Properties of Fe–Cr based alloys as interconnects in a solid oxide fuel cell

Four kinds of Fe-Cr based alloys were investigated in this paper. The thermal expansion coefficients of the four samples at 900 °C were between 11 and 13 × 10−6 cm cm−1 K−1. The coefficient of sample Fe-Cr-4 was close to that of yttrium stabled zirconia (YSZ). Compared with traditional alloys, the new type of Fe–Cr based alloys had decreased thermal expansion coefficients. With the increase of oxidation time, the weight gains of Fe-Cr-1 and -4 tended to be stable. The oxide scale of 3Cr2O3·Fe2O3 formed on the surface of Fe-Cr-1 and -4 was inactive and helpful to restrain the samples from internal oxidation. But the FeCr2O4 and Cr1.3Fe0.7O3 formed on the surface of Fe-Cr-2 and -3 had no such effective restraint mechanism. Fe-Cr-1 and -4 exhibited better oxidation resistance than Fe-Cr-2 and -3.