Quasi-Static Characterization of Polyamide-Based Discontinuous CFRP Manufactured by Additive Manufacturing and Injection Molding

Abstract:

Generating serial components via additive manufacturing (AM) a deep understanding of process-related characteristics is necessary. The extrusion-based AM called fused layer manufacturing (FLM), also known as fused deposition modeling (FDM™) or fused filament fabrication (FFF) is an AM process for producing serial components. Improving mechanical properties of AM parts is done by adding fibers in the raw material to reinforce the polymer. The study aims to create a more detailed comprehension of FLM and process-related characteristics with their influence on the composite.Thereby, a short carbon fiber-reinforced polyamide (CarbonX™ Nylon, 3DXTECH, USA) with 12.5 wt.‑% fiber content, 7 μm fiber diameter, and 150 to 400 µm fiber length distribution was investigated. To separate process-related characteristics of FLM, reference specimens were fabricated via injection molding (IM) with single-batch material. For the mechanical characterization, quasi-static tensile tests were carried out in accordance to DIN 527‑2. Quality assessment including void content and void distribution was performed via micro-computed tomography (CT).The mechanical characterization clarifies effects on mechanical properties depending on process-related characteristics of FLM. CT scans show higher void contents of FLM specimens compared to IM specimens and void orientation dependent on printing direction. FLM shows process-related characteristics which generally strengthen mechanical properties of polymers. Nevertheless, tensile strength of FLM specimens decrease by more than 28% compared to quasi-homogenous IM specimens.

• Periodical: Key Engineering Materials (Volume 809)
• Pages: 386-391
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.809.386
• Online since: June 2019
• Authors: Patrick Striemann*, Daniel Hülsbusch, Michael Niedermeier, Frank Walther
• Keywords: Additive Manufacturing, Computed Tomography, Fiber Orientation, Material Extrusion, Short Carbon Fibre

References

[1] J. M. Chacón, M. A. Caminero, E. García-Plaza, P. J. Núñez, Additive manufacturing of PLA structures using fused deposition modelling: Effect of process parameters on mechanical properties and their optimal selection, Materials and Design 124 (2017) 143-157.

DOI: 10.1016/j.matdes.2017.03.065

[2] C. Ziemian, M. Sharma, S. Ziemian, Anisotropic mechanical properties of ABS parts fabricated by fused deposition modelling, InTech Mechanical Engineering (2012) 159-180.

DOI: 10.5772/34233

[3] V. Kishore, C. Ajinjeru, A. Nycz, B. Post, J. Lindahl, V. Kunc, C. Duty, Infrared preheating to improve interlayer strength of big area additive manufacturing (BAAM) components, Additive Manufacturing 14 (2017) 7-12.

DOI: 10.1016/j.addma.2016.11.008

[4] D. Croccolo, M. De Agostinis, G. Olmi, Experimental characterization and analytical modelling of the mechanical behavior of fused deposition processed parts made of ABS-M30, Computational Materials Science 79 (2013) 506-518.

DOI: 10.1016/j.commatsci.2013.06.041

[5] M. Spoerk, F. Arbeiter, H. Cajner, J. Sapkota, C. Holzer, Parametric optimization of intra- and inter-layer strengths in parts produced by extrusion-based additive manufacturing of poly(lactic acid), Journal of Applied Polymer Science 134 (2017) 1-15.

DOI: 10.1002/app.45401

[6] P. Striemann, M. Eichenhofer, D. Schupp, M. Niedermeier, D. Huelsbusch, F. Walther, Compression testing of additively manufactured continuous carbon fiber-reinforced sandwich structures, Materials Testing 60 (2018) 801-808.

DOI: 10.3139/120.111216

[7] F. Ning, W. Cong, J. Qiu, J. Wei, S. Wang, Additive manufacturing of carbon fiber reinforced thermoplastic composites using fused deposition modeling, Composites Part B 80 (2015) 369-378.

DOI: 10.1016/j.compositesb.2015.06.013

[8] H. L. Tekinalp, V. Kunc, G. M. Velez-Garcia, C. E. Duty, L. J. Love, A. K. Naskar, C. A. Blue, S. Ozcan, Highly oriented carbon fiber-polymer composites via additive manufacturing, Composite Science and Technology 105 (2014) 144-150.

DOI: 10.1016/j.compscitech.2014.10.009

[9] M. Dawoud, I. Taha, S. J. Ebeid, Mechanical behavior of ABS: An experimental study using FDM and injection moulding techniques, Journal of Manufacturing Processes 21 (2016) 39-45.

DOI: 10.1016/j.jmapro.2015.11.002

[10] J. F. Rodríguez, J. P. Thomas, J. E. Renaud, Mechanical behavior of acrylonitrile butadiene styrene (ABS) fused deposition materials. Experimental investigation, Rapid Prototyping Journal 7 (2001) 148-158.

DOI: 10.1108/13552540110395547