The residual stress in a brazed joint of metallic bipolar plates of PEMFC: A numerical model

• Stress gradient is generated at the interface between the plate and filler metal.
• The clamping pressure has little influence on residual stress in brazed joint.
• The residual stress decreases along with the brazing gap increasing.
• The residual stress in brazed joint with SAC305 is smaller than that with BNi-2.

Bipolar plates are regarded as the core of the proton exchange membrane fuel cell. In order to obtain a connected stainless steel bipolar plate with low residual stress and small deformation, the brazing process is commonly used for bipolar plate connection. In this study, a numerical model was developed to calculate the residual stress in a brazed joint. Clamp pressure, brazing gap, and solder type were investigated. The results showed that clamping pressure had little influence on residual stress and the residual stress decreased with an increase in the brazing gap, which provided a reference for controlling brazed residual stresses for stainless steel bipolar plates.