Effect of post-treated methods on corrosion resistance of MF-DC magnetron sputtering Al coating on TC4

Abstract

Purpose

This study aims to investigate the effect of post-treatment on anti-corrosion performance of Al coating on the surface of Ti-6Al-4V (TC4) fastener.

Design/methodology/approach

The Al coatings with different layer structures were prepared on TC4 by middle-frequency and direct-current combined magnetron sputtering. The cross-sectional morphology and surface roughness of coatings were characterized by scanning electron microscope and atomic force microscope. The corrosion resistance was evaluated by electrochemical method. The monolayer coating was post-treated by Alodine chemical conversion, Ar⁺ bombardment and a combination of two methods above.

Findings

The results show that the interfaces in bilayer and trilayer coatings reduce the defects. Ar⁺ bombardment reduces the corrosion current density, and Alodine chemical conversion leads to a higher pitting corrosion potential. The combined post-treatment has the highest polarization resistance.

Originality/value

The corrosion resistance of the Al coating is enhanced as the layer quantity increases. The combination of two post-treatments, Ar⁺ bombardment and Alodine chemical conversion, could achieve an overall improvement in corrosion resistance of Al coating.

Citation

Li, W., Zhang, Y., Xu, Y., Jiao, G., Zuo, D., Lu, W., Cheng, Q., Yu, J. and Chen, Y. (2024), "Effect of post-treated methods on corrosion resistance of MF-DC magnetron sputtering Al coating on TC4", Anti-Corrosion Methods and Materials, Vol. 71 No. 1, pp. 12-19. https://doi.org/10.1108/ACMM-07-2023-2857