Laser cleaning is a special form of laser structuring in which the base material should not be affected as much as possible. Short to ultra-short pulses vaporise unwanted impurities and layers such as oils as well as rust and oxide layers without contact. The laser cleaning process is ideally suited for weld seam preparation and post-processing, but also as a preparatory manufacturing step for other processes. In contrast to sandblasting, the component surface is not damaged. A major advantage of laser cleaning is that, unlike many other cleaning processes, it does not require the use of chemical agents and therefore has no impact on the environment.
The process can be implemented with nanosecond pulsed systems, but also with ultra-short pulse lasers. The advantage of the longer pulses is a significantly faster processing speed, the disadvantage is a slight heat input into the component.
Partially laser-cleaned surface (left), where the base material is not removed (confocal false-colour image, right).
Components to be welded are sometimes in an insufficiently cleaned condition or still have residues from the upstream manufacturing process, e.g., after milling. These contaminations and residues can be completely removed by laser cleaning - provided that the processing zone is accessible.
Stainless steel joints that have already been welded often show so-called annealing colours if the gassing process is insufficient. These can also be completely removed with a laser cleaning process.