Effects of N2 Pressure on Properties of Titanium Nitride Films By Filter Cathodic Vacuum Arc for Bipolar Plates in PEM Fuel Cells.

This research is aimed to synthesize titanium nitride (TiN) thin films on stainless steel 304 using metal vacuum arc surface coating technique. A titanium rod is used as cathode. Plasma is generated by applying the arc pulse voltage of 450 V between the electrodes in N2 atmosphere. The pressure of N2 is varied from 10-5 to 10-3 torr when compare with uncoated-stainless steel 304. The bias voltage for substrate is -1 kV. Then the properties of the films are investigated. Firstly, microstructures of TiN thin films are indentified by X-ray diffraction method (XRD) and the cross-section scanning electron microscopy (SEM) is used to measure the thickness. Secondly, the corrosion resistance is examined by electrochemical test in 1 M H2SO4 solution at 25 degrees C. The electrical resistivity is analyzed by interfacial contact resistance measurements.