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    6/18/2024
    Laser welding: Beautiful, high-quality welds in record time

    What is a laser? A laser is a device that produces a powerful and focused beam of light in a narrow spectrum of light. The word "laser" is an abbreviation for "Light Amplification by Stimulated Emission of Radiation". Simply put, a laser device gradually amplifies light of selected frequencies, thereby creating a special light. Compared to normally scattered light, this light can transmit large amounts of energy over longer distances. This property is used in many industries and also in welding. Comparison with traditional welding methods Laser welding offers many advantages over traditional welding methods such as TIG (Tungsten Inert Gas), MIG/MAG (Metal Inert Gas/Metal Active Gas) and MMA (Manual Metal Arc). Laser welding differs from traditional methods in that it does not use an electric arc to generate heat, but a high-energy light beam. Laser welding is much faster and more efficient. Even inexperienced welders can achieve very strong and aesthetically pleasing welds in a very short time. After welding, there is no need to clean the welds with grinding or chemical processes. This means that laser welding eliminates some steps, which increases efficiency and reduces the cost of welders and consumables. Laser welding offers the advantage of a good weld width to depth ratio. It can heat the material to a great depth even with a narrow weld. The heat affected zone is therefore smaller - and the subsequent deformation of the material is also smaller. Laser welding can also be performed contactless and from a distance, which is an advantage for welding in hard-to-reach places. The rapid hardening of the material allows welding in various positions. Advantages and disadvantages of laser welding Laser welding offers many advantages, but there are also disadvantages that need to be considered. - Advantages: High welding speed and efficiency. It creates strong and aesthetically pleasing welds. No additional grinding and cleaning of welds is required. Deeper penetration with smaller heat affected zone Possibility of contactless welding. Fast hardening of the material, which allows welding in various positions. - Disadvantages: Greater demands on precision in preparing welded parts so that gaps do not form. Higher initial investment in laser equipment. Higher safety requirements due to dangerous radiation The principle of laser welding - heating thanks to energy Laser welding is the process of joining two materials by emitting a powerful beam of light. The laser beam is focused on a small area of the material's surface, creating a very high temperature. When the laser interacts with the surface, the material reflects part of the laser beam. Part of the beam is absorbed by the material and converted into thermal energy (this is why, for example, higher power is needed when welding highly reflective materials). This causes the material to melt and then cool and crystallize, creating a welded joint. When the laser hits the surface of the material, the material begins to heat up, melt, and vaporize. As the temperature changes, the reflectivity of the material also changes. (The higher the temperature, the lower the reflectivity.) The material also begins to vaporize, creating a “pit” and allowing the laser beam to penetrate deeper. As the laser beam continues to shine, the pits deepen. When the laser stops shining, the molten metal around the pit flows back and, after cooling and solidifying, the two welds are joined together. Materials that can be welded by laser welding A laser welder is used for very precise and fast welding of metal and thermoplastic materials, often for welding thin materials, sensitive and difficult-to-weld metals that are not easy to weld with arc methods. Laser welding can be used on a wide range of materials. These include structural steels, alloy steels, duplex, Cr/Ni, high-strength low-alloy steels, carbon steels, refractory metals, chemically active metals, aluminum, titanium, nickel, magnesium and even copper, brass, silver and gold. Laser welding is also suitable for materials with high electrical and thermal conductivity, as well as for electrically non-conductive materials and materials with different physical properties. Laser welding without filler material, but also with it Laser welding provides the possibility of welding without additional material. Filler Welding: In this type of welding, additional material in the form of wire is added to the area being joined. This filler material helps to fill the gap between the materials and creates a strong weld. An example would be a fillet weld of thicker material on the inside. Fillerless welding: In fillerless welding, materials are joined directly without the use of additional material. This process is ideal for thin materials and allows for the creation of precise and fine welds. An example of this is the external fillet weld of thin sheet metal. Laser welding safety precautions Safety in laser welding is essential! When working with a laser, especially with laser welders, it is important to follow protective measures. Laser welders belong to the highest class of laser, class 4, where there is a risk of irreversible damage to the retina in the eye and skin burns. To protect your eyes, it is therefore necessary to use special glasses designed for working with lasers that filter the relevant spectrum, or a welding helmet with a built-in filter. Protective workwear is also important for skin protection. Safety is key, which is why laser welding is performed in the workplace, which protects people and flammable materials from the reflected beam. Types of laser welders by radiation source Based on the source of laser radiation, we distinguish 3 types of lasers: gas CO2 lasers solid-state Nd:YAG lasers fiber lasers CO2 gas lasers Gas lasers are lasers that use gases as the active substance to create the laser beam. CO2 lasers are probably the best known gas lasers and are mainly used for laser marking, laser cutting and laser welding. Solid-state Nd:YAG laser welding machines Nd:YAG lasers use a solid (crystal or glass) mixed with a rare earth element (neodymium, chromium, erbium, thulium or ytterbium) as a source of optical amplification. Nd:YAG lasers generate a beam by passing light through YAG (yttrium aluminium garnet) single crystals activated by neodymium (Nd) ions. The Nd:YAG laser can be pulsed or operated continuously. The most famous solid-state laser is the ruby laser, which uses a synthetic ruby crystal - it is the first functional laser ever constructed. The Nd:YAG laser is commonly used in materials processing applications - e.g. engraving, etching, marking various metals and plastics, or for metal surface enhancement processes such as laser cleaning, cutting, welding. Fiber laser welding machines A fiber laser is a special type of solid-state laser that is a separate category. In fiber lasers, the gain medium is an optical fiber (quartz glass) doped with a rare earth element. This type of laser differs precisely in the properties of the optical fiber to guide light: the laser beam is more direct and smaller than in other types of lasers, which makes it more precise. Fiber lasers are also known for their small footprint, good electrical efficiency, low maintenance and low operating costs. They are used in many applications, including material processing (e.g. laser cleaning, texturing, cutting, welding, marking), but also in medicine and the weapons industry. Types of laser welders by operating mode If we were to look at the operating mode of laser welders, all types of lasers can operate in one of two ways - their laser beams can be either pulsed or continuous. With continuous lasers, there is a constant flow of energy, which means that the laser continuously emits one uninterrupted laser beam. In pulsed lasers, the laser beam is interrupted at regular intervals to build up energy and achieve a higher peak power than in continuous lasers. The laser beam is released in the form of pulses that have a specific duration called the pulse width. Is laser technology the future of welding? Laser welding is a modern and efficient method of joining materials. Compared to traditional welding methods, it offers advantages such as speed, weld strength and reduced grinding requirements. Although it has some limitations, laser welding is an invaluable tool in many industries where joining materials with high precision and quality is required.

    zvaranie co2 mig mag
    6/18/2024
    What is MIG and MAG (CO2) welding?

    MIG and MAG welding methods (not quite correctly known as CO) are currently some of the most widely used welding methods in the world. MIG/MAG welders are thus gaining great popularity in both domestic and industrial use. By definition, both are “arc welding processes that create metal joints by heating them with an electric arc that is created between a continuously fed welding wire and the weldment.” Simply put, the welder continuously feeds the welding wire through the welding torch, and the electric arc that is created when the wire contacts the weldment melts the metal, then solidifies, forming a weld. What gas should be used for MIG and MAG welding? The shielding gas CO 2 (carbon dioxide) is used in MAG (Metal Active Gas) welding . Therefore, the term CO 2 welding should only be used for MAG welding. CO 2 is used pure or as a mixture of CO2 and argon (so-called corgon: 82% argon and 18% CO2), mainly for welding stainless steel. Exceptionally, we can also encounter three-component mixtures with an admixture of oxygen. The difference between pure CO 2 and a mixture of CO 2 + argon is primarily in their properties during use , to which we must adapt the choice of a pressure reducing valve. Carbon dioxide cools significantly when expanding, which can cause problems with freezing and subsequently gas flow. Therefore, it is good to use a pressure reducing valve with heating. It is by adding argon that we eliminate this problem, and therefore it is generally recommended to use the mixture. The truth is that when using pure CO 2 , the resulting weld is less porous, but this is a minimal difference that does not have a significant impact on the quality of the weld in ordinary and often professional welding. Argon and helium are typically used in MIG (Metal Inert Gas) welding , mostly for welding aluminum and other non-ferrous metals. Why are MIG/MAG methods called CO welding? The popular, not entirely correct, name CO 2 or CO welding is used precisely because of the MAG method, where carbon dioxide can be used as a gas. Even though carbon dioxide is not used in MIG welding, a MIG/MAG welder is often called a CO welder. Before various mixtures were used, CO 2 was the most widely used gas and, despite the imprecise name, the name was extended to include MIG welding and is still used today. What is the difference between the MIG and MAG method? It can be said that the only difference between MIG and MAG welding is the type of shielding gas. One actively intervenes in the welding process (active), the other only protects it (inert). We explain the difference between MIG and MAG in more detail in the article Preparing for welding with a CO2 welder. Basics of CO2 welding. Advantages of MIG/MAG welding over other methods These welding methods are very popular worldwide for their high quality welds, and at low costs. MIG/MAG welding has the following advantages: the ability to join different types of materials and thicknesses, components and accessories are easily available and affordable, very high welding efficiency, possibility of welding in all positions, in an overhead position using special tubular wires, nice appearance of the weld bead, less heat input compared to other methods, minimum spatter and slag residues allowing for quick and easy cleaning of the weld (beautiful clean weld after quick cleaning, especially during pulse welding), It is intended for robotic applications, automation and semi-automatic applications. Why use the MIG/MAG method? lower costs per meter of weld than with other welding methods, lower costs for additional material, minimal cleaning work after welding. Limitation of MIG MAG welding MIG/MAG welding is not suitable for outdoor welding, where the shielding gas is likely to be blown away by the wind. For outdoor welding, it is better to use MMA welding with a coated electrode. MIG/MAG welders for hobby and professional use Classic MIG/MAG welding is still one of the most widely used welding methods used in most companies, but also by smaller tradesmen. To achieve optimal welds, it is important to choose a welding source, i.e. MIG/MAG welder, for a specific application, along with accessories and filler material.

    OIP
    6/18/2024
    Sheet metal bending

    Bending - explanation, procedure, how to do it and recommendations Bending is a technological operation in which a material is permanently deformed in the desired direction and shape. By using force and bending moment appropriately, the desired shape change is achieved without a significant change in the basic cross-section of the bent material. The material is stretched on the outside and compressed on the inside. Bending can be simple or can consist of individual steps and a combination of V- and U-shaped bends. It is usually bent cold, in the case of thick materials it is bent hot. A great advantage of this technology is the deformation strengthening of the material itself, which necessarily occurs. Nowadays, it's impossible to do without bending. Bent parts and products are very widespread on the market today. They are found almost everywhere around us, whether separately or in finished units and products. Thanks to the development of bending, there has been a huge development, there has been an increase in efficiency, a reduction in production costs, and a simplification of work procedures. It is used in every industrial sector, especially: mechanical engineering, automotive industry, agriculture, construction, shipbuilding, railways, storage, handling equipment, traffic signs, public lighting, fences, doors, gates… Basic classification of bending machines: manual: Advantages - affordable due to low price Disadvantages - low accuracy, only suitable for thin materials motor: outdated and inefficient CNC press brakes: precise, efficient What material can be bent? The base material must have sufficient ductility for bending. This is necessary to prevent it from breaking. Scratch protection When bending materials where the emphasis is on the smoothness of the surface and the final appearance, protective inserts are used, most often silicone or plastic. Some sheets, especially stainless steel and aluminum, have a protective film on them (see the gallery) which, with appropriate adjustment and tuning of the bending process, will last without damage. The original surface on the protected side will retain its original intact appearance. The order of bends needs to be thought out in advance – Springback: after the bending force is relieved, the material returns by a certain angle. This angle is called the springback angle and must be taken into account when bending. This means that the bent material must bend more than the springback angle to achieve the desired dimension. This angle depends on the properties of the material itself. -Minimum bending radius: this is the minimum dimension and if it is exceeded, the fibers of the material on the outer stretched side will break and it will be damaged. This dimension depends on the plasticity of the material, the type of material, its thickness, quality and the method of bending. The 5 biggest mistakes when bending: -incorrect bend order: Bends must be planned in advance so that the part can be inserted between the prism and the knife -inappropriate parameter setting: The pressure force is unnecessarily high and the knife is pressed into the bent material -material unsuitable for bending: Brittle material breaks or tears at the outer edge - Failure to respect the orientation of the material fibers: The properties of the material are already influenced during its production. For example, rolled sheet metal has a different springback angle when bending depending on the orientation of its fibers. It is important that the customer is aware of this and that this fact is taken into account when designing the component. -dirty, deeply scratched, corroded material: We do not bend such material

    Zvar 01 1536x1152
    6/18/2024
    How to learn to weld – 7 steps for beginners

    Welding is one of the most important skills for any home handyman. Whether you need to fix something in your home or garden from time to time, want to make one of the many gadgets based on a photo from social media, or are thinking about welding as a possible form of income-generating activity, this article will guide you through the basic steps that will help you learn how to weld. Almost anyone can learn to weld, the important thing is to start and learn to weld correctly. Before you start welding, it is important to think about what you expect to get out of it. It is worth considering asking yourself the following questions: How much time do I want to devote to welding? Is it just an occasional use of welding in the workshop, or do I want to gradually develop into a professional TIG welder who can weld every weld 100%? How much money do I want to invest in equipment? Welding is not possible without an initial investment in equipment. However, you can buy equipment for under €200, or even in the thousands of euros. What kind of welding space do I have available? Of course, welding can be done both indoors and outdoors, but each environment has its own limitations in terms of welding technology. What materials would I like to weld? Each material has its own specific welding requirements. It is therefore important to clarify whether you want to weld only standard (carbon) steel, anti-corrosion (stainless) steel or, for example, also aluminum. 1. Choose a welding method There is a wide range of welding methods, the most common arc technologies today are: Manual metal arc welding (MMA) – the technology that requires the least initial equipment, but is slightly more difficult to master the correct technique. Inert/active gas welding (MIG/MAG) – the technology known as CO2 welding is simpler than electrode welding in terms of welding technique. However, as the name suggests, you will need a gas cylinder, which performs the same function as the electrode casing. Flux Cored Arc Welding (FCAW) – similar to MIG/MAG welding, but the shielding gas is replaced by the filler metal of the tube electrode, eliminating the need to use a gas cylinder (gas may or may not be used). Tungsten inert gas welding (TIG) – a technology that can produce very high-quality welds, but at the cost of more sophisticated technology and lower welding speed. For a beginner with a smaller budget, it is ideal to start with covered electrode welding, where you will master the basic technique and welding parameters. For a higher budget, it is worth considering purchasing a CO2 welder (MIG/MAG), while it is possible to use flux cored wire to start, eliminating the need to buy a gas cylinder and other accessories. 2. Choose a quality welding machine If you have decided on one of the above arc welding methods, you will not be able to do without a welding machine. When choosing, pay attention to the following parameters (not all of them may be present for different methods): Welding method – some welders support one welding technology, others can be used for multiple technologies. A common combination is MMA/TIG welders , or welders that allow a combination of all of the above methods. Welding current range – the current range determines what diameters of electrodes or welding wires you will be able to use. Input voltage – can be 230 V or 400 V. You need to find out what options you have at the place where you want to weld. You don't want to end up in a situation where you can't connect the welder to the mains. Load factor – indicates the percentage value and the amount of current. For example, a load factor of 60% with a value of 120 A indicates that the welder can work with a current of 120 A for 6 minutes out of 10. If you weld for longer than 6 minutes, the welder may overheat. Welding current polarity – determines in which current connection the welder can operate. It can be DC+, DC+ and AC. Different coated electrodes and different materials require different connections. It is a good idea to choose a welder that at least allows you to change the polarity from DC+ to DC-. Additional functions – many welding machines today offer functions to simplify welding, such as HOT START, ANTI STICK, etc. Reviews for MMA/TIG and MIG/MAG welders can also help you choose the right welder. 3. Get welding accessories A welding machine alone is not enough to start welding. In addition to it, you will need at least a filler material, which, after melting, will become the weld itself. When welding with a covered electrode, welding electrodes will be enough (as usual). For MIG/MAG and FCAW welding, you will need a coil of welding wire as a filler material, along with the correct feed rollers. For TIG welding, the filler material is a metal welding rod. You should choose all types of filler material depending on the material you will be welding. For methods where gas is used to protect the weld, you will also need a system with a gas bottle, a pressure reducer and hoses, through which you can get the gas through the welding torch to the weld. In the MAG welding method (CO2 welding), carbon dioxide CO 2 or a mixture of argon and CO 2 is most often used as the shielding gas. In MIG and TIG welding, argon or mixtures of argon and helium are used. 4. Don't forget about safety at work Welding, in addition to the pleasant feeling of a job well done, also brings with it the risk of injury. To avoid unnecessary health complications, use the following protective equipment: Welding helmet – probably the most basic piece of equipment for every welder. When an electric arc burns, a large amount of ultraviolet, infrared and visible radiation is emitted into the environment. In addition to not being able to see what and where you are welding, this radiation can significantly damage your eyesight. Welding gloves – welding also generates a large amount of heat, which welding gloves can protect you from. Proper clothing – splashing of molten metal from welding is not uncommon. You should therefore wear clothing that does not easily catch fire, ideally leather gloves, an apron or a full leather suit. Quality footwear – if you don’t want to throw away your favorite designer sneakers, it’s better to replace them with quality, sturdy footwear when welding. Also, don’t forget to lace up your shoes properly, because a drop of molten metal in your shoe is not a pleasant experience. There are also leather protective equipment to protect your feet. Respiratory protection – also because this area is underestimated, respiratory diseases are one of the most common problems among welders. For occasional welding in well-ventilated areas, this may not be necessary, but if you are considering long-term welding work, consider purchasing a filtration device. 5. Prepare the material for welding To ensure the best possible weld quality, you must not neglect the preparation of the material before welding. Steel sheets must be free of rust, grease and other impurities in the welding areas and under the connection point of the ground cable. It is advisable to grind the surface around the weld to a metallic shine. The same applies to stainless steel and aluminum, where grinding will damage the surface oxide layers, which would otherwise have an adverse effect on the weld. 6. Lay your first weld bead After thorough preparation, it is finally time to start welding. Check the connection of the welding cables to the connectors of the welding machine. If you are using an electrode, insert it with the metal end into the welding pliers. If you have welding wire, insert it into the feeder, insert the correct rollers and push the wire out so that the end of the wire comes out of the welding nozzle. Cut off the protruding part of the wire with pliers. Set the welding parameters according to the filler material used and the material being welded; for MIG/MAG and TIG welding, do not forget to set the gas flow. Connect the core cable to the material being welded. Look at where you want to weld, put on your helmet and cut off the electrode/start the welding current and move the pliers with the electrode or the welding nozzle as smoothly as possible in the direction of welding. When welding with a coated electrode, do not forget to move the electrode to the welding point, otherwise the arc will go out. If you dare to TIG welding, hold the welding torch with one hand and add material from the welding rod to the weld pool with the other hand. Watch how the weld is formed before your eyes. After the arc goes out in TIG and MIG/MAG welding, leave the nozzle at the weld point for a while so that the gas protects the weld metal until it solidifies and cools down slightly. Congratulations, you've completed your first weld.