Metal 3D printing of new structured surface BPPs for PEMWEs by Cold Gas Spraying.

For decades, thermalspraying has been used for the production of coatings all over the world because of its versatility in industry for machinery and tools preservation, surfaces protection and corrosion prevention. The study, here shown, demonstrates the possibilities of Cold Gas Spray (CGS) for the cost-reductive production of a component of PEMWEs, the Bipolar Plates (BPPs), by metal 3D printing. In this process, the incorporation of a mask between the nozzle exit and the substrate will drastically transform the BPP production to a very fast and automatic bottom-up process where material is deposited layer-by-layer for building up the three-dimensional flow field patterns from a flat surface. The aim of this work is to CGS deposit Ti, and other metals, for creating 3D patterned surfaces corresponding to the flow fields of BPPs used in PEMWEs. Microstructure and topography of 3D printed BPPs will be inspected by microscopy techniques, whilst adhesion and flexural strength will be measured according to international standards. For evaluating the fulfilment of BPPs requirements, interfacial contact resistance and corrosion resistance, the new BPPs will be characterized following David’s methods and with potentiodynamic test in O2-saturated H2SO4 solutions, respectively. Keywords: CGS, H2 production, PEMWEs, structured surfaces, metal 3D printing.