Seal glass compatibility with bare and (Mn,Co)3O4 coated Crofer 22 APU alloy in different atmospheres

To prevent gas mixing and leakage during solid oxide fuel/electrolyzer cell operation, the interconnect/seal glass interface should bond well and remain stable. A SrO–La2O3–Al2O3–SiO2 (SABS-0) seal glass has been bonded to bare Crofer 22 APU alloy and (Mn,Co)3O4 coated Crofer 22 APU alloy. The stability of the interconnect/SABS-0 interface has been studied in air and H2/H2O atmospheres at 800 °C for 1000 h. The interconnect/seal glass interaction involves the oxidation of the bare and (Mn,Co)3O4 coated Crofer 22 APU alloy surfaces, inter-diffusion of elements, chemical reaction, and the devitrification of the SABS-0 glass. The study shows that the thermal treatment atmosphere greatly affects the interfacial stability of both bare Crofer 22 APU/SABS-0 and (Mn,Co)3O4 coated Crofer 22 APU/SABS-0 samples. The interfacial stability is better in the H2/H2O atmosphere for both samples. The instability of the (Mn,Co)3O4 coating under the thermal treatment conditions degrades the interfacial compatibility of the (Mn,Co)3O4 coated Crofer 22 APU/SABS-0 sample.