Effect of Y on oxide film formation and ignition behavior of magnesium-rare earth alloy

The incorporation of Y significantly improves the fire resistance of the Mg-3Nd-2Gd-0.2Zr-0.2Zn (EV32) alloy. The findings indicate a significant increase in the ignition point of the alloy upon Y addition, notably reaching 813.9 ℃ for the EV32–3Y (wt.%) alloy. Additionally, the calculated residual stresses of the Y₂O₃ and Gd₂O₃ films were 2.732 GPa and 2.569 GPa respectively, showcasing a distinct correlation between Y concentration and improved fire resistance. This enhancement can be attributed to the formation of denser oxide films, especially Y₂O₃ and Gd₂O₃, effectively reducing the susceptibility of the oxide film to thermal stress-induced tearing. The study elucidates the vital role of Y addition in enhancing fire resistance, thoroughly investigating the mechanisms that impact both the formation of oxide films and ignition within the alloy structure. These findings not only contribute to a deeper comprehension of magnesium alloy performance under high-temperature conditions but also offer valuable theoretical guidance for enhancing its fire resistance through alloy design and application.