Numerical analyses of Manufacturing of an AA8111 Pin-shaped Bipolar Plate by Hot Metal Gas Forming

In this paper, to fabricate a pin-shaped bipolar plate for a proton exchange membrane fuel cell, the deformation behavior of a thin 8111 aluminum alloy sheet by the hot metal gas forming (HMGF) process was investigated. The effect of gas pressure, forming time, pin diameter, pin height, and die fillet radius on the specimen profiles, as well as the thickness distribution were analyzed by finite element method using ABAQUS 6.10 software. In addition, experimental tests were performed to validate numerical outputs. The results indicated that the sheet thinning rate grew sharply by the gas pressure exceeding 4 MPa. The specimens were cracked following decreasing the die fillet radius to 0.1 mm. Furthermore, the die filling rate was high at the beginning of forming time and then diminished gradually after 1000 sec. Moreover, the thickness reduced sharply by augmenting the ratio of pin height to diameter to over 0.4. Finally, perfect specimens were produced in experiments, which verified the feasibility of fabricating a pin-shaped bipolar plate out of a thin AA8111 sheet by the HMGF process.