Nozzle flow behavior of aluminum/polycarbonate composites in the material extrusion printing process |
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Authors: | Xinzhou Zhang Lan Chen Caleb Kowalski Tom Mulholland Tim A. Osswald |
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Affiliation: | 1. Department of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 China;2. Polymer Engineering Center, Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706 |
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Abstract: | This article investigates the effects of nozzle diameter, resin viscosity, and filler size and volume content on the melt flow properties and clogging of composites in the material extrusion additive manufacturing process. The flow behavior was systematically characterized by a custom nozzle flow test (NOFT) device, thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Results indicated that the viscosity of the material, the particle size, and the diameter of the nozzle were important factors for clogging. TGA results showed deviations from the designed filler volume fraction, which could be due to the buildup of filler material in the nozzle and subsequent partial clogging. SEM observations showed that particle agglomeration tended to be more prevalent in strands with high filler volume content. The agglomeration could be seen near the edge of the strand. A model for the clogging formation in NOFT was summarized into four stages: particle deposition on the wall of the nozzle, creation of dendrites, particle agglomeration, and particle clogging, which explained the clogging mechanism in the NOFT. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47252. |
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Keywords: | aluminum powder flow behavior fused filament fabrication nozzle flow test |
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