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通过800℃高温下的氧化实验,结合X射线衍射仪、扫描电子显微镜、电子探针显微分析仪,研究了金属Al复合Fe3Si有序合金的高温氧化行为.结果表明:元素Al很好地改善了Fe3Si的高温抗氧化性能,其氧化动力学曲线由抛物线加直线的混合规律转变为完全的二次抛物线型,且氧化增重降低了近一个数量级;氧化动力学主要机制是Al通过亚晶界由基体内部向外扩散并形成保护性氧化膜Al2O3,阻止Si和Fe的向外扩散氧化;同时氧化膜保护性的好坏还受到氧化产物Al2O3的相结构以及扩散通道等诸多因素的影响.
The high-temperature oxidation behavior of Al composite Fe3Si ordered alloys was investigated by means of oxidation experiment at 800 ℃ and X-ray diffraction, scanning electron microscopy and electron probe microanalysis. The results showed that Al The oxidation kinetics of Fe3Si at high temperature showed that the oxidation kinetics curve changed from a parabola to a straight line to a complete quadratic parabola and the oxidation weight gain was reduced by nearly one order of magnitude. The main mechanism of oxidation kinetics was Al through subgrain It diffuses from the inside of the substrate and forms a protective oxide film Al2O3 to prevent the outward diffusion and oxidation of Si and Fe. Meanwhile, the protective properties of the oxide film are affected by many factors such as the phase structure of the oxidation product Al2O3 and the diffusion channel.