Improving corrosion resistance of AZ31B magnesium alloy via a conversion coating produced by a protic ammonium-phosphate ionic liquid

THIN SOLID FILMS

卷:568

Article

Elsentriecy, Hassan H.^1,2  Qu, Jun¹  Luo, Huimin³  Meyer, Harry M., III¹  Ma, Cheng¹  Chi, Miaofang¹ 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN USA

[2] Cent Met Res & Dev Inst, Cairo, Egypt

[3] Oak Ridge Natl Lab, Energy & Transportat Sci Div, Oak Ridge, TN USA

关键词: Magnesium;    Corrosion;    Conversion coating;    Protic ammonium-phosphate ionic liquid;   

DOI  :  10.1016/j.tsf.2014.08.010

来源: Elsevier

【 摘 要 】

Magnesium alloys are susceptible to corrosion because of their high reactivity and low electrode potential. The present work introduces a conversion coating using a protic ammonium-phosphate ionic liquid (IL). Initial results on the AZ(31)B Mg alloy have demonstrated substantially improved corrosion resistance for the IL treatment at 300 degrees C (IL_300C) compared to the treatment at room temperature. Potentiodynamic polarization analysis of the IL_300C treated Mg surface in a NaCl solution exhibited a strong passivation behavior. No pretreatment is needed and the treated surface morphology is well preserved. Cross-sectional nanostructure examination using transmission electron microscopy and element mapping using energy-dispersive X-ray spectroscopy have revealed the IL_300C conversion coating to be a 70-80 nm thick with a two-layer structure. Further surface chemical analysis using X-ray photoelectron spectroscopy suggested such an IL conversion coating possibly composed of metal oxides, metal phosphates, and carbonaceous compounds. (C) 2014 Elsevier B. V. All rights reserved.

【 授权许可】

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