Introduction

1. Laser light

Laser light  is electromagnetic radiation. This radiation has a broad spectrum and many different frequencies. We know electromagnetic radiation with a frequency between 380 and 780nm as visible light. We know laser light in many different wavelengths (and therefore colors). Various wavelengths are used for industrial applications. The various wavelengths have specific advantages and disadvantages when using them. For laser welding and laser cleaning, we use laser light that is in the invisible infrared spectrum. This laser light has a wavelength of 1080nm. This wavelength is sufficiently absorbed by metals such as steel and stainless steel for laser welding. Laser welding of aluminum is possible, but often more difficult due to the high reflection of the aluminum.

2. Reflection

Like visible light, invisible infrared light also reflects. Reflections can be distinguished in specular reflections and diffuse reflections. When welding with the laser, part of the laser light will be absorbed by the metal and converted into heat. This heat creates the weld pool.

Another part of the light beam will reflect. Depending on the type of material and the surface condition, the light is reflected in the room. The intensity of the light decreases considerably with diffuse reflection. However, it is likely that these reflections will still have a dangerous energy density during laser welding.

Using the right protective equipment reduces the risks, and work can be done safely.

3.Absorption

The laser light generated in the laser source is transported to the welding gun using a fiber. Lenses are fitted in the welding gun, ensuring the laser beam is focused. The energy density at the focal point is large enough to melt the underlying material. You can now laser weld.

Not all materials absorb the laser light equally well. Steel and stainless steel can be welded well with the hand laser because the absorption is relatively high. Other metals, such as aluminum, can be welded, although considerably more energy is reflected.

4.Wobble

Due to the high energy density of the laser, a very small weld pool is created. The laser can move the laser spot with a high frequency to enlarge this weld pool. This movement can take different forms. We usually use the linear variant of this wobble movement for manual laser welding.

5.Automation

For laser welding, welding guns can also be supplied on a cobot or robot. By using a fiber laser for this application, the number of applications for automated laser welding is considerably greater than the laser welding machines previously available on the market.