Characterization of HVOF Sprayed Inconel -718 Coating on Boiler Steel

Thermal spray processes stand for a cost-effective technique for improving the surface properties of engineering components with a vision to boost their durability and performance under different operating conditions. Among the various techniques of thermal spraying, high velocity oxy-fuel (HVOF) thermal spray process is one of the thermal spraying technique known for wear and corrosion applications because of its significant benefits such as high bond strength, low porosity and low stress coatings. In this present investigation, Inconel 718 powder was deposited on T22 boiler steel by HVOF thermal spray process. The coatings were examined using X-Ray diffraction (XRD), Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). The XRD analysis revealed the formation of Ni as principal phase. The deposited IN 718 coatings exhibited splat like layered morphologies due to deposition of successive molten and semi molten powder particles. The EDS analysis of the coating showed richness in Ni, Cr and Fe with high amount of oxygen. Surface roughness and micro-hardness of the coating was also measured.

Keywords: HVOF, IN 718, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM)