THE EFFECT OF Y ON THE OXIDATION OF Mg-Zn-Zr ALLOYS

摘要

The effects of Y addition up to 5.13% (in weight) to Mg-Zn-Zr alloys on oxidation behaviors under atmospheric ambient conditions were investigated in this study. Samples were heated in the ambient atmosphere at 400°C, with samples cooled to room temperature for mass measurement after some period time of cumulative exposure to obtain kinetic curves. XRD is used to analyze the mixture of oxides. Scanning electron microscopy combined with energy dispersive spectroscopy was used to study the scale microstructure and to obtain composition-depth profiles through the oxide layers. The oxidation results show that the weight gains for the alloys containing low Y concentration are obvious. The oxide films are thick and porous on the alloys containing low Y and thin and protective on alloys containing relatively high Y concentration. The addition of Y into Mg-Zn-Zr alloys results in the formation of protective film which is resistant to oxidation.