to the cutting zone. According to the principle of operation, this radiation resembles a plasma arc or gas flame, but has a much higher power concentration - up to 5,000 W.

metal laser cutting machine

Operating the laser machine is quite simple. To carry out laser cutting of parts, consumables are fixed on the work table. Then the parameters of the future part (length, width) are set in the control unit, and the type and thickness of the sheet metal are indicated.

Focus calibration and selection of the distance from the cutter to the surface to be cut occurs automatically. Temperature control also occurs in automatic mode. If the technical process requires the supply of auxiliary gases, then cylinders with the necessary substance must be connected to the equipment. For this purpose, pipes equipped with valves are provided.

The protective cover protects the operator and other personnel from small metal particles.

Laser cutting of what materials is possible

Laser cutting is possible if the base material is:

• Regular steel. The maximum thickness of the steel sheet should not exceed 20mm, otherwise you need to turn to another method.
• Stainless steel. The thickness limit is 16 mm. It is with such indicators that it will be possible to avoid the occurrence of flash or it will be possible to remove it without consequences. Laser cutting of stainless steel with a thickness of more than 16 mm is only possible in the melt mode, and the cutting area will be rough and with excess material difficult to remove.
• Brass. For laser cutting of this metal, sheets with a thickness of no more than 12 mm are suitable, since the resistance of the material is quite high. The accumulation of flash cannot be avoided, but it is easily eliminated.
• Aluminum alloy. You can cut sheet metal with a thickness of no more than 10 mm. Flash also forms in the cutting zone.

laser cutting aluminum

Each type of metal has its own type of laser.

Attention! The principle of laser cutting is not applicable to the following metals: tungsten, titanium, brass, molybdenum, oxidized aluminum. All of them have high strength, which leads to failure of laser equipment.

Advantages and disadvantages of laser cutting

Laser cutting has a number of positive qualities. For example:

• When it is carried out, there is no mechanical impact on the surface being treated. This allows you to cut materials that would otherwise be damaged or deformed during normal cutting.
• Many types of metals can be processed, including aluminum alloys and various types of steel.
• Most often, laser cutting of sheet metal is not accompanied by flash. Otherwise, it can be easily removed from the surface without leaving scratches.
• The parts do not heat up when cutting. You can use laser cutting of sheets even for those metals that have high thermal conductivity.
• Material cutting is fully automated. The cutting error is no more than 0.1 mm, the percentage of waste is minimal. This allows us to reduce production costs.
• High productivity of laser equipment, resulting in significant savings in cutting time.
• There is no need to purchase expensive molds or molds.
• Versatility of equipment. A variety of types of parts can be produced using a metal laser cutting attachment.
• If necessary, sheet metal cutting equipment can be used to mill and drill holes of the required diameter and depth.
• It is possible to engrave surfaces. Metal laser cutting

The advantages of laser cutting come with some disadvantages:

• Sheet metal to be cut by laser cannot be thicker than 40 mm, and its area cannot be more than 1500 by 3000 mm.
• This cutting method is relatively expensive.
• It is not possible to produce internal threads.
• Equipment adjustment is required before each use.

Laser cutting of parts: examples

By resorting to laser cutting, you can obtain parts used in mechanical engineering in a relatively short period of time; components for commercial equipment (including racks, cabinets, supporting installations, shelves, etc.

); decorative elements for room design; parts for signs, billboards and other advertising media; stencils, templates and much more. Laser-cut elements of heating equipment - stoves, chimneys, boilers, as well as parts of fences and gates - are also popular.

The principle of laser cutting is used in the manufacture of many parts of elevator equipment and vending machines.

laser cut parts

As you can see, laser cutting is used in cases where it is necessary to obtain high-quality parts with a minimum cutting width, smooth and even edges, and at the same time it is possible to neglect some change in the color of the product at the cutting site.

Which is better: metal cutting with laser or plasma?

Plasma cutting differs from laser cutting in that the metal is melted using a plasma arc, while a plasma jet removes the melt.

Plasma cutting is used for processing thin sheet metal, but it is economically feasible to use it for thick surfaces: copper (up to 80 mm), cast iron (up to 90 mm), aluminum (up to 120 mm), steel (up to 150 mm).

Good quality of the holes is guaranteed if their diameter is not less than the diameter of the surface cut by the plasma. The lower edges of the holes are usually smaller than the upper edges. The cutting surface is conical and ranges from 3 to 10 degrees.

You can read about the features of plasma welding here.

Laser operation is most effective when cutting steel up to 6 mm thick. Focused laser radiation produces high-quality narrow cuts; the diameter of the holes produced in the lower part is slightly larger than in the upper part. The deviation of the cutting edge from the specified parameters is about 0.5 degrees.

When choosing between plasma and laser, you should focus primarily on the type and thickness of the material to be processed. In addition, it is worth considering that laser equipment is more expensive, but if it is necessary to cut a large number of holes in a part, the hourly cost of using a plasma machine is higher.

Finally

The principle of laser cutting can be applied in all cases where high-precision cutting of parts, milling or engraving is required. The equipment, regardless of its type (solid-state, gas, fiber), allows cutting sheets of metal almost automatically.

At the same time, a neat cutting surface, a minimum amount of flash or its complete absence, a minimum cutting error, and high productivity are guaranteed. The advantages of laser cutting outweigh its disadvantages, the most significant of which is cost.

When choosing between laser and plasma cutting, you should pay attention to the price of the equipment and the hourly cost of its operation, as well as the thickness of the working material.

Source: https://svarkaed.ru/svarka/poleznaya-informatsiya/lazernaya-rezka-spetsifika-protsessa-oborudovanie-materialy.html

Design and principle of operation of laser cutting machines

Laser cutting machines are used for non-contact processing of various metals with high precision. There are no analogues in terms of technology level, quality of cutting or engraving and ease of operation. The processed workpieces do not require any modifications after the work, and the cost of their production is low.

Design and principle of operation

The laser machine is designed for engraving and cutting metal products . Structurally, it consists of the following components:

• radiation and transformation systems;
• emitter with resonators;
• control system;
• governing bodies;
• a unit that moves the laser over the working surface.

The design depends on the types of equipment:

• gas - equipped with a pumping system for inert gases (neon, helium), a glass flask with a radiating tube;
• solid-state, pump lamps, pulse lamps, working fluid (ruby) and a system of mirrors (reflective, translucent) are installed;
• gas-dynamic - a nozzle is provided to accelerate gases, a cooling system;

The beam density is 100 MW/cm2. When the surface of the workpiece is irradiated, it rapidly heats up and melts. Due to thermal conductivity, the beam is able to penetrate deep into the metal. In the heating zone, when the boiling temperature is reached, it evaporates.

Types of laser cutting

Depending on the beam power, laser machines allow you to perform the following types of processing:

Cutting parts by melting is advantageous for the following reasons:

• the laser resource is higher than with evaporation;
• less electricity consumption;
• cutting of workpieces of various thicknesses is allowed;
• precise adjustment of the beam by the control system - focusing, tilt angle;
• high quality of the ends of parts after processing;
• When gases are added, the likelihood of oxide formation decreases.

The evaporation method is suitable for small thicknesses. It requires significant energy consumption, so in practice it is used quite rarely. Manufacturing parts becomes economically unprofitable.

Advantages and disadvantages

Laser cutting machines have the following advantages:

• ease of processing of fragile parts;
• low degree of error when positioning the laser above the surface being treated;
• convenient control system;
• cutting workpieces of any shape;
• ease of engraving and cutting products made of hard alloys;
• cutting thickness: copper, brass - up to 1.5 cm, steel, aluminum - up to 2 cm, stainless steel - up to 5 cm;
• high processing speed;
• minimum cost of finished products.

Main disadvantages:

• complexity of design, maintenance, repairs;
• high cost of equipment and components;
• limited thickness of workpieces;
• significant energy consumption;
• special safety requirements for installation and operation.

Cutting workpieces of any shape

Selection principles

Equipment for laser cutting of metal is selected according to the following criteria:

• productivity, processing speed, beam positioning above the working surface;
• the type of emitter (metal or ceramic), its service life, reliability, design features;
• the brand under which the machine was manufactured;
• warranty period from the manufacturer;
• the type of materials of the parts used in the laser positioning device, especially the guides;
• purpose, operating conditions for which the industrial machine is designed;
• convenience and ease of management;
• possibilities for expanding functionality;
• requirements for the premises where the equipment will be installed;
• the cost of a specific model, components, consumables.

Machine design

The design and layout of metal laser cutting equipment ensures ease of use as well as productivity. Ease of chip removal, available space for moving the workpiece relative to the laser, cooling efficiency - these are the main parameters that depend on the location of the structural elements.

It is important to pay attention to the following nodes:

• lifting table;
• laser;
• cooling system;
• optics

Lifting table

The laser cutting machine is equipped with a lifting table designed to secure and move the workpiece relative to the beam. The movement can be linear along the vertical coordinate axis. It has different load capacity, area, and can be moved using a mechanical or electric lifting drive.

Laser power and cooling

A metal laser cutter is equipped with lasers of different powers to perform different tasks. The higher the power, the better the processing, the greater the permissible thickness of the workpieces, but also the higher the energy consumption.

For efficient operation and installation, it is necessary to ensure high-quality cooling of the tube. The service life of the laser will depend on this. Usually a water system with a flow sensor to control the cooling is sufficient.

Optics

A laser cutting device involves installing optics, the purpose of which is to focus the beam. It can be of the following types:

• long-focus, used for processing thick workpieces;
• short-focus, used for engraving or cutting thin sheet metal.

Prices

The cost of equipment depends on the following factors:

• manufacturer;
• functionality;
• laser type;
• optical system;
• working surface area;
• cooling systems.

How to make a laser cutting machine with your own hands

You can only create a machine for cutting metal with a laser beam with your own hands, since it is easy to select components for it, and their prices are low. The main elements for assembly are the laser itself and the control system for its operation.

You can purchase a laser in specialized stores or remove it from finished products (laser pointer, laser disc drive). To create a control circuit, you will need the following components:

• capacitors 100 pF, 100 µF;
• resistors with a nominal value of 2 to 5 Ohms;
• soldering board;
• focusing optics;
• cylindrical metal body, suitable for LED flashlight;
• multimeter

Beginners are recommended to purchase a ready-made printed circuit board with installed elements in radio electronics stores. An alternative is to choose a ready-made circuit, make a board based on it, and solder it yourself.

You also need to prepare additional components for assembly in advance:

• housing for radioelements and laser;
• stepper motors, their control boards;
• emitter voltage regulator;
• rubber toothed belts, metal pulleys under them;
• fastening elements;
• ring type switches;
• USB controller for digital control;
• cooling system;
• metal tubes (guides) and boards (for the body).

Step-by-step manufacturing process:

1. The body of the donor device is disassembled, and the laser head is removed from it.
2. A rectangular frame is made from wooden planks.
3. Transverse guides are mounted inside the body, and longitudinal guides are mounted on them, to which the frame is attached.
4. Pulleys are connected to the moving bar, motors are installed, and belts are put on.
5. The laser head is fixed to the moving frame.
6. A cooling system is being installed.
7. A control board is connected to the laser.
8. The wiring from the control board is routed to the front panel of the case, and monitoring and control systems are connected.
9. The USB controller is connected, it is coordinated with the software on the PC, and the settings are made.
10. The operation of the equipment is checked in basic modes.

Exploitation

Features of operation of machines for laser cutting for metal:

• it is necessary to ground the equipment;
• turn on water cooling during operation;
• to increase the accuracy of processing metal surfaces, it is necessary to adjust the optics;
• it is prohibited to cut parts that do not meet the operating requirements stated by the manufacturer;
• for stable operation of electronics, it is necessary to provide high-quality power supply;
• it is important to regularly carry out technical inspections, replace worn parts and consumables;
• guides require high-quality periodic lubrication;
• keep equipment clean.

The machine allows you to process metal surfaces with a laser beam that has high energy, coherence, and a constant wavelength.
When it hits the surface of the workpiece, it is heated to the melting point. As a result of this effect, one part of the metal evaporates, and the other goes into the molten metal phase. A simple and affordable laser for cutting metal

Design and principle of operation of laser cutting machines Link to main publication

Source: https://metalloy.ru/stanki/dlya-rezki/lazernoj

Laser cutting of metal - what is it?

In modern industry, many automated methods of processing materials are used, one of the most accurate is laser cutting of metal. The laser processing unit can be based on a solid-state, gas or fiber laser.

The laser cutting method allows you to process workpieces of the most complex shapes, both flat and three-dimensional. The minimum thickness of metal sheets is 0.2 mm. The maximum varies for different materials: 30 mm for steel, for aluminum and stainless steel alloys - 25 mm, brass - 12 mm; copper up to 15 millimeters. The lower the thermal conductivity of the material, the easier it is to cut it with a laser.

Operating principle of the laser cutting device

The shaped cutting process is controlled by a computer. It is he who, in accordance with the drawing, along a given trajectory, directs a high-power laser at a metal workpiece, which is located on the coordinate table.

Under the influence of a focused beam several micrometers thick, but with high energy, the metal at the points of contact melts and then evaporates. The areas adjacent to the cut also heat up, but remain undamaged.

Moreover, regardless of the thickness of the material, the edges of the cut are perfectly smooth, without burrs or sagging. Therefore, additional machining of the part is not required.

Vapors from the working area are removed using oxygen blowing (for ferrous metal) or a stream of air or nitrogen (for workpieces made of stainless steel, aluminum and brass).

Advantages of laser cutting over other metalworking methods

Laser cutting allows you to:

• Increase labor productivity on production lines. Thanks to the software, you can quickly and flexibly set up your machines.
• Reduce time and reduce production costs by excluding cutting, milling, die-cutting or stamping operations from the technological process. The product can be processed in one step.
• Reduce the amount of waste, because the computer itself selects the optimal, economical layout when cutting.
• Process particularly brittle alloys, as well as easily deformable, non-rigid products. Spot heating does not affect the deformation of the part. Also, the product does not need to be fixed on the table, because there is no direct contact between the tool and the workpiece.
• Manufacture single products or use cutting in small-scale production, when it is not profitable to order expensive molds for the production of a small batch.

Laser cutting of metal is confidently replacing other types of metalworking. But although this cutting method has many advantages, due to the high cost of the equipment, it is more expensive than traditional ones. It should be used in cases where cutting speed and quality are decisive.

Source: https://metalproces.ru/info/65-lazernaya-rezka-metalla

Metal laser cutting technology - equipment, features, video

Laser cutting, or LBC (Laser Beam Cutting) as it is referred to around the world, is a process in which the material in the cutting area is heated and then destroyed by a laser.

Industrial metal cutting using laser

The essence of laser cutting of metal

Laser cutting of metal, as its name implies, is performed using a laser beam produced using a special installation. The properties of such a beam make it possible to focus it on a surface of a small area, while creating energy characterized by high density. This leads to the fact that any material begins to actively degrade (melt, burn, evaporate, etc.).

A metal laser cutting machine, for example, allows you to concentrate energy on the surface of the workpiece, the density of which is 108 watts per square centimeter. In order to understand how this effect can be achieved, it is necessary to understand what properties a laser beam has:

• A laser beam, unlike light waves, is characterized by a constant wavelength and frequency (monochromaticity), which makes it easy to focus it on any surface using conventional optical lenses.
• Exceptionally high directivity of the laser beam and a small angle of divergence. Thanks to this property, laser cutting equipment can produce a highly focused beam.
• A laser beam has another very important property - coherence. This means that many wave processes occurring in such a beam are completely consistent and are in resonance with each other, which increases the total radiation power several times.

The processes that occur when cutting metal using a laser are clearly visible in the videos given in the article. When the beam is exposed to the surface of the metal, rapid heating occurs and subsequent melting of the area being treated.

Several factors contribute to the rapid spread of the melting zone deep into the workpiece, including the thermal conductivity of the material itself. Further exposure of the laser beam to the surface of the product leads to the fact that the temperature in the contact zone reaches the boiling point and the material being processed begins to evaporate.

Laser cutting process in schematic form

Laser cutting of metal can be performed in two ways:

• melting metal;
• evaporation of the metal being processed.

In order to cut metal using the evaporation method, high equipment power is required and, as a result, significant energy consumption, which is not always feasible from an economic point of view. The use of this method is also limited by strict requirements for the thickness of the processed products. That is why this method is used only for cutting thin-walled parts.

Laser cutting of metal using the melting method has become much more widespread. Recently, laser cutting by the melting method is increasingly carried out using gases (oxygen, nitrogen, air, inert gases), which are blown into the cutting zone using special installations (a video of this process can be easily found on the Internet).

This technology allows you to reduce energy costs, increase work speed, and use low-power equipment for cutting thick metal. Of course, this cannot be considered laser cutting in its pure form; it would be more correct to call it gas laser technology.

Laser cutting of steel 10mm

The use of oxygen as an auxiliary gas when performing laser cutting allows you to simultaneously solve such important problems as:

• activation of the metal oxidation process (this reduces its reflectivity);
• increase in thermal power in the cutting zone (since metal burns more actively in an oxygen environment);
• blowing out small particles of metal and combustion products from the cutting zone with oxygen supplied under a certain pressure (this facilitates the flow of gas into the processing zone).

Types of laser cutting equipment

Metal laser cutting equipment is divided into three main types.

Gas laser cutting machines

Gases in such installations, used as a working fluid, can be pumped along a longitudinal or transverse pattern.

The operating principle of such lasers is to excite gas atoms under the influence of an electrical discharge, as a result of which the particles begin to emit monochromatic light. Slit-type installations running on carbon dioxide are widely used in modern industry.

They are quite compact, yet powerful and easy to operate (there are a lot of videos on the Internet showing the operation of such installations).

Operating principle of a gas laser

Solid state units

The design of such equipment consists of two main elements: a pumping lamp and a working fluid, which is most often used as a rod made of artificial ruby. The composition of the latter also includes neodymium yttrium garnet. A pump lamp in such devices is necessary in order to transmit the required radiation to the working fluid. Most often, such laser cutting machines operate in pulse mode, but there are also models that operate continuously.

Operating principle of a ruby ​​laser

Gas dynamic equipment

In gas-dynamic installations, the working gas is preheated to 2–3 thousand degrees, then passed through a special nozzle at high speed (above the speed of sound), and then cooled. Such equipment is very expensive, as is the process of forming the laser beam itself, so its use is very limited.

If you watch a video of a laser machine in operation, it is very difficult to determine which group it belongs to. To do this, you need to get an idea of ​​​​the design of such equipment.

Any equipment for laser cutting, no matter what group it belongs to, contains the following elements:

• a system responsible for the transmission and formation of gas and radiation (such a system includes a nozzle, a gas supply device, an alignment laser, rotating mirrors, optical elements, etc.);
• an emitter equipped with cavity mirrors, containing an active medium, devices for pumping and providing modulation, if necessary;
• a system for managing all parameters of equipment operation and monitoring their compliance;
• a unit that ensures movement of the workpiece and the laser beam.

Source: http://met-all.org/obrabotka/rezka/tehnologiya-lazernoj-rezki-metalla.html

Metal cutting with a laser and features of the use of the laser method, advantages, scope of application

Laser cutting of metal is a relatively new method of processing it; currently it is one of the most relevant and optimal. The process is incredibly precise and highly technologically advanced. It is flexible and fast, allowing you to significantly reduce material costs, increase production flexibility, and ultimately obtain high-quality products.

Laser cutting refers to technologies for cutting and cutting materials using high-power lasers. Most often it is used in large industrial productions.

The laser beam is focused and most often controlled by a computer. With its help, you can provide a high concentration of energy and, regardless of the thermophysical properties of the material, cut almost any material.

During the cutting process, the metal, the section of which is being cut, begins to melt under the influence of laser beams, ignites, evaporates, or is blown out by a gas jet. As a result, we get narrow cuts, and the heat-affected zone will be minimal.

The features of laser cutting are:

• it does not have a mechanical effect on the metal during processing.
• Deformations, if present, are minimal. They can be temporary and appear during the process, or residual, appearing after the material has completely cooled.

It is for this reason that using this cutting method it is possible to process even non-rigid and easily deformable parts or metal workpieces, and everything will be done with high precision.

Laser radiation has high power, which ensures good work performance and the quality of cut surfaces will be excellent.

Control of laser radiation is relatively simple and easy, thanks to which it will be possible to cut along a complex contour on three-dimensional or flat parts or workpieces, while the process will have a high degree of automation.

This technique is possible using technological installations based on the following types of lasers:

• fiber;
• gas;
• solid state.

All of them can operate in pulse-periodic or continuous radiation mode.

The use of laser cutting in industrial production is regularly growing, but it can still fully replace other traditional methods of cutting metals.

Compared to other industrial installations, laser equipment is still very expensive, although their costs have recently begun to decline.

For this reason, laser cutting of metals is effective only when other, more accessible traditional methods of processing materials cannot provide the expected result.

Advantages of laser technique

This technique is performed by burning through sheets of metal using laser beams. Compared to other methods of cutting metal products, it has a number of advantages, some of which have already been mentioned above:

• due to the absence of mechanical contact, this method can process even brittle types of metal, as well as those that are easily deformed.
• It is possible to process products based on hard metal alloys.
• there is the possibility of high-speed processing of thin-sheet steel.
• When it comes to the production of limited quantities of metal products, then laser cutting in this case is a more preferable option than making expensive molds for casting or compression molds.
• To automate the process, use an available drawing program to create a drawing file. Then transfer the file to a computer installation that can withstand errors even at small sizes.
• The technique is universal. Using a laser, you can process products made of steel and other metals of varying degrees of complexity. The maximum permissible error will be no more than 0.5 mm.
• The thermal load on the metal is minimal, which allows you to work with any type of material, from stainless steel to non-ferrous metals.
• This method of cutting materials eliminates the need for additional processing, thanks to which you will save both your time and money.
• The technology is characterized by high productivity due to high processing speed, as well as proper material consumption. You will receive a minimum of waste thanks to the precise placement of elements on the sheet blank.
• high precision of work - laser cutting equipment is equipped with working heads with a diameter of about one millimeter, which ensures high dimensional accuracy. Cutting is possible even when it comes to even the smallest parts.
• Laser cutting can be completed in the shortest possible time, while the high quality of work remains unchanged. The laser power is adjusted differently each time and takes into account the characteristics of the work and the type of material.

Steel in any condition, aluminum or its alloys, as well as other non-ferrous metals are suitable for laser processing The most commonly used types of metal sheets are:

• steel (diameter 0.2 - 20 mm);
• stainless steel with a diameter of 0.2 - 12 mm;
• aluminum alloys from 0.2 to 20 mm;
• brass (0.2 - 12 mm);
• copper sheets from 0.2 to 15 mm.

Depending on the material used, one or another type of laser is used. Materials with low thermal conductivity are best processed, since in them the laser energy is concentrated in a smaller volume of material, and vice versa. If the metal has high thermal conductivity, then burrs may appear. This method can also process not only metals, but also other materials, in particular wood.

Cooling and power consumption

The laser itself, as well as its optics, including focusing lenses, require cooling. Depending on the model of the installation and its size, excess heat can be removed using airflow or coolants. Often the coolant is water that passes through a refrigeration unit or heat exchanger.

As for energy consumption, the efficiency of lasers used in production is 5-15 percent. Efficiency and energy consumption depend on the following factors:

• installation power output;
• laser operating parameters;
• compliance of the laser with a particular type of work.

When determining the feasibility of using this or that equipment, it is necessary to take into account its cost, as well as the cost of its maintenance and upkeep. Currently, the operating costs of fiber optic equipment are half the cost of a carbon dioxide laser.

But the power consumed for cutting depends on the following factors:

• speed of work;
• processing environments;
• material thickness;
• his type.

Laser metal processing is used in various industries. Thanks to this method, you can quickly and efficiently produce fasteners, brackets, housings for various devices and much more.

Customers of products manufactured in this way are:

• manufacturers of warehouse and commercial equipment;
• interior designers;
• advertising campaigns, etc.

You can even cut out very complex parts from metal sheets, perform milling, make grooves, and also give the cuts the most attractive appearance.

Thanks to the laser cutting method, it is possible to achieve ideal cut quality, the production process is as efficient as possible, and the amount of consumables is reduced to a minimum. And the cutting of parts using the laser method is carried out extremely precisely.

The technique is practically irreplaceable when processing rapidly deforming metals; the materials do not require further processing, and the finished products can be immediately used for their intended purpose, which is of particular importance in some industries.

Source: https://tokar.guru/stanki-i-oborudovanie/dlya-raboty-s-metallom/lazernaya-rezka-metallov-opisanie-processa-preimuschestva.html

What is laser cutting: cutting technology, advantages, disadvantages

Laser metal cutting is a technology used to cut metal sheets as well as other products, which is achieved through the use of a laser beam.

Its undeniable advantages are: absolutely straight cuts and the ability to cut out the most intricate shapes, which makes it possible to use laser cutting of metal to create high-precision parts and various, even the most complex, designs.

This scientific solution is now actively used by construction companies, manufacturers of furniture and advertising products, and it is also used for the production of signs and decorative elements.

Process [edit | edit code]

For laser cutting of metals, technological installations based on solid-state, fiber lasers and gas CO2 lasers operating in both continuous and pulse-periodic radiation modes are used. The industrial use of gas laser cutting is increasing every year, but this process cannot completely replace traditional methods of separating metals.

Compared to many of the installations used in production, the cost of laser cutting equipment is still quite high, although recently there has been a tendency towards its reduction.

In this regard, the laser cutting process becomes effective only if there is a justified and reasonable choice of the area of ​​application, when the use of traditional methods is labor-intensive or completely impossible.

Benefits [ edit | edit code]

Laser cutting is carried out by burning through sheet metal with a laser beam. This technology has a number of obvious advantages over many other cutting methods:

• The absence of mechanical contact allows the processing of fragile and easily deformable materials;

• Materials made of hard alloys can be processed;

• High-speed cutting of thin sheet steel is possible;

• When producing small batches of products, it is more expedient to laser cut the material than to make expensive molds or casting molds for this;

• To automatically cut the material, it is enough to prepare a drawing file in any drawing program and transfer the file to the computer of the installation, which will withstand errors of very small quantities.

Areas of use of laser processing

Currently, the use of fairly high-precision laser cutting equipment is necessary in order to create the following structures:

• creation of various parts for mechanical engineering;
• creation of all kinds of shelves, racks and other structures used in the retail industry;
• some elements of the chimney, stoves and boilers are created using laser cutting;
• forged fences and some parts for gates and doors;

If we take into account all the advantages of laser metal processing, it becomes clear why many enterprises are switching to this particular method of working with thin sheet metal.

Processed materials [ edit | edit code]

Any steel of any condition, aluminum and its alloys, and other non-ferrous metals are suitable for laser cutting. Typically used sheets of the following metals:

• Steel from 0.2 mm to 30 mm
• Stainless steel from 0.2 mm to 40 mm
• Aluminum alloys from 0.2 mm to 25 mm
• Brass from 0.2 mm to 12.5 mm
• Copper from 0.2 mm to 16 mm

Different types of lasers are used for different materials.

Metals with low thermal conductivity are best processed, since in them the laser energy is concentrated in a smaller volume of metal, and vice versa, when laser cutting metals with high thermal conductivity, burr can form.

Many non-metals, such as wood, can also be processed.

Before the advent of laser cutting

Not a single enterprise associated with the manufacture of structures and metal products can do without equipment for cutting parts from sheet metal. Flame cutting technology was widely used in the first half of the last century.

With this method, the cutting zone is heated and melted with a gas mixture based on propane and oxygen. In general, this equipment has proven itself well and is actively used to this day.

But this cutting method also has its limitations in application:

• Impossibility of cutting high-alloy steels, stainless steels, alloys of non-ferrous metals;
• Temperature deformation of parts made of sheet steel less than 5 mm thick;
• Low cutting speed;
• Significant cutting width.

Energy consumption[ edit | edit code]

The efficiency of industrial lasers can vary from 5% to 15%. Energy consumption and efficiency will depend on the laser's power output, its operating parameters, and how well the laser is suited to the specific job.

When determining the feasibility of using a particular type of laser, both the cost of the laser together with the equipment that serves it, and the cost of maintaining and servicing the laser are taken into account.

In the 10s of the 21st century, the operating costs of a fiber laser were about half of the operating costs of a carbon dioxide laser.

The amount of required power required for cutting depends on the type of material, its thickness, processing environment, processing speed.

Cutting sheet metal and other profiles is one of the most important operations in the creation of metal structures.

It is this operation that largely determines the quality of the product and its cost. Over the years, many technologies have been invented and put into operation for cutting sheet and other profiles.

The essence of metal cutting

Cutting metal, regardless of its shape, is a procurement operation. It is at the stage of its implementation that the future details of the metal structure take on their features. At machine-building enterprises, and in production complexes of other industries, there are entire procurement divisions equipped with a variety of equipment designed to form blanks, or even finished parts. It all depends on the equipment and tools used.

Source: https://instanko.ru/drugoe/lazernyj-raskroj.html

Metal laser cutting technology: what is it, pros and cons

Laser cutting of metal is a modern method of cutting metal blanks and disassembling metal structures. It is capable of cutting almost any metal and is characterized by high accuracy and quality of the cut surface.

The high cost of purchasing and maintaining equipment is holding back the widespread adoption of laser cutting.

Industrial use

Lasers are used in various sectors of the economy - from medicine to entertainment technology. Steel cutting with industrial lasers began to be used at the end of the last century , and they gained popularity in engineering enterprises of a wide range of profiles: from aerospace to the production of household appliances. In addition to cutting, metal welding is also carried out using a laser.

The following types of optical emitters are used at manufacturing enterprises:

• solid-state , the light beam is amplified in an artificial ruby ​​crystal, and powerful LEDs or discharge lamps are used to pump the pulse;
• gas , a light pulse originates in a volume of ionized inert gas;
• fiber , the working area is made of fiber optics.

Fiber devices are especially suitable for cutting non-ferrous metals and stainless alloys. Due to the special properties of the medium, the emitted laser beam is little scattered on the reflective surface of the part.

Gas emitters develop the highest power.

Features of the technological process

The metal cutting process is divided into three main stages:

• at the beginning of the cut line, a narrowly focused laser beam causes sharp heating of the metal to the melting point, and a primary shell is formed;
• the metal on the surface begins to boil and evaporate;
• After cutting through the workpiece, the operator or control program guides the laser cutter along the intended cutting line, dividing the workpiece into separate parts.

Complete evaporation of the metal layer is possible only for thin-sheet workpieces. For thicker parts, metal molecules are removed from the cut by a jet of active gas.

At the same time, the gas performs the function of cooling the cutting line and increases the cutting speed. The width of the laser beam and the resulting cut is a fraction of a millimeter. This ensures the highest processing accuracy, allows for minimal allowances and greatly reduces metal loss compared to other cutting methods.

Why does a laser beam cut metal?

The laser beam concentrates high energy into a very limited area. The impact of a high-energy light beam heats up the metal of the workpiece, bringing it in a narrow zone to the melting temperature and destroys the crystalline structure of the material.

The metal atoms torn out from the lattice are partially evaporated and partially carried away from the melted edge by a gas stream.

The short duration of the impact prevents the edge from melting deep into the workpiece, minimizing the thermal load on the part and the deformations caused by heating.

Modern complexes

There are laser systems of various levels and purposes on the market. Some of them are designed to replace gas cutting machines. Sheets of metal are laid on a working base, and laser cutters are moved above them using portals.

Such installations allow cutting steel sheets up to 15 meters long and up to 20 mm thick . The movement of the cutters is controlled by a CNC unit into which a pre-prepared cutting program is loaded.

On such lines, metal waste is reduced several times compared to gas cutting.

More compact installations are designed for particularly precise forming of parts from metal, plastic or wooden blanks. They allow you to process metal with an accuracy of thousandths of a millimeter, cutting off “extra” material from the workpiece in accordance with a three-dimensional model. Such machines are used in instrument making, aerospace and defense industries, and for decorative cutting in art workshops.

Small-sized hand-held laser cutters of limited power are also available on the market. With their help, you can cut sheet metal or perform artistic cutting of metal.

Modes

The quality of cutting is influenced by a number of parameters. These include:

• head movement speed;
• thickness and material of the workpiece;
• emitter power;
• beam energy density;
• focal length;
• working environment.

Thus, conventional low carbon structural steels can be cut much faster than stainless alloys . The use of oxygen as an active medium makes it possible to increase the cutting speed by half compared to air.

The cutting accuracy and quality of the cut surface will also be determined by a combination of key installation parameters. The surface is characterized by the following properties:

• roughness;
• presence of melting;
• thermal impact zone;
• deviation of the edge from perpendicular to the surface.

Figure 3 Dependence of surface parameters on operating modes

The cutting accuracy is determined by the cutting speed and the beam focusing width.

Types of metals that can be processed

Laser cutting can work with almost all types of metals and their alloys . They cut both sheets, profiles, and pipes. In addition, the technology allows cutting non-metallic materials. A laser cutter for plastic or wood makes it possible to make highly artistic jewelry.

The method makes it possible to process such chemically active metals as aluminum and titanium, for cutting which other methods require great efforts. The laser beam deals with the refractory oxide film. The area and time of exposure are so limited that the metal does not have time to react with oxygen and nitrogen in the air.

Varieties

All laser cutting installations have the following main components in their design:

• source of light energy;
• a resonator with a semi-permeable mirror that provides periodic emission of a coherent beam of light when it reaches a given intensity;
• beam control and focusing system.

Based on power, laser cutters are divided into the following categories:

• low-power: up to 6 thousand watts, as a rule, these are solid-state lasers;
• average power from 6 to 20 thousand watts, with a gas working medium;
• powerful: from 20 to 100 thousand watts, have a gas-dynamic design.

Scheme of operation of a gas emitter.

Solid-state installations are made on the basis of artificial ruby ​​crystals, less often from special types of glass with the addition of calcium fluorite . They quickly issue the first pulse and, with good cooling, can operate in continuous mode.

In gas lasers, a beam of light energy is emitted by a column of ionized gas under the influence of an electrical discharge. The gas mixture consists of nitrogen, helium and CO2.

In a gas-dynamic system, a flow of ionized gas circulates through the vessel. At the point of constriction, the pressure rises sharply and during the discharge additional energy is released, providing high beam power.

Equipment

Laser cutting equipment is named according to the operating principle of the laser . Solid-state cutters have a simple design, limited dimensions and are used in compact machines of low power. Once turned on, it is almost instantly ready for use. Hand cutters are equipped with such lasers.

A gas laser is more complex in design; it necessarily includes a pump to maintain the design pressure of the working medium. A glass flask with gas is a rather fragile structural element, so such lasers are used only on stationary machines of medium power.

Gas-dynamic installations are even more complex: they also include a circulation pump that provides the required gas flow rate, heating and cooling systems. The complex design makes it possible to achieve very high power and cut thick workpieces.

For thin metal

Laser cutting of thin metal is often the only way to obtain a workpiece with the specified parameters for dimensional accuracy and surface quality.

Cutting thin sheets by mechanical methods leads to curvature of the edges, and by thermal methods - also to thermal deformations.

Modern equipment with program control allows you to cut thin metal quickly, with high accuracy and constant speed, preventing overheating and deformation of the material . Flexible adjustment of beam power, beam width and focusing distance allows you to cut even foil without distortion.

How to make a cutter yourself

Schematic diagram of a cutter for DIY assembly.

The simplest low-power laser cutter can be made at home. For this you will need:

• laser pointer;
• flashlight housing;
• DVD-RW drive;
• electric soldering iron;
• hand tools.

The device is made in the following order:

• remove the laser LED from the DVD drive;
• install it instead of a low-power LED from a pointer;
• When installing, you must strictly observe the alignment of the LED;
• assemble a power supply circuit for the device;
• assemble a structure from the front part of a laser pointer and a flashlight body that can accommodate 3 AAA batteries

Sketch of a homemade cutter.

Of course, such a cutter will not cut a sheet of metal or plywood, but it will be able to cut paper, cardboard and foil with high precision.

Source: https://svarka.guru/vidy/thermo/lazernaya-rezka-metalla.html