| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 102 === The present study focuses on developing a materials system for the SOFC interconnect application. This study has utilized a low thermal expansion material HRA929 as the substrate and designed a coating composition based on CALPHAD-based phase diagram simulation at 800°C. The ingots of coating compositions were prepared by vacuum arc melting (VAM); coating process was magnetron sputtering, and a 1 m thin film of the coating was deposited on the surface of HRA929. Isothermal oxidation tests were conducted to observe the growth of oxide scale and interdiffusion between coating and substrate. Four-wire method was employed to measure the high temperature area specific resistance (ASR) of the system. Thermal mechanical analysis was performed to measure the coefficient of thermal expansion (CTE). The ASR performance and oxidation resistibility of our materials system were comparable to commercialized material, while the CTE of coating and substrate was similar. The phase stability of the interface between coating and substrate was stable after 100 hours exposure at 800°C. Moreover, this materials system exhibited phase stability at the interface and interdiffusion was minimized, hence the life of acting as interconnect can be prolonged. Furthermore, the compatibility of coating and LSM was good and the formation of (Mn,Cr)3O4 can suppress the outward diffusion of Cr.
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