Forming of Archimedean Spiral Bipolar Plates using Hot Gas Forming Process and its Characteristics Evaluation

Membrane fuel cells are considered as highly efficient energy generators that do not cause environmental pollutions. In this regard, bipolar plates are the main component of the fuel cells given that they have the following required characteristics; good flexural strength and high electrical conductivity. In the current study, some experiments have been carried out to investigate the forming process of Archimedean spiral aluminum bipolar plates. Thus, an experimental setup is designed and fabricated in order to make the process possible. Additionally, the effects of process parameters on the geometrical characteristics of the product are studied using a response surface methodology and as a result, the optimum values are specified. Thus, 5 different levels were considered for 3 input parameters. Experimental results show that gas temperature has the most significant influence on the channel depth and thinning percentage, whereas the time of applying gas pressure has the least effect. In fact, when the gas temperature increases from 200˚C to 400˚C, the channel depth increases from 0.28 to 0.84 mm. Finally, the optimum process parameters are specified as follows: gas pressure of 38 bar, temperature of 308˚C, and process time of 10 sec.