The high temperature oxidation and ignition behavior of Mg-Nd alloys part I: The oxidation of dilute alloys

The high temperature oxidation behavior of magnesium (Mg) alloys containing neodymium (Nd) was investigated at low level concentrations (0.3 and 0.5 wt.%). Continuous heating experiments carried out in dry air-flow revealed, interestingly, that the ignition temperature (T-i) is raised from 640 degrees C (of pure Mg) to up to 770 degrees C at 0.5 wt.% Nd addition. No significant improvement was detected with 0.3 wt.% Nd. The analyses of the surface indicate that the two alloys form different oxide morphologies when oxidized at 500 degrees C for 12 h in air. Although a more dense oxide scale forms with 0.3 wt.% Nd addition compared to pure Mg, the ignition results showed that the Nd addition below 0.5 wt.% is not effective on the oxidation resistance. The presence of Nd2O3 plays an indirect protective role delaying Mg evaporation and ignition. (c) 2013 Elsevier B.V. All rights reserved.