Evaluation of Properties of Crofer Stainless Steel Produced by Mechanical Alloying for Using as Interconnect Plates of Solid Oxide Fuel Cells

This study has examined the properties of Crofer 22APU stainless steel produced by mechanical alloying for using as interconnect plates in solid oxide fuel cells.This alloy was produced by mixing the source powders and mechanical alloying for 40 hours. For creating a sample with high density, spark-plasma sintering was applied at 1100 °C and 50 Mpa stress for 10 minutes. To achieve the desired properties such as low electrical resistance and high oxidation resistance, a number of samples were coated by manganese-cobalt using electrodiposition technique at current density of 150 mA/cm 2 for 40 minutes. Then, considering the properties required for an interconnect plate of solid oxide fuel cell, oxidation resistance and electrical resistance of the coated and uncoated samples were investigated. Oxidation behavior of the coated and uncoated samples, after 100 hours oxidation in air at 800°C did not follow any rule and its curve was a sinus type. The electrical resistance of uncoated samples was in the range of 0.1-0.2 mOhm.cm2, but the electrical resistance of the coated samples after 100 h oxidation reached to a less ammount than that of the corresponding uncoated ones. The alloy produced by mechanical alloying method, compared with commercial ones produced by casting methods, showed similar oxidation behavior after 100 h oxidation, but it had a surface electrical resistance far less than its commercial ones.