Effect of minor Gd addition on microstructure, mechanical performance, and corrosion behavior of Mg–Y–Gd alloys

Effects of minor Gd addition on the micro-structure, mechanical performance, and corrosion behavior of Mg-1Y alloys were systematically studied. With the addition of increased Gd content, the hydrogen evolution rate of Mg-Y-Gd alloys decreased from 2.0 to 0.5 mm/y. Moreover, the alloying Gd in Mg-Y-Gd alloys leaded to the transformation of the active Mg24Y5 phase into the Mg5(GdY) phase. The high corrosion resistance of Mg-1Y-0.6Gd alloy can be attributed to the fine grain size, uniform distribution of surface potential, and the formation of protective corrosion passivation film rich in Gd2O3 and Y2O3.