“…The fracture mode of upright orientation is brittle failure, while the flat and on-edge orientations change to ductile fracture, which are identical with previous literatures. 21,37 Besides, the mechanical properties of CF/PEEK are better than PEEK in every direction.Figure 2.(a) Building orientations of specimens. (b) Tensile strength of specimens with different building orientation.…”
As a rapidly developing additive manufacturing technology, fused deposition modeling (FDM) has become widespread in many industry fields. It can fabricate complicated geometries using filament of thermoplastic materials such as PP, polylactic acid, acrylonitrile butadiene styrene, etc. However, poor mechanical properties of raw materials limit their application. Poly-ether-ether-ketone is a type of special engineering plastic with high performance, which could be further reinforced by adding carbon fibers (CFs). During FDM process, the mechanical properties of printed parts are largely subject to careful selection of process parameters. To improve the mechanical properties of PEEK and CF/PEEK 3D-printed parts, the effects of various process parameters including building orientation, raster angle, nozzle temperature, platform temperature, ambient temperature, printing speed, layer thickness, infill density, and number of printed parts on mechanical properties were investigated. The tensile fracture interfaces of printed parts were observed by scanning electron microscope (SEM) to explain the influence mechanism of process parameters. In the single factor experiments, flat and on-edge specimens show the best tensile and flexural strength, respectively; the specimens with raster angle ±45° and 0° show the best tensile and flexural strength, respectively. When the nozzle temperature at 500°C, platform temperature at 200°C, ambient temperature at 150°C, printing speed is 20 mm/s, layer thickness is 0.2 mm, and infill density is 100%, the printed parts exhibit the best mechanical properties.
“…The fracture mode of upright orientation is brittle failure, while the flat and on-edge orientations change to ductile fracture, which are identical with previous literatures. 21,37 Besides, the mechanical properties of CF/PEEK are better than PEEK in every direction.Figure 2.(a) Building orientations of specimens. (b) Tensile strength of specimens with different building orientation.…”
As a rapidly developing additive manufacturing technology, fused deposition modeling (FDM) has become widespread in many industry fields. It can fabricate complicated geometries using filament of thermoplastic materials such as PP, polylactic acid, acrylonitrile butadiene styrene, etc. However, poor mechanical properties of raw materials limit their application. Poly-ether-ether-ketone is a type of special engineering plastic with high performance, which could be further reinforced by adding carbon fibers (CFs). During FDM process, the mechanical properties of printed parts are largely subject to careful selection of process parameters. To improve the mechanical properties of PEEK and CF/PEEK 3D-printed parts, the effects of various process parameters including building orientation, raster angle, nozzle temperature, platform temperature, ambient temperature, printing speed, layer thickness, infill density, and number of printed parts on mechanical properties were investigated. The tensile fracture interfaces of printed parts were observed by scanning electron microscope (SEM) to explain the influence mechanism of process parameters. In the single factor experiments, flat and on-edge specimens show the best tensile and flexural strength, respectively; the specimens with raster angle ±45° and 0° show the best tensile and flexural strength, respectively. When the nozzle temperature at 500°C, platform temperature at 200°C, ambient temperature at 150°C, printing speed is 20 mm/s, layer thickness is 0.2 mm, and infill density is 100%, the printed parts exhibit the best mechanical properties.
“…This can improve the FFF processing and interlayer bonding. [73][74][75] Another way to potentially lower the viscosity is to decrease the amount of conductive filler. This is expected to reduce the conductivity of the filament, unless appropriate countermeasures are taken.…”
The progress of Industry 4.0 and the advancement of robotic design are revealing a significant gap in the capabilities of current manufacturing techniques and the selection of materials that are available in electronics. Present‐day electrical systems largely rely on metals, but there is a driving need to develop new electrically conductive objects with a wide range of material properties, including expanded flexibility and softness, and with increasingly complex geometries. Electrically conductive composites can replace traditional metal‐based systems. In particular, thermoplastic composites become electrically conductive with the incorporation of conductive fillers or polymers while retaining to a large extent the processability of the thermoplastic matrix. This is where fused filament fabrication (FFF), an additive manufacturing (AM) technique capable of processing a variety of thermoplastic‐matrix feedstock materials, can be leveraged to create electrically conductive objects with new functionalities. While there is an increasing number of publications describing the FFF of electrical objects such as sensors and circuits, there is no comprehensive review outlining the functioning mechanisms, drawbacks, and advantages of FFF as applied to conductive materials. The present review fills this lacuna by offering a critical analysis of the specific challenges and solutions to promote FFF of electrically conductive polymers and composites.
“…It was reported that this addition of plasticizer improved the interfacial bonding of printed parts through an improved degree of healing. In another study [ 46 ], benzene-derivate plasticizers obtained from the pyrolysis of trisilanolphenyl polyhedral oligomeric silsequioxane (POSS) were successfully used to improve the mesoscale interface bonding of 3D printed PEEK. In addition, a method based on atmospheric pressure cold plasma treatment of the polymer filament is under development [ 47 ].…”
3D printed neat thermoplastic polymers (TPs) and continuous fiber-reinforced thermoplastic composites (CFRTPCs) by fused filament fabrication (FFF) are becoming attractive materials for numerous applications. However, the structure of these materials exhibits interfaces at different scales, engendering non-optimal mechanical properties. The first part of the review presents a description of these interfaces and highlights the different strategies to improve interfacial bonding. The actual knowledge on the structural aspects of the thermoplastic matrix is also summarized in this contribution with a focus on crystallization and orientation. The research to be tackled to further improve the structural properties of the 3D printed materials is identified. The second part of the review provides an overview of structural health monitoring technologies relying on the use of fiber Bragg grating sensors, strain gauge sensors and self-sensing. After a brief discussion on these three technologies, the needed research to further stimulate the development of FFF is identified. Finally, in the third part of this contribution the technology landscape of FFF processes for CFRTPCs is provided, including the future trends.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
