Microstructural charactistics of plasma sprayed nicrbsi coatings and their wear and corrosion behaviors

Abstract

Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxida-tion. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffrac-tion analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolu-tionary process of the corrosion structure and phase of the coating in the accelerated corrosion ex-periment is directly visualized by using scanning electron microscopy and energy spectrum analy-sis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by micro-hardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion re-sponses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.