Investigating the Corrosion Resistance of Ti-Al Coating on Structural Steel Components

Abstract

Carbon steel is widely used in infrastructure, manufacturing, and structures due to its cost-effectiveness and robust mechanical properties. However, the susceptibility of steel structures to corrosion in various working environments has been a longstanding concern. In this study, we explored the potential of titanium-aluminum (Ti-Al) coating as a surface treatment to enhance the corrosion resistance of low-carbon steel. The coating was applied using the arc spraying technique, where two materials were melted by an arc and then distributed onto the substrate using compressed air. To evaluate the corrosion resistance of the coated samples, we conducted immersion tests following the ASTM G31 standard for durations of 625 and 1000 hours. Additionally, electrochemical technique was employed to assess the anti-corrosion performance of both the Ti-Al coating and the substrate. Surface characterization was carried out using scanning electron microscopy equipped with energy- dispersive X-ray spectroscopy (SEM-EDX), as well as measurements of hardness and roughness. The SEM-EDX analysis revealed uniform distribution of titanium and aluminium across the surface and within the coating. Moreover, the coating significantly altered the surface roughness. Electrochemical corrosion testing indicated that the Ti-Al coating exhibited lower corrosion current and corrosion potential, suggesting its potential to enhance the corrosion resistance of the substrate. The SEM-EDX revealed cracks on the coating surface and the oxidation level of the coating surface varied with immersion time. The hardness of the coating was found to be relatively lower than that of the substrate, while the surface roughness was higher. Overall, the findings suggest that Ti-Al coating holds promise for enhancing the corrosion resistance of steel structures, as evidenced by its low corrosion current density and corrosion potential in corrosive environments.