Interaction mechanisms between slurry coatings and solid oxide fuel cell interconnect alloys during high temperature oxidation

► Six coatings as corrosion protection on a Fe22Cr alloy at 900°C in moisturized air. ► Parabolic oxidation rate constant reduced with 50–90% of that for uncoated alloy. ► Three types of interaction mechanisms between oxide scales and coatings classified. Six different coatings consisting of fluorite-, corundum-, spinel- or perovskite-type oxides were deposited on a Fe22Cr alloy (Crofer 22APU) and oxidized at 900°C in moisturized air. Five of the coatings prevented break-away oxidation otherwise observed for the uncoated alloy, and the parabolic oxidation rate constant was reduced with 50–90% of that for uncoated alloy. One coating consisting of MnCo2O4 did not significantly affect the oxidation rate of the alloy, and just as for uncoated samples break-away oxidation occurred for MnCo2O4 coated samples. The interaction mechanisms between the growing oxide scales and applied coatings can be classified according to three types.