Mg9Al0.5Zn0.3Be熔体表面氧化行为
来源期刊：中国有色金属学报2000年第5期
论文作者：曾小勤 王渠东 吕宜振 丁文江 卢晨 朱燕萍 翟春泉 徐小平
文章页码：667 - 670
关键词：氧化膜； 铍； 镁合金； 自由能
Key words：oxide film； beryllium； magnesium alloy
摘 要：在Mg9Al0.5Zn合金中添加0.3%铍， 镁合金液抗氧化性能得到极大提高， 可以直接暴露在大气中熔炼。 X射线衍射表明，合金表面有结构远较氧化镁致密的氧化铍生成， 从而导致整个氧化膜致密程度提高。 利用俄歇电子能谱(AES)进行氧化膜元素深度剖析发现，在含0.3%铍的镁合金液表面生成的氧化膜可以分为3个亚层： 最外层为氧化镁层；中间层为致密复合层， 由氧化铍、氧化镁和氧化铝组成； 内层为氧化膜向基体的过渡层。 热力学分析表明， 氧化膜中的这种分层结构同镁的高蒸汽压以及自由能变化吻合。
Abstract: After adding 0.3% beryllium, the oxidation resistance of the liquid magnesium alloy Mg-9Al-0.5Zn was enhanced greatly and it even can be melted exposingto air. X-ray diffraction indicated that beryllium oxide, which was much compacter and tougherthan magnesia, formed on the melt surface. AES depth profile analysis showed that the surface oxide film could be divided into three sublayers. The outside layer was mainly made up of magnesia, the middle layer, which consisted of beryllium oxide, magnesia and aluminum oxide, was compound and compact, the inside layer was a transition layer to substrate. Thermodynamic analysis indicated that the structure of the surface oxide film was accordant to the change of free energy and high vapor pressure of magnesium.
