Laserstrahl-Auftragschweißen mit Hochleistungs-Diodenlasern

Currently, intricate problems of surface treatment can be solved through precision cladding using advanced laser technology. However, the high prices of CO2 and Nd:YAG lasers as well as the low absorption of the CO2-irradiation limit the applications. The current availability of high-power diode lasers makes laser cladding essentially more efficient and practicable. By one-step cladding with a 1.4kW diode laser, protection layers of Co-based alloys, a carbide-reinforced Ni alloy, and alumina can be deposited onto steels and aluminium-based light alloys. For tasks of repair and remanufacturing, multilayer stacking of me-tal alloys can be easily performed. The layers are dense with a finedendritic structure and are metallurgically or chemically bonded to the substrate. Comparison of the cladding results for tracks produced with CO2 and diode lasers has shown that the use of diode irradiation obviously increases the absorption by a factor of 2.5. First examples of application are the repa ir of wear damaged punches and dies, and the hardfacing of engine valves.