A new process of forming metallic bipolar plates for PEM fuel cell with pin-type pattern

摘要

Bipolar plates are the most important and expensive components of a fuel cell. These plates can be fabricated by different processes, such as machining graphite plates, producing composite materials, and forming metallic sheets. Due to some benefits of the metallic plates, especially with stainless steel sheets, they have recently been more noticeable. There are various flow field patterns with different applications in these plates, being classified into simple and complex ones in forming process for spiral or parallel and multiarray pin-type examples, respectively. In this study, hydroforming, stamping, and hybrid hydroforming-stamping methods have been used to investigate the forming capability of multi-array pin-type pattern, and, consequently, to compare the results of filling percentage and thickness distribution of these methods. According to the results, samples formed by the hybrid method have shown desirable filling percentage and thickness distribution. The effect of preload pressure of this method on thickness distribution has subsequently been studied and it was observed that the thickness distribution of the formed sample was enhanced by maximizing the pressure of the hydroforming stage.