Laser welding is an advanced and modern method of joining materials that finds application in many industries. Thanks to its precision, speed, and high quality of welds, it is considered one of the most effective welding methods. In this article, you will learn what laser welding is, how it works and what advantages it has, as well as what applications make this technology irreplaceable in modern production.
What is laser welding?
Laser welding involves using a concentrated laser beam to melt and join materials. This process is extremely precise because the laser beam can be accurately directed to the joining point. The energy of the laser beam melts the edges of the materials, which after solidification create a durable and aesthetic weld.
One of the most interesting aspects of laser welding is its ability to create welds of exceptionally small width, ranging from 0.2 to 13 mm. Moreover, thanks to the extremely high energy density, this process minimizes the heat impact on other areas of the material. The result is not only increased precision, but also reduced deformation of the welded elements.
This technology works perfectly both on macro and micro scale - from joining elements in heavy and automotive industries, to perfect and most aesthetic welds in the furniture industry.
Types of laser welding
There are many laser welding methods that differ in application and characteristics. Here is an overview of the most important ones:
Heat conduction welding
This method involves heating the material to its melting temperature without reaching the vaporization temperature. Energy is delivered to the surface of the material and then dispersed by thermal conductivity to its interior. This process allows for the creation of a weld pool without deep penetration. It is an ideal solution for welding thin materials, such as steel and aluminum sheets up to 1.5 mm thick. Gas lasers, such as CO₂, and solid-state lasers (e.g., Nd:YAG) are often used in this technique because they minimize material deformation and ensure high precision.
Deep penetration welding
In this method, laser energy penetrates deep into the material, exceeding the melting and vaporization temperature. A characteristic vapor-plasma channel is formed, which allows for welds with a high depth-to-width ratio (up to 10:1). This technique is particularly useful in welding thick steel elements and metal alloys. High-power lasers, such as fiber lasers, are used in the process, which are efficient even with materials with a high reflection coefficient, such as aluminum.
Hybrid welding
Hybrid laser welding combines laser technology with other methods, such as arc welding (MIG/MAG). The laser beam creates a vapor channel, and an additional energy source provides the filling material. This method is characterized by high welding speed, the ability to join imprecisely fitted elements, and reduced deformation. It is widely used in the shipbuilding, automotive, and construction industries.
Laser microwelding
This is a process designed for welding very small elements with exceptional precision. Pulsed lasers (e.g., Nd:YAG) are used, which allow for minimizing the heat impact on adjacent areas of the material. Microwelding is used in electronics, jewelry production, and medicine, where precision is crucial.
Here it is worth adding about pulse welding, which is a technique used in MIG/MAG methods, involving cyclical increasing and decreasing of the welding current intensity. This allows for precise control of the amount of heat introduced into the material, which is particularly beneficial when welding thin sheets and materials susceptible to thermal deformation.
Laser joining of thermoplastics
Laser welding is also used in plastics. The laser energy is absorbed by the material, causing it to melt locally and create a permanent connection. This technique is used, among others, in the production of medical and electronic components.
The most important features of laser welding
The laser welding process offers many advantages that make it one of the most advanced and efficient technologies in the industry. By adjusting parameters such as laser light pulse energy, laser beam focus position, or protective gas flow rate, the process can be adapted to different materials and production requirements.
Here are the most important advantages of this technology:
-
precise energy delivery - thanks to a laser beam with high power density, the welding process is characterized by a small width of the heat-affected zone. The ability to regulate energy allows for welding both thin materials, such as aluminum sheets with a thickness of 1.5 mm, and thicker elements such as steel structural elements.
-
high welding speed - laser welding allows achieving much higher welding speeds than traditional welding. This makes the process more efficient, which is particularly important in serial production. High speed does not negatively affect the quality of welds.
-
versatility of applications - laser welding enables joining a wide range of materials, such as metals or glass. With this method, it is also possible to weld low-carbon steels. The ability to adjust parameters (e.g., speed or welding time) allows for joining different types of materials while maintaining high weld quality.
-
minimizing heat impact on the material - thanks to the precise setting of the laser beam focus, energy is concentrated in a strictly defined place, which limits the heat impact on surrounding areas (so-called very narrow HAZ - heat affected zone). As a result, the welds are durable, and the risk of deformation or thermal damage to the material is reduced to a minimum.
-
cleanliness and aesthetics of the process - in the laser welding process, there is no need to use additional filling materials, which affects the economic aspect. Additionally, thanks to the limited heat-affected zone, aesthetic, smooth welds are obtained, which often do not require further processing. Another advantage of laser welding is the absence of spatter, which not only improves the aesthetics of the execution but also increases work safety and reduces the need for cleaning elements.
-
ease of automation - laser welding is easy to integrate with automatic systems (robotic welding), which makes it an ideal solution in modern production lines. Controlling laser energy and welding speed allows for full control of the process, increasing efficiency and repeatability.
Check out: Robotic laser workstations from Fanuci
It is also worth emphasizing that laser welding can be supported by the addition of material in the form of welding wire. In this case, it is possible to weld with small gaps while still achieving a solid connection. For larger gaps, devices equipped with a 2W head are recommended, which ensure efficient work and excellent results.
What are the limitations of laser welding?
This technology, although modern and effective, also has its limitations. It is worth thoroughly analyzing the advantages and disadvantages of laser welding to decide whether it will be appropriate for a given application. Among the most important disadvantages are the high purchase costs. Nevertheless, currently, various series of devices are available on the market, including budget ones, so even smaller companies can use this technology.
It is said that a challenge in laser welding is the limited ability to weld some materials, such as metals with a high reflection coefficient (highly reflective), e.g., copper. However, it is worth remembering that this is a myth. Laser welding is entirely possible, but what is crucial for such materials (e.g., stainless or black steel) is the application of appropriate welding parameters (such as laser power) and consideration of coating thickness.
Check out: Laser welders from Fanuci
Shielding gases in laser welding
In laser welding, shielding gases play a key role, affecting the quality and characteristics of the weld. Argon is most commonly used due to its availability and low reactivity, allowing for effective protection of the molten metal pool. Helium, although more expensive, provides better plasma control due to its high ionization energy, making it indispensable in projects where high precision is important. Nitrogen is mainly used in welding stainless steel, where it can strengthen the weld, but its interaction with aluminum or carbon steel can lead to the formation of nitrides, which reduce the quality of the connection. Carbon dioxide, on the other hand, is an economical choice for welding low-carbon steels, offering smooth welds, although it does not protect against steel oxidation.
Applications of laser welding
Laser welding finds applications in many industries thanks to its versatility and unparalleled precision. Here are the most important examples:
-
locksmithing, railings, and gates - laser welding enables the creation of durable and precise connections, which is extremely important for elements requiring strength and precision.
-
steel structures - laser welding technology allows for effectively joining large steel elements, while guaranteeing high quality and compliance with structural requirements.
-
gastronomy - in the gastronomy industry, laser welding is used to produce stainless steel dishes and accessories, where durability and hygienic surface execution are priorities.
-
furniture industry - this technology is particularly valued in the production of fittings and loft furniture, where welds are required to be both precise and aesthetically pleasing.
-
automotive industry - laser welding is used to join body elements, chassis, and engine components. Fast joining ensures durability and aesthetics, which are crucial in modern car production.
-
aircraft equipment - in aviation, every gram of mass counts. Laser welding makes it possible to create lightweight and durable structures that meet the highest safety standards.
-
medical industry - laser welding is used in the production of surgical instruments and implants. The cleanliness of the process and the high precision of this method allow for the creation of elements with complex shapes.
-
electronics - miniaturization of electronic devices requires precise welds. Laser welders are ideal for joining small components without the risk of damaging them.
-
plastics - thanks to the ability to adjust process parameters, laser welding is also used in joining thermoplastic materials. The laser energy is absorbed by the material, creating durable connections in electronic or medical products.
What materials can be laser welded?
One of the most commonly welded materials is carbon steel, used in heavy industry and automotive, where weld durability and deep penetration are important. Thanks to the laser, it is possible to obtain strong and tight connections that withstand high mechanical loads.
Another material that works perfectly with this technology is aluminum. Laser welding of aluminum allows for joining lightweight and durable elements of any shape, while minimizing heat impact on surrounding areas.
Lasers can also weld titanium, copper, and even difficult-to-weld materials such as nickel alloys or some plastics.
Types of lasers used in laser welding
Laser welding uses various laser technologies that differ in the type of beam-amplifying medium, the wavelength of the emitted wave, and the operating mode. Among the most commonly used types of lasers, the following can be distinguished:
-
Fiber lasers - using an ytterbium (Yb) fiber as the active medium. They emit waves in the range from 980 to 1100 nm, providing continuous emission or ultra-fast pulses in Q-Switch technology. They are characterized by compact design and high efficiency.
-
Molecular CO₂ lasers - emitting waves with a length of 10.6 μm, available in continuous and pulsed modes. They are widely used in industry due to their versatility and ability to precisely cut and weld various materials.
-
Solid-state lasers - including crystalline lasers such as Nd:YAG (yttrium aluminum garnet) and YVO₄ (yttrium orthovanadate). They emit radiation in the range of 10.6 μm in continuous or pulsed modes. Due to their construction, they are perfect for welding materials with high density and hardness.
-
Ruby lasers - generating waves with a length of 694.3 nm. They have the ability to achieve high power through optical pumping using a flash lamp. They are used in processes requiring high precision.
-
Semiconductor lasers - based on laser diodes that emit waves with a length of 1070 nm. They can operate in continuous or pulsed modes, and their pumping is done electrically. They are efficient, compact, and can emit light in a wide spectral range - from visible to infrared.
Each of the mentioned types of lasers offers specific advantages, adapted to various industrial requirements. For example, a laser welder for metal using fiber technology allows for precise joining of high-density materials, such as stainless steel or aluminum, ensuring high quality welds with minimal heat impact. On the other hand, CO₂ lasers work well with non-metallic materials, thanks to their ability to effectively cut and weld plastics.
How to choose the right laser welder?
The choice of the right laser welder depends on the material, type of connection, and production requirements. The type of laser - fiber, CO₂, or Nd:YAG - is crucial, as each offers specific advantages. The beam power affects the penetration depth, which enables welding of both thin and thicker elements. Adjusting welding parameters, such as speed or protective gas intensity, affects the quality of the resulting weld. Modern laser welders offer the possibility of automation, thereby increasing the efficiency and repeatability of the process (repeatable welds are mainly found in mass production), while minimizing operating costs.
Learn more: Comprehensive guide to laser welders
Is laser welding safe?
On the topic of welding, it is worth addressing the issue of safety, as operating a laser welder requires training and knowledge of health and safety rules. Improper use can lead to serious consequences. Adherence to health and safety rules in welding not only protects the health of operators but also ensures the efficiency and reliability of the process. Is laser welding safe? Yes, but only on the condition of following established procedures.
Laser welding - technology that changes the future of industry
Investing in laser welding is a step towards innovation that not only improves production quality but also increases its efficiency. It is a technology of the future that is already changing the face of welding today and provides a competitive advantage to companies that implement it.
If you are looking for a reliable and modern solution, laser welding using Fanuci devices is a choice that will meet even the most demanding expectations.
Bibliography:
-
Dominik Wyszyński, Laser welding - selected methods, "Welding Technology Review", Vol. 88 12/2016, https://distantreader.org/stacks/journals/pspaw/pspaw-717.pdf, online access [15.01.2025]
-
Agnieszka Twardowska, Technological lasers designed for welding, "Annales Universitatis Paedagogicae Cracoviensis Studia Technica", III (2010), https://rep.up.krakow.pl/xmlui/bitstream/handle/11716/10535/AF074--25--Lasery-technologiczne--Twardowska.pdf?sequence=1&isAllowed=y, online access [15.01.2025]
-
Manufacturing techniques. Welding technology. Laboratory, edited by A. Ambroziak, https://dbc.wroc.pl/Content/7156/PDF/Techniki_wytwarzania.pdf, Wrocław 2010, online access [16.01.2025]