ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Investigation of the effect of conversion bath aging time on V/Zr-based conversion coating formation and corrosion resistance ability

Zhichun Cui, Jianzhong Li, Donghai Qiu, Wenhu Yang, and Zhiying Zhang

School of Metallurgy, Northeastern University, Shenyang, China

E-mail: lijz@mail.neu.edu.cn

Received: 2 July 2023  Accepted: 7 August 2023

Abstract:

The effect of aging time of V/Zr-based conversion bath on coating formation and corrosion resistance ability was investigated. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to investigate the morphology and composition of the conversion coating. Neutral salt spray (NSS), electrochemical impedance spectroscopy (EIS), and Tafel polarization tests were used to characterize the corrosion resistance of the conversion coating. The results showed that as the aging time of the solution increased, V ions were more completely hydrolyzed and converted to VO₃⁻ ions, and the presence of VO₃⁻ promoted the formation of the conversion coating. In addition, the vanadium element in the conversion coating tends to exist in the form of V₂O₅, and the proportion of V₂O₅ increases with the aging time of the conversion bath. The increase in aging time of the conversion bath also has a positive effect on improving the corrosion resistance of V/Zr-coated aluminum alloys.

Keywords: Aging time; Vanadium; Zirconium; Conversion coating; Corrosion

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03071-0

Chemical Papers 78 (1) 263–273 (2024)