Influence of the microstructure on the corrosion behavior of AXJ530 magnesium alloy in 3.5% NaCl solution
By Amira, S.; Dubé, D.; Tremblay, R. & Ghali, E.
Published in Materials Characterization
2008
Abstract
The influence of the microstructure on the corrosion behavior of AXJ530 magnesium alloy has been investigated at room temperature in a 3.5% NaCl solution at pH 6 and 25 °C. Specimens of AXJ530 alloy were cut out from ingots and from billets cast in permanent mould with and without electromagnetic stirring. The corrosion behavior of the AXJ530 specimens was studied by potentiodynamic polarization, electrochemical noise analysis, and immersion tests. The phase composition, the morphology of corroded surface and its evolution with time were also analyzed. Potentiodynamic polarization studies and electrochemical noise analysis indicate that the corrosion resistance of ingot specimens is lower than the specimens cut from billets. A study of the surface of specimens after immersion tests has shown that the different corrosion behavior can be ascribed to the specific morphology, distribution and volume fraction of phases in the microstructure of specimens.