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Laser Welding |
Laser beam welding is being used in an increasingly wider range of industries, from the production of medical devices and microelectronics to shipbuilding. The automotive industry, in particular, takes advantage of this technology’s benefits:
- Low heat input
- Small heat-affected zone (HAZ)
- Low distortion rate
- High welding speed
These benefits have made laser welding the process of choice for many applications that previously used resistance welding. By adding single-sided access, laser welding is even more strategically advantageous |
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| High-power CO2 lasers 20-20,000 watts (2–20 kW) have been used for many years for welding car bodies, transmission components, tailored blanks, heat exchangers and pipes. Solid-state lasers (e.g., diode-pumped Nd:YAG, disc and fiber lasers) have been recently scaled up in power and add the benefit of beam delivery via optical fibers. These are easily manipulated by robots, allowing a number of 3D applications (e.g., laser cutting and welding of car bodies). |
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With high-power laser welding, laser energy melts and evaporates the metal. The pressure of the vapor displaces the molten metal so that a cavity, known as a keyhole, is formed. The keyhole supports the transfer of the laser energy into the metal and guides the laser beam deep into the material.
In this way, keyhole welding allows for very deep and narrow welds and is therefore also called “deep penetration welding.”
Welding gas plays an important role in laser welding and fulfills several tasks:
- Shielding of the weld pool and the HAZ
- Protection of the optics against fumes and spatter
- Root protection
- Plasma control during CO2 laser welding
The weld plasma is a cloud of ionized metal vapor and gases that can form above the keyhole. This cloud affects laser radiation and has the potential to interrupt the welding process. To control this plasma, helium (which has a high ionization potential) can be used as a shielding gas. |
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Helium, however, is expensive; Linde has therefore developed several argon-based shielding gases for laser welding that offer performance and quality gains, including:
Linde LASGON® C Laser Welding Gases: Laser beam welds are expected to exhibit high quality, high rates of reproducibility and little distortion. Linde Gas AG has developed LASGON C1 shielding gas, a mixture of helium, argon and carbon dioxide. It is especially suitable for use with non-alloy and low-alloy steel, including galvanized sheet metal. Its composition allows relatively high welding speeds while producing little heat, resulting in clean, even and high-quality weld seams. LASGON C1 also guarantees an increase in welding-process stability, which has a positive effect on cost-effectiveness.
Linde LASGON H Laser Welding Gas: LASGON H, a family of special laser welding process gases, was developed for laser welding applications with stainless steel components (e.g., pipes, sensor casings and cabinets). Compared to pure noble gases, LASGON H allows higher welding speeds and produces less oxide build-up, resulting in a clean and shiny surface.
To determine which LASGON gas mixture is most suitable for your unique needs, be sure to Contact Us. |
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