Formability Evaluation of Microchannels of Aluminum Bipolar Plate Stamped Under Pulsating Load

Abstract

The weight of a bipolar plate is one of the most crucial properties from the viewpoint of improving the power density of a protonexchange membrane fuel cell (PEMFC) stack. Aluminum alloys have good material characteristics such as low electrical resistivity, high thermal conductivity, and low density. Furthermore, they are less expensive and easily machinable compared to graphite when used for fabricating bipolar plates. In this study, the use of AA5052 for fabricating a bipolar plate was investigated. The results of the feasibility experiments conducted to develop fuel cells with AA5052 bipolar plates having multiple microchannels were presented. The formability of microchannels under various types of pulsating loads was estimated for different punch loads and die radii using 0.3 mm thick AA5052 sheets. For a 0.1 mm die radius, the optimum formability was obtained for five cycles of sine wave dynamic loading with a maximum load of 90 kN. The experimental results demonstrated the feasibility of the proposed technique for fabricating bipolar plates.