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Additive manufacturing (AM) enables the production of complex geometries that are not accessible by conventional processes. Fused deposition modeling (FDM) 3D printing is an important choice for many industries, particularly for additive manufacturing of microelectronic systems. The various physical properties of printing polymer materials, such as geometry, rheological behavior, and others, need to be taken into account in the printing process. In our study, a semi-crystalline polypropylene polymer PP is used in the FDM process, as it is characterized by deformability due to crystallization. We investigate the thermomechanical behavior of a semi-crystalline polymer PP (polypropylene) with different material deposition geometries ranging from a parallelepiped filament to a cylindrical filament in a numerical model developed. A coupling (to temperature vs. time evolution during printing) of solid mechanics, heat transfer, and crystallization kinetics equations was considered to build the Multiphysics numerical model capable of predicting temperature profiles, residual stresses, and degree of crystallization during the FDM process. The results obtained with the numerical model provide a reliable approach to predicting and adjusting the actual thermomechanical behavior of a printed electronics package. The values are calculated and compared to the six points in the two samples. The results show that the change in deposit shape resulted in a maximum deviation of 3.3 MPa for residual stress and 0.376 for the degree of crystallization, while a decrease was observed in the selected points with an average deviation of 1.81 MPa and 0.193 for residual stress and the degree of crystallization, respectively. This is due to the effects of the modification of the shape model on the temperature profile model, with the change in the 3D structures of the printed polymer material; the methodology presented in this paper allows the numerical model to be validated with an experimental study of the literature. The paper proposes future work and an experimental study to validate the results of the numerical model. [ABSTRACT FROM AUTHOR]

Braille is a universal tactile writing system for the blind and visually impaired. Braille can be printed in several ways, including embossing, screen, or UV ink-jet printing. In this study, we propose to use three-dimensional, 3D, printing technology to print dots of the Braille alphabet. The 3D model was designed with CAD software and then overprinted with Fused Deposition Modelling, FDM, technology with polylactide filament. Then, the quality of braille dots was assessed according to the standard for Braille. The estimated height (0.5 mm) and diameter (1.3 mm) for Braille dot were not achieved for the designed model. The measured values of the Braille dots were 0.38 ± 0.03 mm and 1.0 ± 0.07 mm for the height and diameter, respectively. The dot quality was assessed with an optical microscope. The distribution and location of the Braille can be acceptable, but the reproduction of dot shape, curvature, and dimensions is not compatible with the standard for Braille dots. Despite that, Braille is readable, and FDM can be a cheap solution to develop customized and unique plates with Braille imitating conventional Braille dots embossed in cardboard. [ABSTRACT FROM AUTHOR]

This study delves into the manufacturing strategies employed for fabricating tensile samples utilized in the mechanical characterization of material extrusion (MEX) components constructed with polyaryletherketone (PAEK) for aerospace applications. Two distinct methods were investigated for obtaining tensile test samples: direct cutting and extraction from a box. These methods were examined under both as-printed and annealing conditions. Quasistatic tensile tests were conducted along the building direction to evaluate the impact of processing conditions on the adhesion of overlying layers. The results unveiled significant disparities in mechanical behavior and crystallinity between directly printed samples and those derived from the box. The Young's modulus exhibited marginal influence; however, the tensile strength of directly printed samples measured at 30 MPa (prior to annealing), corresponding to 50% of the strength observed in samples cut from the box (60 MPa). Moreover, the elongation at rupture of directly printed samples was found to be less than 2%, while that of cut samples exceeded 8%. Notably, directly printed samples exhibited a significant degree of incipient crystallization (12.18%), contrasting with the lower level of crystallinity observed in samples cut from the box (3.27%). These findings underscore the importance of recognizing the limitations associated with direct sample printing, emphasizing its crucial role in accurately characterizing components destined for the aerospace industry. Furthermore, this understanding is pivotal for optimizing the performance and reliability of MEX-printed PAEK components in aerospace engineering applications. [ABSTRACT FROM AUTHOR]

This study delves into optimizing production parameters and 3D printing (3Dp) conditions for alkaline‐treated 10% hemp fiber‐reinforced polycarbonate (PC) composites. Initially, composite filaments were extruded at 250°C (PCH250) and 230°C (PCH230) to assess the impact of varying melt mixing temperatures on thermal behavior. Thermal characterization was conducted using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC analysis indicated consistent glass transition temperatures (Tg) across pure PC and the composites, while TGA revealed minimal thermal degradation in PCH230 compared to pure PC. Subsequently, to ascertain the optimal 3D printing temperature, specimens were printed at temperatures elevated by 10°C relative to their melt mixing temperatures (PCH250/260 and PCH230/240), followed by mechanical evaluation via tensile testing. PCH230/240 exhibited superior mechanical properties, demonstrating a 12% increase in tensile strength and a 29% increase in Young's modulus compared to pure PC. Additional testing at 230°C printing temperature (PCH230/230) demonstrated enhanced mechanical strength over PCH250/260 but inferior performance relative to PCH230/240, attributed to incomplete interlayer adhesion observed through SEM analysis. Consequently, the optimal composite melt mixing temperature was determined to be 230°C, with an accompanying 3D printing temperature of 240°C for optimal mechanical performance. Highlights: 3D printable, 5% NaOH treated hemp fiber reinforced polycarbonate composite.Printing composite with 3D printing device at different temperatures230°C process temperature gives the best thermal properties.240°C 3Dp temperature provides the best mechanical and morphological properties. [ABSTRACT FROM AUTHOR]

The study examined the degradation process of various types of polymers used to form models using the fused deposition modeling (FDM) and three-dimensional printing (3DP) methods and used in the investment casting method. Commercial filaments made of polylactide (PLA), acrylonitrile butadiene styrene terpolymer (ABS), high-impact polystyrene (HIPS), polyamide 12 (PA12), poly(methyl methacrylate) (PMMA), and polypropylene (PP) were used to produce gypsum molds. The assessment included organic volatile compounds (VOCs) released during mold heating and model degradation, which is characteristic of this technological process. The screening qualitative chromatographic analysis of decomposition products sampled from various points of the production hall made it possible to define potential threats related to the processing of selected polymers and the necessary preventive measures. Furthermore, passive diffusion-type samplers were used at the sampling stage of VOCs emitted to the gaseous phase to reduce nuisance and user interference. Studies have been completed to characterize the thermoplastic polymer degradation process. The coupled thermogravimetry (TGA) with analysis of gaseous products by infrared spectroscopy with Fourier transformation (FT-IR) has been used. The presented results are the first to compare and rate the use of this still-developing novel aspect of castings by the method of fused models. [ABSTRACT FROM AUTHOR]

The study of the blood flow through arterial walls is an important subject due to different chemical reactions and magnetohydrodynamic having an impact on the arterial walls during the treatment of cancer, malignant tumors, drug targeting and endoscopy. So, this paper aims to present a comprehensive investigation of the blood bioconvective flow of Carreau–Yasuda (C–Y) nanofluids in an arterial. Variable velocity conditions near the walls are considered. The flow domain is filled by a porous medium and a time-dependent magnetic field is assumed. The impacts of an exponential chemical reaction are considered and the viscous dissipation in the case of the C–Y model is formulated and examined. The fully implicit finite difference method is applied to solve the dimensionless governing system. The case of the shear thinning (n = 0.5) and shear thickening (n = 1.5) are analyzed for the variations of the governing parameters such as Weissenberg (0.001 ≤We ≤ 0.1) and parameter of the porous medium (0 ≤ β ≤ 2). The major outcomes revealed that the friction coefficient is improved as the C–Y parameter is raised. Also, values of heat and mass transfer are higher in the case of the shear thinning compared to the shear thickening. [ABSTRACT FROM AUTHOR]

Multi-material additive manufacturing (MMAM) significantly enhances the design flexibility and performance diversity of manufacturing by integrating materials with different characteristics into a single object. However, augmenting the interface strength of MMAM parts is a crucial step in ensuring the overall quality and performance of the components. In this study, we propose a strategy that combines mechanical interlocking structures with FDM path planning to enhance interface strength. To achieve this goal, we designed three mechanical interlocking structures: Dovetail, Hook, and Cross. These structures not only meet the requirements of continuous extrusion processes but also exhibit non-disassemblable characteristics. Taking into account their slicing profiles and the characteristics of their fracture forms, the interface strength was further enhanced during the forming process by adjusting the nozzle's movement path and controlling the extrusion amount of consumables. The experimental results indicate that, with a layer count of 5 and an embedding distance of 4 mm, all three mechanical interlocking structures exhibit superior tensile performance. Under the collaborative action of path stitching, the interface strength of the three mechanical interlocking structures is enhanced, the Dovetail structure demonstrates a notably superior performance among them, showcasing an average strength limit increase of 304.09% (8.89 MPa). The experimental results not only validate the enhancement of interface strength through the combination of mechanical interlocking structures and FDM path planning but also reveal the relationship between strength limits and contact area. The varied patterns in strength limits resulting from different approaches to increasing the contact area of the two materials provide insights for investigating other structural parameters. [ABSTRACT FROM AUTHOR]

This study investigates the additive manufacturing (AM) process of 30% ceramic‐reinforced composite PLA material using the fused deposition modeling (FDM) technique. The effects of various printing parameters on tensile strength, build time, and material consumption are comprehensively analyzed through a combination of the Taguchi method, analysis of variance (ANOVA), and gray relational analysis (GRA). Experimental design parameters include nozzle diameter, infill density, infill pattern, wall line count, print speed, and layer height. Statistical analyses reveal significant contributions of these parameters to mechanical properties and production efficiency. Single and multi‐objective optimizations of the responses were performed. The single optimization resulted in a significant increase in tensile strength from 39.9 to 48.10 MPa. Production time was reduced from 16 to 9 min; material consumption decreased from 4.95 to 2.43 g for tensile test specimens. The use of GRA in multi‐objective optimization has led to a significant improvement of 8.31% in the gray relational grade (GRG) when compared to the initial parameter settings. These findings provide valuable insights for optimizing FDM processes in the fabrication of composite PLA materials. This contributes towards the advancement of additive manufacturing technology and its applications across various industries. and its applications across various industries. Highlights: Tensile strength increased while reducing build time and material consumption.Optimal printing parameters were identified for a composite PLA material.Layer height and nozzle diameter were effective parameters. [ABSTRACT FROM AUTHOR]

This research aims to enhance the surface quality, mechanical properties, and biocompatibility of PEEK (polyether–ether–ketone) biomimetic dental implants through laser polishing. The objective is to improve osseointegration and implant durability by reducing surface roughness, increasing hydrophilicity, and enhancing mechanical strength. The methodology involved fabricating PEEK implants via FDM and applying laser polishing. The significant findings showed a 66.7% reduction in surface roughness, Ra reduced from 2.4 µm to 0.8 µm, and a 25.3% improvement in hydrophilicity, water contact angle decreased from 87° to 65°. Mechanical tests revealed a 6.3% increase in tensile strength (96 MPa to 102 MPa) and a 50% improvement in fatigue resistance (100,000 to 150,000 cycles). The strength analysis result showed a 10% increase in stiffness storage modulus from 1400 MPa to 1500 MPa. Error analysis showed a standard deviation of ±3% across all tests. In conclusion, laser polishing significantly improves the surface, mechanical, and biological performance of PEEK implants, making it a promising approach for advancing biomimetic dental implant technology. [ABSTRACT FROM AUTHOR]

This study is on the mechanical properties of bronze infill poly lactic acid composites fabricated by fused deposition modelling. By changing the nozzle temperature, printing speed, layer thickness and infill density the mechanical properties of the composites were studied. Tensile, flexural and impact strength tests were conducted on the composite specimen. Mathematical models were developed using response surface methodology and the significance of the models was tested using analysis of variance. Increase in infill density and nozzle temperature increased the strengths of the composites. Increase in layer thickness and printing speed decreased the strengths of the composite specimen. Tensile strength is primarily influenced by infill density (38.82%), flexural strength is primarily influenced by Nozzle Temperature contributes (44.02%) while Infill density (58.12%) plays the major role in contributing the impact strength followed by other parameters. The highest tensile strength, flexural strength, impact strength values obtained in this study are 19.3 (N/mm2), 36.08 (N/mm2) and 0.26 (kJ/m2) respectively. The mechanism of the fractured specimen was investigated using scanning electron microscopy. Fracture mechanisms such as cracks, infill gaps, voids, interface, delamination, hillocks, particle pull out, delamination had an effect on the fracture of composite specimens. [ABSTRACT FROM AUTHOR]

The aim of this study was to optimize a set of technological parameters (travel speed, extruder temperature, and extrusion rate) for 3D printing with a PEEK-based composite reinforced with 30 wt.% glass fibers (GFs). For this purpose, both Taguchi and finite element methods (FEM) were utilized. The artificial neural networks (ANNs) were implemented for computer simulation of full-scale experiments. Computed tomography of the additively manufactured (AM) samples showed that the optimal 3D printing parameters were the extruder temperature of 460 °C, the travel speed of 20 mm/min, and the extrusion rate of 4 rpm (the microextruder screw rotation speed). These values correlated well with those obtained by computer simulation using the ANNs. In such cases, the homogeneous micro- and macro-structures were formed with minimal sample distortions and porosity levels within 10 vol.% of both structures. The most likely reason for porosity was the expansion of the molten polymer when it had been squeezed out from the microextruder nozzle. It was concluded that the mechanical properties of such samples can be improved both by changing the 3D printing strategy to ensure the preferential orientation of GFs along the building direction and by reducing porosity via post-printing treatment or ultrasonic compaction. [ABSTRACT FROM AUTHOR]

Background: The intersubject variability which was related to the genetic makeup was the major cause of change in pharmacological and pharmacokinetic behavior of same dosage form in varied human being. 3D printing technology will help therapy evolve and eliminate the limitations of conventional technologies. Nebivolol's (NBL)-limited oral bioavailability is mainly due to its poor aqueous solubility. The research aims to combine advanced 3D printing technology and nanotechnology to design customized therapy and enhance the functionality of NBL using a statistical approach. Results and discussion: The results of the phase solubility indicated that NBL was a poorly aqueous soluble drug. Its solubility was increased by employing nanoparticle drug delivery, which is a promising solubility enhancement technique. The 32 full factorial design was employed to develop and optimize bionanoparticles (BNPs) by solvent evaporation technique using poly (lactic-co-glycolic acid 50:50) (PLGA 50:50) and poloxamer-407 as a surfactant. The BNPs were characterized by % encapsulation efficiency (% EE), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC), transmission electron microscope (TEM), zeta potential, polydispersity index (PDI), particle size, in vitro drug release, etc. The BNPs loaded of NBL were further incorporated into the multichannel 3D-controlled release tablets made by PVA filaments employing fused deposition modeling (FDM) technology optimized by central composite design (CCD). Multichannel 3D-printed bionanoparticles-loaded tablet (M3DPBT) was optimized using CCD. All designed M3DPBTs were evaluated for post-fabrication parameters. The optimized M3DPBT could release more than 85% NBL within 10 h. Conclusions: The newly fabricated M3DPBT was found stable. The amount of PLGA 50:50 and Polaxomer was significant for developing BNPs. % infill and layer height were observed as critical for the designing M3DPBT. The combined novel 3D printing and nanotechnology technology will open a new direction for patient compliance and better therapeutic effects. Designing and developing of M3DPBT is substantially improve the patient compliance and therapeutic effectiveness of Nebivolol. [ABSTRACT FROM AUTHOR]

AbstractThis study investigates the integration of modal analysis and topology optimization in the design of a robotic arm to enhance both its reliability and efficiency. The primary objectives are to reduce the weight and minimize the vibration of the robotic arm. Initially, the kinematics and dynamics of the robotic arm were examined to identify the joint experiencing the highest torque. Finite element analyses (FEA) were then conducted on this critical joint to assess its vibration characteristics and redesign the joint for improved performance through topology optimization. Comparative analysis of the initial and optimized designs has highlighted significant improvements in weight reduction and vibration control. The selected robot arm component was manufactured using fused deposition modeling (FDM). Experimental modal analysis validated the theoretical predictions, demonstrating the effectiveness of the optimized design. The selected component of the robotic arm was redesigned using three different topology geometries and two different unit cell sizes for each, resulting in a maximum weight reduction of 29.37%. Stresses were reduced by 41% under critical operating conditions, which contributed significantly to the system’s reliability. The improvements in efficiency were measured through reductions in weight and vibration, demonstrating the enhanced dynamic performance of the robotic arm. The optimized design was validated through experimental modal analysis, confirming the effectiveness of the redesign. This study underscores the synergy of modal analysis and topology optimization in advancing robotic arm technology, providing a comprehensive approach to design optimization for enhanced reliability. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) and melt electrowriting (MEW) are techniques that use polymer fibers as building blocks for printing complex 3D structures, with fibers at the macroscopic and micrometer scale. Here, FDM and MEW are used to produce fibers of shape memory polymer at two different scales, and compare the performance of these fibers, in terms of shape fixity, shape recovery, and self‐healing properties. FDM and MEW are used for 4D printing of a shape memory polymer blend of thermoplastic poly(ε‐caprolactone) (30% by wt.) and a soft thermoplastic elastomer polyurethane (70% by wt.) at two different scales. The shape transformation from a programmed temporary state to the printed permanent shape in response to temperature as the stimuli imparts the 4D aspect to the printing. The mean fiber diameter of shape memory polymer produced by FDM and MEW is 340 and 40 µm, respectively. The manufactured fibers show an excellent shape fixity ratio (≈95%) and shape recovery properties (>84%). MEW fibers show a 1.5x faster recovery rate than FDM fibers due to the scaling effect. The excellent shape memory properties are complemented by self‐healing characteristics in the printed fibers. Additionally, MEW of a shape memory polymer is directly performed on a cylindrical collector to obtain tubular constructs which can potentially be used as stents for coronary or vascular applications. [ABSTRACT FROM AUTHOR]

The lateral load-carrying mechanism of vertically installed and battered minipiles is evaluated using 1g-physical and numerical modelling. Single minipiles with batter angles of 0°, ± 25° and ± 45° are tested under lateral load in medium dense and dense sand. The minipiles are instrumented with fibre Bragg grated optic fibres to obtain a strain profile (two-dimensional) along the minipile shaft. A calibrated numerical model is further adopted to produce p–y curves for battered minipiles at various node deflections. The ratio of soil reaction of battered minipiles to vertically installed minipiles is observed to change with both deflection and depth of the minipile. An analytical solution is developed based on the decomposition of lateral load into skin friction and passive pressure for battered minipiles. A reduction factor is proposed that considers a decrease in passive pressure when the minipile is loaded in the opposite direction of the batter. The analytical solution is capable of accounting for soil properties, pile rigidity and the angle of inclination of battered minipiles. The analytical method is subsequently verified for cohesive soils using full-scale field results. The ratio of the ultimate lateral load of battered minipiles to vertical minipiles presented in the literature corroborated the findings of this study. [ABSTRACT FROM AUTHOR]

Metal Fused Filament Fabrication provides a simple and cost-efficient way to produce dense metal parts with a homogenous microstructure. However, current limitations include the use of hazardous and expensive organic solvents during debinding for flexible filaments the stiffness of filaments made from partly water-soluble binder systems. In this study, the influence of various additives on different partly water-soluble binder systems, with regard to the flexibility and properties of the final parts, was investigated. Furthermore, a method using dynamic mechanical analysis to quantify the flexibility of filaments was introduced and successfully applied. For the first time, it was possible to produce flexible, partly water-soluble filaments with 60 vol.% solid content, which allowed the 3D printing of complex small and large parts with a high level of detail. After sintering, density values of up to 98.9% of theoretical density were achieved, which is significantly higher than those obtained with existing binder systems. [ABSTRACT FROM AUTHOR]

The layer-by-layer deposition of molten polymer filament in fused deposition modeling (FDM) has evolved as a disruptive technology for building complex parts. This technology has drawbacks such as the anisotropic property of the printed parts resulting in lower strength for parts printed in the vertical Z direction compared with the other two planes. In this manuscript, we attempt to address these challenges as well as the lack of standardization in sample preparation and mechanical testing of the printed parts. The paper focuses on process parameters and design optimization of the ZX build orientation. Type I tensile bars in ZX orientation were printed as per the ASTM D638 standard using two (2B) and four (4B) tensile bar designs. The proposed design reduces material loss and post-processing to extract the test coupons. Printing a type I tensile bar in the ZX orientation is more challenging than type IV and type V due to the increased length of the specimen and changes in additional heat buildup during layer-by-layer deposition. Three different polymer composite systems were studied: fast-crystallizing nanofiller-based high-temperature nylon (HTN), slow-crystallizing nanofiller-based polycyclohexylene diethylene terephthalate glycol-modified (PCTG), and amorphous carbon fiber-filled polyetherimide (PEI-CF). For all the polymer composite systems, the 2B showed the highest strength properties due to the shorter layer time aiding the diffusion in the interlayers. Further, rheological studies and SEM imaging were carried out to understand the influence of the two designs on fracture mechanics and interlayer bonding, providing valuable insights for the field of additive manufacturing and material science. [ABSTRACT FROM AUTHOR]

Featured Application: Real-time monitoring of the elastic properties of materials during the printing process. This study demonstrated the potential of a non-destructive evaluation (NDE) method to assess the elastic properties of materials printed under various parameters. A database was created documenting the relationship between the elastic properties (Young's modulus, shear modulus, and Poisson's ratio) of PLA (polylactic acid) materials and selected printing parameters such as temperature, speed, and layer height. PLA, which is widely used in additive manufacturing, offers convenient testing conditions due to its less demanding control compared to materials like metals. Ultrasonic testing was conducted on specimens printed under different nozzle temperatures, speeds, and layer heights. The results indicated that an increase in the printing temperature corresponded to an increase in material density and elastic properties of the material. In contrast, an increase in layer height led to a decrease in both density and the elastic properties of the material. Variations in the nozzle speed had a negligible effect on density and did not show a notable effect on the elastic moduli. This study demonstrated that ultrasonic testing is effective in measuring the elastic properties of PLA materials and shows the potential of real-time ultrasonic NDE. [ABSTRACT FROM AUTHOR]

Previous studies have reported that PLA-Al-based composite-based structures may be used in aerospace, automobiles, and biomedical applications. The present study investigated the fracture, morphological and mechanical characteristics of composite 3D-printed materials comprising polylactic acid (PLA) and aluminum (Al) metal powder. In the first stage, materials extrusion-based printing of PLA-Al composite structures was performed by material extrusion process varying the layer thickness (0.15, 0.20, and 0.25 mm), infill density (60, 80, and 100%) and infill pattern (Grid, Line, Zigzag). In the second stage, investigations have been made on the mechanical and morphological characteristics of the manufactured composite structures. The findings of the tensile study demonstrate that the composite structure prepared using 0.20 mm layer thickness, 80% infill density, and zigzag infill pattern possessed the highest tensile strength (39.13 MPa) and the minimum tensile strength (18.47 MPa) was noticed when it was manufactured using 0.15 mm layer thickness, 60% infill density and grid infill pattern. The results of the morphological analysis showed that the samples had a consistent microstructure with few visible cracks. These results suggest that 3D-printed PLA-Al composites have considerable mechanical and morphological characteristics, with possible applications in a variety of fields, like aviation, automobiles, and healthcare. [ABSTRACT FROM AUTHOR]

One of the most widespread versions of additive manufacturing technologies (AM) is fused filament fabrication (FFF) or fused deposition modeling (FDM), using polymer melts to print freeform structures. Due to specific rheological and processing conditions, interlayer adhesion, shrinkage, and warpage problems, standard polymer grades do not always meet all requirements, so more polymers must be combined to achieve the optimum solution. These combinations include traditional blending technologies (with or without compatibilizer additives), reactive extrusion, and mixing incompatible phases with mechanical interlocking. Combining layers of different polymers in laminated structures, improving the interlayer strength of one-component prints, and developing core-shell filaments also require solving compatibility problems. This mini-review shows representative examples from blending engineering polymers, high-performance polymers, multilayer and coextruded structures, and biodegradable polymers and discusses the solutions characterizing the extrusion-based additive manufacturing technologies, which sometimes differ from multicomponent materials used in injection molding.

Braille is a universal tactile writing system for the blind and visually impaired. Braille can be printed in several ways, including embossing, screen, or UV ink-jet printing. In this study, we propose to use three-dimensional, 3D, printing technology to print dots of the Braille alphabet. The 3D model was designed with CAD software and then overprinted with Fused Deposition Modelling, FDM, technology with polylactide filament. Then, the quality of braille dots was assessed according to the standard for Braille. The estimated height (0.5 mm) and diameter (1.3 mm) for Braille dot were not achieved for the designed model. The measured values of the Braille dots were 0.38±0.03 mm and 1.0±0.07 for the height and diameter, respectively. The dot quality was assessed with an optical microscope. The distribution and location of the Braille can be acceptable, but the reproduction of dot shape, curvature, and dimensions is not compatible with the standard for Braille dots. Despite that, Braille is readable, and FDM can be a cheap solution to develop customized and unique plates with Braille imitating conventional Braille dots embossed in cardboard.

Abstract Background The intersubject variability which was related to the genetic makeup was the major cause of change in pharmacological and pharmacokinetic behavior of same dosage form in varied human being. 3D printing technology will help therapy evolve and eliminate the limitations of conventional technologies. Nebivolol's (NBL)-limited oral bioavailability is mainly due to its poor aqueous solubility. The research aims to combine advanced 3D printing technology and nanotechnology to design customized therapy and enhance the functionality of NBL using a statistical approach. Results and discussion The results of the phase solubility indicated that NBL was a poorly aqueous soluble drug. Its solubility was increased by employing nanoparticle drug delivery, which is a promising solubility enhancement technique. The 32 full factorial design was employed to develop and optimize bionanoparticles (BNPs) by solvent evaporation technique using poly (lactic-co-glycolic acid 50:50) (PLGA 50:50) and poloxamer-407 as a surfactant. The BNPs were characterized by % encapsulation efficiency (% EE), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC), transmission electron microscope (TEM), zeta potential, polydispersity index (PDI), particle size, in vitro drug release, etc. The BNPs loaded of NBL were further incorporated into the multichannel 3D-controlled release tablets made by PVA filaments employing fused deposition modeling (FDM) technology optimized by central composite design (CCD). Multichannel 3D-printed bionanoparticles-loaded tablet (M3DPBT) was optimized using CCD. All designed M3DPBTs were evaluated for post-fabrication parameters. The optimized M3DPBT could release more than 85% NBL within 10 h. Conclusions The newly fabricated M3DPBT was found stable. The amount of PLGA 50:50 and Polaxomer was significant for developing BNPs. % infill and layer height were observed as critical for the designing M3DPBT. The combined novel 3D printing and nanotechnology technology will open a new direction for patient compliance and better therapeutic effects. Graphical abstract Designing and developing of M3DPBT is substantially improve the patient compliance and therapeutic effectiveness of Nebivolol.

The purpose of this study is to examine the entropy generation for a Magnetohydrodynamic flow of a Casson fluid subject to a vertical cone. Here the impact of reaction by chemical and diffusion-thermo is scrutinized. Physical aspects of radiative flux transverse to the surface are deliberated. The governing non-linear PDEs and the expression for entropy generation are non-dimensionalized with the help of dimensionless quantities. Finite difference technique is implemented to get numerical and graphical results for the non-linear system. Bejan number for the heat transfer is also examined. The results obtained shows that entropy generation and Bejan number are strongly influence by the embedded flow parameters.

The present objective is to numerically analyze the induced magnetic field (IMF) effect of an unsteady MHD flow of Casson fluid through two infinite vertical plates. The effect of radiative heat has been scrutinized. Governing non-dimensional PDEs of the flow are discretized by the finite difference method to some algebraic system of equations, which is then numerically solved concerning the boundary conditions. The effects of the radiations, magnetic Prandtl number, Prandtl number, Hartmann number, and Casson parameter on temperature profile, velocity profile, and induced magnetic field have been depicted through graphs. The radiative effect and Prandtl number have considerable influence on the surface drag force and also on the rate of heat transfer.

The melt deposition modeling method (FDM) is one of the increasingly widespread additive manufacturing methods, known as 3D printing, based on the layered assembly of material filaments. However, it is seen that the parts produced with FDM in the aviation industry do not have the desired dimensional and geometric tolerance values. For this reason, different manufacturing methods are used to bring the parts produced by the FDM method to the desired tolerance values. In this study, experiments were carried out to improve the tolerance values of the holes on the plates made of polycarbonate material, which is widely used in prototyping and production tools (welding, drilling, fixing) with FDM, and the optimum processing parameters were determined using the integrated design of experiment and TOPSIS methods. According to the obtained results, the optimum drilling parameters for the plate without pre-drilling case could be obtained by selecting HSS as the drill material, using cutting fluid, and setting the feed rate to 390.9091 mm/min and the spindle speed to 1000 rpm. For the pre-drilled plate, the optimum drilling parameters were again obtained by selecting the drill material HSS, using cutting fluid and applying the feed rate to 369.6970 mm/min and the spindle speed to 781.8182 rpm. [ABSTRACT FROM AUTHOR]

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Fused deposition modeling (FDM) is a commonly used additive manufacturing (AM) technique in both domestic and industrial end-product fabrications. It produces prototypes and parts with complex geometric designs, which has the major benefits of eliminating the need for expensive tooling and flexibility. However, the produced parts often face poor part strength due to anisotropic fabrication strategies. The printing procedure, the kind of material utilized, and the printing parameters all have a significant impact on the mechanical characteristics of the printed item. In order to predict the mechanical properties related to printed components made with the use of FDM and Polylactic Acid (PLA) material, this study concentrates on developing a prediction model utilizing Artificial Neural Networks (ANNs). This study used the Taguchi design of experiments technique, utilizing (L25) orthogonal array as well as a Neural Network (NN) method with two layers and 15 neurons. The effect of FDM parameters (layer thickness (mm), percentage of infill density, number of top/bottom layers, shell thickness (mm), and infill overlap percentage) on ultimate tensile and compressive strength (UTS and UCS) was examined through analysis of variance (ANOVA). With an ANOVA result of 67.183% and 40.198%, respectively, infill density percentage was found to be the most significant factor influencing UCS and UTS dependent on other parameters. The predicted results demonstrated valuable agreement with experimental values, with mean squared errors of (0.098) and (0.326) for UTS and UCS, respectively. The predictive model produces flexibility in selecting the optimal setting based on applications.

Abstract Polylactic acid (PLA) based scaffolds have attained considerable attention in recent years for being used as biodegradable implants in bone tissue engineering (BTE), owing to their suitable biocompatibility and processability. Nevertheless, the mechanical properties, bioactivity and biodegradation rate of PLA need to be improved for practical application. In this investigation, PLA-xMn composite filaments (x = 0, 1, 3, 5 and 7 wt%) were fabricated, characterized, and used for 3D printing of scaffolds by the fused deposition modeling process. The effect of Mn addition on the thermal, physical, mechanical, and structural properties, as well as the degradability and cell viability of 3D printed scaffolds were investigated in details. The obtained results indicate that the PLA-Mn composite filaments exhibit higher chain mobility and melt flow index values, with lower cold crystallization temperature and a higher degree of crystallinity. This higher flowability led to lower dimensional accuracy of 3D printed scaffolds, but resulted in higher interlayer adhesion. It was found that the mechanical properties of composite scaffolds were remarkably enhanced with the addition of Mn particles. The incorporation of Mn particles also caused higher surface roughness and hydrophilicity, a superior biodegradation rate of the scaffolds as well as better biocompatibility, indicating a promising candidate for (BTE) applications.

Abstract The article presents the application of 3D technologies in STEAM education through a conducted scientific research, highlighting the role of 3D modeling and 3D printing as an innovative approach in achieving an interdisciplinary learning model. The research included the following stages: preparation for designing a detailed 3D steam locomotive model; analysis of process difficulties; giving students and lecturers the opportunity to perform a specific modeling task, using basic primitives from solid geometry, as well as a questionnaire to analyze and evaluate the skills and knowledge of the participants in the 3D modeling field. In this context, the preparation process of a 3D steam locomotive model for educational purposes, using Autodesk 3ds Max software, is presented, and the 3D printing technology FDM is examined. We issued a challenge to the participants in the research to design a non-complex 3D model, using unfamiliar 3D modeling software Blender, within a limited time. The questionnaire covered topics in education, science, art, STEAM, and 3D modeling. The goal is to showcase the role of the integration of 3D technologies in educational environments with the idea of developing key skills and knowledge in learners.

This study investigates the influence of the substrate temperature in material extrusion (MEX) on tensile behavior of PLA samples. A full factorial experimental plan was conducted by varying the deposition speed and the interlayer time. Infrared thermography was conducted to determine the influence of the deposition conditions on the temperature of the substrate just before the deposition of the next layer. Tensile tests were conducted along the "upright direction" to determine the influence of the thermal history on the interlayer adhesion. The results indicate the strong influence of the interlayer time on the thermal history and the mechanical behavior. The temperature of the substrate before subsequent overlying deposition was mainly influenced by the interlayer time, while it was less affected by the deposition speed. The Young modulus of the samples was poorly affected by the adopted process conditions; on the other hand, the maximum strength and the elongation at rupture were strongly affected by the interlayer time. The identified variances in mechanical behavior underscore the pivotal significance of sample dimensions in dictating the ultimate mechanical characteristics of vertically oriented samples. These outcomes illuminate the intricate interaction between deposition speed and interlayer duration, highlighting their substantial influence on mechanical performance. [ABSTRACT FROM AUTHOR]

The present study investigates the impact of scanning speed, printing temperature, and layer height on the density, dimensions, errors of parallelism, and surface finish of cubical specimens made of PLA/wood biocomposite and manufactured by Fused Deposition Modelling (FDM). The study examined 64 specimens, each produced with a unique set of process parameters. The Response Surface Methodology (RSM) was employed to evaluate the effects of process parameters on the examined properties of the manufactured cubes. RSM analysis revealed the statistical significance of direct proportion between the layer height, printing temperature, and x-and y-dimensions of the manufactured specimens (with P-values of 0, 0, 0.002, and 0, respectively). Also, the scanning speed and error of parallelism in z-oriented faces were statistically correlated (with a P-value of 0.035). For layer height and cube density, an indirect proportion was observed (with a P-value of 0). Compared to the regression model, ANN exhibited better performance at process parameters effect evaluation. The worse performance of regression models can be attributed to their limited capacity to represent non-linear relationships, while ANN models can capture the complex non-linear nature of the process, leading to better performances (R2 close to 100%). An evaluation of the defects in the specimens was carried out using the go/no-go diagram. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM), a type of additive manufacturing is widely used for complex mold design, single‐part tool manufacturing, and prototyping. The FDM process, especially with fiber‐reinforced filament, induces intricate changes that influence microstructure and properties, highlighting the necessity for a thorough understanding to maximize FDM utilization. This study comprehensively examines microstructural changes and mechanical attributes in polyamide (PA) and carbon fiber‐reinforced polyamide (CF‐PA) before and after FDM printing. Through various characterization techniques including X‐ray diffraction, thermal gravimetric, differential scanning calorimetry, tensile testing, micro‐Computed Tomography (μ‐CT), and fractography, insightful perspectives were obtained. Results reveal substantial fiber breakage, resulting in a 33.03% decrease in the average fiber length from filament to printed parts. X‐ray μ‐CT scans illustrated a more pronounced fiber alignment in CF‐PA filament than in the CF‐PA printed sample. TG analysis confirms approximately 20 wt.% CF content in the filament, with negligible residue in pure PA filament and samples. DSC shows enhanced thermal stability with CF reinforcement, while XRD confirms amorphous behavior in filament and printed parts. Tensile tests reveal anisotropic properties in FDM samples. The addition of short CFs increases Young's modulus but decreases strength. Examination of fractured surfaces reveals different failure modes for filament and printed coupons. [ABSTRACT FROM AUTHOR]

The article presents the results of the technical–economical study regarding the optimization of fused deposition modeling (FDM) parameters (the height of the layer deposited in one pass—Lh and the filling percentage—Id) for the manufacture of Polyethylene Terephthalate Glycol (PETG) and Acrylonitrile Styrene Acrylate (ASA) parts. To carry out this technical–economical study, was used the fundamental principle of value analysis, which consists of maximizing the ratio between Vi and Cp, where Vi represents the mechanical characteristic, and Cp represents the production cost. The results of the study show that for tensile specimens made of PETG, the parameter that significantly influences the results of the Vi/Cp ratios is the height of the layer deposited in one pass, (Lh), and in the case of the compression specimens made of PETG, the parameter that significantly influences the results of the Vi/Cp ratios is filling percentage (Id). In the case of specimens manufactured via FDM from ASA, the parameter that decisively influences the results of the Vi/Cp ratios of the tensile and compression specimens is the filling percentage (Id). By performing optimization of the process parameters with multiple responses, we identified the optimal parameters for FDM manufacturing of parts from PETG and ASA: the height of the layer deposited in one pass, Lh = 0.20 mm, and the filling percentage, Id = 100%. [ABSTRACT FROM AUTHOR]

This study investigates the impact of key parameters in fused deposition modeling (FDM), i.e., infill density and bed temperature, on the shape memory properties of four-dimensional (4D) printed shape memory polymer (SMP). Two thermo-mechanical programming methodologies, namely programming during printing (PDP) and programming after printing (PAP), are used to examine their effects too. Increasing the infill percentage greatly improves the ability of the material to regain its original shape. This is achieved by increasing the amount of material and minimizing gaps between layers, which helps to build up the pre-strain, which causes shape morphing. On the other hand, higher bed temperatures decrease the shape recovery by slowing down cooling, decreasing residual strain, and minimizing thermal stresses. Compared to PAP samples, PDP samples show a significant 40 % increase in shape memory index (SMI), indicating the considerable influence of FDM printing rather than post-printing programming process. [ABSTRACT FROM AUTHOR]

In this work, the authors investigated the impact of extrusion-based printing process on the structural characteristics of bio-based resins through rheological measurements. Two commercially available filaments made from unfilled and wood-filled polylactide (PLA) polymers were considered. Three-dimensional specimens were prepared by printing these filaments under various operating conditions, i.e., changing the extruder temperature and printing rate, and examined using time sweep tests. Specific cycle rheological testing was conducted on pelletized filaments to simulate temperature changes in the printing process. The rheological characteristics of unprocessed materials, in terms of storage (G′) and loss (G″) moduli, were found to be slightly affected by temperature changes. For a pure polymer, the G′ slope at a low frequency decreased over time, showing that the polymer chains evolved from a higher to a lower molecular weight. For wood-filled materials, the G′ slope rose over the testing time, emphasizing the formation of a percolated network of structured filler within the matrix. On the other side, the rheological parameters of both materials were strongly impacted by the printing extrusion and the related conditions. At lower nozzle temperatures (200 °C), by decreasing the printing speed, the G′ and G″ curves became increasingly different with respect to unprocessed resin; whereas at higher nozzle temperatures (220 °C), the influence of the printing speed was insignificant, and all curves (albeit distant from those of unprocessed matrix) mainly overlapped. Considerations on degradation kinetics of both materials during the printing process were also provided by fitting experimental data of complex viscosity with linear correlation over time. [ABSTRACT FROM AUTHOR]

This study investigates the impact of infill density on the mechanical properties of fused deposition modeling (FDM) 3D-printed polylactic acid (PLA) and PLA reinforced with carbon fiber (PLA+CF) specimens, which hold industrial significance due to their applications in industries where mechanical robustness and durability are critical. Exposure to cooling lubricants is particularly relevant for environments where these materials are frequently subjected to cooling fluids, such as manufacturing plants and machine shops. This research aims to explore insights into the mechanical robustness and durability of these materials under realistic operating conditions, including prolonged exposure to cooling lubricants. Tensile tests were performed on PLA and PLA+CF specimens printed with varying infill densities (40%, 60%, 80%, and 100%). The specimens underwent tensile testing before and after exposure to cooling lubricants for 7 and 30 days, respectively. Mechanical properties such as tensile strength, maximum force, strain, and Young's modulus were measured to evaluate the effects of infill density and lubricant exposure. Higher infill densities significantly increased tensile strength and maximum force for both PLA and PLA+CF specimens. PLA specimens showed an increase in tensile strength from 22.49 MPa at 40% infill density to 45.00 MPa at 100% infill density, representing a 100.09% enhancement. PLA+CF specimens exhibited an increase from 23.09 MPa to 42.54 MPa, marking an 84.27% improvement. After 30 days of lubricant exposure, the tensile strength of PLA specimens decreased by 15.56%, while PLA+CF specimens experienced an 18.60% reduction. Strain values exhibited minor fluctuations, indicating stable elasticity, and Young's modulus improved significantly with higher infill densities, suggesting enhanced material stiffness. Increasing the infill density of FDM 3D-printed PLA and PLA+CF specimens significantly enhance their mechanical properties, even under prolonged exposure to cooling lubricants. These findings have significant implications for industrial applications, indicating that optimizing infill density can enhance the durability and performance of 3D-printed components. This study offers a robust foundation for further research and practical applications, highlighting the critical role of infill density in enhancing structural integrity and load-bearing capacity. [ABSTRACT FROM AUTHOR]

This study investigated the effect of two critical variables for environmental process sustainability, i.e., extruder temperature and printing rate, on thermomechanical performance and accuracy in overall sample sizes, when printing bio-based materials. In this context, 3D specimens produced from basic polylactide (n-PLA) and wood-filled PLA polymer (f-PLA) were realized using extrusion-based additive manufacturing technology (MEX) by varying the nozzle temperatures (200 °C, 210 °C, and 220 °C) and speed (from 70 mm/s to 130 mm/s). Dynamic mechanical analysis (DMA) was carried out on the produced specimens, providing information on changes in storage modulus at testing temperature of 30 °C (E′30) and glass transition temperature (Tg) for each printing condition. Measurements of sample sizes allowed for printing precision considerations as a function of processing temperature and speed. The results revealed similar trends in E′30 changes in printed specimens at a fixed extruder temperature as a function of printing speed for n-PLA and f-PLA. Infrared spectroscopy was performed on printed samples and unextruded material to attest potential material degradation under various operating conditions. Finally, images of sample surface allowed to verify the homogeneity of the diameter of the extruded material and the layer–layer contact at the interface. [ABSTRACT FROM AUTHOR]

This article examines the effects on mechanical properties of carbon fibre reinforced with nylon produced using fused deposition modelling technology. Experimental analysis was carried out by varying fused deposition modelling parameters namely the bed temperature, nozzle temperature and outer thickness to determine their impact on mechanical properties. To investigate the effects of these parameters' tests were carried using design of experiments and mathematical equations were developed. In order to ensure the accuracy of the mathematical equations, analysis of variance (ANOVA) method is employed. Utilising scanning electron microscopy, the microstructure behind the fractured specimens was investigated. Carbon fibre nylon composites have established tensile strengths between 22.75 and 32.65 N/mm2, flexural strengths between 20.12 and 25.89 N/mm2 and impact strengths between 0.37 and 0.71 kJ/m2. The fractured composites are characterised by infill gap, pullout, pores, cavities, smearing, accumulate, debonding of layers, delamination, infill particles, cracks, clusters and breakage. This material can find its application in industries like aerospace, automotive and other engineering applications. Also, this study acts as a database for other researchers carrying their work in this area. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) based scaffolds have attained considerable attention in recent years for being used as biodegradable implants in bone tissue engineering (BTE), owing to their suitable biocompatibility and processability. Nevertheless, the mechanical properties, bioactivity and biodegradation rate of PLA need to be improved for practical application. In this investigation, PLA-xMn composite filaments (x = 0, 1, 3, 5 and 7 wt%) were fabricated, characterized, and used for 3D printing of scaffolds by the fused deposition modeling process. The effect of Mn addition on the thermal, physical, mechanical, and structural properties, as well as the degradability and cell viability of 3D printed scaffolds were investigated in details. The obtained results indicate that the PLA-Mn composite filaments exhibit higher chain mobility and melt flow index values, with lower cold crystallization temperature and a higher degree of crystallinity. This higher flowability led to lower dimensional accuracy of 3D printed scaffolds, but resulted in higher interlayer adhesion. It was found that the mechanical properties of composite scaffolds were remarkably enhanced with the addition of Mn particles. The incorporation of Mn particles also caused higher surface roughness and hydrophilicity, a superior biodegradation rate of the scaffolds as well as better biocompatibility, indicating a promising candidate for (BTE) applications. [ABSTRACT FROM AUTHOR]

This systematic review interrogates the literature to understand what is known about the environmental sustainability of fused filament fabrication, FFF (also known as fused deposition modeling, FDM), based on life cycle assessment (LCA) results. Since substantial energy demand is systematically addressed as one of the main reasons for ecological damage in FFF, mitigation strategies are often based on reducing the printing time (for example, adopting thicker layers) or the embodied energy per part (e.g., by nesting, which means by printing multiple parts in the same job). A key parameter is the infill degree, which can be adjusted to the application requirements while saving printing time/energy and feedstock material. The adoption of electricity from renewable resources is also expected to boost the sustainability of distributed manufacturing through FFF. Meanwhile, bio-based and recycled materials are being investigated as less impactful alternatives to conventional fossil fuel-based thermoplastic filaments. [ABSTRACT FROM AUTHOR]

FDM is the world's most widely used and certified additive manufacturing technology because of its simplicity of use and production flexibility compared to other additive manufacturing techniques. Several input process variables impact the surface quality of manufactured components. The present study investigated the effect of print speed, acceleration, and jerk on the surface roughness of FDM-fabricated parts. The surface roughness of PLA-fabricated items is minimized by optimizing all three input parameters. To investigate the effect of input variables on surface roughness, a total of 20 test specimens were developed and fabricated using a face-centered central composite design technique. The surface roughness has been measured on the lateral sides of components in two directions (along the x-axes and y-axes). Further, the hybrid genetic algorithms-artificial neural networks (GA-ANN) heuristic optimization tool, in which GA is integrated with ANN, is employed to find the best feasible combination of input variables. It is observed that the surface roughness obtained for the x-axis direction is 0.0551512 μm at (speed: 20 mm/s; acceleration: 1137 mm/s2; jerk: 29.36 mm/s) and for the y-axis direction is 11.8919 μm at (speed: 98.60 mm/s; acceleration: 988.35 mm/s2; jerk: 16.508 mm/s). The optimized values are validated experimentally. [ABSTRACT FROM AUTHOR]

The present objective is to numerically analyze the induced magnetic field (IMF) effect of an unsteady MHD flow of Casson fluid through two infinite vertical plates. The effect of radiative heat has been scrutinized. Governing non-dimensional PDEs of the flow are discretized by the finite difference method to some algebraic system of equations, which is then numerically solved concerning the boundary conditions. The effects of the radiations, magnetic Prandtl number, Prandtl number, Hartmann number, and Casson parameter on temperature profile, velocity profile, and induced magnetic field have been depicted through graphs. The radiative effect and Prandtl number have considerable influence on the surface drag force and also on the rate of heat transfer. [ABSTRACT FROM AUTHOR]

Entropy generation is a crucial aspect of fluid dynamics and happens during all flow processes. In a sense, entropy indicates how to minimise thermal energy losses. This study examines entropy generation for a magnetohydrodynamic Casson fluid flow subject to a vertical cone. Here, impact of reaction by chemical and diffusion-thermo is scrutinized. Physical aspects of radiative flux transverse to the surface are deliberated. The governing non-linear PDEs and the total entropy expression are non-dimensionalized with the dimensionless quantities. Finite difference technique is implemented to get numerical and graphical results for the non-linear system. Entropy generation and Bejan number for the heat transfer has been analysed through plots and tables. The obtained results demonstrate that the embedded flow parameters have a considerable influence on both Bejan number and entropy generation. Bejan number with the influence of Casson parameter has a proportional effect with the Hartmann number and it falls with the rise in Dufour effect. [ABSTRACT FROM AUTHOR]

Physics is commonly perceived as a challenging academic discipline, with a contributing factor being the limited availability of educational resources to support students. Consequently, there arises a need to develop a module focused on the incorporation of technology in physics education. The integration of technology within pedagogical modules refers to the practice of including various technological Implementations in educational content. This study aimed to investigate and rank the most efficient technological implementations for designing a pedagogical hybrid physics module for students in grades 9-12 in the Sultanate of Oman. A literature review was conducted concerning the integration of technology in hybrid learning and physics education. Qualitative and quantitative research methodologies were employed for data collection, the data were analyzed utilizing Fuzzy Delphi Method (FDM). To establish the FD instrument, a panel of six experts was consulted through semi-structured interviews. This panel identified 13 significant technology Implementations for the development of the module. Subsequently, a group of 12 experts was surveyed to identify the essential technology Implementations. Consequently, four technology Implementations were excluded, while the accepted Implementations were then prioritized using FDM. The findings revealed that Mobile instant messaging claimed the top position, with Artificial Intelligence (AI) ranking at the lowest position. [ABSTRACT FROM AUTHOR]

This study intends to evaluate the influence of temperature stratification on an unsteady fluid flow past an accelerated vertical plate in the existence of viscous dissipation. It is assumed that the medium under study is a grey, non-scattered fluid that both fascinates and transmits radiation. The leading equations are discretized using the finite difference method (FDM). Using MATLAB software, the impacts of flow factors on flow fields are revealed with particular examples in graphs and a table. In this regard, FDM results show that the velocity and temperature gradients increase with an increase of Eckert number. Furthermore, tables of the data indicate the influence of flow-contributing factors on the skin friction coefficients, and Nusselt numbers. When comparing constant and variable flow regimes, the constant flow regime has greater values for the nondimensional skin friction coefficient. This research is both innovative and fascinating since it has the potential to expand our understanding of fluid dynamics and to improve many different sectors. [ABSTRACT FROM AUTHOR]

This paper shows the three-point bending strength analysis of a composite material consisting of polyamide doped with chopped carbon fiber and reinforced with continuous carbon fiber produced by means of the material extrusion (MEX) additive manufacturing technique. For a comparison, two types of specimens were produced: unreinforced and continuous fiber-reinforced (CFR) with the use of carbon fiber. The specimens were fabricated in two orientations that assure the highest strength properties. Strength analysis was supplemented by additional digital image correlation (DIC) analysis that allowed for the identification of regions with maximum strain within the specimens. The utilization of an optical microscope enabled a fractographic examination of the fracture surfaces of the specimens. The results of this study demonstrated a beneficial effect of continuous carbon fiber reinforcement on both the stiffness and strength of the material, with an increase in flexural strength from 77.34 MPa for the unreinforced composite to 147.03 MPa for the composite reinforced with continuous carbon fiber. [ABSTRACT FROM AUTHOR]

Additive manufacturing has many techniques and has been frequently used and studied recently. The fused deposition modeling (FDM) method, which is one of these techniques, is a widely used three-dimensional (3D) printing method that works with the extrusion principle. The parameters used during printing affect the properties of the final product. This study investigated the effect of print angle, infill density, and perimeter count parameters on the tensile strength characteristics of FDM-printed PLA samples by the response surface method (RSM), an experimental design method. The tensile strengths of the samples produced according to the test lists obtained using the Box–Behnken design were determined. A model equation showing the effect of the relevant parameters was created. From the experiments, the compatibility of the model equation with the experimental results has been demonstrated. The highest tensile strength values were achieved in cases where the print angle was 90°, the infill density was 100%, and the number of walls was 5-6. [ABSTRACT FROM AUTHOR]

Although various additive manufacturing techniques are used intensively to mold materials for solid oxide fuel cell (SOFC) applications, 3D printing has not been applied to obtain sealants which are crucial components for SOFC stacking. It is essential to develop different methods for molding sealing products based on glasses and glass-ceramics which are the most promising materials for SOFC stacking. This study reveals the potential of fused deposition modeling (FDM) for the production of complex shape objects for the sealing of tubular SOFC in the example of the composition based on thermoplastic, thermoplastic elastomer, oil, and a filler (glass sealant). The highest filler content in the mixture is 63 wt %. Two aluminosilicate sealants of different compositions are used as the filler and the printed products are successfully applied for tubular supporting anode|sealant|steel joints. • FDM is successfully used to obtain products for tubular SOFC sealing. • Bubbles in the sealant volume do not violate the sealing. • Tubular supporting anode|sealant|steel joints are prepared using printed products. [ABSTRACT FROM AUTHOR]

This study explores the reinforcement potential of nano graphene in a poly latic acid (PLA) matrix. The present work introduces a framework to select reinforcement for the formation of composite that will be feasible to manufacture by using additive manufacturing. Main objective of this research work is to develop the composition of PLA-nano graphene composite to make it feasible to be printed by fused deposition modeling based additive manufacturing. In order to achieve the same, the problem of selecting a reinforcement and constituents of composite is discussed in detail. Based on the literature review, four compositions (1.5 %, 3 %, 4.5 %, and 6 % nano-graphene by weight to PLA) are prepared to find out the optimum composition. In this study, the effects of nano graphene loading on the melt flow behaviour of PLA-graphene composites for extrusion-based fused deposition modeling (FDM) were investigated. The objective was to determine the optimal nano graphene loading that would yield the optimum melt flow index with desirable best mechanical properties. Tests have been performed for three samples of each of four compositions 1.5 %, 3 %, 4.5 %, and 6 % nano Graphene by weight to PLA. The results found that with increasing nano graphene content, both the melt flow index as well as mechanical properties increased significantly. However, when the nano graphene loading reached 6 wt%, a decrement in these parameters was observed due to the agglomeration of fillers onto each other within the composite structures. Therefore, it is concluded that out of the remaining compositions (1.5 %, 3 %, and 4.5 % nano graphene by weight to PLA), 4.5 wt% is an optimal loading level for obtaining desired processing performance and mechanical properties from PLA-graphene composites for FDM application. [ABSTRACT FROM AUTHOR]