On the formation features, microstructure and microhardness of single laser tracks formed by laser cladding of a NiCrBSi self-fluxing alloy
Abstract
In the present paper, the influence of laser cladding conditions on the powder flow conditions, as well as the microstructure, phases and microhardness of an Ni-based self-fluxing alloy coating are described. The optimal granulations of a self-fluxing alloy powder and the relationship between the flow of powder of various fractions and the flow rate and pressure of the transporting gas have been determined. The laser beam speed, track pitch and the distance from the nozzle to the coated surface influence the height and width of single tracks. Regularities in the formation of microstructure under different cladding conditions are defined, as well as regularity of distribution of elements over the track depth and in the transient zone. The patterns of microhardness distribution over the track depth for different cladding conditions are found. These patterns as well as the optimal laser spot pitch allowed obtaining a uniform cladding layer.
- Publication:
-
Optics and Lasers in Engineering
- Pub Date:
- July 2018
- DOI:
- 10.1016/j.optlaseng.2018.02.004
- Bibcode:
- 2018OptLE.106...32D
- Keywords:
-
- Laser cladding;
- Ni-based self-fluxing alloy;
- Powder flow;
- Single track microstructure;
- Elements distribution;
- Single track microhardness