Abstract
Thermally sprayed coatings of self-fluxing alloys are mainly fused using an autogenous flame. This subsequent fusing step reduces the porosity of the coating and achieves a pronounced metallurgical bonding. Therefore, an enhancement of the coating adhesion and intersplat cohesion as well as the corrosion and wear resistance are achieved. During this non-automated fusing step, the coating quality is significantly influenced by the operator's handling of the flame fusing process. By means of an alternative fusing using laser, can improve the reproducibility and automatability. In this work, the effect of different laser parameter settings and structural defects on fusing depth, microstructure evolution and tribological properties of thermally sprayed self-fluxing coatings and bulk materials is discussed. Gas atomized powder of conventional NiCrBSiFe self-fluxing alloy was processed by powder flame spraying and by spark-plasma sintering (SPS) as reference state. The findings reveal the potential of laser fusing to achieve a significant improvement in the coating quality and property profile of a wide variety of initial structures related to the process conditions.
