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.