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Materials Science in Additive Manufacturing Thixotropic metal 3D printing

printability during extrusion deposition. Bismuth-based Author contributions
alloy was selected as the testing material for printability
study. In particular, the effects of nozzle diameter, extrusion Conceptualization: Yifan Fei, Jack Zhou, Donggang Yao
speed, nozzle-to-substrate distance, and platform moving Investigation: Yifan Fei, Jie Xu, Donggang Yao, Richard
speed and acceleration on the printability were examined. Chiou, Jack Zhou
Accordingly, the extrusion and printing system was Formal analysis: Yifan Fei, Jie Xu
optimized to achieve desired printing results. The final
printing test demonstrated that the integrated system is Writing – original draft: Yifan Fei, Jack Zhou, Donggang
capable of effectively processing raw alloys in the thixotropic Yao
sate and then directly printing by extrusion deposition. Writing – review & editing: Yifan Fei, Donggang Yao, Jack
6. Future work Zhou

While this research has developed a novel thixotropic References
material extrusion and printing system for alloys, a number 1. Hong DH, Chou DT, Velikokhatnyi OI, et al., 2016,
of studies can be carried out for optimizing the design and Binder-jetting 3D printing and alloy development of
process, as well as achieving fundamental understanding new biodegradable Fe-Mn-Ca/Mg alloys. Acta Biomater,
of the processing dynamics and principles. Follow-up 45: 375–386.
studies could particularly focus on the following areas. 2. International Organization for Standardization, 2015,
First, the SSM extruder design can be refined and updated. Additive Manufacturing General Principles Terminology.
The ideal extrusion system design should produce SSM ISO/ASTM 52900, Geneva, Switzerland.
filament that can be applied to a fused deposition modeling
(FDM) printing machine. However, the current auger bit 3. Roh S, Parekh DP, Bharti B, et al., 2017, 3D printing by
multiphase silicone/water capillary inks. Adv Mater,
was not suitable for continuous filament extrusion. The 29: 1701554.
material transforming channel can also be redesigned
to fit more materials. A material cooling and collecting 4. Goh GD, Yeong WY, 2018, Mode I Interlaminar Fracture
system is one other desired component of the system. Toughness of Additively Manufactured Carbon Fibre
rd
Second, the thixotropic printing system can be modified Thermoplastic. In: Proceedings of the 3 International
Conference on Progress in Additive Manufacturing,
to add gas protection to facilitate processing of a broader p505–510.
range of chemically active metals such as zinc-based and
magnesium-based bio-metals. Besides, the extrusion- 5. Zhou LY, Fu J, He Y, 2020, A review of 3D printing
based printing system resulting from this study was technologies for soft polymer materials. Adv Funct Mater,
limited by the substrate moving mechanism and extrusion 30: 2000187.
plunger. The extruded material’s solidification speed needs 6. Yu YZ, Liu FJ, Zhang RC, et al., 2017, Suspension 3D printing
to be investigated to determine a suitable degree of rigidity. of liquid metal into self-healing hydrogel. Adv Mater Technol
In addition, local material cooling rate and substrate Us, 2: 1700173.
heating temperature may affect the material rigidity that 7. Ladd C, So JH, Muth J, et al., 2013, 3D printing of free
can support the multiple layer printing. A motorized standing liquid metal microstructures. Adv Mater,
X-Y-Z moving platform with precision temperature 25: 5081–5085.
control may improve the printing capability for complex 8. Hashmi S, 2014, Comprehensive Materials Processing,
mutilayer geometry printing. Last but not the least, a series Newnes.
of processing-structure-property studies can be performed
to better understand the process dynamics/kinetics during 9. Gao W, Zhang YB, Ramanujan D, et al., 2015, The status,
challenges, and future of additive manufacturing in
thixotropic extrusion and printing. As mentioned earlier, engineering. Comput Aided Design, 69: 65–89.
the dynamics of die swell is worth a focused study.
10. McKinley GH, Renardy M, 2011, Wolfgang von ohnesorge.
Funding Phys Fluids, 23:127101.
The authors acknowledge financial support from NSF https://doi.org/10.1063/1.3663616
under Grant No. 2027823 and No. 2027871. 11. Derby B, 2010, Inkjet printing of functional and structural
materials: fluid property requirements, feature stability, and
Conflict of interest resolution. Annu Rev Mater Res, 40: 395–414.

No potential conflict of interest was reported by the 12. Joshipura ID, Ayers HR, Majidi C, et al., 2015, Methods to
authors. pattern liquid metals. J Mater Chem C, 3: 3834–3841.

Volume 1 Issue 1 (2022) 12 http://doi.org/10.18063/msam.v1i1.5