The alloy design of metallic interconnect of SOFC-The thermal expansion property of iron-chromium alloy with the addition of nickel and manganese

• Main Authors: Ian-Bo Chen, 陳彥伯
• Other Authors: Shuang-Shii Lian
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/59088109283235618405

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 96 === The Iron-Chromium alloy metallic interconnect of solid oxide fuel cell(SOFC) has the advantages of high electric conductivity, good thermal conductivity, excellent imperviousness for hydrogen and oxygen to prevent direct oxidant, and good mechanical properties as well as easily to fabricate. However, there are some shortcomings in high-temperature applications; the differences of thermal expansion coefficient with ceramic solid electrolyte of fuel cell will create mismatch between interface, and chromium is apt to volatilize at high temperature, which are still needed to overcome In the previous experiment, we’ve already got that Fe-12Cr and Fe-16Cr are the better composition in thermal expansion behavior. To improve the characters of these two components being SOFC interconnect, we added some micro-element in these alloy. To obtain a good ferritic interconnect, all alloys are BCC in the experiment. Use thermodynamic software Thermo-Calc to make sure the construction of alloys. Choose nickel and manganese as micro-element to improve the character of alloys. We also change the concentration of the micro-elements in the experiment of thermal expansion, microstructure observation, and high temperature resistance. Fe-12Cr-0.5Ni exhibits the best thermal expansion behavior compared to YSZ. Fe-16Cr-1Mn is the best composition in the high temperature resistance experiment. In the ten compositions in the experiment, Fe-12Cr-1Mn is the most suitable composition for SOFC metallic interconnects.