What is laser welding

Laser welding: essence and principle of technology

Laser welding is a metal welding method that is intended for particularly precise joining of products. It is often used when there is a complex configuration of contact between elements that are being welded. This technology is not used so often, but it still has a lot of positive features.

With its help you can get an aesthetic, even and smooth seam without deformation or bending. Welding is suitable for joining products made of stainless steel, aluminum and even silver. Of course, these are not all the characteristic qualities of this type of welding; there are other features that deserve special attention.

general characteristics

Laser welding of metals is carried out using special equipment. This method appeared not so long ago, but it has managed to gain great popularity. It is used in various industries to create a durable permanent connection. This welding method has high accuracy, good performance and excellent joint quality.

Heating and melting in the working area occurs using a laser beam. The light flux generated by the laser is monochrome. All waves have the same length. This is what greatly simplifies the control of flows, which is done by focusing lenses and deflecting prisms. The laser exhibits the phenomenon of wave resonance, which increases the launch power many times.

All these properties help to understand what laser welding is. During this technology, different welding machines can be used - semi-automatic, automatic and even robotic, which carry out work without human presence. Each of them delivers a laser beam that heats and melts a selected area of ​​the metal product.

Laser welding technology

The operating principle of laser welding is based on the following properties:

• coherence . This indicator is based on the relationship between the phases of the thermal field of the laser beam in different zones;
• monochromatic . This property is characterized by the small width of the spectral lines emitted by the source;
• direction . When carrying out the welding process, the beam does not dissipate as it moves from the source to the product being welded.

Source: https://osvarka.com/vidy-i-sposoby-svarki/lazernaya-svarka

Laser metal welding

Laser metal welding is one of the newest methods for creating permanent joints. It features exceptional precision, productivity and high weld quality. Heating and melting of metal in the working area is carried out by a laser beam. The method allows you to weld dissimilar materials. Despite the high cost and complexity of the equipment, the popularity of this method is constantly growing. Household-grade devices are becoming available for home workshops.

Laser welding

Conditions and methods of the process

To achieve high beam power, it must be focused. It is carried out during a series of successive reflections from the front and rear hemispherical mirrors. When the beam intensity exceeds a threshold value, it passes through the center of the front mirror and further, through a system of guide prisms, to the working area.

Laser welding of metals can be carried out with different relative positions of the workpieces being joined. The depth of metal penetration in the working area can be adjusted in a wide range - from surface to through. The work can also be carried out with a continuous beam or intermittent pulses.

The method allows you to weld both parts made of thin sheet metal, as well as complex profiles and parts of large thickness.

The following types of process are distinguished:

• At the joint. It is carried out without filler materials and flux powders in a protective gas atmosphere.
• Overlapping. The welded edges are superimposed on one another. It is necessary to ensure that the workpieces are pressed against each other.

Laser butt welding

Compact household-grade devices allow you to do laser welding yourself.

Laser metal welding machines

To carry out spot or continuous laser welding you must:

• laser with power source;
• optical focusing unit;
• mechanism for moving the beam in the working area;
• devices for supplying inert gases to protect the work area.

Based on the design of the active emitter, all laser welding machines are divided into two types:

Laser welding machine LTA4-1 Laser welding machine LTSK435-20

Both types can operate in either pulsed or continuous mode.

Lasers with a solid active element

Such installations can emit light flux both continuously and in discrete pulses. The active emitter is made from pink artificial ruby ​​by mixing aluminum oxide and chromium ions. The ends of the rod are polished, creating mirror surfaces on them that reflect light. Chromium ions irradiated by radiation from a pump lamp re-emit light at the laser frequency.

They operate in the following way:

• The rod-shaped active element is placed together with the pump lamp inside the working housing.
• The energy of periodic flashes of the lamp accumulates in the active element, focusing and reflecting from the end mirrors.
• Upon reaching the threshold intensity of the light beam, it passes through the radiation of the working pulse.

Laser with solid active element

Devices with a solid active body operate at a wavelength of 0.69 microns. Their power reaches several hundred watts.

Devices with elements based on a gaseous medium

Installations with a gaseous active body consume higher voltage and allow developing greater power - up to tens of kilowatts. In such devices, the pump lamp irradiates not a solid-state rod, but a gas mixture in a flask. The mixture uses carbon dioxide, nitrogen and helium.

It is under pressure of several atmospheres. Two (or more) electrodes periodically initiate an electrical discharge in the gas mixture. The pulse is also amplified by multiple reflections from the end mirrors.

When the intensity reaches a threshold value, a coherent pulse passes through the semi-permeable mirror and is directed through the optical system into the working area.

Diagram of a device with an element based on a gaseous medium

Gas installations operate with wavelengths of about 10 microns. Practical efficiency reaches 15%

Features of working with thin-walled metal

When welding workpieces of medium and large thickness, it is necessary to penetrate the material through the entire thickness. For this purpose, high intensity radiation is used. A feature of laser welding of thin-walled metals is the high risk of burning through the sheet. To avoid this, the following characteristics must be strictly controlled:

• radiation power;
• beam speed;
• focusing of the working spot.

Welding of thin-walled workpieces is carried out at minimum power. In continuous mode, the speed of movement of the working spot is increased. In pulse mode, the pulse duration is reduced and their duty cycle is increased.

Laser welding of thin-walled metals

If, at minimum power, the flux density is still too high, deliberate defocusing of the beam is used. This reduces efficiency, but eliminates sheet burning and metal spattering.

Differences in technology for different metals

There are differences in the technological process for different metals and their alloys.

When welding steel workpieces, mechanical cleaning of rust and other contaminants is required. Parts must be thoroughly degreased and dried. The presence of moisture in the seam area can lead to increased hydration of the seam material and a decrease in its strength and durability.

Similar mechanical preparation and degreasing are required for most non-ferrous metals and alloys.

Stainless alloys can only be welded end-to-end. Overlapping can cause thermal stresses in the material.

Due to the high speed of the beam, oxides do not have time to form in the working area. This allows you to weld stainless and titanium alloys without the use of flux powders and an atmosphere of protective gases. This unique ability makes the laser method indispensable for welding critical structures in the nuclear, aerospace and defense industries.

Manual welding

Technological progress in recent years has made it possible to create a compact machine for manual laser welding. There are many models on the market with different parameters and functionality.

They allow you to:

• repair of small and miniature structures;
• spot welding;
• surfacing operations;
• repair of small molds;
• soldering of electronic components;
• disinfection of medical products.

Manual welding

The cost of such devices is still significant. It will pay off provided there is a large amount of work.

Application of laser welding

The method is used to connect particularly critical structures or in cases where it is not possible to connect workpieces using other methods. The most common method in areas such as:

• High precision devices.
• Products made of light non-ferrous metals.
• Connecting cast iron blanks.
• Welding plastic.

A very important area of ​​application of laser welding is the defense industry.

The main advantages of the method are as follows:

• a limited heating zone reduces the risk of material warping;
• when using flexible light guides, it is possible to work in narrow and hard-to-reach places;
• the welding machine without additional modifications is suitable for cutting structures and cutting sheet metal;
• exceptional quality and durability of seams;
• high performance;
• lack of consumables.

Disadvantages, like any existing technology, are also present:

• high cost of the device;
• low efficiency;
• high requirements for employee education and experience.

Ultimately, comparing the advantages and disadvantages of laser welding, more and more enterprises and even small workshops are deciding to switch to a new technology.

Despite the different dimensions and power, laser welding equipment belongs to one of the main types: with a solid or gaseous working fluid. They differ only in the method of excitation of light radiation. With metal, both types of laser welding machines work the same way.

Solid State Installations

Such devices are often used in continuous radiation mode. They are characterized by higher operating frequencies and limited efficiency and power. Solid-state units are often used for welding small-sized and thin-walled products.

Pulsed solid state laser

Gas apparatus

If it is necessary to connect workpieces of large thickness, devices with a gaseous working fluid are used. Radiation is excited in a gaseous environment by an electric discharge. Such devices weld parts up to 20 millimeters. This method makes it possible to achieve high beam powers and higher efficiency values. However, the device is more complex; it uses a fragile glass bulb.

Gas laser

Hybrid installations

Hybrid welding systems have been developed for complex welding configurations and thick sheets. Next to the laser head there is a semi-automatic electric arc burner.

Hybrid laser-arc gas shielded welding process

The wire is used as a filler material and fills the welding gap, participating in the formation of the suture material.

Source: https://stankiexpert.ru/spravochnik/svarka/lazernaya-svarka-metalla.html

Metal laser welding technology and devices

Among the methods used for welding metal parts and structures, the most advanced method that provides a high-quality, neat seam is laser metal welding.

It is used when high demands are placed on the accuracy of the resulting forms. This is achieved due to the high precision of the weld, which during laser welding has a small width and sufficient depth.

A thin weld is obtained by exposing metal to powerful laser radiation in a limited area of ​​its influence, causing heating in this area to high temperatures in a short period of time.

Conditions and methods for carrying out the welding process

To ensure the effectiveness of the beam energy, it must be focused. For this purpose, mirrors that reflect and focus the laser beam are used. Coherent beams have minimal spread and target precisely defined areas of the weld area.

This type of welding can be carried out:

• in different positions and with any arrangement of welded edges;
• using complete and partial melting of the metal area being fused;
• continuously or in pulses.

Using this method, you can connect both thin-walled metal sheets and products with large overall dimensions.

The more accurately the laser beam is focused, the higher the power of its radiation.

Equipment for laser welding

The following equipment is used to perform laser welding:

• laser radiation source;
• transport unit and systems for beam focusing;
• if necessary, the presence of a gas environment to protect the metal;
• system for moving the beam and the product itself.

The laser device includes an emitter and a power supply. The radiation is provided by a generator that produces rays in a special environment.

Two types of lasers are used as such a medium: solid-state and gas-based.

review of the E-fiber AF laser welding machine with a rotary drive:

Features of laser welding of thin-walled metals

Unlike thick-walled metals, which require deep fusion to successfully join, for thin metals the depth of fusion is a significant factor. When laser welding thin metals, you cannot overdo it.

The parameters influencing this value are:

• laser radiation power;
• speed of work;
• degree of focusing of the laser beam.

In the case of a continuous process, t is the duration of its implementation. If the work is carried out in pulse mode, then t is the pulse duration. At high power densities (E), boiling of the metal may occur in the area affected by the beam, leading to through defects.

For thin metals, the characteristics of this indicator are especially important. In addition to the exposure time, it is affected by the degree of beam focusing. To reduce the radiation density for thin metals, the beam is defocused using electronic control of the device settings.

By changing the indicators (E) and (t), it is possible to ensure the operating mode for different metal structures with a minimum thickness.

Differences in laser welding technology for different metals

Laser welding technology for various metal alloys has its own characteristics.

For example, before working with steel products, they must be cleaned: remove scale, get rid of corrosion.

The product must be dry. This will help avoid the formation of pores, oxide film and cracks in the seam itself. The latter is especially important when welding pipes made of steel alloys. The welding area must be degreased.

Pre-treatment is also necessary for products made of aluminum, magnesium and non-ferrous metals.
If stainless steel pipes are made, they are strictly butt welded. An overlapping seam is not allowed due to the stresses that arise in the metal.

The speed of laser welding eliminates the formation of oxide compounds in the melt zone, so it does not require the creation of a protective environment or vacuum, unlike other types of welding.

This property is especially important when welding titanium alloys. They are used in critical products in the nuclear and aviation industries. Therefore, to avoid the formation of grains in the zone where this metal is heated to high temperatures, laser welding is often used.

Conclusion

The laser method of welding metals is especially in demand today in many areas. Using this technology, materials with different electrochemical properties can be contactlessly connected. This allows you to carry out work in hard-to-reach places. Work can be carried out in small areas with great precision.

However, its use is limited by significant costs due to the high price of the equipment.

(1 5,00 out of 5)

Source: https://plavitmetall.ru/svarka/lazernaya-oborudovanie.html

Laser welding of metals: areas of application, types, types of lasers for welding

In the production of many complex metals, welding is a key part of the manufacturing process. The connection is carried out using different types of heating. Laser welding of metals has often been used recently. How laser welding is carried out and what types of welding exist will be discussed in the article.

Metals are joined using laser welding mainly when other joining methods are useless or problematic. Equipment for laser connection is quite expensive, so you should buy it only when you are sure that the work cannot be done by other methods.

So, the scope of application is as follows:

• production of instruments and other precision mechanisms;
• production of complex products based on low-melting metals;
• production of cast iron parts;
• production of plastic products.

This technology began to be used in industry only about 20 years ago, and if possible, you can buy machines for only stationary type, but also manual ones for welding at home.

Advantages and disadvantages

Laser joining of metals has its pros and cons. As for the advantages, they are as follows:

• the metal area heats up slightly, which greatly reduces its warping during operation;
• the laser beam is transmitted through fiber optics, thanks to which it reaches even hard-to-reach places;
• laser equipment can be used not only for welding metal, but also for cutting it;
• it ensures high quality welds;
• The welding process provides good performance and is easy to control.

But the technology also has its drawbacks:

• the equipment is very expensive;
• the welding machine has low efficiency;
• The installation operator must be highly qualified.

But despite its disadvantages, the laser is the only option for achieving precision welding or joining of low-melting materials.

Types of welding

Laser welding comes in two types:

• Butt joint - in this case additives and flux are not used. A minimum joint between metals is allowed, no more than 0.2 mm. The same value is the maximum for focusing the laser beam on the joint. Welding is carried out by means of “dagger” penetration of the metal over the entire thickness with a laser radiation intensity of up to 1 mW/cm2. In this case, the seam must be protected from oxidation by argon or nitrogen, and helium will protect it from breakdown of laser radiation;
• Lap - metal sheets are superimposed on each other, they are connected through powerful radiation. Welding is carried out with local clamping of parts. The maximum permissible gap between metal surfaces during operation is 0.2 mm. If it is necessary to improve the quality of the parts being joined, a double seam is used.

When welding metals, two types of lasers are used:

This or that type of laser is selected depending on the purpose of using the equipment.

Solid State

In this case, the active body is a ruby ​​rod with glass and an admixture of neodymium or yttrium aluminum garnet, which is doped with neodymium or ytterbium. The rod is located in the lighting chamber. To excite the atoms of the active body, a pump lamp is used, which creates powerful flashes of light.

There are two mirrors at the ends of the active body:

• partially transparent;
• reflective.

The laser beam will come out through a partially transparent mirror, in advance it is reflected many times in the ruby ​​rod and amplified. Solid-state lasers are not very powerful, ranging from 1 to 6 kW .

Using these lasers, only small and not thick parts are welded, most often these are microelectronic objects, for example, thin wire leads with a diameter of 0.01-0.1 mm based on nichrome, gold or tantalum. Spot welding of foil-based products with a point diameter of about 0.5−0.9 mm is also allowed. In the same way, a sealed cathode seam is made on picture tubes of modern televisions.

The cathode is a tube with a length of 2 mm, a diameter of 1.8 mm and a wall thickness of 0.04 mm . A bottom 0.12 mm thick based on a chromium-nickel alloy is welded to such a tube. Such small products are cooked thanks to a high degree of beam focusing, as well as precise dosage of energy by adjusting the pulse duration within certain limits.

Gas

Gas lasers are more powerful; the active body in them is a gas mixture . Gas is pumped from the cylinders using a pump through a gas discharge pipe. Energy excitation of the gas occurs due to an electrical discharge between the electrodes. There are mirrors at the ends of the gas discharge tube. The electrodes are connected to a power source, and the laser itself is cooled using a water system.

The main disadvantage of equipment with longitudinal gas pumping is its dimensions. But lasers with transverse gas pumping are more compact. The total power can be from 20 kW or more, thanks to which it is possible to connect metals with a thickness of up to 20 mm at high speed - about 60 m/h.

The most powerful designs are gas-dynamic . They use gases for operation that are heated to temperatures from 1000 to 3000 K. The gas in them quickly flows through a Lavl nozzle, as a result, adiabatic expansion occurs, and then the gas is cooled in the resonator zone.

When cooled, excited molecules move to a lower energy level and coherent radiation is emitted. Pumping can occur using another laser or other powerful energy sources.

Powerful structures allow welding steel 35 mm thick at a speed of about 200 m/h.

Welding with a laser is carried out under atmospheric conditions; there is no need to create a vacuum, but the molten metal must be protected from air. Typically gases such as argon are used. The process is characterized by the fact that due to the high thermal power of the beam on the surface of the welded product, the metal intensively evaporates. The vapors are ionized, as a result of which the beam is scattered and screened.

Therefore, when high-power equipment is used, in addition to shielding gas, plasma suppression gas is also supplied to the welding zone. It is usually helium, which is much lighter than argon and will not scatter the beam. To simplify the process, you need to use special gas mixtures that have plasma suppression and protective functions. In this case, the burner must supply gas so that it can blow off the ionized steam.

During operation, the beam slowly penetrates into the part and pushes the liquid metal of the weld pool to the rear wall of the crater. This provides “dagger” penetration under conditions of large depth and small width of the seam .

The high concentration of energy in the beam makes it possible to achieve high operating speeds, and also ensures a good thermal cycle and high strength of the weld metal.

Laser welding machines

For this type of welding work, equipment of both mobile and compact types is used; full-size equipment can also be used to connect large parts.

Often for industrial purposes, machine models such as:

• LAT-S - it is used for laser welding itself, as well as metal surfacing. It has high power, thanks to which you can achieve high performance in terms of performance. It can be equipped with automatic coordinate tables, making it possible to process complex structures at high speed. The machine includes two modules. The first contains a power source and a device for cooling the laser, and the second module is a movable frame where the laser emitter is located. The two modules move easily thanks to the wheels at the base. For stationary work with the machine, immobility is ensured by a special mechanical lock;
• MUL-1 - this machine is small-sized, used for laser welding and surfacing of metals. It can also be used to solder gold and silver. You can weld jewelry with this machine easily and with high precision. The equipment is often used for jewelry repair and production. Small metal parts can be welded without high heat, even joining eyeglass frames is allowed. The device is convenient in that a voltage of 220 V is sufficient for operation. Depending on the selected mode, the power of the device ranges from 1.9 to 2.5 kW;
• LAT-400 - used for connecting large-sized products. The system includes a high-power solid-state laser, power supply and cooling device. The laser has high power and productivity, thanks to which even complex work can be carried out at high speed. The equipment is connected via a three-phase network of 380 V. At peak load, the power of the device is about 13 kW. The installation is equipped with a mechanized system, which is driven by a DC motor. This allows you to easily move the laser head in three planes.

Manual laser welding is carried out using the following devices:

• WELD-WF is a portable device that allows you to carry out work even in hard-to-reach places. It includes a manipulator that connects to the fiber. The generated laser radiation is transmitted along the fiber. Since there is feedback, using the device you can get the highest quality seam compared to equipment that does not have such options. The device has a power of only 1.5 kW and operates on a 220 V network. It is suitable for various repair work when dismantling is difficult or time-consuming;
• The CLW120 is a hand-held, low-power unit that is perfect for work that requires pinpoint precision and laser spot welding. In addition, it can be used to join non-ferrous and ferrous metals, stainless steel or titanium alloys. Equipment power - 10 kW, network requirements - 220 V.

Almost all of the listed devices are equipped with a binocular, which protects vision from the negative effects of the laser beam and at the same time helps to magnify the treatment object several times so that the work is done efficiently and accurately.

Source: https://tokar.guru/svarka/lazernaya-svarka-metallov-i-ee-osobennosti.html

Laser welding: features of the technology (how it works), pros and cons, where it is used

An excellent way to combine glass with metal is the laser welding method. With his assistance, instant and elegant metal welding becomes possible.

There are automatic and semi-automatic ways of doing the work. When using such modes, a solid seam is formed.

Next, you will learn what laser welding is and what pros and cons it has.

General information

Welding occurs using special equipment. The automatic mode works without human intervention, semi-automatic under the supervision of a welder. The second name for this method is “laser beam welding”, since the beam heats and melts the metal.

It has parameters that allow you to connect elements together. The beam beam is located in a certain area. Significant energy is concentrated on a small piece and the element melts.

It is enough for instant welding of elements of considerable thickness. Kvant 15 is one of the best laser devices. It is often used for welding various elements with a thickness of up to 3 mm.

Dentists use this device to develop prosthetics. With his assistance, welding stainless steel is possible. There are 2 types of devices: solid-state and gas. There is also a third type of welding called laser arc welding.

It has all the functions of both methods of joining metals. The device is not often used in everyday life, so we will focus our attention on two types of welding.

Using a Solid State Laser

Solid-state lasers are used with special-purpose electrodes. They come in ruby, glass, and with the addition of neodymium.

In the figure below you can see a detailed diagram. The power of this device is no more than 6 kW. In this regard, solid-state lasers are used for welding parts of small thickness.

This laser allows welding of gold elements, nichrome, tantalum. It becomes possible to melt wire up to 1 mm thick. Spot welding of foil parts is also acceptable.

Using a Gas Laser

Gas lasers are stronger than solid-state lasers, therefore, their range of use is larger. Here argon replaces electrodes. The figure below shows a detailed diagram. Large size and weight are a big disadvantage of such lasers.

However, behind the weighty frame hides a power that reaches 20 kW. This means that the device is capable of welding elements without slowing down (the average welding speed is 60 m per hour).

The most impressive lasers are gas-dynamic. The gas must be heated to ultra-high pressure in order for it to function. The device welds metal at a speed of 200 m per hour and produces 100 kW.

They are used exclusively in large enterprises.

With this installation you can weld: aluminum; stainless steel; glass The scope of use of this equipment is very impressive. However, there is an important detail to consider.

During laser welding, the welding area must be protected from oxygen, as the weld may be of poor quality. Since the metal instantly evaporates, the light beam dissipates very quickly.

To prevent this, it is necessary to supply a gas that inhibits the plasma. Helium is often used for this, since it is not a barrier to argon and does not allow the laser to scatter.

Professionals use a combination of argon and helium in the process in equal proportions, simultaneously implementing 2 options: protective and suppressive.

Advantages and disadvantages

Accuracy is the main prerogative of laser welding. These devices never make mistakes; with their assistance, you project the beam into the area you need and the margin of error is reduced to a minimum.

Even when working with tiny elements. At the same time, the connection remains of excellent quality.

Gas-powered lasers weld parts together to form a neat seam. Thanks to this privilege, they do not change their shape even under the influence of extreme temperatures, since the area of ​​​​increased thermal pressure is projected into one area.

The following function is not available for some welds. The beam can be aimed from a long distance, which is very convenient in inaccessible areas. Let's give an example: there is a device that can troubleshoot pipelines located under water.

This is acceptable when using reflective surfaces. The direct beam can be reflected in the direction you want. This makes it possible to weld in the most unpredictable places.

The pinnacle of professionalism is welding several parts at the same time, using one installation for this purpose.

To achieve this goal, a prism is used that scatters the beam and distributes it in several directions. It becomes possible to reduce welding costs and increase productivity.

The only disadvantage is its high technological complexity and high price. Not all masters will appreciate the advantages of the equipment and will want to master the necessary technique.

Summarize

If you really want to improve your skills, then you need to master the laser electric welding method.

You will be able to effortlessly join metals of any size, and you will have access to instant and high-quality welding of aluminum and stainless steel.

We wish you success in your work!

Source: https://prosvarku.info/tehnika-svarki/svarka-lazerom

Laser welding of metals: advantages and disadvantages, do-it-yourself cutting, what types of devices and installations are there? – Thermal welding on Svarka.guru

Welding is a very important process in manufacturing. Such a device, where a laser is used as an energy source, is called laser welding, which is used to join similar and dissimilar metals. This is the most modern method for welding metal parts, which in recent years has increasingly attracted attention.

This type of welding was created in the 60s of the twentieth century. The advantage of laser radiation is its high energy accumulation. This makes it possible to connect various metals and alloys with thicknesses ranging from a micrometer to one centimeter.

Laser radiation creates a weld in this way: it is directed into a focusing system, where it is converted into a smaller beam, absorbs, heats and melts the materials being welded. Laser welding uses guide mirrors to focus energy.

Microwelding connects material up to 100 microns thick, mini-welding melts at a depth of 0.1 to 1 mm, macro-welding is capable of soldering parts with a thickness of more than 1 mm. Depending on the position of the parts and the laser beam, the soldering pattern can be:

• end-to-end;
• overlap;
• corner;
• other options.

Application area

The greatest welding efficiency is observed in products with a thickness of up to 10 mm . The method is not widely used for economic reasons, since the cost of installation and additional equipment is high.

This processing is used in cases where other types of welding cannot be used and precise preservation of the structure of the part is required after all manipulations. The concentrated impact of the energy beam guarantees minimal changes in the properties and geometry of the product. This is an excellent solution for joining difficult-to-weld metals, without the need for additives, vacuum chambers and other additional elements.

Technical feature

Laser welding arose according to the developments of N.G. Basov, H. Towns, A.M. Prokhorov.
Specialists managed to obtain pulsed and continuous action devices. Their advantages include an increased concentration of the energy beam. The melting process is carried out at high power, which makes it possible to process dissimilar metals up to several centimeters thick.

Technical features:

• high melting rate;
• saving properties and geometry;
• minimum residual stress indicator;
• no need for filler materials or special chambers with a protected environment.

The precision of laser welding makes it possible to process products of complex configurations.

These nuances make this type of welding one of the most advanced in modern enterprises. The disadvantages include the cost of installation; for some manufacturers the purchase is unprofitable.

How to make a laser cutter for your garage

Many people are interested in how to make laser welding on their own? Since the equipment is quite expensive and not everyone can afford it, you can try to make a simple cutting machine yourself using a laser. With it, you can cut a variety of patterns on durable steels, cut metal components, or join simple steel products.

To make this you will need a laser pointer. Additional components will also be needed:

• a flashlight that runs on batteries;
• an old DVD-ROM from which you will need to remove the matrix with a laser drive;
• soldering iron and screwdrivers.

At the initial stage, it is necessary to completely disassemble the drive of the old computer disk drive. It is from this that you need to remove the device. Everything should be done carefully and carefully so as not to damage the main device. The drive must be a write drive.

Afterwards, the red diode is removed; it is this that burns the disk while recording information to it. Using a soldering iron, the diode mounts are soldered. This item is very sensitive and should not be thrown.

Next, the laser pointer is disassembled; you can watch how this is done in a video on the Internet. The diode from the pointer is replaced by a red light bulb from the drive. The body part is made from a flashlight. And rechargeable batteries will be needed to power the laser cutter.

Source: https://instanko.ru/osnastka/lazernaya-svarka.html

Laser welding of metals: how the machine and equipment for welding copper with a laser works

Laser welding is one of the modern methods that allows you to connect and cut metal parts.

Its work is based on the use of a focused laser beam, which makes it possible to make seams on very thin metal.

Differences in welding technology for parts made of different metals

Different metals are welded in accordance with different technological standards. Working with steel workpieces requires preliminary cleaning of contaminants, including rust. Also, the product must be thoroughly degreased and dried.

Technology for welding thick metal.

The presence of moisture in the area where parts are connected can lead to increased hydration and, as a result, to a decrease in its strength and durability.

Due to the high speed of the beam, laser welding machines allow the formation of a seam without oxides. As a result, it becomes possible to join stainless and titanium alloys without flux and inert gases.

This unique ability makes such installations indispensable when welding especially critical structures.

Developments in technology in recent years have made it possible to create a compact device for manual laser welding. Today there are many models presented in stores. All of them boast different parameters and functionality.

Bottom line

Laser metal welding is a unique technology that allows you to join thin materials, stainless and titanium alloys. The main feature of this technology is the formation of a high-quality, neat seam without any defects associated with deformation of parts.

Thanks to these advantages, this type of welding has become widespread in various industries.

Source: https://tutsvarka.ru/vidy/lazernaya-svarka

Equipment for laser metal welding: technology and devices

Laser welding , GOST 28915-91 - a method of joining parts using a concentrated energy beam. It is used for melting various materials in the electrical and radio engineering fields. The benefits include productivity and environmental friendliness.

By energy

Laser welding methods are classified according to several criteria. The varieties differ in technical characteristics and economic aspects. These features are taken into account when choosing a specific installation.

Each type differs in power density. The process is carried out at E=1-10 MW/cm2. If you reduce this indicator, then another type of welding will be more economically suitable, one of which is electric arc. Three main modes are used, which differ in several parameters:

1. t>10-2 s, E=1-10 MW/cm2 . This mode involves the use of continuous lasers. It is suitable for machining structural steels.
2. t

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What is laser welding? Advantages and disadvantages

Laser welding is one of the types of fusion welding with heating of the working area by laser radiation energy. It belongs to the thermal class of welding technologies and is included in the same group as plasma, arc and electron beam welding.

physical characteristics

Laser welding of metals differs from other types of welding technologies in its high energy density in the heating spot - up to 1 MW per sq. cm. This ensures a high rate of heating and cooling of the weld zone, which significantly reduces the thermal effect on the heat-affected zone. Therefore, the welding process does not cause structural changes in the material, leading to softening, deformation and cracking.

The size of the focusing spot of an industrial installation can vary from 0.2 to 13 mm. The depth of material penetration is directly proportional to the laser radiation energy, but also depends on the location of the focal plane of the beam.

During a welding operation, a zone of molten material is mixed along a predetermined path with a laser beam, creating a weld along the line of motion.

It turns out to be narrow and deep, so its shape is fundamentally different from the welds of other welding technologies.

Types and modes of laser welding

Laser welding technology includes two types of welding joints: spot and seam. In this case, industrial installations can generate two types of laser radiation: continuous and pulsed.

For a point connection, only pulsed radiation is usually used, and for a suture connection, both continuous and pulsed radiation are used. In the second case, the weld is formed by overlapping pulsed heating zones, so the welding speed depends on the pulse frequency.

Spot welding is usually used to join thin metal parts, and seam welding is used to form deep welds.

Hybrid laser welding refers to welding technologies that use filler materials. In this case, welding equipment is supplemented with wire, tape or powder feed mechanisms. Filler materials are fed into the melting zone synchronously with the movement of the welding head, and their thickness corresponds to the width of the weld and the diameter of the spot.

Technological features

The speed of movement and energy modes of the welding process depend on the width of the weld, as well as on the type and thickness of the materials being welded. For example, steel sheets 20 mm thick are welded with a gas laser at a speed of several hundred meters per hour. This figure is an order of magnitude higher than the limiting characteristics of electric arc welding.

Laser technology is especially effective when working with alloy steels, cast iron, titanium, copper, copper alloys, thermoplastics, glass and ceramics. The high energy density in the heating spot destroys surface oxide films, preventing the formation of new oxides. This allows laser beam welding of titanium, aluminum and stainless steel without the use of fluxes or inert gases.

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Laser welding of aluminum: technology, conditions, methods, equipment - Website about

The density of aluminum is 2.7 g/cm3, which puts it among the lightest metals, but at the same time it also has a fairly high thermal conductivity. When heated, this metal quickly oxidizes, while it is extremely fragile and not durable.

Alloys of this metal are more often used in industry; they are stronger. Almost all of them, with the exception of heat-strengthened ones, can be easily connected to each other during welding. However, aluminum welding, despite its apparent simplicity, has some peculiarities in execution.

All aluminum welding methods cannot be carried out in a dirty workshop, but only in a room where there is not a lot of dust. Also at an average air temperature of 18 - 22 degrees Celsius and where the relative humidity is at 70%.

Work method:

• The oxide film on the surface of aluminum will begin to melt only at temperatures above 2000 degrees.
• Considering that the thermal conductivity of this metal is one of the highest, welding of aluminum with an electrode should be carried out with a short arc and at high power. Before starting work, the electrodes must be dried.
• The use of welding equipment for welding aluminum must take into account that with high thermal conductivity, the metal has a low melting point, which means it can easily be burned through.
• With any method of welding aluminum, at the end of the work a crater forms on the finished seam. Its brewing requires special skill.

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In order to avoid unnecessary problems, welding on aluminum must be carefully prepared. The choice of welding speed should be in favor of the faster one. Work with one electrode must be carried out continuously.

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The most acceptable technology is aluminum welding, which first uses a chemical surface treatment method. So without degreasing the metal and electrodes, it’s better not to start the process.

And to make the effect of such peeling more effective, before processing the metal, it can be thoroughly cleaned with a brush.

Aluminum welding methods and technologies

When spot welding, aluminum or its alloys must be in layers whose thickness is a maximum of 6 millimeters and a minimum of 0.04. The permissible gap between tightly fitting elements is 0.3 millimeters.

The suture method assumes a thickness of hermetically sealed parts of no more than 4 millimeters.

Both methods require constant arc power and high wire feed speed. At the same time, high-quality work can be carried out not only with the help of argon arc welding, but also with semi-automatic equipment, an inverter, and also a laser.

• Argon welding of aluminum alloys is the creation of a seam in an argon environment with non-consumable tungsten electrodes. Here, alternating current and high arc ignition frequency are required. An argon arc apparatus can be purchased for 40,000 rubles.
• Semi-automatic welding is similar to working with steel. Here, too, the wire is fed in a protective environment through the torch. The average price of a semi-automatic machine is 50,000 rubles.
• Welding aluminum with an inverter is no more difficult than with any other equipment. But a prerequisite is that before starting work, special electrodes (for example, OZA, OZA-1, OZANA, OZANA-1, OZR, OZR-2) must be calcined in a special oven. Such an inverter can be purchased for an amount close to 60,000 rubles.
• Laser welding of aluminum is characterized by minimal heat transfer, which allows, at a minimum, to reduce warping of parts.

If work is carried out in a protected environment, then argon in its pure form is applicable only for thin layers. Adding helium will help you weld successfully on thicker pieces.

Theoretically, any device is suitable for aluminum. It is much more important to carry out the preparatory stage correctly and accurately determine the aluminum welding mode.

• A non-consumable electrode during manual welding can be used to correct existing welding defects, as well as for vertical and ceiling work.
• Due to the fact that aluminum can melt no more than 75%, automatic welding with a non-consumable electrode is successfully used for double-sided welding.
• For large width surfacing, a consumable electrode can be used.
• Welding of aluminum structures, the thickness of which is about 20 millimeters, must be carried out at high power with consumable electrodes of large diameter.

Some modern welding machines are equipped with an automatic welding wire feed system, which is very convenient. Read the recommendations on how to choose and use welding wire correctly.

And if you want to use such a device at home, choose a model that can be connected to a regular outlet. This article contains recommendations for choosing a home welding machine.

Among professional devices, we can recommend plasma modifications. Read here in more detail about the advantages and disadvantages of using plasma metal welding.

Use of additives

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Advantages of using additives:

• Can be used when joining parts that will undergo further heat treatment.
• Allows you to avoid metal cracking during the process and increase the strength of the seam.
• They make it possible to increase tensile and shear strength.
• Used when working with metal elements of the car chassis.
• They have maximum resistance to chemical corrosion.

Welding aluminum wires

Then there are two soldering methods:

• Cover the joint with rosin, melting it with a hot soldering iron. You will need to add rosin a few more times. Instead, you can use the same machine oil that is used to lubricate sewing machines.
• Clamp the twisted wires with the holder of the welding machine, then work with the carbon electrode in automatic mode.

After completing any type of work, the soldering area is isolated with tape or a plastic cap.

Are you looking for a universal device for working with different types of metals? Pay attention to the semi-automatic welding machine: an affordable and functional welding method.

And if you need a compact model for your home, choose an inverter. Find out from this page the difference between a welding machine and an inverter.

Classic transformer devices are quite heavy and bulky. Read the link about modern portable welding machines of various types and designs.

Cold welding of aluminum

Cold welding for aluminum is a very plastic putty in structure, created on the basis of epoxy resin, which allows them to form a dense, hard surface when dried. It is commercially available as a repair rod filled with a special composition.

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The required amount of substance is cut off, then it must be thoroughly kneaded for several minutes, and then the hole or crack must be sealed with this elastic mass.

Many craftsmen prefer not to suffer with an agronomist, but to use this method when welding aluminum radiators.

Aluminum and its alloys are widely used in all industrial sectors. But welding work with them is complicated by the fact that at high temperatures they oxidize and melt extremely quickly.

The main thing in this process is the destruction of this film while maintaining the integrity of the metal. To carry out high-quality work, it is necessary to take into account the thickness of the metal parts, as well as the fact that this metal, despite its low density, has a high specific strength.

• 3 types of metal welding Welding is usually called the production of a rigid, permanent connection between two metal surfaces. As a rule, permanent connection []
• 3 semi-automatic aluminum welding machines Welding work is an urgent need in every enterprise and production without exception. A welding machine will also be useful to satisfy []

Source: https://nzmetallspb.ru/tehnologii/lazernaya-svarka-alyuminiya-tehnologiya-usloviya-sposoby-oborudovanie.html

What is laser welding? Advantages and disadvantages

Laser pulse welding is an uncommon but still noteworthy method of joining metals and glass. Using this method, fast, high-quality and aesthetic laser welding of stainless steel, laser welding of aluminum and even welding of silver is possible.

The entire process takes place in automatic or semi-automatic mode, so the seam is always strong and durable, because the likelihood of human error is low. In this article we will briefly describe what laser welding is and what advantages and disadvantages this technology has.

general information

Laser welding of metals is carried out using special equipment. As we wrote above, it can be semi-automatic (work under the control of a master) and automatic, up to robotic models that carry out work without human presence. The essence of welding using such equipment is simple: the metal is heated and melted by a laser beam, which is why this method is often simply called “laser beam welding.”

The laser beam has a number of very important characteristics that allow parts to be welded. For example, a beam of beam is concentrated strictly at one point and does not scatter. Thanks to this feature, a large flow of energy is concentrated in one small area, due to which the metal melts. This energy is enough for fast and high-quality welding of even thick metals.

One of the most versatile laser systems is Kvant 15. Such equipment is often used for welding homogeneous and dissimilar metals up to 3 millimeters thick. For example, such a laser welder is widely used in dentistry to create dentures. It can also be used for laser welding of stainless steel.

All laser systems are divided into two types: solid-state and gas. There is also laser arc welding. This is a hybrid of laser and arc welding, which has all the advantages of both methods of joining metals. Laser-arc welding is very technologically advanced and is rarely used in home workshops or small factories, so we will dwell in more detail on the first two types of laser welding.

Application of Solid State Laser

A solid-state laser is used in conjunction with special electrodes. Electrodes can be ruby, glass, or with neodymium impurities. The schematic of a standard solid-state laser is shown in the picture below. The power of such laser systems is extremely low and does not exceed 6 kW. Therefore, solid-state lasers are used for welding parts of small thicknesses. For example, parts that are needed in microelectronics.

This laser can be used to weld parts made of gold, nichrome or tantalum. You can melt wire with a diameter of less than 1 millimeter. You can also spot weld foil parts.

Application of laser with gas

Gas lasers are more powerful than solid-state lasers, so their scope of application is much wider. Here, instead of electrodes, a protective inert gas, often argon, is used. You can see the diagram of a gas laser in the picture below.

The only drawback of gas lasers is their considerable size and weight. But it is completely justified, because behind the bulky heavy body there is a lot of power, reaching 20 kW. This means that with the help of such equipment you can join even the thickest parts without slowing down (the average speed of gas laser welding is 60 meters per hour).

But the most impressive, of course, are gas-dynamic lasers. To operate they require heating the gas to very high temperatures. The laser itself produces up to 100 kW and welds metal at a speed of 200 meters per hour. Of course, such installations are used only in very large industries.

Using a gas installation of any power, laser welding of aluminum alloys, laser welding of car bodies, laser welding of stainless steel and even laser welding of glass becomes possible. So the scope of application is really wide.

There is also one nuance that needs to be taken into account. It doesn’t matter what you have to do: laser welding of aluminum alloys, stainless steel or glass, in any case, the welding zone needs protection from oxygen. Everything here is the same as with conventional manual arc welding. The welding zone can be severely damaged by oxygen, and the weld will turn out to be of poor quality. We have already written above that gas laser welding uses argon, but sometimes this is not enough.

If the installation is too powerful, the laser beam can quickly dissipate due to the rapid evaporation of the metal. To avoid this, in addition to argon, you need to supply a gas that suppresses the plasma. Helium is often used for these purposes, since it does not interfere with argon and does not allow the beam to scatter. Experienced craftsmen use an equal mixture of argon and helium in their work, providing two functions at once: protective and plasma suppression.

Advantages and disadvantages

The benefits of laser welding can be summed up in one word: precision. Laser installations never make mistakes; with their help, you can direct the beam to a specific point and the likelihood of an error will be minimal. Even when working with very small parts. At the same time, the connection quality is always very good.

Powerful lasers that use gas in their work weld the part quite deeply, leaving a narrow seam. Due to this advantage, parts do not deform even when exposed to very high temperatures, since the zone of increased thermal stress is focused at one point.

The next plus is simply not possible for most types of welding. The laser beam can be directed from a fairly long distance, which is extremely convenient in hard-to-reach places. For example, there is a laser device capable of repairing underwater pipelines. This is made possible through the use of mirrors. The beam is direct, but it can always be reflected in any necessary direction. All this allows you to perform laser welding in the most unexpected places.

The pinnacle of skill is welding two or more parts at the same time, using just one installation. For this, a prism is used, which splits the beam and directs it in several directions at once. Using this method, you can reduce welding costs and increase productivity.

The only drawback is the high price of laser systems and their technological complexity. Not every welder will appreciate the benefits of laser welding and wish to obtain the appropriate qualifications.

Instead of a conclusion

Laser electric welding is a truly modern technology that is worth learning if you want to improve your professional skills. Using a laser welder, you can easily join metals of large and small thicknesses; you will have access to fast and high-quality laser welding of aluminum alloys and stainless steel. We wish you good luck in your work!


Source: https://svarkaed.ru/svarka/vidy-i-sposoby-svarki/chto-takoe-lazernaya-svarka-preimushhestva-i-nedostatki.html