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Additive Manufacturing (AM) techniques, particularly Fused Filament Fabrication (FFF), have revolutionized prototyping and low-volume production. Improving the tensile properties of FFF-printed parts is a primary objective to elevate their functional utility. This study aimed to investigate the effects of annealing time (ATM), annealing temperature (ATP), and nozzle diameter (ND) on the tensile strength (TS) of two commonly used printing materials: Polyethylene Terephthalate Glycol (PETG) and PETG reinforced with carbon fibre (PETG-CF). Samples with varying ND (0.4 mm, 0.6 mm, and 0.8 mm) underwent annealing at ATP of 80°C and 100°C for ATM of 60 min and 120 min, respectively. Subsequent tensile tests were meticulously conducted, and regression models were employed to comprehensively analyse the influence of these control factors on TS. The findings from the tensile tests on annealed specimens revealed substantial improvements in TS for both PETG and PETG-CF materials. Statistical analysis, Taguchi method (TM), and response surface methodology (RSM) indicated that ND exerted a more pronounced impact on TS compared to ATM and ATP. By identifying the optimal control factor combinations for each material, the study pinpointed that the best TS was achieved at 0.8 mm ND, 120 minutes ATM, and 100°C ATP for PETG-CF. The remarkable enhancement in tensile properties for annealed FFF-printed parts underscores the potential of PETG-CF to replace structural metallic components in critical applications within the automotive and aeronautical industries. [ABSTRACT FROM AUTHOR]

The emergence of additive manufacturing has enabled scientists to efficiently construct complex geometries, facilitating the development of novel, high-impact energy-absorbing structures suitable for a wide range of industrial applications. The present study conducted flexural and impact test to quantitatively assess the energy absorption capabilities of polymer composites fabricated through fused filament fabrication. Specifically, the polymer composites investigated were multi-walled carbon nanotubes reinforced poly-lactic acid, carbon fibre reinforced poly-ethylene terephthalate glycol, and carbon fibre reinforced poly-lactic acid. The investigation also examined the influence of different infill patterns and nozzle hole diameters on the polymer composites. The investigation depicts that by altering the process parameters, the flexural strength is improved from 21.079 MPa to 70.653 MPa by 235.18%. The experimental study of impact specimens utilising the Izod impact test demonstrates that the rectilinear infill pattern and a nozzle hole diameter of 0.6 mm result in the highest energy absorption of 37.76 kJ/m2 for carbon fibre reinforced poly-lactic acid. The study revealed that the energy absorption of the specimens was significantly influenced by both the independent and interaction effects of process variables. The application of the fused filament fabrication demonstrates an improved energy absorption, making it suitable for manufacturing of vehicle and aircraft components. [ABSTRACT FROM AUTHOR]

Additive manufacturing is becoming more and more significant for the production of engineering products. The global community of designers and manufacturers will undoubtedly benefit from identifying the process factors that could lead to superior mechanical behaviour. The incorporation of fibres and nanoparticles in polymer matrix is one of the most significant advancements in polymer fabrication. This study intends to investigate how the flexural behaviour of dissimilar polymer composites viz carbon fibre reinforced poly lactic acid (CF-PLA), carbon fibre reinforced poly ethylene terephthalate glycol (CF-PETG) and multi walled carbon nano tubes reinforced PLA (MWCNTs-PLA) are affected by process parameters viz nozzle diameter (0.2 mm, 0.4 mm, 0.6 mm), and infill pattern (triangular, honeycomb, rectilinear) through fused filament fabrication (FFF). Flexural testing was carried out on the fabricated specimens, and post to the testing, fractography has been carried out and statistical analysis of the observations is performed utilizing analysis of variance and Taguchi method. According to the observations, flexural strength of the polymer composite specimen increases with increase in nozzle diameter (ND). The flexural behaviour is also directly impacted with the variation of infill pattern (IP). Process parameter variations affect target factors differently depending on the fabricating material. For flexural behaviour, IP contributes 68.27% to CF-PLA, while ND contributes 88.96% to CF-PETG and 77.59% to MWCNTs-PLA. Overall, the highest flexural strength, 70.372 MPa, is exhibited by the specimen with ND 0.6 mm and rectilinear IP for MWCNTs-PLA as fabricating filament material. This study will aid researchers and designers in developing FFF-fabricated electrochemical energy storage devices with improved flexural behaviour of functional parts for a wide range of applications. [ABSTRACT FROM AUTHOR]

Fused Filament Fabrication (FFF) is the most prevalent additive manufacturing technique, which involves extruding a softened thermoplastic filament through the nozzle of a heated extruder. For improving the mechanical properties of the FFF-printed PLA parts one of the options is to add reinforcing material, such as carbonaceous materials or metal particles. The present study deals with analysing and comparing mechanical properties of carbon fibre reinforced poly lactic acid (CF-PLA), graphene reinforced PLA (Gr-PLA) and multi walled carbon nano tubes reinforced PLA (MWCNTs-PLA) composites by FFF. The selected process parameters used in this study are raster angle (0°, 45°, 90°), feed rate (20 mm/s, 40 mm/s, 60 mm/s) and layer height (0.1 mm, 0.15 mm, 0.2 mm) and based on different combinations, elongation at break, modulus and tensile strength are examined. MWCNTs-PLA exhibits overall maximum tensile strength, 37.438 MPa with 15.384% elongation at break for layer height 0.1 mm, raster angle 0° and feed rate 20 mm/s as compared to other selected specimens. Fractography analysis is also done to better understand the failure modes of specimens. To examine the dependency of the tensile strength on the process parameters, ANOVA, Taguchi's L9 array Design of Experiment (DOE) is utilized indicating that layer height has the highest contribution of 56.713% for Gr-PLA, but raster angle has the highest contribution of 54.899% and 76.16% for CF-PLA and MWCNTs-PLA, respectively. This work will help in better understanding of how different parameters effects the material properties for PLA composites. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop a novel approach to enhance the flexural strength of polymer composites used in the fabrication of prosthetic sockets. The effects of control factors such as nozzle hole diameter and internal filling pattern on the flexural behavior of three distinct composite materials were examined: poly lactic acid reinforced with carbon fiber (PLA‐CF), polyethylene terephthalate glycol reinforced with carbon fiber (PETG‐CF), and PLA reinforced with multi‐walled carbon nanotubes (PLA‐MWCNTs), fabricated through fused filament fabrication. During study, samples of each composite material were created using 3D printing technology and underwent flexural testing. Fractography was then performed on the samples, and statistical analysis techniques, including Taguchi's method and response surface methodology (RSM) were used to analyze the results. The study found that the flexural behavior of the prosthetic socket materials varied significantly based on the control factors used. Specifically, a nozzle hole diameter of 0.6 mm and a rectilinear internal filling pattern with PLA‐MWCNTs composite material had the highest flexural strength among the three materials tested. Through this study, the authors demonstrated the potential to improve the design and manufacture of prosthetic sockets, which can lead to better functionality and comfort for the user. The low‐cost transtibial prosthetic socket developed in this study using the optimized composite material and 3D printing technology shows promise as an application in the field of prosthetics. This research can pave the way for the development of even stronger and more durable prosthetic sockets in the future. [ABSTRACT FROM AUTHOR]

Friction stir processing (FSP) is a most widely used severe plastic deformation (SPD) technique used for enhancement of mechanical properties and refinement of microstructure in metals, alloys and also in surface alteration, surface composites, and metal matrix composites. This work deals with the integration of FSP with fused filament fabrication (FFF), a popular additive manufacturing (AM) method. The research work comprises of four parts, first being 3d printing of poly lactic acid (PLA) and acrylonitrile butadiene styrene (ABS) parts through FFF, then multiple reinforcements like multi-walled carbon nanotubes (MWCNTs), aluminum oxide (Al2O3) and silicon dioxide (SiO2) are filled into the grooves, then in the third step FSP is performed on the 3D specimens with variations in rotational and travel speed of the tool with threaded pin profile. Finally, tensile strength is examined and the effect of different reinforcements is studied. The results indicate that MWCNTs reinforced PLA is found to have the highest strength (37.41 MPa) which is 72.6% more than the lowest strength (21.67 MPa) obtained for SiO2 reinforced PLA. However, in the case of other polymer, SiO2 reinforced ABS exhibited maximum strength (14.71 MPa) amongst other reinforcements for ABS. The ductility is decreased for all the FFF specimens after FSP and PLA composites exhibited improved surface profiling parameters as compared with ABS composites after FSP. Also, fractography is performed to understand the failure modes of specimens filled with different reinforcements. [ABSTRACT FROM AUTHOR]

Understanding and improving 3D printing process models are very important for designing building defect‐free 3D printers. Most studies have failed to present detailed process design and modeling of material extrusion (MatEx)‐based additive manufacturing (AM) in a systematic approach that considers all process parameters such as nozzle diameter, nozzle angle, and velocity. It is studied that the accuracy and consistency of a MatEx 3D fabricated product depend on the pressure drop across various nozzle zones. This paper identifies the constraints affecting the performance of the MatEx AM process and presents mathematical modeling related to various process parameters. Also, the paper shows expressions for pinch wheel feed mechanism, liquefier, and nozzle geometry of the MatEx process in terms of independent variables, such as liquefier temperature, nozzle geometry, and feed rate. This will be helpful in computing the precise design parameters of MatEx‐based 3D printers. The complex mathematical expressions developed are pivotal for the effective regulation of the 3D printing process. It not only provides new and better designs for MatEx machines with precise operation and better resolution but also opens the scope for further scientific development to expand the capability of proposed approach for both specific applications and the field. [ABSTRACT FROM AUTHOR]