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从以下几个方面对硅基陶瓷在燃气条件下的腐蚀行为和机理进行了分析。气氛中氧的分压大小是决定活化氧化与稳定氧化的关键。材料的纯度、烧结助剂以及孔隙率、孔隙尺寸及分布都会对氧化产生影响。燃气产物中的水蒸汽,会促进SiO_2氧化膜的析晶,加速氧化过程。燃气中的非金属杂质(S、Cl等)的存在,使得SiO_2膜遭到破坏。S和NaCl盐分反应后形成的Na_2SO_4沉积于材料的表面,从而导致热腐蚀,使得材料表面出现融蚀,加速氧化过程的进行。
The corrosion behavior and mechanism of Si-based ceramics under gas condition are analyzed from the following aspects. The partial pressure of oxygen in the atmosphere determines the key to activation and stabilization of oxidation. The purity of the material, sintering aids, and porosity, pore size and distribution all contribute to the oxidation. Water vapor in gas products will promote the crystallization of SiO 2 oxide film and accelerate the oxidation process. Gas in the presence of non-metallic impurities (S, Cl, etc.), making the SiO 2 film was destroyed. The formation of Na_2SO_4 formed after the salt reaction of S and NaCl is deposited on the surface of the material, resulting in hot corrosion, resulting in the ablation of the surface of the material and accelerating the oxidation process.