Electrodeposition of Cu Sn alloy coatings with enhanced corrosion resistance durability and self cleaning properties

Abstract

In this study, a Cu-Sn superhydrophobic coating was fabricated on the surface of X70 steel via the electrodeposition method, resulting in an optimal contact angle of 164.2 ± 1.2°. Compared to the X70 substrate, the Cu-Sn coating exhibits superior corrosion resistance. In a 3.5 wt% NaCl solution, the polarization resistance (Rp) is 71,037 Ω·cm2, approximately 48 times higher than the substrate; the corrosion current (Icorr) is 2.23 × 10− 7 A/cm2, roughly two orders of magnitude lower than that of the substrate. This enhancement is attributed to the addition of Sn, which combines with Cu to form a Cu-Sn alloy with a micro-nano structure, effectively improving the hydrophobicity and corrosion resistance of the coating. However, excessive SnSO4 can hinder the formation of the micro-nano structure, leading to aggregation on the coating surface. In addition, the coating exhibits excellent self-cleaning properties and mechanical stability. After undergoing rigorous mechanical stability tests, including tape peeling, sandpaper abrasion, water drop impact, and sand erosion, the contact angle remains above 155°. These results are significant for addressing the issue of long-term durability and stability of superhydrophobic coatings in industrial applications and provide new prospects for the deposition of metals or alloys.