Abstract
Spinels have excellent electrical conductivity and good thermal expansion coefficient (TEC) matching to the SOFC metallic interconnects. Under solid oxide fuel cell (SOFC) operating temperature (600_850 ºC), the use of ferritic stainless steels results in Cr migration via Cr2O3 scale into the cathode where cathode poisoning is caused. In order to minimize poisoning of the cathode, the interconnect material has to be coated.In the present study, Co-Fe spinel powder was synthesized through a solid state reaction. In the next step, the electrophoretic deposition (EPD) method was used to apply the CoFe2O4 spinel, as an oxidation-resistant layer, on SUS 430 in a potential of 300 V. The coated and uncoated samples were then pre-sintered in air at 900 °C for 3 h followed by cyclic oxidation at 800 °C for 500 h. In order to study the effect of reducing pre-sintering atmosphere on oxidation resistance, the coated specimen was pre-sintered in 5% H2/Ar at 900 °C for 3 h followed by cyclic oxidation at 800 °C for 500 h. The investigation of the oxidation resistance of the samples revealed that the Kp for pre-sintered coating in 5% H2balArwas nearly 2270 times smaller than that of the one pre-sintered in air.
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