Optimization and tribological evaluation of graphene oxide coating on surface-textured AISI 52100 steel using Taguchi method

The tribological characteristics of graphene oxide (GO) coatings deposited by the electrophoretic deposition method on a novel honeycomb laser-engraved pattern on AISI 52100 alloy steel surface are evaluated and compared with that of commonly engraved patterns like Sierpinski, Gosper, Hilbert, and Peano. The electrophoretic deposition parameters were optimised using the Taguchi method with ethanol as electrolyte. The most critical parameter was identified to be post-deposition heat treatment temperature and the impact of the same on crack density for GO coating is found to be proportional to the coefficient of friction (COF). Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDX) were used to analyse the coated samples and tribological tests were carried out using pin-on-disc equipment. The results reveal that the GO-coated honeycomb structure achieved superior tribological performance compared to other engraved patterns, with the lowest mean COF (0.18) and wear loss (0.29 × 10⁻³g), indicating a 58.6% decrease in COF and a 90% reduction in wear loss relative to the pure substrate. The results show that GO-coated honeycomb-engraved surfaces exhibit enhanced tribological behaviour, making them suitable for low-friction components in automotive, aerospace, and bearing applications.