Nickel powders are used in various powder metallurgy applications, including sintered metal filters, catalysts, or sintered electrodes in batteries and fuel cells. Filamentary-type nickel powders are made up of highly irregular-shaped, chain-like particles; such morphology provides an advantage in the manufacturing of highly porous metal membranes for filtration applications. However, the vastly irregular shape is not optimal for the spreading of powder in powder bed additive manufacturing (AM) technologies. For example, in Binder Jetting 3D Printing (BJP), the powder bed needs to be compacted well layer-by-layer for the binder to properly adhere between layers, ensuring a printed part without cracks and with smooth surface finishing and reasonable green-part strength. BJP allows for the fabrication of porous parts with an open-cell porous structure via pores-by-processing, thereby enabling novel designs of porous membranes to be fabricated. Therefore, there is great interest in enabling the smooth powder spreading of irregular filamentary nickel powder to facilitate BJP. Here, different methodologies to resolve this issue will be discussed, including the preparation of nickel powder feedstock incorporating binder and/or pore formers. Furthermore, the resulting morphology of the sintered parts will be analysed, to illustrate the BJP porous structures formed from irregular filamentary nickel powder feedstocks. Overall, this provides a platform for understanding the issues facing powder-bed AM technologies when highly irregular-shaped powders are involved.
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Publisher Copyright
Funding Info:
This research / project is supported by the A*STAR - RIE2020, INDUSTRY ALIGNMENT FUND - INDUSTRY COLLABORATION PROJECTS (IAF-ICP)
Grant Reference no. : I2001E0056