The use of continuous fiber as reinforcement in polymer additive manufacturing technologies enhances the mechanical performance of the manufactured parts. This is the case of the Carbon-Fiber reinforced PolyAmide (CF/PA) used by the MarkForged MarkTwo® 3D printer. However, the information available on the mechanical properties of this material is limited and with large variability. In this work, the in-plane mechanical properties and the interlaminar fracture toughness in modes I and II of Markforged’s CF/PA are experimentally investigated. Two different standard specimens and end-tabs are considered for the in-plane properties. Monolithic CF/PA specimens without any additional reinforcement are used for the interlaminar fracture toughness characterization. Two different mode I specimen configurations are compared, and two different test types are considered for mode II. The results show that prismatic specimens with paper end-tabs are more appropriate for the characterization of the in-plane material properties. The use of thick specimens for mode I fracture toughness tests complicates the characterization and can lead to erroneous results. Contrary to what has been reported in the literature for the same material, fracture toughness in mode I is lower than for mode II, which agrees with the normal tendency of traditional composite materials.
Bibliographical noteFunding Information:
This research was funded by the Spanish Ministry of Science, Innovation and Universities (MCIU), the Spanish Research Agency (AEI) and the European Regional Development Fund (FEDER, UE), grant number RTI2018-094435-B-C32. The first author has received financial support from Universidad Polit?cnica Saleciana during this research as part of his PhD.Support from the research group GIMAT at Universidad Polit?cnica Salesiana and technical support from the research group AMADE at Universitat de Girona are acknowledged.
Acknowledgments: Support from the research group GIMAT at Universidad Politécnica Salesiana and technical support from the research group AMADE at Universitat de Girona are acknowledged.
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- 3D-printed composite
- Experimental characterization
- Interlaminar fracture toughness