Properties of C-doped CrTiN films on the 316L stainless steel bipolar plate for PEMFC

C doped CrTiN films were deposited on 316L stainless steel by magnetron sputtering technology to investigate corrosion resistance and electrical conductivity. The sputtering current of the C target alter to obtain various C contents. The carbon target currents are 0 A, 3 A and 6 A, respectively. The result of SEM confirms that deposited films have a dense and uniform microstructure. CrTiN coating consist of Cr, CrN and TiN phases. With the increase of C carbon target currents, Cr crystal structure vanishes, and the amorphous carbon and carbides appear. The result of the potentiodynamic polarization test in the simulate PEMFC environment reveals that C doped CrTiN coating can improve samples’ corrosion resistance. At 1.1 V (vs. SHE) potentiostatic tests, the C-6A has the lowest current density, 6.09 × 10−7 A/cm2. Interfacial contact resistance decreases with the addition of C atoms. The C-6A coated sample has the lowest interfacial contact resistance values, 5.5 mΩ cm2. •C doped CrTiN films with different C contents is deposited on stainless steel.•Cr crystal structure vanishes, and the amorphous carbon and carbides appear.•C doped CrTiN coating can improve samples' corrosion resistance.•Interfacial contact resistance decreases with C incorporation.