화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.156, No.1, B93-B98, 2009
Ni-Mo-Cr alloy for Interconnect Applications in Intermediate Temperature Solid Oxide Fuel Cells
As part of an effort to develop robust metallic interconnects for intermediate temperature solid oxide fuel cells, a Ni-Mo-Cr alloy is designed, prepared, and investigated in terms of its microstructure, mechanical property, thermal expansion behavior, oxidation resistance, and electrical property. The developed Ni-Mo-Cr alloy possesses a good thermal expansion compatibility with cell components with a coefficient of thermal expansion smaller than 14x10(-6)/degrees C at temperature below 800 degrees C. Upon oxidation at 750 degrees C in air, the oxide scale consisted of two kinds of oxide with densely packed and Cr-free NiMn2O4 on top of continuous Cr2O3, and MoNi3 intermetallic compound layer is formed underneath the oxide scale. Two stages of parabolic oxidation kinetics are observed with oxidation rate decrease after 250 h of oxidation, and good thermal cyclicability of the oxide scale is demonstrated. The area-specific resistance (ASR) as a function of oxidation time shows the similar tendency to the oxidation weight gain, giving an ASR at 750 degrees C of 4.48 m Omega cm(2) for oxidation at 750 degrees C in air for 1000 h and an extrapolated ASR of 22 m Omega cm(2) for 40,000 h oxidation.