本論文是以鐵基(iron-based alloys)及鎳基(nickel-based alloys)為基底的金屬合金為研究對象，且皆為固態氧化物燃料電池(SOFC)之金屬連接板材，實驗是將材料置於SOFC運作的溫度800℃並通入空氣氣氛的操作環境下，比較鐵基(iron-based alloys)及鎳基(nickel-based alloys)合金的高溫氧化行為和熱膨脹係數間的差異。並使用掃描式電子顯微鏡(SEM)、電子微探儀(EPMA)及X-Ray繞射(XRD)等分析儀器來觀察氧化層之顯微組織。使用熱機械分析儀(TMA)及熱重分析儀(TGA)來量測熱膨脹係數舆氧化層的成長速率。研究發現氧化層皆含有相當比例的Cr元素，且表面會生成Cr-O的化合物，其中材料表面也會生成Mn–Cr–(Fe)spinel析出相與Cr2O3析出強化相，此外在氧化速率結果顯示出Crofer22與ZMG232等兩種鐵基合金相較於其他合金氧化速率較慢，有助於SOFC導電的穩定性。在鐵基(iron-based alloys)合金中Crofer22與ZMG232與SOFC其他元件的CTE也顯的最為接近與匹配。 Ten iron-based alloys and nickel-based alloys were subjected to oxidation treatment in hot air environment for various period of time. All of them were alloys that can be applied to interconnect of solid oxide fuel cell (SOFC). The resulted oxide scale was analyzed by scanning electron microscopy (SEM), electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). The parabolic growth rates of oxide scale layer were verified from the thickness of oxide scales by thermal gravimetric analysis (TGA) depth profiles. The high operating temperature of SOFC requires that the coefficients of thermal expansion (CTE) of the components by thermal mechanical analysis (TMA) thermal stresses. In order to prevent the destruction in the structure of SOFC caused by thermal stress, the CTE of its component should be match when it is operated under high temperature. In study, all the alloys contain a certain amount of Cr, and Cr2O3 and (Mn, Fe)Cr2O4 spinel compound are produced on the surface oxide. Other spinels containing Cr, Mn, Fe, and Ni are also formed on it; the compositions depend on the composition of the steels and any other materials in contact with the interconnects. As a result, it is needed to understand the role of spinels in the oxidation of interconnects. The oxide scales on Crofer22 and ZMG232 exhibited the lowest area-specific resistance, and that is consistent with its slower oxidation kinetics. It stability of electrical conductivity will helpful in SOFC. The CTE of iron-based alloys (e.g. Crofer22 and ZMG232) are matched in SOFC other components.
