What is laser welding?
Welding is the process to join two parts by melting the contact surface between them.
Laser welding relies on the absorption of the radiation by a material, then intense localised heating leading to the superficial melting of the two parts brought into contact.
Although butt welding is well suited to sheet metals of several millimetres thick, it is preferable to turn to transparent welding for metallic microwelding or the welding of thermoplastics.
Transparent laser welding
This process consists of traversing the first part and reaching the second, while applying a tightening force so that the two parts can blend together. With plastics, the first part is often transparent to the wavelength of the laser. It is the second part, which is absorbent, that leads to a large increase of the temperature at the interface and which, by conduction, also melts the transparent part. In the case of metals, a thin molten pool is generated up to the second part and it is by resolidifying that the two parts will be bonded. Note that with plastics, certain techniques enable two black plastics to be welded together, or even two transparent plastics.
Very clean welds
Laser welding is differentiated from traditional techniques by its speed and the quality of its results. In fact, the welded joints are extremely clean, fine and can be of highly complex forms. The resulting adhesion is very good and ages very well. It is also possible to weld different materials together such as for example plastic on metals or plastics of different types.