Sputtered Ni coating on ferritic stainless steel for solid oxide fuel cell interconnect application

Ni coating was deposited on ferritic stainless steel by means of magnetron sputtering method for intermediate temperature solid oxide fuel cell (SOFC) interconnects application. The steel with the sputtered Ni coating was evaluated at 800 °C in air corresponding to the cathode environment of SOFC. The oxidation investigations indicated that the oxidation rate of the steel with Ni coating was close to that of the bare steel after 100 h thermal exposure, in spite of its mass gain being higher than that of the bare steel. The oxide scale formed on it consisted of double layers containing an inner layer of Cr2O3 and an outer layer of NiO with (Ni,Fe,Cr)3O4. The area specific resistance (ASR) of the double-layer oxide scale was lower than that of the Cr2O3 scale thermally developed on the bare steel.