MIG, TIG AND LASER WELDING?

You might be a pro at MIG and TIG welding, but have you ever wondered about laser welding and how it can benefit your welds? Laser welding is a modern technology that is used in a variety of situations to provide super clean welds, so if you are interested in welding for a business or hobby, you should learn about what laser welding technology could mean for you. How Does Laser Welding Work? Welding is a deep and complex hobby with lots of experimentation happening all the time; as a result, various methods and schools of welding are available to learn with many sticking firmly with TIG welding and others proclaiming that only a specific recipe of shielding gases can provide the ultimate welding experience. Those participating in laser welding are no different; innovative individuals have already experimented with the technology enough to split laser welding into two distinct modes: conduction limited welding and keyhole welding. A conduction limited weld occurs with power density less than 10­­­5W/cm2 and the radiation from the laser is only absorbed at surface level. As a result, conduction limited welds offer high width to depth ratio. Keyhole welding ramps up the power density to provide deeper penetration, typically over 10­­­6W/cm2 where the laser is condensed onto a small spot. Visually, the area that has been cut by the laser is quickly filled with metal vapours and plasma that are the result of having vaporised the metal with the laser. This result offers high depth to width which is highly sought after. The size of the beam used in laser welding can be as small as two-thousandths of an inch. The intensity of the beam and the material being welding may mean that filler material is needed if too much of the metal is vaporised by the laser. What Are the Benefits of Laser Welding? Characterised by high-efficiency and high-speeds, the heat-affected zone is quite small, and deformation of the workpiece is minor – furthermore, rapid cooling means that the surrounding material does not suffer from annealing. Weld depth can even be ten times larger than the weld width. One of the greatest advantages to laser welding is that, unlike MIG and TIG, lasers can successfully weld dissimilar metals, and the high level of control available means that there is less scrap too – meaning that laser welding could be more profitable for businesses in the future. The lack of splatter and no-contact welding means that laser welding is preferable for constructing medical instruments as laser is more hygienic than MIG or TIG. The supreme quality of the finish also means that it benefits work on jewellery items and precious metals. What Are the Disadvantages of Laser Welding? One of the biggest drawbacks keeping businesses from converting to laser welding technology is the expense; the welding plants are expensive, meaning that deciding to purchase one can be a difficult decision for any company. The higher chance that a laser weld will require filler material due to the laser’s propensity to vaporise the workpiece rather than stopping at just melting the metal is also considered a disadvantage. The cost of filler material can also be quite expensive, but this cost is often offset by the higher turnout of laser welding operations. What do You Need to Laser Weld? You will need the specialist technology that allows you to laser weld, as well as filler material on hand and, like all welding processes so far, shielding gases to protect the heated material surface and the welding puddle. Helium and helium-argon solutions are the most recommended shielding gases for laser-welding, though take note that argon can accelerate the generation of plasma and so it is not recommended for beams exceeding 3 kw. Like MIG and TIG welding, laser welding also supports a lot of experimentation with different shielding gases for different materials and strengths, so ensure that you research your weld before contacting your welding gas suppliers for your new shielding gases. If you’re interested in pursuing laser welding techniques, check back on our blog for future updates on the subject. Alternatively, if you think that you’re going to stick with your usual welding methods, don’t forget to stay in touch with us for welding supplies, including welding gas for MIG and TIG welding.

For more information on MIG, TIG AND LASER WELDING? talk to Adams Gas