纯钛燃料电池双极板软模成形工艺研究

目的 研究软模成形过程中塑性应变比r值对双极板成形深度及壁厚的影响，探究不同工艺参数对双极板尺寸的影响规律。方法 通过单向拉伸实验得到纯钛极薄带的力学性能参数，然后采用橡胶软模成形方法制备纯钛燃料电池双极板，利用光学显微镜对制备的双极板尺寸及壁厚进行测量并深入分析。结果 TD取向的r值最大为2.56，沿该方向成形时，纯钛极薄带在载荷为300 kN、软模硬度为77HA条件下得到的双极板深度最大，为0.293 mm;同时，其壁厚减薄较小，在减薄最严重的位置壁厚减薄率仅为13.52%。结论 较大的载荷与适宜的软模硬度能得到较好的双极板深度，对双极板周期无影响;双极板深度、壁厚与r值有关，r值越大，纯钛极薄带抵抗壁厚减薄的能力越强，成形深度越大。

Soft Mold Forming Process of Pure Titanium Bipolar Plate for Fuel Cell

The work aims to study the effects of plastic strain ratio r on the forming depth and wall thickness of bipolar plate during soft mold forming process and explore the effect law of processing parameters on the size of bipolar plate. The mechanical properties of pure titanium strip were obtained through uniaxial tensile test, and the pure titanium bipolar plate for fuel cell was prepared by rubber soft mold forming method. Optical microscope was used to measure and analyze the size and wall thickness of the bipolar plate. The maximum r value on TD direction was 2.56. Along this direction, the deepest depth of bipolar plate (0.293 mm) was obtained under the load of 300 kN and soft mold hardness of 77HA. At the same time, the wall thickness reduction was small, and the wall thickness reduction rate was only 13.52% at the most serious position. Larger load and appropriate soft mold hardness lead to better bipolar plate depth, and have no effect on bipolar plate cycle. The depth and wall thickness of the bipolar plate are related to the r value. The greater the r value is, the better the ability of the pure titanium ultra-thin strip to resist the wall thickness reduction, and the greater the forming depth.