Fabrication and Oxidation Behavior of the Cu–Fe Spinel Coating for SOFC Steel Interconnect Applications
Yue Pan, Yuting Liu, Dongyang Shi, Jian Wang, Yongmin Xie, Ruixiang Wang, Zhifeng Xu
Abstract
Cu–Fe spinel has recently attracted considerable interest as a protective coating for solid oxide fuel cell steel interconnects. In this study, Cu–Fe spinel coatings were deposited on SUS 430 steel substrates via a coating route of the dip-coating process. Oxidation tests were investigated in laboratory air at up to 800 °C for five (5) 24 h (24 h) cycles up to 120 h. The area-specific resistance (ASR) of the samples was measured by a standard four-probe method. The experimental results indicated that the CuFe 2 O 4 spinel powders with fine grain size were successfully synthesized from the sol–gel method. The oxidation kinetics of Cu–Fe spinel-coated steel obeyed a parabolic law, showing a parabolic rate constant of 1.38 × 10 –14 g 2 cm –4 s –1 . The ASR value of the coated samples was about 11.2 mΩ cm 2 at 800 °C. The Cu–Fe spinel coating improved both the high-temperature oxidation resistance and the electrical conductivity of the steel interconnects.