Study on the Preparation and Corrosion Resistance of Ti-Zr-V Series Conversion Coating on the Surface of 6061 Aluminum Alloy

Aluminum alloy 6061 is widely used in the industrial field, but its poor corrosion resistance has a significant impact on the reliability of equipment components. To address the corrosion resistance issue of 6061 aluminum alloy, a novel Ti-Zr-V conversion coating was prepared on its surface in this study, and the conversion parameters were optimized. The morphology, element distribution and content, composition of compounds, and corrosion resistance of the prepared Ti-Zr-V conversion coating were comprehensively analyzed and evaluated using scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, copper sulfate spot test, and electrochemical experiments. The research results showed that the conversion parameters had a significant impact on the corrosion resistance of the conversion coating. The optimal conversion parameters were a pH value of 4.5 and a conversion time of 5 min, with the optimal addition amount of the auxiliary film former NaVO3 being 0.6 g/L. Under these conditions, the Ti-Zr-V conversion coating prepared was relatively dense, with fewer grooves, the longest spot resistance time, and the best corrosion resistance. Its surface mainly consisted of titanium dioxide, zirconium dioxide, vanadium pentoxide, V2O3, aluminum oxide, and a small amount of fluoride compounds. Electrochemical analysis also demonstrated that the corrosion rate of TiZrVCC decreased by approximately 87.12% compared to the aluminum alloy 6061 substrate, providing a theoretical basis and technical support for the further promotion and use of aluminum alloy.