Proton Exchange Membrane Fuel Cells (PEMFCs) are of interest in transportation applications due to low operating temperature and high performance. Nickel foam flow fields are considered instead of graphite and metal-based flow channels due to high corrosion resistance, low weight, uniform distribution of reactants to catalyst sites, and ease of manufacturing. A fuel cell stack fixed to the mainframe of a vehicle experiences extreme vibrations due to road unevenness, acceleration, and braking. The vehicular vibrations will result in small relative displacements within the stack. The relative slippage between the open-cell metal foam flow fields and other parts in a fuel cell causes fretting damage. The durability of the parts associated with the material degradation results in a loss in performance of PEMFC during prolonged service and is a major concern. This study is directed towards understanding the possible relative displacements between components due to vehicular vibrations through numerical simulation. Besides, the material degradation due to fretting in nickel struts is investigated using simulated experiments.

The numerical analysis of PEMFC subjected to external loads revealed a relative slippage of a few tens of microns between the components and varies in different regions of the PEMFC stack. The microcontact fretting experiments conducted indicate the variation in friction and wear characteristics in the nickel foam struts. The fine wear debris of size less than ten microns are generated during service. The size of debris is large enough to block the voids of the microporous layer in GDL and affect the performance of PEMFC in due course. The micro mechanisms of wear debris generation and the amount of debris generated in a 50-cell stack for about 9000 h of operation are discussed.