Mechanical and Corrosion Resistance of Cold Sprayed Zinc (CSZ) Nano Composite Coating Enhanced by SiO2-GO Hybrid Material

Abstract The purpose of this study is to provide an effective solution for improving the mechanical strength and corrosion resistance of cold sprayed zinc (CSZ) coating. In this paper, a convenient method to prepare SiO2-GO hybrid material by surface modification of GO with SiO2 is introduced, so as to improve the dispersibility of GO in CSZ coating and the hydrophobic performance of the coating. Characterization of GO and SiO2-GO by XRD, FT-IR spectrum, Raman spectrum and SEM proves the success of hybridization. The surface state, physical properties and electrochemical properties of the SiO2-GO/CSZ composite coating were studied. The SiO2-GO in the CSZ coating has good dispersion. Composite coating has low surface energy and hydrophobic effect, and the contact angle reaches 125.78°. Compared with GO/CSZ coating, the tensile adhesion of SiO2-GO/CSZ coating was significantly enhanced, reaching 0.7 MPa. Tafel polarization curve and electrochemical impedance test showed that the addition of 0.4 wt.% SiO2-GO can greatly improve the barrier time and cathodic protection cycle of CSZ coating under the protection of topcoat. The initial corrosion resistance of 0.4 wt.% SiO2-GO/CSZ improved by 24%. After soaking in 3.5 wt.% NaCl solution for 50 days, it still had good coating structure and corrosion resistance.