Laser welding is a constantly evolving technology that offers numerous advantages and applications across various industrial sectors. In this article, we’ll examine the key aspects of laser welding and how to make the most of this technique in various manufacturing processes. Here are 7 reasons to use it and choose this technique.
What Is Laser Welding and How Does It Work?
Laser welding is a technique that uses a laser beam as a concentrated heat source to join different metal components together. This process is particularly widespread in the automotive industry, as it creates a thin, deep, inconspicuous, and highly durable weld.
The laser beam is generated and directed toward the workpiece to be welded using mirrors or optical fibers, and then focused onto the workpiece’s surface. The light energy is converted into thermal energy (heat), which locally heats the metal to very high temperatures.
As the focused laser beam moves relative to the workpiece, the metal begins to melt under the laser’s energy, creating a weld bead and allowing the process to advance along the joint being welded. To prevent oxidation of the molten pool during welding, an inert gas—such as argon, helium, or nitrogen—is blown onto the molten pool area.
Why use it? Here are the characteristics of laser welding
1 - Speed and precision
One of the main features of laser welding is its high processing speed, which can reach approximately 10–12 m/min. Furthermore, the laser welding process offers unmatched precision, thanks to the ability to focus the light beam on very small areas, achieving high specific energy and minimizing imperfections and burrs along the edges.
2 - Penetration Depth and Parameter Adjustment
Laser welding allows the penetration depth to be adjusted by varying both the power and the diameter of the laser spot. Depending on the power used and the spot diameter, the weld will be shallower or deeper. In the case of deep welds, the laser beam causes the metal to vaporize locally; it then liquefies again, forming the molten pool until it cools completely, thereby joining the parts.
3 - Versatility in Materials and Thicknesses
Laser welding allows for working with a wide range of materials—both organic and inorganic—and thicknesses. Among the metals that best absorb the wavelengths used in solid-state laser welding, steel and stainless steel offer the best results. In fact, it is possible to achieve more precise welds much more quickly, especially compared to less absorbent metals such as copper, silver, and aluminum.
4 - Durable and Aesthetically Pleasing Results
One of the main advantages of laser welding is the ability to achieve durable and aesthetically pleasing results, with deep, fine weld beads. The key difference from more conventional techniques, such as TIG and MIG welding, lies in the fact that no new material is added to the sheet metal being worked on. This means that no visible, unsightly residues are produced.
5 - Low distortion and reduced thermal stresses
Laser welding involves limited heat input, resulting in minimal distortion of the workpiece and reduced thermal stresses. This helps minimize thermal distortion during the process and produces a weld bead that is mechanically very robust.
6 - Welding under extreme and difficult conditions
The laser welding process can be performed under any conditions, even in vacuum environments or in hard-to-reach areas, thanks to the ability to guide the laser beam with extreme precision.
7 - Elimination of the rework process
Laser welding generally does not require additional processing, such as welding, sandblasting, polishing, or edge sealing. Furthermore, the process produces no burrs or minor impurities.
Laser welders are highly configurable, allowing the parameters of each machine to be adjusted for specific applications. The higher the power of the laser welder, the more configuration options are available, and the more versatile the machine becomes. Laser welding can be performed with or without filler material. The choice between these options depends on several factors, such as the quality of the joints and the presence of misalignments in the workpieces. With wire-fed welding, it is possible to improve joint quality, eliminate air pockets, and prevent misalignments. Furthermore, it is possible to achieve strong, high-quality welds while preventing the formation of cracks or fissures caused by the solidification of certain welded materials.