Microstructural and micromechanical characterization of intergranular oxidation in Fe-15Cr alloy

Fe-Cr alloy has great potential as an interconnect material for SOFCs at temperatures up to 800 degrees C, with Cr providing excellent oxidation resistance through the formation of a protective chromium oxide layer. However, internal brittle oxides formed at grain boundaries (GBs) can lead to severe cracking and cause material failure. Here, we report the formation of internal GBs oxide in an Fe-15 wt%Cr alloy. We carried out microstructural and chemical characterization of the intergranular oxide and performed micromechanical testing and FEM simulation to study the fracture behavior at the GBs. Our findings provide insights for improving the oxidation resistance in the material design.