Decrease of Electrical Conductivity Activation Energy of Co-coated AISI ۴۳۰ Alloy for the Application of SOFCs

The application of conductive coatings on ferritic stainless steel can decrease electrical conductivity. Theaim of this research was to investigate the electrical conductivity of cobalt coated AISI ۴۳۰ ferritic stainlesssteel by pack cementation technique. Coated coupons were analyzed using scanning electron microscopy(SEM). Electrical conductivity of the coated substrates was measured as a function of temperature byoxidizing the samples from room temperature to ۷۰۰ ºC. Also electrical conductivity has been measuredas a function of oxidation time during isothermal oxidation at ۷۰۰ ºC. Results showed the increase oftemperature caused to the decrease of electrical conductivity and also, the coating layer converted to cobaltspinels during annealing in isothermal oxidation. The formation of MnCo۲O۴, CoCr۲O۴, CoFe۲O۴ and Co۳O۴spinels improved electrical conductivity activation energy of coated substrates (۰.۰۳ eV) compared touncoated substrates (۰.۰۳۹ eV).

Keywords:

Cobalt , AISI ۴۳۰ , Electrical conductivity activation energy , Solid oxide fuel cell