Application of a direct laser melting process for fabricating a micropattern in bipolar plates used in direct methanol fuel cells

摘要

Direct laser melting (DLM) technology is applied to fabricate the micropattern of bipolar plates in a direct methanol fuel cell (DMFC). For the micropatterning, a DLM process with 316L stainless steel (SS316L) powder has been used. For the target point of 1 mm melt height, the DLM process conditions are optimized and an eight-layer structure is successfully formed. The performance of a bipolar plate made by the DLM micropatterning is compared with a numerical control (NC)-machined bipolar plate. For the DLM micropatterned bipolar plate, the kinetic energy in the fuel causes a more rapid chemical reaction due to the increased surface area of rough side walls. The smaller fluid rate loss enhances circulation of the fluid and, consequently, the efficiency of the micropatterned bipolar plate made by the DLM process is significantly improved. Furthermore, the use of SS316L powder material as a micropatterned material reduces the fabrication cost as well as size of the fuel cell stack.