Corrosion resistance performance of Zr based conversion coating developed on aerospace aluminum alloy

Yoganandan, G and Pradeep, Premakumar and Balaraju, JN (2013) Corrosion resistance performance of Zr based conversion coating developed on aerospace aluminum alloy. In: CORCON 2013, 2013-09-30, New Delhi.

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    Abstract

    A zirconium based conversion coating (ZrCC) was developed on aerospace aluminum alloy (AA2024) in order to improve its corrosion resistance. Various corrosion inhibitors such as Ce, Mo and W oxyanions were also added in the conversion bath and their corrosion inhibition performance was studied. Electrochemical impedance spectroscopy (EIS) results revealed that the cerium incorporated zirconium (ZrCeCC) showed higher charge transfer resistance value (13.4 kΩ.cm2) compared to zirconium-molybdenum (ZrMoCC) and zirconium-tungsten (ZrWCC) conversion coatings. The EIS results also revealed that low frequency impedance of ZrCeCC did not change significantly with respect to immersion time in 3.5% NaCl solution for up to 168h. The potentiodynamic polarization (PDP) results showed that both ZrCC and ZrCeCC exhibited lower icorr values of 0.83 and 0.6 μA.cm-2 respectively. The damage tolerance study results revealed that the ZrCeCC offered active corrosion protection to the substrate from the chloride ion attack. X-ray photoelectron spectroscopy (XPS) results revealed that both Zr and Ce elements existing in the multivalent oxidation state. The morphology (FE-SEM) and composition analysis (EDAX) of the developed coatings before and after corrosion studies were also thoroughly examined.

    Item Type: Conference or Workshop Item (Paper)
    Uncontrolled Keywords: Corrosion resistance;Electrochemical impedance spectroscopy (EIS);Aluminum alloy
    Subjects: AERONAUTICS > Avionics & Aircraft Instrumentation
    Division/Department: Surface Engineering Division, Other, Surface Engineering Division
    Depositing User: Mrs Manoranjitha M D
    Date Deposited: 29 Jul 2015 10:41
    Last Modified: 29 Jul 2015 10:41
    URI: http://nal-ir.nal.res.in/id/eprint/12268

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