Wire-based laser metal deposition (LMD-w for short) is an additive manufacturing process in which a metal wire is welded onto a workpiece as a filler material using a laser.
Process stability and control are of great importance here. In the research project "TopCladd - Adaptive Laser Cladding for Precise Metal Coating Based on Inline Topography Characterization", the Aachen research partners have equipped a coaxial LMD-w system with an OCT system for the first time in order to stabilize and actively control the laser process. OCT is a measuring method for the non-contact and high-resolution representation of tomographic sectional images based on short-coherent interferometry. It can not only record the welding process, but also control the quality during the process and thus reduce rejects. The LMD-w will therefore be used as a fully-fledged 3D printing process in the future.
The integration of OCT into the laser metal deposition process makes it possible to precisely map the surface structure of the entire fusion track. In future, OCT will make it possible to apply not just one or two layers on top of each other during laser metal deposition, but any number of layers.
