CORRELATION BETWEEN MICROSTRUCTURE AND ELECTROCHEMICAL PROPERTIES IN MICROARC OXIDATION COATED MAGNESIUM ALLOY

摘要

Magnesium alloys are promising biomaterials with potential application of human bone replacement. However, there is a drawback due to their high corrosion rates. In this work, AZ31 magnesium alloys were coated using microarc oxidation (MAO) process. Two oxidation durations, 15 minute and 20 minutes, were used. The samples were immersed in a simulated body fluid (SBF) for up to six days. Then the electrochemical behaviors of the two samples were investigated. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) experiments were used. The micro and marcoscopic images of the samples were examined. The results show that the 20-minute MAO coated sample has a denser coating and better corrosion resistance than the 15-minute coated sample.