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烧结致密的α－ＳｉＣ在静态空气气氛中经１２００℃×１０ｈ氧化，在其表面形成一层致密的氧化膜，该层氧化膜具有β－方石英晶体结构．氧化膜的生长由Ｏ２通过ＳｉＯ２晶格间隙的扩散控制． ＳｉＣ／Ｆｅ界面反应剧烈，界面稳定性极差. ＳｉＣ表面氧化能有效阻挡该界面反应，提高其稳定性． ９００℃以下长时间保温，氧化 ＳｉＣ／Ｆｅ界面十分平直，无明显反应的迹象，界面十分稳定．但随着温度的升高，界面稳定性越来越低，在局部区域内开始发生反应，并逐渐扩展到整个界面，最终导致氧化膜遭到破坏，失去阻挡界面反应的作用．氧化膜与ＳｉＣ、Ｆｅ热膨胀系数不匹配所造成的应力集中，以及氧化膜中存在的孔隙可能是导致氧化膜在热处理过程中遭到破坏的主要原因．
The dense α-SiC sintered in a static air atmosphere at 1200 ℃ × 10h oxidation, the surface of the formation of a dense oxide film, the layer of oxide film has β-cubic quartz crystal structure. The growth of the oxide film is controlled by the diffusion of O2 through the interstitial lattice of SiO2. The reaction of SiC / Fe interface is fierce, and the interface stability is extremely poor.The oxidation of SiC surface can effectively block the interface reaction and improve its stability. 900 ℃ for a long time insulation, oxidation of SiC / Fe interface is very straight, no obvious signs of reaction, the interface is very stable. However, with the increase of temperature, the interfacial stability is getting lower and lower, and the reaction begins to occur in the local area and gradually expands to the entire interface, eventually resulting in the destruction of the oxide film and losing the function of blocking the interface reaction. The stress concentration caused by the mismatch between the thermal expansion coefficient of SiC and Fe, and the porosity existing in the oxide film may be the main reason that the oxide film is destroyed during the heat treatment.