Laser cladding is based on the melting of powder or wire materials with the energy of a laser beam in a gas shielding with simultaneous overmelting of the base metal. The material in this area is melted at very high speed, creating a very thin layer of liquid material on the surface of the welded workpiece. At the same time it is fused with the metal of the substrate, which is melted only to a very shallow depth, resulting in a high-quality metallurgical bond between the deposited layer and the substrate. The deposit is heated and solidifies in a shield gas at a rate of 106°C/s. This ensures a very high metallurgical purity and a very fine-grained structure of the deposited metal. The hardness of laser-coated welds is also higher than that of welds produced by other processes with the same chemical composition of the coating. Due to the very high-power density of the laser beam, the thermal influence on the weld metal is very low, resulting in low welding stresses and deformations.
The ability to control the over-weld depth of the base metal very precisely ensures that the proportion of base metal in the weld bead can be very low, from around 3-5% to 10%. This is particularly important in powder coating. The chemical composition of the laser resin is usually not significantly different from that of the filler already used in the first layer. This means that the required coating properties can already be achieved in the first layer, with post-processing not exceeding 0.1-0.3 mm. Depending on the technology used (type of machine, shape of filler material), it is possible to produce 0.1-5 mm thick welds in a single pass with a straight laser head path.
Selected materials on which we perform laser cladding
Structural and tool steels
Hot and cold formable steels
Nickel-base alloys and high-temperature austenitic and austenitic-ferritic steels