Preparation and electrochemical characterization of Mn-Mo oxyanion pore-filled oxide layers on aerospace aluminum alloy

Balaraju, JN and Yoganandan, G and Zong, Chen and Low, Christopher and Qi, Guojun (2013) Preparation and electrochemical characterization of Mn-Mo oxyanion pore-filled oxide layers on aerospace aluminum alloy. In: Heat treatment & Surface Engineering Conference and EXPO 2013, 16 May 2013, Chennai Trade Centre, Chennai, T.N..

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    Abstract

    Sulphuric acid anodization process was carried out to grow oxide layers on unclad AA 2024 alloy. To enhance the corrosion resistance of plain oxide layer (PO), post treatments such as immersion in boiling water (HTO) and Mn-Mo oxyanions conversion bath (PMO) were carried out. Results obtained from electrochemical impedance spectroscopy (EIS) studies showed that the Mn-Mo infused oxide layer maintained the charge transfer resistance (Rct) value of about 106 Ωcm2 even after 7 days of immersion in 3.5% NaCl solution. Scanning vibrating electrode technique (SVET) results revealed that the plain and boiling water sealed oxide layers exhibited anodic corrosion activity immediately after the immersion into NaCl solution. Whereas, the distribution of anodic and cathodic sites over the surface of Mn-Mo infused oxide layer was insignificant even after 7 days of immersion. The EIS immersion study clearly revealed the self-healing behavior of the PMO in NaCl solution until 7 days of immersion. This corrosion inhibition mechanism was corroborated with the help of energy dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS) results.

    Item Type: Conference or Workshop Item (Paper)
    Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
    Division/Department: Surface Engineering Division, Surface Engineering Division, Other, Other, Other
    Depositing User: Mr. BS Shivaram
    Date Deposited: 25 Sep 2013 16:15
    Last Modified: 25 Sep 2013 16:15
    URI: http://nal-ir.nal.res.in/id/eprint/11796

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