XU Zu-bin,SONG Ying-wei,SHAN Da-yong,HAN En-hou.Influence of Film-forming Temperature on the Formation of Microcracks and Corrosion Resistance of Phosphate Conversion Films on AZ80 Magnesium Alloy[J],45(12):23-27
Influence of Film-forming Temperature on the Formation of Microcracks and Corrosion Resistance of Phosphate Conversion Films on AZ80 Magnesium Alloy
Received:February 21, 2016  Revised:December 20, 2016
View Full Text  View/Add Comment  Download reader
DOI:10.16490/j.cnki.issn.1001-3660.2016.12.004
KeyWord:magnesium alloys  phosphate conversion film  film-forming temperature  microcrack  corrosion resistance
           
AuthorInstitution
XU Zu-bin 1.Key Laboratory for Nuclear Materials and Safety Evaluation, Institute of Metals Research, Chinese Academy of Sciences, Shenyang , China; 2.National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing , China
SONG Ying-wei Key Laboratory for Nuclear Materials and Safety Evaluation, Institute of Metals Research, Chinese Academy of Sciences, Shenyang , China
SHAN Da-yong Key Laboratory for Nuclear Materials and Safety Evaluation, Institute of Metals Research, Chinese Academy of Sciences, Shenyang , China
HAN En-hou Key Laboratory for Nuclear Materials and Safety Evaluation, Institute of Metals Research, Chinese Academy of Sciences, Shenyang , China
Hits:
Download times:
Abstract:
      The work aims to study the effect of film-forming temperature on the microcracks and corrosion resistance of phosphate conversion films on magnesium alloy based on statistics of size and area of microcracks on the surface of conversion films at different film-shaping temperatures and electrochemical test. Morphology of microcracks obtained at different temperatures was observed by scanning electron microscopy (SEM). Width and area of microcracks on the surface of conversion films were measured by Image-pro-plus software, and corrosion resistance of the conversion films was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Statistical results showed that the microcrack width and area of the conversion film prepared at 50 ℃ were the minimum, 2.68 μm and 1067 μm2, respectively; for the conversion film prepared at 30 ℃, the maximum, 3.14 μm and 1391 μm2, respectively; for the conversion film prepared at 70 ℃, 2.74 μm and 1170 μm2, respectively. The electrochemical test indicated that self-corrosion current of the conversion film prepared at 50 ℃ was the minimum, Jcorr=20.3 μA/cm2, and radius of capacitance arc in the electrochemical impedance spectroscopy was the maximum. Microcracks narrow down and decrease with the increase of film-forming temperature. However, the microcracks broaden and increase at higher temperature. At the film-forming temperature of 50 ℃, the micro cracks are the least and narrowest and are provided with the best corrosion resistance.
Close