The mechanical response and fracture behavior of two architected 3D-printed hardened cement paste (hcp) elements, ‘lamellar’ and ‘Bouligand’, were investigated under uniaxial compression. A lab-based X-ray microscope was used to characterize the post-fracture crack pattern. The mechanical properties and crack patterns were analyzed and compared to cast hcp. The role of materials architecture and 3D-printing-induced weak interfaces on the mechanical properties and fracture behavior are discussed. The pore architecture that inadvertently forms in the design of solid architected materials dictated the overall mechanical response and fracture behaviors in both 3D-printed architected materials. While no specific crack pattern or microcracking was observed in the cast element, lamellar architecture demonstrated a crack pattern following weak vertical interfaces. Bouligand architectures, on the other hand, exhibited a helical crack pattern with distributed interfacial microcracking aligned with the helical orientation of filaments. As a result, the bouligand architected elements showed a significant 40% increase in work-of-failure compared to cast counterparts. The enhanced energy absorption was obtained without sacrificing the strength and was attributed to higher fractured surface and microcracking, both of which follow the weak helical interfaces.
Carbon fiber reinforced polymers (CFRPs) offer exceptional properties that make them highly relevant in the aerospace industry, such as high thermal conductivity and an outstanding strength‐to‐weight ratio. Advances in additive manufacturing have expanded the aerospace applications of CFRPs, even allowing for in‐space fabrication of complex structures. Understanding the stability of CFRPs in the harsh conditions of low Earth orbit (LEO) is crucial. LEO exposes materials to extreme environmental factors, such as vacuum, radiation, atomic oxygen, and temperature fluctuations, which can accelerate degradation. To investigate the space‐environment effect on material, changes in properties of 3D‐printed CFRPs are compared with CFRPs made through forging and conventional compression molding. Surface analyses examine morphological, chemical, and matrix composition changes, along with an evaluation of mechanical integrity. Remarkably, the naked 3D printed CFRPs withstood 8 months of LEO exposure similar to the compression molded CFRP samples, with changes in chemical properties limited to the sample's outer surface. Further, despite no protective coatings are used, limited surface erosion and no variation in mechanical strength are observed. These results provide relevant information for the development and deployment of novel 3D printed CFRPs materials for a wide spectrum of terrestrial and space applications.
more » « less- NSF-PAR ID:
- 10480012
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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