Thermodynamics and Kinetics of Immersion Behavior of IC221M Alloy as a Separator in Molten Carbonate Fuel Cell

The thermodynamic and kinetic behavior of nickel aluminide IC221M alloy in molten eutectic of lithium/sodium carbonate was investigated. The nickel aluminide IC221M alloy was produced by vacuum arc re-melting (VAR) method. Surface layer products formed after immersion in molten carbonate at 600, 650 and 700 oC were examined by SEM and XRD. The results along with weight difference calculations showed that IC221M alloy doesn’t have a good resistance at 650 and 700 oC . It was evidenced that the destruction of the alloy is a diffusion-controlled process. The activation energy of the process was calculated to be 423 kJ/mol and the process kinetics were controlled by aluminum diffusion in γ´ phase.