Effect of ageing time on corrosion behavior of Mg-10Gd-4.8Y-0.6Zr extruded-alloy

The corrosion behaviors of Mg-10Gd-4.8Y-0.6Zr extruded-alloys with various ageing time were investigated by immersion test and electrochemical measurements. The results show that the corrosion rate of the experimental alloy decreases with the increase of ageing time from 0 to 108 h. The corrosion resistance of the experimental alloy was found to increase with the increase of the size of the precipitate phases. The open circuit potential of the experimental alloy increases with the increase of the ageing time. The potentiodynamic polarization curves show that the cathodic over-potential increases with the increase of ageing time, leading to a decrease in the current density of anodic current plateau with the increase of ageing time.