Flame resistance and oxidation behavior of Mg-Y-Ce-Zr alloys

In this paper, Mg-XY-1.5Ce-0.6Zr (X = 0.5, 1, 2, 3, 4.5, 6.5 wt%) alloys with different contents of element Y (1 wt% to 6.5 wt%) were prepared. The flame resistance, oxidation behavior, microstructure and phases of the resulting alloys with varying proportions of elements Y and Ce were investigated thoroughly. The results showed that the flame resistance of Mg-2Y-1.5Ce-0.6Zr alloy with 2 wt% of element Y was the highest and the corresponding ignition point was 920 °C. The contents of elements Y and Ce on the surface of the alloy changed at different temperatures. A dense oxide film composed of Y₂O₃ and MgO was formed on the surface after oxidation reaction for 90 min at 550 °C. The thermodynamic calculations showed that the chemical reaction activity of Y was higher than that of Mg and Ce, and the element Y could easily diffuse on the alloy surface at high temperature. (paper)