About this Abstract |
Meeting |
2021 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2021)
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Symposium
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Special Session
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Presentation Title |
Characterizing the Internal Morphology of Transition Regions in Large-scale Extrusion Deposition Additive Manufacturing
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Author(s) |
James C. Brackett, Zaky Hussein, Elijah Charles, Tyler Smith, Ahmed Hassen, Seokpum Kim, Vlastimil Kunc, Chad Duty |
On-Site Speaker (Planned) |
James C. Brackett |
Abstract Scope |
A dual-hopper feed system that was developed for the Big Area Additive Manufacturing (BAAM) system allows for transitioning between different materials while maintaining continuous deposition. This technique creates a step-change in material feedstock by rocking the pellet feeding system to alternate which hopper is currently supplying material, allowing for multi-material construction. The step-change in feedstock material produces a transition region that is characterized by a compositional gradient and blended internal morphology. Initial cross-sectional imaging of the transition region revealed a non-homogenous blend of materials with distinct domains of each material, likely due to incomplete mixing within the screw. This study used a carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS) and an unfilled ABS to characterize the internal structure and to correlate it to mechanical performance by tracking microhardness across cross-sections of the transition region. Blending capability of the conventional printing hardware was also compared to that of a static-mixing nozzle. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |