Abstract
Integrating Multiple Materials (MM) into large-scale Additive Manufacturing (AM) is a key for various industrial applications wishing to incorporate site-specific properties into geometrically complex designs that are difficult to manufacture with traditional techniques. Printing with multiple materials is typically accomplished by using layers as natural material boundaries, but having the capability to switch between materials within a single layer without pausing would further expand MM possibilities. This study used Cincinnati Incorporated's Big Area Additive Manufacturing (BAAM) system to explore material transitions with a novel dual-hopper that enables in-situ material blending of a pelletized feedstock. Constructing MM and functionally graded material (FGM) structures requires depositing a specific material composition at a specific geometric location to achieve a desired performance. Accurately implementing this with the BAAM's blended extrusion system requires a thorough understanding of the transition between distinct material compositions. This study characterizes a step-change transition between neat acrylonitrile butadiene styrene (ABS) and carbon fiber-reinforced ABS. Three distinct techniques were compared for analyzing the fiber content, and the transition zone between materials was characterized as a function of transition direction. The transition process was consistent to within 0.7 wt% carbon fiber variation between different layers and prints. The transition between materials was found to be directionally dependent, with ABS to CF/ABS having a transition length of 3.5 m compared to 3.2 m for CF/ABS to ABS. Furthermore, the transition from Material A to Material B was found to be repeatable with a possible variance in transition length of 0.3 m.
Original language | English |
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Article number | 101750 |
Journal | Additive Manufacturing |
Volume | 38 |
DOIs | |
State | Published - Feb 2021 |
Funding
Research sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. This research was supported by the DOE Office of Energy Efficiency and Renewable Energy, Manufacturing Demonstration Facility. The authors are grateful for the equipment and assistance provided by Cincinnati Incorporated and for the materials supplied by Techmer Engineered Solutions. The University of Alabama Birmingham's Materials Science Department provided assistance with testing and data collection. The authors are also would like to thank the Oak Ridge Institute for Science and Education for its contributions through the Higher Education Research Experiences Program. Research sponsored by the U.S. Department of Energy , Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. This research was supported by the DOE Office of Energy Efficiency and Renewable Energy, Manufacturing Demonstration Facility. The authors are grateful for the equipment and assistance provided by Cincinnati Incorporated and for the materials supplied by Techmer Engineered Solutions. The University of Alabama Birmingham’s Materials Science Department provided assistance with testing and data collection. The authors are also would like to thank the Oak Ridge Institute for Science and Education for its contributions through the Higher Education Research Experiences Program. This manuscript has been authored in part by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/%20downloads/doe-public-access-plan ).
Keywords
- 3D printing
- Extrusion
- Functionally graded materials
- Large-scale
- Multi-material