Manufacturing of titanium bipolar plates via stamping process for PEM fuel cells

Bipolar plates (BPPs) play an important role in PEM fuel cells from weight and cost points of view. In this paper, the manufacturing of titanium BPPs is studied experimentally and numerically. In this regard, a stamping die with a parallel pattern is conducted to perform the experiments. Then, the process was simulated using the finite element (FE) method. By comparing simulation and experiment results, it was found that the results are in good agreement and hereupon, the accuracy of the FE model was verified. To evaluate the formability of the titanium sheet (with a thickness of 0.1 mm), a set of FE experiments were designed using the response surface methodology (RSM). The die clearance, forming velocity, and friction coefficient were considered input parameters, and the maximum thickness reduction of the sheet was assumed to be the output. Contour plots were used to analyze the effects of the input parameters on the formability of the titanium sheet. The results revealed that a lower friction coefficient causes an increase in thickness reduction and finally tearing in the formed BPPs. Moreover, changing the forming velocity has no significant effect on the maximum thickness reduction.