Advantages of laser metal deposition by using zoom optics and MWO (modular welding optics)

Laser Metal Deposition (LMD) using powder additive materials has been successfully introduced into industry for the use in wear and corrosion applications and as repairs of e.g. turbine components, moulds, and dies and is increasingly being employed for varied 3-D applications as well. For a variation of the track width an adaptation of the laser beam diameter in the interaction zone is mandatory. The zoom optics presented in this paper enables a variation of the laser beam diameter for producing different track widths during the process of machining. Compared to the conventional optics, the extensive adjustment of a powder nozzle to the working point is unnecessary. The variation of the laser beam diameters is generated by adjusting the lens positions. In the interaction zone the laser beam diameter can be varied from d = 0.6 mm to d = 2.4 mm. The power density distribution produced corresponds as closely as possible to a top-hat distribution, which is best for Laser Metal Deposition. With this new concept designed zoom optics can be applied with different laser sources.