Influence of Laser Cladding Parameters on the Distribution of Elements in the Beads of Nickel-Based Ni-Cr-B-Si Alloy

The authors explore the beads obtained by laser cladding with nickel-based self-fluxing alloy (grain size 20-80 μm) at different laser beam travel rates against the sample and different cladding distances. They examined the iron, nickel, chrome and silicon content of the coating in dependence on the cladding rate and the microstructure in each zone of a bead. As a result, it was established that the beads after laser cladding have a similar structure morphology in all the examined zones, which confirms that there is intense mixing of the molten-metal pool. A distinct correlation has been found between the distribution of coating elements and the modes of laser cladding: the nickel, chrome, and silicon contents of the coating are decreasing while the iron content is increasing with increased cladding rate. The authors point out a strong effect of radiation shielding caused by the vapours generated during the process of melting the powder particles in the area exposed to laser radiation.