Laser Cladding is a weld build-up process and a complementing coating technology to thermal spray. It is increasingly used instead of PTA (Plasma Transferred Arc) welding and easily outperforms conventional welding methods like TIG (Tungsten Inert Gas) for advanced weld repair applications.
Process description
In laser cladding, the laser beam is defocused on the workpiece with a selected spot size. The powder coating material is carried by an inert gas through a powder nozzle into the melt pool. The laser optics and powder nozzle are moved across the workpiece surface to deposit single tracks, complete layers or even high-volume build-ups.
Process basics
| Typical laser power | 1 – 6 kW |
| Typical build up rate | 0.1 to 12 kg |
| Typical coating thickness | 0.2 to 4 mm (or more) |
| Coating materials | Weldable powders (metals, metallic alloys, carbide blends) |
Key characteristics
| Perfect metallurgically bonded and fully dense coatings |
| Minimal heat affected zone and low dilution between the substrate and filler material resulting in functional coatings that perform at reduced thickness, so fewer layers are applied |
| Fine, homogeneous microstructure resulting from the rapid solidification rate that promotes wear resistance of carbide coatings |
| Edge geometries can be coated and built up with welded deposits |
| Near net-shape weld build-up requires little finishing effort |
| Extended weldability of sensitive materials like carbon-rich steels or nickel-based superalloys that are difficult or even impossible to weld using conventional welding processes |
| Post-weld heat treatment is often eliminated as the small heat affected zone minimizes component stress |
| Excellent process stability and reproducibility because it is numerical controlled welding process |
Typical applications
| Dimensional restoration |
| Wear and corrosion protection |
| Laser additive manufacturing |
