Preparation and properties of the anodized film on Fe-Cr-Al alloy surface

Abstract

Purpose

This paper aims to find a way to improve the surface insulation, corrosion resistance and mechanical properties of Fe-Cr-Al electrothermal alloy, exploring the best oxidation condition and analyzing the oxidation mechanism.

Design/methodology/approach

Electrochemical workstation was used for anodic oxidation, and the effect of current density, ethylene glycol concentration and oxidation time on properties of the film were investigated by resistivity test, scanning electron microscope, electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) and mechanical tests, and the oxidation process was analyzed by X-ray photoelectron spectroscopy (XPS).

Findings

According to the potential-time curves of anodic oxidation and the analysis of XPS, the whole oxidation process can be divided into four stages. When the current density is 0.8 A/dm², the ethylene glycol concentration is 10%, and the oxidation time is 60 min, the film has the best corrosion protection, mechanical properties and surface morphology. The resistivity of the samples is about 13 orders magnitude than that of the matrix.

Originality/value

In this paper, a protective electrically insulating film was prepared by anodic oxidation in an alkaline electrolyte solution. The oxidation conditions were optimized and the oxidation mechanism was analyzed.

Citation

Yang, J., Guo, Y., Zai, W., Ma, S., Dong, L. and Li, G. (2020), "Preparation and properties of the anodized film on Fe-Cr-Al alloy surface", Anti-Corrosion Methods and Materials, Vol. 67 No. 4, pp. 379-386. https://doi.org/10.1108/ACMM-11-2019-2209