ABLATIVE LASER CLEANING OF MATERIALS

On the base of literature data as well as authors ’ works a review of the state-of-the-art in ablative laser cleaning of surface layers of various constructional materials with encrustation produced in physical and technological processes is presented in the paper. The process and mechanisms occurring in the ablative laser cleaning are described. Three types of the most frequently used lasers offer characteristic advantages understood as average power, pulse operation, wavelength, optical feedback with material processed, and fiber delivery. The process of surface layer cleaning of materials and machine elements can be carried out in various ways. In general, when using pulse laser radiation, five different mechanisms of removal of particles, encrustations, or coatings can be applied. So, the process of removal can be performed via following physical processes: surface vibrations, particles oscillations, thermal expansion of particles (or encrustation), generation of so called detonation wave over surface being cleaned, and laser ablation. Lasers are especially useful for removal of layers from many types of substrates like wood, metals, plastics, composites, stones, ceramics, leather, and others. The important advantage of laser cleaning and surface modification is the capability of processing automation which is related to process repeatability, ease of parameters controlling, possibility of strengthening in zones difficult to access, high precision of interaction and high efficiency as well