Alternative to chromium, a hard alloy powder NiCrBCSi (Fe) coatings thermally sprayed on 60CrMn4 steel. Phase and comportements

The purpose of this study was to investigate and to compare microstructural properties, wear resistance, and potentials of thermal spraying of NiCrBSiCFe coatings for a possible replacement of hard chromium plating in mechanical parts repair. The coatings surfaces and cross section were characterized before and after testing behavior using a scanning electron microscopy (SEM) coupled with an analyzer (EDAX). The characterization of phases was carried out by electron microprobe and X-ray diffraction. A good adherence of coating NiCrBCSi (Fe) on steel substrate is explained by formation of large diffusion zone in interface after annealing and by the nature of the structure deposit duplexes. This is explained by the split structure that we were able to characterize and which is composed of a phase lasts type boro carbide-nickel Ni3(BC) and the matrix based Nî reinforced by very fine rich Cr precipitates. These properties are enhanced by cyclic heat treatment.