Search

In this study, the plastic deformation of a metallic bipolar plate with a serpentine flow field was investigated during the stamping process. The strain path and thickness distribution in 304 stainless steel bipolar plates with a thickness of 0.1 mm were determined. To achieve this purpose, the process was simulated by the ABAQUS commercial finite element code, and the validity of the results was evaluated by experimental tests under simple and lubricated conditions. According to the results, the flow of material has a significant effect on the thickness distribution of the central and lateral channels, and the thickness reduction percentage of the central channel in the longitudinal, diagonal, and transverse directions is higher than the lateral one. The maximum thickness reduction in the central channels is observed in the longitudinal direction, while the diagonal direction is considered as a critical direction for lateral channels. Due to the existence of the equibiaxial tension strain path in the diagonal direction, significant thickness reduction is observed in both the side and the rib zone of the channels. However, using lubricant led to a decrease in the thickness reduction percentage by improving the flow of material into the die cavity. Moreover, under lubricated conditions, the critical area is transferred from the side area of the channel in the longitudinal direction to the rib area in the diagonal direction

In the present study, the lubricated and non-lubricated stamping processes are used for fabrication of the metallic bipolar plates (MBPPs) with a thickness of 0.1 mm made of SS3316 with a serpentine flow field. Experimental tests together with the finite element (FE) model are utilized to define the directional thickness distribution. According to the results, considering the friction factor of 0.1 during the FE analysis is capable of providing accurate results in terms of thickness prediction under lubricated conditions. The largest thinning percentages in the modified conditions are found to be 27.02%, 30.40%, and 26.00% in the longitudinal, diagonal, and transverse directions, respectively, indicating that the diagonal direction is the most critical one. Finally, the effect of lubricating condition on wrinkling of the sample is investigated. According to the results, using the lubricated condition during the stamping process would lead to augmentation of the wrinkling of the bipolar plate and also, the wrinkling of bipolar plate’s margin was not symmetrical.