scholarly journals Mechanical and Geometric Performance of PLA-Based Polymer Composites Processed by the Fused Filament Fabrication Additive Manufacturing Technique

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1924 ◽  
Author(s):  
José María Reverte ◽  
Miguel Ángel Caminero ◽  
Jesús Miguel Chacón ◽  
Eustaquio García-Plaza ◽  
Pedro José Núñez ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Mechanical Performance ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Fused Filament Fabrication ◽  
Sem Images ◽  
Tensile Performance ◽  
Interlaminar Shear ◽  
Strength And Stiffness ◽  
Short Carbon

In this work, the effect of short carbon fibre (CF) on the mechanical and geometric properties of 3D printed polylactic acid (PLA) composite parts processed using the Fused Filament Fabrication (FFF) technique have been analysed. Tensile, flexural and interlaminar shear strength (ILSS) tests were performed to obtain the mechanical performance of the different samples. The surface quality and geometric accuracy of the printed specimens were also evaluated. Finally, Scanning Electron Microscope (SEM) images of the printed samples are analysed. The results revealed that the addition of carbon fibres effectively improved all assessed mechanical properties of PLA-CF composites as compared to the neat PLA. In particular, Flat PLA-CF samples showed an average increase in tensile performance of 47.1% for the tensile strength and 179.9% for the tensile stiffness in comparison to the neat PLA. From the flexural behaviour point of view, Flat PLA-CF samples revealed an increase in average flexural strength and stiffness of 89.75% and 230.95%, respectively in comparison to the neat PLA. Furthermore, PLA-CF samples depicted the best ILSS performance. In general, the use of short carbon fibre as reinforcement did not affect the dimensional accuracy of the PLA-CF samples, and even improved the surface roughness in certain cases, particularly in Flat and On-edge orientations.

Effect of nozzle diameter on mechanical and geometric performance of 3D printed carbon fibre-reinforced composites manufactured by fused filament fabrication

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jesús Miguel Chacón ◽  
Miguel Ángel Caminero ◽  
Pedro José Núñez ◽  
Eustaquio García-Plaza ◽  
Jean Paul Bécar
Keyword(s):  
Surface Roughness ◽  
Carbon Fibre ◽  
Mechanical Performance ◽  
Dimensional Accuracy ◽  
Nozzle Diameter ◽  
Fused Filament Fabrication ◽  
Manufacturing Costs ◽  
Content Type ◽  
3D Printed ◽  
Composite Samples

Purpose Fused filament fabrication (FFF) is one of the most popular additive manufacturing (AM) technologies due to its ability to build thermoplastic parts with complex geometries at low cost. The FFF technique has been mainly used for rapid prototyping owing to the poor mechanical and geometrical properties of pure thermoplastic parts. However, both the development of new fibre-reinforced filaments with improved mechanical properties, and more accurate composite 3D printers have broadened the scope of FFF applications to functional components. FFF is a complex process with a large number of parameters influencing product quality and mechanical properties, and the effects of the combined parameters are usually difficult to evaluate. An array of parameter combinations has been analysed for improving the mechanical performance of thermoplastic parts such as layer thickness, build orientation, raster angle, raster width, air gap, infill density and pattern, fibre volume fraction, fibre layer location, fibre orientation and feed rate. This study aims to assess the effects of nozzle diameter on the mechanical performance and the geometric properties of 3D printed short carbon fibre-reinforced composites processed by the FFF technique. Design methodology approach Tensile and three-point bending tests were performed to characterise the mechanical response of the 3D printed composite samples. The dimensional accuracy, the flatness error and surface roughness of the printed specimens were also evaluated. Moreover, manufacturing costs, which are related to printing time, were evaluated. Finally, scanning electron microscopy images of the printed samples were analysed to estimate the porosity as a function of the nozzle diameter and to justify the effect of nozzle diameter on dimensional accuracy and surface roughness. Findings The effect of nozzle diameter on the mechanical and geometric quality of 3D printed composite samples was significant. In addition, large nozzle diameters tended to increase mechanical performance and enhance surface roughness, with a reduction in manufacturing costs. In contrast, 3D printed composite samples with small nozzle diameter exhibited higher geometric accuracy. However, the effect of nozzle diameter on the flatness error and surface roughness was of slight significance. Finally, some print guidelines are included. Originality value The effect of nozzle diameter, which is directly related to product quality and manufacturing costs, has not been extensively studied. The presented study provides more information regarding the dependence of the mechanical, microstructural and geometric properties of short carbon fibre-reinforced nylon composite components on nozzle diameter.

Research Progress on Mechanical Properties of Short Carbon Fibre/Epoxy Composites

2019 ◽  
Vol 12 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Guanghui Zhao ◽  
Jijia Zhong ◽  
Y.X. Zhang
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Weight Ratio ◽  
Epoxy Composites ◽  
Experimental Techniques ◽  
Research Progress ◽  
Future Research ◽  
Short Carbon

Background: Short carbon fibre reinforced epoxy composites have many advantages such as high strength-to-weight ratio, corrosion resistance, low cost, short fabrication time and easy manufacturing. Researches on the mechanical performance of the composites are mainly carried out by means of experimental techniques and numerical calculation. Objective: The study aims to report the latest progress in the studies of mechanical properties of short carbon fibre reinforced epoxy composites. Methods: Based on recently published patents and journal papers, the experimental studies of short carbon fibre reinforced epoxy composites are reviewed and the effects of short carbon fibre on the mechanical properties of the composites are discussed. Numerical studies using representative volume element in simulating macroscopic mechanical properties of the short fibre reinforced composites are also reviewed. Finally, future research of short carbon fibre reinforced epoxy composites is proposed. Results: Experimental techniques, experimental results and numerical simulating methods are discussed. Conclusion: Mechanical properties of epoxy can be improved by adding short carbon fibres. Fiber surface treatment and matrix modification are effective in enhancing interfacial adhesion between fiber and matrix, and as a result, better mechanical performance is achieved. Compared to the studies on equivalent mechanical properties of the composites, researches on the micro-mechanism of interaction between fiber and matrix are still in infancy due to the complexity of both the internal structure and reinforcing mechanism.

Investigation on selective laser sintering of PA12: dimensional accuracy and mechanical performance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Achille Gazzerro ◽  
Wilma Polini ◽  
Luca Sorrentino
Keyword(s):  
Mechanical Performance ◽  
Selective Laser Sintering ◽  
Central Zone ◽  
Dimensional Accuracy ◽  
Laser Sintering ◽  
Point Of View ◽  
Content Type ◽  
Mechanical Performances ◽  
The Many ◽  
Additional Support

Purpose Selective laser sintering (SLS) has passed other techniques, thanks to its high print resolution, its ability to print microscale geometries without any additional support, its surface quality and its long-term thermal stability. However, despite the many advantages of SLS compared to fusion deposition modelling, there are still today some limitations on the materials to be printed. A limit critical from an industrial point of view is the aging of PA12 powder, i.e. the degradation of its physical and chemical performances, due to the high temperatures and the long printing cycles, thus involving a decrease of the mechanical properties of the printed parts. The purpose of this study was to charaterize mechanically and dimensionally specimens printed in PA12 through SLS by means of virgin or aged powder, i.e. powder just used for five printing cycles. Design/methodology/approach To achieve this aim, a set of specimens were designed, built, measured and mechanically tested; the obtained results were put into relationship with the values of the process parameters used to print them. Statistical tools to design the experiments and to analyse the obtained results were used. Findings The results show that the SLS process carried out through a Sintratec machine on PA12 powder has a good repeatability. To obtain the best dimensional and mechanical performances, it is needed to use virgin powder and place the part in the central zone of the printing area. Originality/value There are no scientific articles dealing with the influence of both the aging of the powder and the manufacturing parameters on the dimensional and mechanical characterization of specimens printed with SLS technique in PA12.

scholarly journals A study on extruded filament bonding in fused filament fabrication

2019 ◽  
Vol 25 (3) ◽  
pp. 555-565 ◽  
Author(s):  
Ana Elisa Costa ◽  
Alexandre Ferreira da Silva ◽  
Olga Sousa Carneiro
Keyword(s):  
Control Systems ◽  
Design Methodology ◽  
Mechanical Performance ◽  
Tensile Axis ◽  
Dimensional Accuracy ◽  
Fused Filament Fabrication ◽  
Bonding Quality ◽  
Content Type ◽  
Extrusion Rate ◽  
Forced Cooling

Purpose The performance of parts produced by fused filament fabrication is directly related to the printing conditions and to the rheological phenomena inherent to the process, specifically the bonding between adjacent extruded paths/raster. This paper aims to study the influence of a set of printing conditions and parameters, namely, envelope temperature, extrusion temperature, forced cooling and extrusion rate, on the parts performance. Design/methodology/approach The influence of these parameters is evaluated by printing a set of test specimens that are morphologically characterized and mechanically tested. At the morphological level, the external dimensions and the voids content of the printed specimens are evaluated. The bonding quality between adjacent extruded paths is assessed through the mechanical performance of test specimens, subjected to tensile loads. These specimens are printed with all raster oriented at 90º relative to the tensile axis. Findings The best performance, resulting from a compromise between surface quality, dimensional accuracy and mechanical performance, is achieved with a heated printing environment and with no use of forced cooling. In addition, for all the conditions tested, the highest dimensional accuracy is achieved in dimensions defined in the printing plane. Originality/value This work provides a relevant result as the majority of the current printers comes without enclosure or misses the heating and envelope temperature control systems, which proved to be one of the most influential process parameter.

scholarly journals Tensile Performance of 3D-Printed Continuous Fiber-Reinforced Nylon Composites

2021 ◽  
Vol 5 (3) ◽  
pp. 68
Author(s):  
Mahdi Mohammadizadeh ◽  
Ismail Fidan
Keyword(s):  
Tensile Properties ◽  
Mechanical Performance ◽  
Fiber Type ◽  
Microstructural Analysis ◽  
Fiber Content ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Fused Filament Fabrication ◽  
Wide Range ◽  
Tensile Performance

Fused Filament Fabrication (FFF) is a promising technology for production of fiber-reinforced composite parts with complex geometries. Continuous Fiber Reinforced Additively Manufactured (CFRAM) parts are becoming more prominent due to their mechanical performance, light weight, and recyclability. CFRAM components are lighter, yet they are strong materials with a wide range of potential applications in the automotive industry, aerospace, medical tools, and sports goods. The wide range of applications of these novel materials justifies the need to study their properties. Tensile is one of the most important tests to evaluate the mechanical performance of CFRAM parts. In this paper, a comprehensive study is conducted on tensile properties of CFRAM components. The composite parts are printed using a dual nozzle 3D printing machine and their tensile performance is investigated. Furthermore, the effect of fiber type, fiber content, infill density, infill pattern, and layer thickness on tensile properties was studied. Nylon was used as the matrix and Carbon fiber (CF), fiberglass (FG), and Kevlar were used as reinforcing agents. Microstructural analysis was conducted to investigate the fracture mechanism, internal morphology, interlayer adhesion, and the printing quality of specimens. Finally, a comparative study is conducted on the price and printing time of CFRAM parts. It is observed that fiber inclusion increases the tensile strength up to 2200%; moreover, increasing the fiber content improves the tensile performance of composite. The results obtained demonstrate that CF-reinforced parts have better performance compared to FG and Kevlar-reinforced components. The results show that CFRAM parts have potential to replace metals and conventional composites for engineering applications like the automobile industry.

scholarly journals Experimental and Computational Investigation of Lattice Sandwich Structures Constructed by Additive Manufacturing Technologies

2021 ◽  
Vol 5 (3) ◽  
pp. 95
Author(s):  
Nikolaos Kladovasilakis ◽  
Paschalis Charalampous ◽  
Konstantinos Tsongas ◽  
Ioannis Kostavelis ◽  
Dimitrios Tzetzis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Sandwich Structures ◽  
Volume Ratio ◽  
Dimensional Accuracy ◽  
High Porosity ◽  
Design Strategies ◽  
Fused Filament Fabrication ◽  
Geometrical Structures ◽  
Specific Distribution

Additive Manufacturing (AM) technologies offer the ability to construct complex geometrical structures in short manufacturing lead time coupled with a relatively low production cost when compared to traditional manufacturing processes. The next trend in mechanical engineering design is the adaption of design strategies that build products with lightweight lattice geometries like sandwich structures. These structures possess low mass, large surface area to volume ratio, high porosity, and adequate mechanical behavior, which are properties of great importance in scientific fields such as bioengineering, automotive, and aerospace engineering. The present work is focused on producing sandwich structures with complex lattice patterns like the Triply Periodic Minimal Surface (TPMS) Schwarz diamond structure. The specimens were manufactured with two different Additive Manufacturing procedures employing various relative densities. More specifically, Material Jetting Printing (MJP) and Fused Filament Fabrication (FFF) processes were employed to investigate the performance of Acrylonitrile Butadiene Styrene (ABS) lightweight lattice structures. These structures were examined using digital microscopy in order to measure the dimensional accuracy and the surface characteristics of the utilized AM technologies. Furthermore, three-point bending tests and finite elements analyses have been applied to investigate the mechanical performance of the proposed technologies and designs as well as the influence of the relative density on the Schwarz diamond TPMS structure. The experimental results demonstrate that the investigated structure possesses a remarkable performance in respect to its weight due to the specific distribution of its material in space.

scholarly journals Interlaminar Shear Strength of Carbon Fibre Reinforced Epoxy Composite under the Influence of Environments

1998 ◽  
Vol 7 (1) ◽  
pp. 096369359800700
Author(s):  
M. Zhang ◽  
S.E. Mason
Keyword(s):  
Shear Strength ◽  
Carbon Fibre ◽  
Laminate Composite ◽  
Mechanical Performance ◽  
Epoxy Composite ◽  
Interlaminar Shear Strength ◽  
Curing Conditions ◽  
Interlaminar Shear ◽  
Structural Carbon ◽  
Careful Comparison

The influences of contamination, using a range of contaminants introduced under postcure and pre-cure curing conditions, on the interlaminar shear strength (ILSS) of a cured structural carbon fibre reinforced epoxy composite have been investigated. A careful comparison between the post-cure and pre-cure conditions subjected to the different type of contaminants (water, seawater, acid, alkali and organic) confirmed a definite reduction in the ILSS properties. The results demonstrate that the control of environmental factors such as water, acids, alkalis, salts and organic solvents can have significant effects on the mechanical performance of laminate composite components during the manufacturing process and usage.

scholarly journals Preparation of High Strength Plywood from Partially Delignified Densified Wood

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1796 ◽  
Author(s):  
Matthias Jakob ◽  
Gregor Stemmer ◽  
Ivana Czabany ◽  
Ulrich Müller ◽  
Wolfgang Gindl-Altmutter
Keyword(s):  
Bending Strength ◽  
Mechanical Performance ◽  
Natural Fibers ◽  
High Strength ◽  
Densified Wood ◽  
Thickness Swelling ◽  
Resorcinol Formaldehyde ◽  
Absolute Strength ◽  
Interlaminar Shear ◽  
Strength And Stiffness

Wood and natural fibers exhibit an advantageous combination of good mechanics at comparably low density. Nevertheless, comparing absolute strength and stiffness, wood is clearly inferior to materials such as metals and engineered composites. Since there is a strong correlation between wood density and wood mechanical performance, densification by transversal compression suggests itself as a route towards improved mechanics. Partially delignified densified spruce veneers with excellent tensile properties were produced by means of an alkaline (AL) and an organosolv (OS) approach. Plywood specimens were manufactured using treated veneers glued with a phenol-resorcinol-formaldehyde adhesive and were compared with plywood samples made of native spruce veneers (Ref) and spruce veneer densified after plasticization by water impregnation (H2O). Roughly, the bending strength and the modulus of elasticity of plywood from partially delignified densified wood were improved by a factor of 2.4 and 3.5, respectively. Interlaminar shear strength did not match this improvement after partial delignification. Together with excessive thickness swelling, this might be a drawback of partially delignified densified wood in need for further research.

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