Fabrication And Characterization Of Anodic Films Onto The Fecral Stainless Steel In Ethylene Glycol Electrolyte

The nanoporous film has been widely studied because of its unique properties, of which the self-organizing porous array is significant for various potential applications. Herein, the self-organized porous film with the diameter of 43-104 nm was fabricated on FeCrAl alloy by anodic oxidation in perchloric acid-based electrolyte. And the pore diameter linearly varied with the applied voltage from 40 V to 70 V. The evolution of porous films was investigated via HIM and AFM. The pore depth firstly increased, kept constant and then decreased. The ordered pore was formed within initial 3-5 min. To elucidate the anodizing mechanism, the composition of anodic film and precipitate were analyzed by XPS and FTIR respectively. Possible formation mechanism of the anodic films on the FeCrAl substrate was proposed: the porous film was sourced from the coordination compound, which consisted of metal ions (Fe2+, Fe3+, Al3+ and Cr3+) and carboxyl organic compounds from ethylene glycol oxidization. In the anodic film, the atomic concentration followed the order of Al > Fe > Cr. The study provided for the guideline for enhancing the mechanical strength between metallic substrate and coating.