(上海交通大學(xué) 金屬基復(fù)合材料國(guó)家重點(diǎn)實(shí)驗(yàn)室， 上海 200030)
摘 要: 鎂合金熔煉時(shí)會(huì)發(fā)生劇烈的燃燒，因此必須采取有效的措施對(duì)其加以保護(hù)。合金化阻燃是一種理想的阻燃方法。從熱力學(xué)角度對(duì)鎂合金元素氧化方式的差異作出了解釋，并采用統(tǒng)一的氧化模型分析了兩種氧化膜的形成過(guò)程。研究結(jié)果表明，添加少量的Be或Ca可以提高M(jìn)g9Al0.5Zn合金的燃點(diǎn)。但是，兩種合金中基體元素Mg與合金元素Be和Ca的氧化方式并不相同。加入Be后，Mg發(fā)生外氧化，Be發(fā)生內(nèi)氧化。加入Ca后，Ca發(fā)生外氧化，Mg發(fā)生內(nèi)氧化，因此合金表面氧化膜的物相組成和元素分布也不相同。
關(guān)鍵字: 鈹； 鈣； 鎂合金； 熱力學(xué)
（College of Materials Science and Engineering, Shanghai Jiaotong University，Shanghai 200030, P.R.China）
Abstract: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 ignitionproof 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.
Key words: beryllium; calcium; magnesium alloy; thermodynamics
