Compatibility of a seal glass with (Mn,Co)3O4 coated interconnects: Effect of atmosphere

The interfacial compatibility of an alkaline earth silicate glass (SABS-0) with (Mn,Co)3O4 coated Crofer 22 APU and AISI 441 interconnects has been investigated at 800 °C for 100 h in argon, air, and H2/H2O atmospheres. Detailed microstructural and diffusion studies show that the interfacial compatibility is better for the (Mn,Co)3O4 coated Crofer 22 APU alloy but deteriorates from the H2/H2O to the air or the argon atmospheres for both alloys. Thermal treatment atmosphere mainly affects the inter-diffusion of Cr in the Crofer 22 APU alloy. The (Mn,Co)3O4 layer cannot eliminate the undesirable Cr diffusion for the Crofer 22 APU alloy regardless of the thermal treatment atmosphere. The interfacial reaction for the AISI 441/SABS-0 is so severe that the inter-diffusion of the elements is less significant. Oxidation of the AISI 441 alloy degrades the (Mn,Co)3O4 coating stability and increases the reaction of the coating with the SABS-0 glass, leading to inferior interfacial compatibility.