Lightweight and sustainable materials for coating applications

Abstract

This chapter deals with the development of Cr3C2-25NiCr/cenosphere/MoS2/CaF2, Cr3C2-25NiCr/cenosphere/MoS2/CaSO4, and Cr3C2-25NiCr coatings through plasma spraying on MDN 321 steel substrate. Methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) are used for coating phase composition and microstructure analysis. Sliding wear behavior of substrate and coatings is tested at 200°C-600°C by utilizing a pin-on-disk tribometer. Owing to the existence of cenospheres and action of solid lubricants, frictional coefficient and wear rate of fly ash cenosphere-based Cr3C2-25NiCr/MoS2/CaF2 and Cr3C2-25NiCr/MoS2/CaSO4 compositions are reduced in comparison with Cr3C2-25NiCr coating and substrate at all test parameters. The characterization of the coatings’ worn-out surface reveals lubrication at 200°C by MoS2. At elevated temperature, CaF2 with CaMoO4 formed through tribochemistry further aids lubrication. Micrographs of worn surfaces demonstrate plowing and delamination as the main wear mechanism. © 2023 Elsevier Ltd. All rights reserved.