Zhao Xinyi, Gu Tao, Zhang Haiyang, Wang Zeyu, Butt Hassaan Ahmad, Lei Yucheng
School of Materials Science and Engineering, Jiangsu University, Zhenjiang, China.
Skolkovo Institute of Science and Technology, Moscow, Russia.
Front Chem. 2022 Aug 11;10:980860. doi: 10.3389/fchem.2022.980860. eCollection 2022.
Ignition of magnesium alloys during casting processes limits their processability and applications. For identifying the ignition mechanism of magnesium alloys during solidification, a Mg-Al-Zn alloy was solidified with different cooling rates and pouring temperatures. The oxide scale morphologies and thicknesses were identified by SEM and energy dispersive spectrometer. Based on the experimental results, the oxidation kinetics and heat released were calculated and the relationship between oxidation and ignition was discussed in detail. The calculation results indicate that oxide rupture directly induces combustion of the melt. The rupture route of the oxide scale was determined to be buckling cracks according to the experimental and calculation results. Based on the buckling mechanism of the oxide scale, the ignition criterion during solidification was correlated to the pouring temperature, cooling rate and casting modulus. This work reveals the underlying relationship between ignition and casting process parameters, and it helps to develop new technology for inhibiting ignition of molten magnesium alloys.
铸造过程中镁合金的着火限制了它们的加工性能和应用。为了确定镁合金在凝固过程中的着火机制，采用不同的冷却速率和浇注温度对一种Mg-Al-Zn合金进行凝固。通过扫描电子显微镜（SEM）和能谱仪确定氧化皮的形态和厚度。基于实验结果，计算了氧化动力学和热量释放，并详细讨论了氧化与着火之间的关系。计算结果表明，氧化皮破裂直接引发熔体燃烧。根据实验和计算结果，确定氧化皮的破裂路径为屈曲裂纹。基于氧化皮的屈曲机制，凝固过程中的着火判据与浇注温度、冷却速率和铸造模数相关。这项工作揭示了着火与铸造工艺参数之间的潜在关系，并有助于开发抑制熔融镁合金着火的新技术。
