| Abstract Scope |
This study explores a sustainable method for depositing carbon-based coatings on Ni-Invar and Ti-6Al-4V metallic substrates using the pack carburization process with cyanide-rich Manihot esculenta (cassava) leaves as the carbon source. Comprehensive experimental and computational analyses were employed to investigate the composition, structure, and tribological performance of the coatings. Characterization using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), and lateral force microscopy (LFM) revealed that Ni-Invar substrate developed turbostratic multilayer graphene coatings with minimal carbide formation, achieving ultra-low coefficients of friction (COF) of 0.08 (macro-scale) and 0.0033 (nano-scale). In contrast, Ti-6Al-4V substrates formed coatings rich in titanium carbide and metal carbonates with more disordered carbon structures, resulting in higher COF values of 0.1 and 0.0147, respectively. |