Similar to initial coating, repair welding can also be realized as wire or powder cladding. Before the processing of material, the worn coating is first removed and the workpiece surface is cleaned. The following process is largely identical with cladding. In other words, the laser beam creates a molten pool at the workpiece surface, to which a wire or powder is simultaneously added, which is then melted by the laser. In this way, within a short period of time, very solid new coatings or crack closings can be realized, at which the applied material is connected metallurgically with the basic material.
The process advantages of the diode lasers
With a diode laser, worn tools or other components are repaired or tools are remodeled with a coating layer. Firstly, the contour is prepared mechanically and then either the basic material or a harder metal in the form of powder or wire is added by laser. Examples of successful applications include repair of bearings and shafts, valve seats, and turbine blades.
The homogeneous intensity distribution in the beam of a diode laser (top-hat beam profile) causes especially molten pools. This favors the creation of high-quality surfaces that only need to be post-processed to a lesser extent. Besides, at logistically complex repair situations, the mobility compact design of the lasers turns out to be greatly advantageous.
Repair welding is used to recover the functionality of components. In addition to repairing cracks, laser cladding is applied to renew/repair worn or damaged coatings.