Laser powder cladding is a LMD (Laser Metal Deposition) additive process. It's used to build up material for repairs, changes of design or to lay down a coating of different material onto the base metal, such as a hard surface or corrosion resistant layer.
The process uses an high energy laser beam as the heat source and powder of filler metal is basically spayed into the weld pool. The laser technology, thanks to its focused energy beam, transfers very low heat input to the work piece compared to arc processes. A smaller heat affected zone is observed, as well as low distortions and little dilution.
It also allows the process to be used for cladding very thin walls only a few tenths of a millimeter wide. The added layers are typically 0.2 to 1 mm thick. In order to produce the required height, several layers are deposited one on top of the other until desired thickness is finally achieved. Laser powder cladding can also be used as a 3D printing technique of average accuracy.
The resulting deposit is very high quality, without the presence of cracks or porosity. Due to low dilution - basically they don’t mix up much with each other’s - between base and cladded material during the operation the mechanical and chemical characteristics of both materials are well preserved.