Laser cleaning uses a focused beam of light to eliminate contaminants. The term "ablation" refers to the processes of removing material from surfaces and is accompanied by a shockwave that moves outward, affecting the surrounding surfaces. Laser energy is absorbed into the surface material, leading to the generation of a plasma plume of ablation products. The actual absorption of the laser beam depends on the reflectivity of the material, the quality of the surface and the properties of the contaminant on the surface. When materials are processed with a laser beam, the surface characteristics of the materials may change. In some applications, a surface should be kept finely polished, while in others, the surface should be coarse. Therefore, for a successful finish, laser cleaning techniques should consider the properties of both the material being cleaned and the quality of the surface, and the properties of the contaminant on the surface to be removed. Some of the laser cleaning applications comprise.
Laser cleaning can replace chemical treatments of metal surfaces that have been prepared for joining process i.e., soldering, brazing, welding, and gluing. Substances like petroleum, dirt, fat, and hydrates can be removed in one step using fiber lasers. Low energy short pulses (<1 mJ/pulse) from the high frequency laser leave a metallic surface at its initial roughness.
One of the most popular laser cleaning applications is the elimination of rust. Rust has a high absorptivity; consequently, a thin layer can be removed as easily as lubricant, making the laser a powerful tool. Similar applications, such as the removal of dirt or anodized finishes and the refurbishment of stainless-steel parts, are widely adopted by the automotive industry. For these applications, QCW fiber laser cleaners are available in fixed and handheld cleaning machines.
Some industrial operations that use metal parts require the removal of a layer of metal covering the base metal—for example, the removal of zinc from galvanized steel. The thickness of a zinc layer can range from a few microns (galvanoplasty) to a few millimeters (metallization). In such operations, it is often necessary to completely remove the coating on the surface of the base metal. High output CW fiber lasers can be used to remove non-metallic coatings. In this case, a paint/coating is burned or evaporated with the high temperature metal plasma plume, and the shock waves expel the ash and fumes. Such an installation has been proven to remove even dense coatings, silicon lubricants, or heavy rust.