Innovations in Laser Cladding

摘要

Laser beam build-up welding (cladding) is becoming increasingly established in automotive production, in the aerospace industry, as well as in mould and tool technology. Impulses for this development are the availability of the high power diodes, user-friendly systems, and new hybrid techniques for increased productivity and efficiency. A newly developed modular cladding head allows for easy integration of diode, YAG and CO_2 lasers into machine systems. A mechanical finishing process can be optionally combined in the same machine. The modular head guarantees a stable and controllable cladding process as well as the highest precision in material deposition. For higher cladding rates and lower specific coating costs, innovative developments are aimed at combining laser build-up welding and a "conventional" plasma spraying process. In a one-step process, the laser beam interacts directly with the plasma flame to generate the coating. The coatings are entirely dense and metallurgically bonded to the substrate. Using a 1.3 kW diode laser and a 30 kW plasma spray gun, the cladding speed is increased by a factor of up to 30 compared with "pure" laser cladding. At the same time, the generated structures retain the good properties of laser-clad coatings.