Residual Stress and Dimensional Deviation in a Commercially Pure Titanium Thin Bipolar Plate for a Fuel Cell Using Laser Power Bed Fusion

In this study, the feasibility of commercially pure (CP)-Ti bipolar plates for fuel cells were assessed by designing, manufacturing, and evaluating thin plates fabricated through the laser powder bed fusion (L-PBF) technique. The width, height, and thickness of thin CP-Ti plates were carefully considered in its design to ensure comprehensive evaluation. The maximum displacement was measured through blue light scanning in accordance with the building direction. The finite element model and experimental results showed that the building layer per volume has a linear relationship with the maximum displacement and maximum residual tensile stress along the building direction. Thin plates with a high aspect ratio (198 x 53 x 1.5 mm) had the lowest maximum displacement (0.205 mm) when building in the height direction and had a high correlation coefficient with the finite element model (0.936). Proper aspect ratio design and building strategy enable highly accurate manufacturing of CP-Ti thin plates for fuel cell systems.