Binder Jetting has gained particular interest amongst other Additive Manufacturing (AM) techniques because of its lack of rapid melting-solidification issues present in other Additive Manufacturing (AM) processes, a wide range of applications, and feasible material systems. Understanding and optimizing printing parameters during the powder spreading process is essential to improve the final part’s quality. In this study, a Discrete Element Method (DEM) simulation has been employed to evaluate the powder packing density, flowability, and porosity parameters. Three different powder size groups consisting of two monoidal and bimodal size distributions in the range of 50 μm-109 μm are considered for a thorough investigation into the effect that coarse and fine powders have during the powder spreading step present in a binder jetting process. It was observed that coarser particles result in a higher flowability as opposed to finer ones due to the cohesion effect present in the latter particle size. A bimodal size distribution yielded the highest packing density and lowest porosity in a powder bed layer as the finer particles fill in the voids created between the coarser ones. &nbsp;&nbsp;Keywords: additive manufacturing (AM), discrete element method (DEM), ceramic, ceramic sand, binder jetting, powder size distribution, porosity, layer density, flowability, bimodal distribution.

Discrete-Element Simulation of Powder Spreading Process in Binder Jetting, and the Effects of Powder Size Distribution.

Paper Proceedings: https://asmedigitalcollection.asme.org/MSEC/MSEC2021/volume/85062

2021 International Manufacturing Science and Engineering Conference (MSEC2021)

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