Abstract: In this study, Fe-based amorphous/nanocrystalline composite coatings were synthesized with a low-chromium cost-effective composition of Fe73Cr2Si11B11C3 (at. %) via atmospheric plasma spraying. The effect of heat input (plasma power) on the morphology and devitrification, and its subsequent effect on wear and corrosion performance were investigated. Microstructural characterization revealed that higher heat input led to decrease in porosity as well as high extent of devitrification. Nanoscratch test exhibited that wear resistance improved for coatings deposited at higher spraying power, which was attributed to the formation of well-adhered splats and higher fraction of nano-sized intermetallics (Fe-boride phases). However, precipitation of more crystalline phases caused reduction in the corrosion resistance when coating was deposited at very high plasma power (35 kW). Coating deposited at optimum spray parameters showed superior wear and corrosion resistance owing to the existence of low porosity and high retained amorphous content.
Authors: Anil Kumar, Sapan K. Nayak, Pavan Bijalwan, Atanu Banerjee, and Tapas Laha
Keywords: Fe-based amorphous/nanocrystalline coating, Atmospheric plasma Spraying, Nanoscratch, Corrosion