Be和Ca对 Mg-9Al-0.5Zn合金表面氧化行为的影响

镁合金熔炼时会发生剧烈的燃烧，因此必须采取有效的措施对其加以保护，合金化阻燃是一种理想的阻燃方法。从热力学角度对镁合金元素氧化方式的差异作出了解释，并采用统一的氧化模分析了两种化膜的形成过程。研究结果表明，添加少量的Ｂｅ或Ｃａ可以提高Ｍｇ－９Ａｌ－０．５Ｚｎ合金的燃点。但是，两种合金中基体元素Ｍｇ与合金元素Ｂｅ和Ｃａ的氧化方式并不相同。加入Ｂｅ后，Ｍｇ发生外氧化，Ｂｅ发生内氧化，加入Ｃａ后，Ｃａ发

Effects of Be and Ca on surface oxidation behaviors of Mg-9Al-0.5Zn alloy

When being melted, magnesium alloys were prone to burn heavily, so special measures must be taken to protect it from ignition. Alloying is a effective method to keep magnesium alloy from burning intensively. In terms of thermodynamic principle, the different oxidation behaviors of these two kinds of alloys were analyzed. The thermodynamic forming processes of the oxide films were also explained by constructing a simplified model. When alloy elements of Be and Ca were added, the ignition proof property was improved significantly. The structure and chemical compositions of the oxide film were investigated by XRD and AES. The results revealed that Be is oxidized under the MgO layer and Ca is oxidized in the outmost layer.