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研究了铁在高温氧化过程中的扩散机理,通过氧化增重试验进行了动力学计算;通过X射线衍射,对晶格参数进行了计算,提出高温下Fe的扩散以及Mg对高温氧化的抑制作用机理。结果表明:Mg~(2+)填充氧化层内层FeO的晶格空位,降低了空位浓度,减小了阳离子穿过FeO层的扩散速率,从而降低了氧化速率。Mg~(2+)取代氧化层外层Fe_3O_4中氧八面体中心的Fe~(2+),生成Mg_xFe_((1-x))O和Mg_xFe_((1-x))Fe_2O_4,通过提高八面体扩散能垒,可以降低阳离子穿过该层的扩散速率。
The diffusion mechanism of iron during high temperature oxidation was studied. The kinetics was calculated by oxidation weight gain test. The lattice parameters were calculated by X-ray diffraction. The diffusion of Fe at high temperature and the inhibition of Mg oxidation at high temperature mechanism. The results show that the lattice vacancy of FeO in the Mg2 + -filled oxide layer decreases the vacancy concentration and the diffusion rate of the cation through the FeO layer, thus reducing the oxidation rate. Mg 2+ can replace Fe 2+ in the octahedron of Fe 3 O 4 in the outer layer of oxide layer to form Mg_xFe_ ((1-x)) O and Mg_xFe_ ((1-x)) Fe_2O_4, The diffusion barrier reduces the rate of diffusion of cations through the layer.