A New Forming Method of Titanium Bipolar Plate for PEMFC: Multi-step Rolling Forming
摘要
Fuel cell is an important equipment to promote green development, and bipolar plate is one of the most critical components. The roll forming technology of titanium bipolar plates is studied and a multi-step roll forming method for titanium bipolar plates is proposed. The force and deformation of the titanium bipolar plate during roll forming are analyzed, the forming effect is evaluated in terms of material thinning, cross-sectional profile and forming filling rate, and the feasibility of roll forming is verified by comparing with stamping. Furthermore, the influence of roll forming scheme on forming quality is explored for the first time. The results indicate that compared to conventional single-step roll forming, the multi-step roll forming method reduces the maximum thinning rate by nearly 5% and decreases the true strain in stress concentration regions, such as fillets, by more than 22%. Multi-step roll forming has an advantage over stamping in terms of the thickness uniformity, and the maximum thinning rate is about 4% lower. Starting with the middle channels proves to be the most effective approach for minimizing thinning, with a maximum thinning rate of less than 20%, while achieving a filling rate of 83.84% and improved forming quality.