Mechanical, Anticorrosion, and Tribological Properties of Nanostructured WC-Co/Cr3C2-NiCr Multilayered Graded Coating on Aluminum Substrate

Abstract

This paper examines the application of multilayered hard coatings on aluminum substrates to improve their mechanical, anticorrosion, and tribological properties. In the present study, graded coatings with alternate layers of chrome carbide–nickel chrome (75:25) and tungsten carbide–cobalt (88:12) are applied on aluminum substrates for improvement in mechanical and tribological properties. High-velocity liquid fuel (HVLF) spray technique is employed to coat the materials on the aluminum substrate. Nanosized Cr3C2-NiCr and WC-Co powders with particle sizes ranging from 300 to 1000 nm are employed for coating on aluminum substrates. The tribological properties are tested on a pin-on-disk tribometer under lubricated conditions. It is found that graded coating with alternate layers of Cr3C2-NiCr and WC-Co have shown good tribological properties. The hardness has improved, with coating strength being in acceptable range for application in automotive engines. The corrosion resistance of multilayered coating is excellent and in line with Cr3C2-NiCr coating. The effects of number of coating layers of graded coating on tribological and mechanical properties are found to be significant.