Mg-3.5Y-0.8Ca阻燃镁合金的表面氧化膜结构研究

Characteristics of Oxidation Film on Ignition-proof Mg-3.5Y-0.8Ca Alloys at High Temperatures

通过Y和Ca的同时加入获得了阻燃效果优异的Mg-3.5Y-0.8Ca阻燃镁合金,实现了镁合金在大气条件下的无保护熔炼。XRD,SEM和AES等表面分析结果表明,Mg-3.5Y-0.8Ca阻燃镁合金在高温下暴露于大气中时,合金表面会生成一层以Y2O3为主的氧化膜。Y2O3膜结构致密,铺展性强,在高温下为固态且不易挥发,电导率低,这些性能决定了其是一种优良的保护性氧化膜,能够阻碍镁合金基体的进一步氧化。

A magnesium alloy with excellent ignition-proof property was acquired by adding yttrium and calcium at the same time. The Mg-3.SY-0.8Ca alloy could be immune from ignition at 1173 K for 30 min. XRD, SEM and AES analysis of oxide scale revealed that the oxide film formed on the surface of Mg-3.SY-0.SCa alloy was mainly composed of Y2O3. The Y2O3 film may be considered as an outstanding protective film due to its stable crystal structure, high melting point, low steam pressure, the P-B ratio more than 1, compact structure, low conductivity and excellent ductibility and so on.