固態氧化物燃料電池（SOFC）系統在運轉時，隨著工作溫度的變化，由於不同組件間具有不同的熱膨脹係數值，加上電池堆溫度分佈不均勻，會產生不可忽視的熱應力。當SOFC電池堆處在高溫穩態工作階段時，熱應力會造成電池堆結構件產生潛變變形；另外，在SOFC的運轉過程中亦會因為開機、待機或停機的狀態，反覆的升溫至高溫工作環境及降溫回到室溫，產生的循環熱應力亦會使電池堆結構件產生熱機疲勞損傷，因此，在開發SOFC電池系統的過程中，有必要探討熱循環－潛變交互作用對電池堆結構件耐久強度之影響。依此，配合核研所開發適用於金屬支撐型固態氧化物燃料電池（MS-SOFC）之高溫硬銲合金材料，本計畫將對硬銲合金材料與金屬連接板之接合件進行熱循環－潛變交互作用試驗，分析相關破損機制，進而建立MS-SOFC電池堆接合件耐久結構強度評估模式，作為核研所設計與開發MS-SOFC電池堆組件結合之參考，並協助核研所發展改善電池堆接合件耐久強度之技術。 ;To greatly reduce the start-up time of planar solid oxide fuel cell (pSOFC), it is feasible to use metals as brazing sealant, which has a higher tolerance for fast changes of operating temperature. Therefore, braze seals have been applied to metal-supported solid oxide fuel cell (MS-SOFC) for sealing the anode-electrolyte-cathode assembly and metallic interconnects thanks to a lower operation temperature in MS-SOFC. However, the high-temperature operating conditions could generate significant thermal stresses in a pSOFC stack due to thermal mismatch between components. Such thermal stresses can cause creep deformation and damage in SOFC components at steady operation stage. In addition, during periodic operation of a pSOFC system, the SOFC components are also subjected to cyclic temperature change between room temperature and the high working temperature at steady operation stage. As such interaction of cyclic temperature change and creep mechanism may accelerate degradation of the sealant/interconnect joint robustness, it is necessary to assess such effect on the structural integrity and cycle life of MS-SOFC stack. The aim of this study is thus to investigate the interaction of thermal cycle and creep mechanism in the braze seal/metallic interconnect joint of MS-SOFC. Based on the thermal cycle-creep testing results, it is intended to develop an effective mechanical life assessment method for braze seal/metallic interconnect joints, which can be applied to the MS-SOFC system being developed at the Institute of Nuclear Energy Research.
