The effect of solution temperature and pH on corrosion performance and morphology of nanoceramic-based conversion thin film

Authors

  • H. Eivaz Mohammadloo,

    1. Faculty of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran)
    Search for more papers by this author
  • A. A. Sarabi,

    Corresponding author
    1. Faculty of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran)
    • Faculty of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran).
    Search for more papers by this author
  • A. A. Sabbagh Alvani,

    1. Color and Polymer Research Center, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran)
    Search for more papers by this author
  • R. Salimi,

    1. Faculty of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran)
    Search for more papers by this author
  • H. Sameie

    1. Faculty of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran)
    Search for more papers by this author

Abstract

In the present study, a nanoceramic hexafluorozirconic acid was used as an eco-friendly conversion coating, which is free of the conventional phosphate salts. The effect of practical parameters on morphology and corrosion resistance of the coating was studied. Anti-corrosion behavior of the nanoceramic-based conversion coating on cold rolled steel substrates was evaluated at different solution pH and temperatures, utilizing the electrochemical impedance spectroscopy and direct current polarization. Moreover, the morphology of thin films was studied using field emission scanning electron microscopy (FE-SEM). The results revealed that the conversion thin films formed at a dipping temperature of 20 °C and pH 4.5 showed best anti-corrosion performance. SEM images indicated that increasing solution temperature resulted in micro-cracks creation and lack of consistency on the surface of the conversion coating. Moreover, the morphological structure changed with increasing pH value.

Ancillary