Oxidation behavior of metallic interconnect coated with La-Sr-Mn film by screen painting and plasma sputtering

Two Fe-based alloys, specific company developed and designated as Crofer22APU and ZMG232, have been extensively evaluated and considered as outstanding metallic interconnect materials. Both these alloys contain significant and minute amounts of elemental Cr and La, respectively. In this study, they are coated with films of La-Sr-Mn (LSM) using two methods, screen painting and plasma sputtering, to determine the effect of LSM on corrosion resistance and electrical resistivity of Crofer22APU and ZMG232. They were then treated in a simulated oxidizing environment at 800 degrees C for 200 h. Analytical results indicate that the LSM film changed the oxidation behavior of the base alloys, Crofer22APU and ZMG232. The bare alloys formed Cr2O3, while the coated alloys produced (Mn, Fe) Cr2O4. The electrical resistance of the former oxide at high temperature is several thousand times higher than that of the latter oxide. This remarkable effect of the LSM film on the electrical characteristics warrants further in-depth research. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.