Effect of Homogenization Treatment on the Corrosion Behavior and Mechanism of Mg-Y Alloys

The effect of homogenization treatment on the corrosion behavior and corrosion mechanism of Mg-Y alloys in 3.5 wt% NaCl solution was investigated by electrochemical characterization, immersion testing and SEM observations. The diffusion kinetics model of Mg-Y alloy was established, and the homogenization system was determined. With increasing of homogenization temperature and time, the Mg(24)Y(5)phase gradually decreased, which increased the self-corrosion potential and the high-frequency arc radius. The corrosion resistance of the five alloys could be given as follow: Mg-0.25Y < Mg-8Y < Mg-15Y < Mg-5Y < Mg-2.5Y. The Mg- (0.25, 2.5 and 5) Y show localized corrosion in a wide range and small depth, while Mg- (8 and 15) Y showed localized corrosion in a smaller range and larger depth.