TIG and MIG welding have long been considered a good choice for welding small parts because of their excellent finish. However, this type of welding requires skill and flexibility and, despite their controllability, they have some drawbacks. Laser welding is an excellent alternative, often outperforming the electric arc welding process and its tightly focused beam limits thermal effects. Laser welding is capable of performing welding tasks that cannot be performed by conventional welding methods.

Conventional welding methods

The TIG and MIG processes use a shielding gas to create an inert atmosphere around the weld head. With TIG, the arc is generated by a tungsten electrode and a hand-held filler material is used, while with MIG welding the electrode is a filler wire. These welders can be adjusted to allow precision parts to be welded and the final weld quality is high. Another common method is spot welding, which works by sandwiching the part between a pair of electrodes and energising it. All arc and spot welding processes transfer a large amount of heat to the workpiece, which affects the metallographic structure around the weld.

Samples

Laser welding

The heat required for welding is provided by a tightly focused beam of light as small as two thousandths of an inch in diameter. Welding is carried out by firing a series of short pulses to melt the metal to form a high quality weld. Depending on the specific welding task, the same filler material as for TIG welding may be required. Due to the highly focused laser beam, heat input is minimised and the part can be processed almost immediately.

Advantages of laser welding.

Heated area — the heated area of the weld does not spread to the rest of the material and, due to the rapid cooling, the material can be handled almost immediately after the job is completed.

Deformation — due to the laser welding process, there is minimal deformation and shrinkage of the material.

Weld strength — due to the narrow laser weld seam and the excellent depth to width ratio, the weld strength is truly superior to tungsten inert gas (TIG) and metal inert gas (MIG) welding.

Metals — A wide range of metals can be welded, such as carbon steel, stainless steel, titanium, high strength steel, titanium, precious metals and aluminium.

Samples

One sided — spot welding (which requires contact with both sides of the material) can be replaced by laser welding as it only requires contact with one side.

Precision — Laser welding provides a more precise weld than TIG and MIG welding. You will find it difficult to match the exact weld seam that we can obtain from the laser, i.e. 0.025 mm. In addition, laser welders do not require the skills needed for conventional welding and can work with computer input, unlike conventional welders that require someone to operate the machine.

Scrap — due to the high precision, laser welding produces less scrap as there are virtually no errors.

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