Effect of substrate temperature on structural properties and corrosion resistance of carbon thin films used as bipolar plates in polymer electrolyte membrane fuel cells

In this work, the effects of substrate temperature that was changed from 100 to 500 °C on the structural, chemical and electrical properties of carbon films, prepared by direct current magnetron sputtering technique, on 316L stainless steel as bipolar plate had been investigated. Raman spectroscopy and scanning electron microscopy (SEM) were performed to study the structure and the morphology of the deposited films, respectively. The corrosion resistance and the electrical resistivity were carried out by using corrosion tests and four point-probe technique. The results show that the carbon films change the structure from amorphous to graphite-like by increasing temperatures. At the temperatures higher than 300 °C, the holes and porosities are formed on the film indicating a decrease of film quality. According to our results, corrosion resistance and electrical properties are depended strongly on the substrate temperature.