Processing and mechanical properties of porous Fe-26Cr-1Mo for solid oxide fuel cell interconnects

Porous, ferritic steel was produced by blending, pressing and sintering Fe, Cr, Mo and NaCl powders. During sintering NaCl evaporated to form 40-58% interconnected open porosities, while the metal powders densified and interdiffused to create a nearly dense Fe- 26Cr-1Mo matrix (E-Brite, developed for solid oxide fuel cell interconnects). The foam compressive properties at ambient temperature were in good agreement with the Gibson-Ashby scaling laws for stiffness and strength and demonstrate high mechanical energy absorption. The foam compressive creep response at 850 °C under an argon atmosphere followed the same power law stress dependence as the bulk material, suggesting similar deformation mechanisms in each case. Creep data under argon were compared with a variational composite model and a simple unit cell model taking into account thicker nodes connecting slender struts.