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This research investigates the effects of process parameters of selective laser melting (SLM) on mechanical and metallurgical properties of titanium alloy Ti-6Al-4V fabricated parts. Key printing parameters including scan speed, laser power, and printing strategies, are analyzed for their impact on properties of printed parts using Taguchi L9 statistical approach. It is found that increasing laser power and scan speed decreases strength in both the longitudinal and transverse directions of the printed samples. The study highlights that the bi-directional printing strategy yields the highest strength in both directions, while the stripe strategy results in the lowest strength. Additionally, higher scanning speeds increase porosity, subsequently lowering the overall strength of the printed components. Microstructural analysis reveals the presence of acicular alpha martensite within the prior beta grains in most samples. [ABSTRACT FROM AUTHOR]

This study investigated the fabrication of oriented chopped carbon fiber-reinforced mullite-based refractory using extrusion-based 3D printing technology. Dispersants were incorporated into the printing paste to optimize its rheological properties. The effects of carbon fiber content on paste rheology and castable flowability were also evaluated. At dispersant and carbon fiber contents of 0.2 wt% and 0.3 wt%, respectively, the paste exhibited pronounced shear thinning behavior and notable structural recovery, significantly enhancing its printability. Furthermore, precise adjustments in air pressure and layer height, along with an analysis of shear rate distribution during printing, contributed to improved structural accuracy of the printed bodies. Post-printing, the chopped carbon fibers were oriented in the mullite matrix. Following sintering, the flexural strength of the 3D-printed specimens increased from 6.1 MPa to 6.7 MPa, with concurrent improvements in fracture toughness compared to carbon fiber-reinforced mullite refractory specimens produced by casting. [ABSTRACT FROM AUTHOR]

Increasing environmental concerns and the need for sustainable materials have driven a focus towards the utilization of recycled polylactic acid (PLA) in additive manufacturing as PLA offers advantages over other thermoplastics, including biodegradability, ease of processing, and a lower environmental impact during production. This study explores the optimization of the mechanical properties of recycled PLA parts through a combination of experimental and machine learning approaches. A series of experiments were conducted to investigate the impact of various processing parameters, such as layer thickness and infill density, as well as annealing conditions, on the mechanical properties of recycled PLA parts. Machine learning algorithms have proven the possibility to predict tensile behavior with an average error of 6.059%. The results demonstrate that specific combinations of processing parameters and post-treatment annealing differently improve the mechanical properties (with 7.31% in ultimate tensile strength (UTS), 0.28% in Young's modulus, and 3.68% in elongation) and crystallinity (with 22.33%) of recycled PLA according to XRD analysis, making it a viable alternative to virgin PLA in various applications such as sustainable packaging solutions, including biodegradable containers, clamshell packaging, and protective inserts. The optimized recycled PLA parts exhibited mechanical properties and crystallinity levels comparable to those of their virgin counterparts, highlighting their potential for reducing environmental impact and saving costs. For both as-built and annealed samples, the optimal settings for achieving high composite desirability involved a 0.2 mm layer thickness, with 75% infill for the as-built samples and 100% infill for the annealed samples. This study provides a comprehensive framework for optimizing recycled PLA in additive manufacturing, contributing to the advancement of sustainable material engineering and the circular economy. [ABSTRACT FROM AUTHOR]

Fused Filament Fabrication (FFF) is one of the most popular extrusion based metal Additive Manufacturing (AM) Technologies, which has unique advantages in the rapid prototyping of thermoplastic materials, enabling the fabrication of metal parts with low mechanical anisotropy and no residual stress. However, the mechanical properties and dimensional accuracy of FFF printed parts are susceptible to changes in various printing parameters, which affects the FFF application in large-scale manufacturing. This study experimentally studied the effect of various printing parameters namely layer thickness (0.1, 0.2, 0.3, and 0.4 mm), raster angle (0°, 90°, + 45°/−45°, and 0°/90°), raster width (0.3, 0.35, 0.4, and 0.45 mm), and infill density (70, 80, 90, and 100%) on mechanical properties and dimensional accuracy of 316L stainless steel fabricated by FFF. The results showed that the infill density was the most important factor affecting the mechanical properties, followed by the layer thickness, and it was found that higher values of infill density and lower layer thickness result in better tensile strength. Layer thickness was also the main factor affecting the dimensional accuracy, which increased with the decrease in the layer thickness. [ABSTRACT FROM AUTHOR]

With the advances in additive manufacturing, polyetheretherketone (PEEK), a biocompatible polymer, can be used in biomedical applications such as spinal implants. This paper aims to investigate the evolution of the microstructure of PEEK parts manufactured by material extrusion (MEX)‐based additive manufacturing with different printing parameters. The effect of layer thickness (LT) and nozzle diameter on mechanical properties was investigated using tensile, Charpy impact, and short beam strength (SBS) tests. Two different LTs, 0.1 and 0.2 mm, and two different nozzle diameters, 0.6 and 0.8 mm, were used as printing parameters. By increasing the LT, tensile strength dropped by around 24%, and impact strength by almost 55%. Moreover, altering the LT resulted in a 15% decrease in interlaminar shear strength (ILSS) from the SBS test. In addition, increasing the nozzle diameter also led to a significant reduction in all of the results as tensile strength, Charpy impact strength, and ILSS. The results were also consolidated by scanning electron microscopy. The main findings were that increasing LT leads to an increase in microstructural defects that act as stress concentrators. Following the tests, response surface methodology (RSM) was used to determine optimal printing parameters. In the end, using the optimum printing parameters from the RSM study, a structural analysis of a MEX‐printed spinal implant was conducted through finite element method, considering the loading cases mimicking daily human body motions. Highlights: As layer thickness increased, tensile and impact strength dropped.Tensile and impact strength dropped truly with increasing nozzle diameter.SEM revealed that increasing layer thickness causes more microstructural flaws.FEM analysis showed that PEEK‐based implant provides structural integrity. [ABSTRACT FROM AUTHOR]

The mechanical properties such as tensile behavior of a 3D printed object can be influenced by various printing parameters, including printing temperature, orientation, infill density, and printing speed. This study focuses on investigating the effects of infill density and printing speed. Thirty dog-bone specimens were 3D printed using Fused Deposition Modelling (FDM) technique with Polylactic Acid (PLA) filament. Three different infill density settings (40%, 60%, and 80%) and three printing speed settings (30 mm/s, 60 mm/s, and 90 mm/s) were used. Tensile tests were performed on each specimen using a Universal Testing Machine. The experimental results indicate a clear trend of tensile behaviour with infill density. Increasing the infill density leads to improved tensile behaviour in the specimen. The highest Young’s Modulus and ultimate tensile strength (UTS) were achieved at 541.67 MPa and 24.3 MPa, respectively, with an infill density of 80%. On the other hand, printing speed showed an inverse relationship with tensile behaviour. As the printing speed increased, the Young’s Modulus and UTS decreased. However, the effect of printing speed on the mechanical properties was not as significant as that of infill density. When increasing the printing speed from 30 mm/s to 90 mm/s, the UTS only decreased by 5.61%. In contrast, increasing the infill density from 40% to 80% resulted in a UTS increase of 35.23%.

Purpose: This study evaluates and compares the effect of printing layer thickness (LT) and post-polymerization time (PPT) on the flexural strength and hardness of three 3D-printed resins after thermal aging. Methods: A bar shape (64 × 10 × 3.3 mm) and a disc shape (15 × 2 mm) were designed for flexural strength and hardness testing, respectively. ASIGA, NextDent, and FormLabs 3D-printed resins were used to print specimens with different LTs (25 µm, 50 µm, and 100 µm). Each thickness group was post-polymerized (PP) for different times (15, 30, 60, and 90 min). All printed specimens were thermally cycled (5000 cycles) and then tested, measuring the flexural strength and hardness using a universal testing machine and Vickers hardness tester, respectively. The data were analyzed using ANOVA and a post hoc Tukey’s test (α = 0.05). Results: A PPT of 90 min showed the highest flexural strength. In comparisons of the LTs, 25 µm and 50 µm significantly increased flexural strength compared with 100 µm, which showed the lowest value for each PPT. The hardness increased as the PPT increased for all materials. In our LT comparison, 25 µm and 50 µm significantly increased the hardness for NextDent and FormLabs resins, while only 25 µm showed high hardness compared with 50 µm and 100 µm for ASIGA. Conclusion: Both parameters (LT and PPT) impact flexural strength and hardness. Increased PPT with the minimum LT is recommended.

This study evaluated the influence of various printing layer thicknesses with silicon dioxide nanoparticles (SiO 2 NPs) incorporated as a reinforcement material on the flexural strength of 3D-printed denture base resins. Asiga (DentaBASE, Asiga, Erfurt, Germany) and NextDent (Denture 3D+, NextDent B.V., Soesterberg, The Netherlands) 3D-printed resins were modified with different concentrations of SiO 2 NPs (0.25 % and 0.5 wt%). A total of 180 specimens (bar-shaped, 64 × 10 × 3.3 mm) were fabricated (N = 90/resin). Each resin was subdivided into three groups (n = 30) according to the SiO 2 NP concentration (0 %, 0.25 %, and 0.5 wt%) Each concentration was divided into three groups (n = 10) according to the printing layer thickness (50 µm, 75 µm, and 100 µm). Specimens were printed according to the manufacturer's instructions and then subjected to 10,000 thermal cycles. A three-point bending test was used to measure the flexural strength (MPa). One-way analysis of variance (ANOVA) and Tukey's post hoc tests were used to analyze the data (α = 0.05). For both resins, printing layer thicknesses of 50 µm and 75 µm exhibited significantly higher flexural strength than 100 µm (P < 0.001). The 50 µm thickness showed the greatest flexural strength values (81.65 ± 4.77 MPa and 84.59 ± 6.21 MPa for Asiga and NextDent, respectively). The 100 µm thickness showed the lowest flexural strength values (74.35 ± 5.37 and 73.66 ± 5.55 MPa) for Asiga and NextDent, respectively. The flexural strength significantly increased with the addition of SiO 2 NPs with printing layer thicknesses of 50 µm and 75 µm (P < 0.001), whereas the modified and unmodified groups printed with a 100 µm layer thickness did not differ significantly. Asiga 0.25 %/50 µm and NextDent 0.5 %/50 µm showed the highest flexural strength values (97.32 ± 6.82 MPa and 97.54 ± 7.04 MPa, respectively). Scanning electron microscopy fractured surfaces analysis revealed more lamellae and irregularities with lower printing layer thicknesses and SiO 2 NP concentrations. The flexural strength increased with printing layer thicknesses of 50 µm or 75 µm combined with SiO 2 NP reinforcement. [ABSTRACT FROM AUTHOR]

Large-scale cement-based Additive Manufacturing (AM), also known as 3D Concrete Printing (3DCP), is a promising technique to innovate the construction industry. The durability properties of printed specimens have been studied and compared to those of cast samples in the literature. However, no study has evaluated and quantified the influence of printing parameters on the durability of 3DCP specimens. Aspects such as nozzle offset and the overlap between printed filaments, among others, may influence the porosity of the samples and, therefore, the durability properties. This paper aims to investigate the influence of printing parameters on the durability of 3D manufactured mortar samples. The effects of the printing height and overlap between filaments on the durability properties were analysed in the X, Y and Z axes. An experimental investigation of 39 samples was conducted. Printed and cast specimens were subjected to a curing process for up to 90 days in a water tank at a temperature of 20 °C. Durability tests (oxygen permeability, electrical resistivity, and porosity) were performed at 7, 28 and 90 days. Relationships between the printing variables and durability properties with time were derived. Based on this study, it is concluded that the long-term properties of concrete are significantly sensitive to the overlap between filaments and the nozzle offset. In general, the durability properties were enhanced by modifying the printing parameters. In particular, an overlap of 4 mm showed the most promising results in this regard. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The key parameter in the printing process is the evenness of applying the ink layer on the printing substrate. It determines the quality of the produced prints. One of the many factors affecting the final evenness of the ink layer on the print is the phenomenon of mottling, which is caused by the non-uniform internal structure of the paper. The aim of this work was to analyze the influence of basic printing parameters on the value of the mottling index. The research showed a significant effect of the pressure in the printing unit of the offset machine and the thickness of the ink layer on the printing substrate on the value of the primary mottling index. In addition, the research revealed that the properties of the printing substrate have a significant impact on the value and nature of changes in the mottling index. In this work, using the Fourier analysis, the frequency of optical density fluctuations in solid tone area related to the mottling phenomenon was also studied. No influence of pressure changes in the Nip of the printing unit on this print parameter was found. [ABSTRACT FROM AUTHOR]

The mechanical properties such as tensile behavior of a 3D printed object can be influenced by various printing parameters, including printing temperature, orientation, infill density, and printing speed. This study focuses on investigating the effects of infill density and printing speed. Thirty dog-bone specimens were 3D printed using Fused Deposition Modelling (FDM) technique with Polylactic Acid (PLA) filament. Three different infill density settings (40%, 60%, and 80%) and three printing speed settings (30 mm/s, 60 mm/s, and 90 mm/s) were used. Tensile tests were performed on each specimen using a Universal Testing Machine. The experimental results indicate a clear trend of tensile behaviour with infill density. Increasing the infill density leads to improved tensile behaviour in the specimen. The highest Young's Modulus and ultimate tensile strength (UTS) were achieved at 541.67 MPa and 24.3 MPa, respectively, with an infill density of 80%. On the other hand, printing speed showed an inverse relationship with tensile behaviour. As the printing speed increased, the Young's Modulus and UTS decreased. However, the effect of printing speed on the mechanical properties was not as significant as that of infill density. When increasing the printing speed from 30 mm/s to 90 mm/s, the UTS only decreased by 5.61%. In contrast, increasing the infill density from 40% to 80% resulted in a UTS increase of 35.23%. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different printing orientations and post‐polymerization time with thermal cycling on the translucency of 3D‐printed denture base resins. Methods: Heat‐polymerized (HP) acrylic resin specimens were fabricated and 3D‐printed denture base materials (NextDent, ASIGA, FormLabs) were printed with different printing orientations (0, 45, 90 degrees) and subjected to different post‐polymerization times (15‐, 30‐, 60‐, and 90‐min). All specimens were polished and immersed in distilled water for 1 day at 37°C. CIEDE2000 was used to measure the translucency parameters (TP00) before and after thermal cycling (5000 cycles) recording the color parameters (L*, a*, b*) against a black and white background using a spectrophotometer. k‐factors ANOVA followed by post hoc Tukey's test (α =.05) was performed for statistical analysis. Results: The k‐factors ANOVA test showed a significant effect of resin material, post‐polymerization time, and printing orientation on translucency (p < 0.001). In comparison to HP, all 3D‐printed resins showed lower translucency with all post‐polymerization times and printing orientation (p < 0.001) except FormLabs resin (p > 0.05). For all 3D‐printed resins, the translucency increased, with increasing the post‐polymerization time (p < 0.001) and 60‐ and 90‐min showed the highest translucency. For printing orientation, 90 and 45 degrees significantly showed high translucency in comparison to 0 degrees (p < 0.001). FormLabs showed significantly higher translucency when compared with NextDent and ASIGA per respective printing orientation and post‐polymerization time. The translucency significantly decreased after thermal cycling for all tested resins (p < 0.001). Conclusion: The findings of this study demonstrated that the translucency of 3D‐printed resins is influenced by the printing orientation, post‐polymerization time, and resin type. As a result, choosing a resin type, and printing orientation, with a longer post‐polymerization time should be considered since it may improve the esthetic appearance of the 3D‐printed resins. [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]

The creation of products with personalized or innovative features in the pharmaceutical sector by using innovative technologies such as three-dimensional (3D) printing is particularly noteworthy, especially in the realm of compounding pharmacies. In this work, 3D printed capsule devices (CDs) with different wall thicknesses (0.2, 0.3, 0.4, 0.6, and 0.9 mm) and sizes were designed and successfully fabricated varying printing parameters such as extrusion temperature, printing speed, material flow percent, and nozzle diameter. The physicochemical, pharmaceutical, and biopharmaceutical performance of these CDs was evaluated with the aim of achieving an immediate drug release profile comparable to hard gelatin capsules (HGC) for use in magistral compounding. It was observed that the disintegration time of the CDs increased with wall thickness, which correlated with a slower drug release rate. CDs with configurations presenting 0.4 mm wall thickness and sizes comparable to HGC n° 0, 1, and 2 demonstrated satisfactory weight uniformity, short disintegration times, and immediate drug release, indicating their potential as effective devices in future compounding pharmacy applications. In addition, a modified Weibull-type model was proposed that incorporates wall thickness as a new variable in predicting dissolution profiles. This model improves the process of selecting a specific wall thickness to achieve the desired dissolution rate within a specified time frame. [ABSTRACT FROM AUTHOR]

In the fused filament fabrication (FFF) based additive manufacturing process, finding optimum printing parameters for achieving the required mechanical properties of the FFF-built part is challenging. In this study, a representative volume element (RVE) based mesoscale approach was developed to describe the influences of printing parameters on the mechanical behaviors of the 3D printed parts. It was shown that the stress-strain curves up to failure obtained from RVE simulations were well verified by experimental tensile test data of printed PLA samples. Then, effective tensile properties of samples manufactured using different raster angles (0°, 45°/−45°, and 90°) and a wide range of layer heights and widths were predicted and correlated with their respective local damage occurrences. The raster angle strongly affected the elastic modulus and tensile strength. The orientation between interlayer voids and loading direction governed local stress distribution, interface failure, and total deformation of FFF samples. An increased layer height and decreased layer width resulted in a more significant fraction of voids between layers and thus lowered stiffness and tensile strength. The introduced RVE model can serve as a simple tool for determining homogenized responses and studying local stress-strain developments and failure of complex printed parts according to the used printing parameters. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluates and compares the effect of printing layer thickness (LT) and post-polymerization time (PPT) on the flexural strength and hardness of three 3D-printed resins after thermal aging. Methods: A bar shape (64 × 10 × 3.3 mm) and a disc shape (15 × 2 mm) were designed for flexural strength and hardness testing, respectively. ASIGA, NextDent, and FormLabs 3D-printed resins were used to print specimens with different LTs (25 µm, 50 µm, and 100 µm). Each thickness group was post-polymerized (PP) for different times (15, 30, 60, and 90 min). All printed specimens were thermally cycled (5000 cycles) and then tested, measuring the flexural strength and hardness using a universal testing machine and Vickers hardness tester, respectively. The data were analyzed using ANOVA and a post hoc Tukey's test (α = 0.05). Results: A PPT of 90 min showed the highest flexural strength. In comparisons of the LTs, 25 µm and 50 µm significantly increased flexural strength compared with 100 µm, which showed the lowest value for each PPT. The hardness increased as the PPT increased for all materials. In our LT comparison, 25 µm and 50 µm significantly increased the hardness for NextDent and FormLabs resins, while only 25 µm showed high hardness compared with 50 µm and 100 µm for ASIGA. Conclusion: Both parameters (LT and PPT) impact flexural strength and hardness. Increased PPT with the minimum LT is recommended. [ABSTRACT FROM AUTHOR]

The 3D sand printing (3DSP) technology provides a richer realization path for the sustainable development of the manufacturing industry. It has the advantages of one-time molding, reducing design constraints and machining amount, and easy control of casting dimensional accuracy. Therefore, studying the impact of process parameters of the printing process on printing efficiency, resource consumption, and carbon emissions is the basis for the sustainable development of 3DSP technology. In this paper, starting from the main influencing parameters such as printing layer thickness, recoater speed, printing angle, and single printing quantity, a relationship model between printing parameters and carbon emission sources is constructed. A total factor carbon emission prediction model of 3DSP process including the impact of capital and labor is established. Build an influence relationship with printing parameters as independent variables and carbon emissions as dependent variables. Taking the sand casting industry as an example to verify the above model, the experimental results show that the thickness of the printing layer has the greatest impact on carbon emissions. When the layer thickness is 0.36 mm, the speed of the recoater is 0.22 m/s, the printing angle is (0°, 0°, 90°), and the single print quantity is 84, the total carbon emission is the lowest and 28.77% less compared to the parameter with the highest carbon emission. The average relative error of the predictive model is 1.929%. The results of this study can provide some new ideas for sustainable development of additive manufacturing technology. [ABSTRACT FROM AUTHOR]

ObjectivesThe influence of printing parameters on the marginal and internal fit of three-dimensional (3D) printed interim fixed partial dentures (IFPDs) has been understudied. This investigation sought to elucidate the impact of printing orientation and post-curing time on these critical factors.MethodsA total of 260 3-Unit IFDPs were printed using two different resins (130/NextDent C&B MFH and 130/ASIGA DentaTOOTH). For each material, specimens were printed with three different angulations (0-, 45-, and 90-degree in relation to the z-axis). Each was further divided into 4 groups (n = 10) according to post-curing time (30-, 60-, 90-, and 120 min), while the green state (GS) group at 0-degree remained without post-curing as a control. Each specimen was scanned and then superimposed on the original CAD file. The marginal and internal fit of premolar and molar restorations were evaluated using the silicone replica technique. Digital scanning of the master die, both with and without a fit checker, was followed by data superimposition to compare the master die with the fit checker of each sample. 3D comparisons were conducted using initial and best-fit alignment methods, and the root mean square error (RMS) was calculated to quantify marginal and internal fit at each abutment and for the overall restoration. Statistical analysis was performed using JMP® software (JMP®, Version 16, SAS Institute Inc., Cary, NC, USA, 1989–2022) with a significance level 0.05 for all tests.ResultsFor the ASIGA group, 0-degree orientation generally exhibited better fit than 45- and 90-degree orientations, with some variations based on post-cure time. For marginal fit, ASIGA crowns typically showed better results with 90-degree orientation, while NextDent crowns demonstrated consistent performance across orientations. Post-curing time also influenced marginal fit, with longer durations generally resulting in improved outcomes.ConclusionWith different printing orientations and post-curing times, ASIGA and NextDent resins can produce IFDPs with acceptable internal and marginal fit. However, NextDent resin consistently outperformed ASIGA in terms of overall fit. Further research is needed to evaluate the long-term clinical performance of these materials.

The direct ink writing (DIW) technique is considered efficient for manufacturing complex-shaped Cf/SiC composites. However, the SiC slurry with high load has poor flow ability and covering-fibers properties, resulting in numerous gaps between the ceramic matrix and fibers. This study utilized DIW to manufacture Cf/SiC composites and improved the slurry's printing ability by adjusting the binder content. Moreover, the printing parameters, such as the angle between the fiber nozzle and slurry nozzle and the slurry nozzle size, were optimized to enhance the accuracy of the body structure and the filling effect of the slurry on the fiber gaps. The results showed that a binder content of 0.4 wt% produced excellent thixotropic, viscoelastic, and shear thinning behavior in the slurry. By using a fiber nozzle angle of 60° and a nozzle diameter of 1.55 mm, the slurry effectively filled the gaps between the fiber bundle and matrix, reducing the number and size of pores in the SiC matrix. These improvements greatly enhance the density, strength, and fracture toughness of the Cf/SiC composites. Therefore, this research demonstrated that optimizing the printing parameters not only improved the structural accuracy of the printed bodies but also greatly enhanced the properties of the ceramic matrix composites. [ABSTRACT FROM AUTHOR]

3D printing technology has revolutionized product development in numerous industries. Due to 3D printing, innovative ways of directly giving drugs to patients, anatomical models for surgical planning and training, and tailored prosthetics and other medical equipment are all within the realm of possibility in the medical industry. 3D printing in healthcare has sparked a paradigm shift in creating medical implants and prosthetics. As a result of their exceptional mechanical, thermal, electrical, and optical qualities, polymers and composites made of them have gained widespread use in the medical industry. In this review article, we look at the most recent and cutting-edge benefits of 3D printing technology to create medical products out of polymers and composites. This article summarizes recent findings in patient-specific medical device and prosthesis design and manufacture and anatomical model development for surgical training and planning. Various 3D printing techniques, i.e., stereolithography, fused deposition modeling, and selective laser sintering methods, were examined, along with the pros and cons. Finally, we discuss the importance of 3D printing, which could significantly alter how medical devices are designed and produced, enhancing healthcare services and improving patient outcomes. [ABSTRACT FROM AUTHOR]

Copyright of Al-Nahrain Journal for Engineering Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The importance of geometrical control of three dimensional (3D) printable concrete without the support of formwork is widely acknowledged. In this study, a numerical model based on computational fluid dynamics was developed to evaluate the geometrical quality of a 3D printed layer. The numerical results were compared, using image analysis, with physical cross-sectional sawn samples. The influence of printing parameters (printing speed, nozzle height, and nozzle diameter) and the rheological behavior of printed materials (yield stress), on the geometrical quality of one printed layer was investigated. In addition, the yield zone of the printed layer was analyzed, giving insights on the critical factors for geometrical control in 3D concrete printing. Results indicated that the developed model can precisely describe the extrusion process, as well as the cross-sectional quality. [ABSTRACT FROM AUTHOR]

Aluminum–air (Al–air) batteries are considered one of the most promising next-generation energy storage devices. In this paper, we carry out an orthogonal experimental study on the SLM printing process parameters in 3D-printed Al–air battery anodes. The surface roughness, densification, and discharge performance of the electrodes under different process parameters are observed to reveal the effects of different process parameters on the forming quality and discharge performance of aluminum–air battery anodes. The results show that the laser power is the most important factor affecting the surface roughness of the porous aluminum anode, and the scanning spacing is the most important factor affecting the densification. The best printing parameters for the porous aluminum anode can be obtained when the laser power is 325 W, the scanning speed is 1000 mm/s, the scanning spacing is 0.12 mm, and the thickness of the powder spread is 0.03 mm. At this time, the surface roughness of the porous aluminum anode obtained by this process parameter is 15.01 μm, the densification is 94.97%, and the discharge is stable with a high value. In addition, we also carry out data validation to ensure that the data we obtain are optimal and valid. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, an additive manufacturing process for extruding fully compounded thermosetting elastomers based on fluorine-containing polymer compositions is reported. Additive manufacturing printers are designed with a dry ice container to precool filaments made from curable fluoroelastomer (FKM) and perfluoroelastomer (FFKM) compounds. A support tube guides the stiffened filament towards the printer nozzle. This support tube extends near the inlet to a printer nozzle. This approach allows low-modulus, uncured rubber filaments to be printed without buckling, a phenomenon common when 3D printing low-modulus elastomers via the fused deposition modeling (FDM) process. Modeling studies using thermal analyses data from a Dynamic Mechanical Analyzer (DMA) and a Differential Scanning Calorimeter (DSC) are used to calculate the Young's modulus and buckling force, which helps us to select the appropriate applied pressure and the nozzle size for printing. Using this additive manufacturing (AM) method, the successful printing of FKM and FFKM compounds is demonstrated. This process can be used for the future manufacturing of seals or other parts from fluorine-containing polymers. [ABSTRACT FROM AUTHOR]

Specimens with the structure of a face-centered cubic were produced using several sets of printing conditions. An experimental testing is conducted to carefully evaluate the microstructural analysis and compressive strength of this structure. The results include the measurement of mechanical properties, such as the peak stress. Fused deposition modeling is employed for the additive manufacturing of experimental specimens made from shape memory polymer thermoplastic polyurethane (MM-3520). We take into account the impact of printing factors on lattice structures, such as layer thickness, printing temperature, and printing speed. Analyzing the microstructure of the printed specimens exhibits that the specimens with highest printing temperature, lowest printing speed and thinner printing layer have better layers adhesion and lower porosities. All the mechanical tests are performed on specimens with the same structure and at a relatively constant density. Among the tested printing parameters, using a layer height of 0.1 mm, a printing temperature of 230 °C, and a printing speed of 20 mm/s yields the highest strength in the specimens. However, specimens printed with a layer height of 0.2 mm, a printing temperature of 220 °C, and a printing speed of 30 mm/s also exhibit good strength, albeit slightly lower than the maximum values. Additionally, when using these specific settings (0.3 mm – 210 °C – 40 mm/s), the mechanical qualities are minimized, yet the stress-strain curves exhibit characteristics similar to elastomers.

With the emergence and expansion of additive manufacturing processes, especially the fused deposition modeling process, extensive research has been conducted on these processes. One important research area is strengthening the printed parts by the fused deposition modeling method. One of the main areas of research is related to the strengthening of printed parts by the fused deposition modeling method. This process enables the production of complex structures and the customization of parts. On the other hand, polylactic acid material is one of the main materials used in this process, which has been noticed over other materials due to its biocompatibility and biodegradability properties. In this research, the effect of annealing heat treatment on the compressive strength and modulus of porous samples has been investigated with the approach of using them in tissue engineering as a scaffold for bone tissue. The samples are 3D printed with wiggle, grid, and honeycomb patterns and with filling percentages of 40, 70, and maximum. In addition, the effect of two parameters, the extrusion width, and the layer height, has also been investigated. To create porous structures with interconnected porosities, the pattern of filling in each layer is rotated to a certain extent, and this causes the introduction of new porous structures that can have wide applications such as being used as scaffolds in tissue engineering. After evaluating the compressive mechanical properties of the samples, the same samples were heat treated, and then their compressive mechanical properties were also evaluated. The obtained results show that the maximum compressive strength and modulus occur in the sample with an extrusion width of 0.6 mm, layer height of 0.25 mm, wiggle filling pattern, and maximum filling percentage. The values of compressive strength and modulus for the non-heat-treated sample are equal to 84.51 MPa and 2.28 GPa respectively and for the heat-treated sample, it is equal to 105.44 MPa and 2.29 GPa respectively. [ABSTRACT FROM AUTHOR]

With the growing global need for housing and infrastructure, 3D concrete printing (3DCP) has emerged as an innovative construction method offering several potential benefits including design flexibility, speed, and sustainability. However, enhancing the reliability of 3DCP involves managing a variety of parameters that influence various aspects of the 3D printed structure. Process parameters like nozzle velocity, nozzle diameter, nozzle height, and material flow velocity have a major impact on the structural stability and filament shape. This project aimed to develop fast and accurate data-driven models for predicting and classifying filament shape based on process parameters. A print experiment systematically varied process parameters across 144 samples. The resulting filament geometry (width, height, contact width) was measured and classified by quality. Models were trained on this data to predict filament width, contact width, filament height, and classify filaments. These models can be utilized with any buildable material -- a material with a high enough yield stress to bear the weight of upper layers without significant deformation. This condition does not restrict this study's scope as it is a prerequisite for all 3DCP applications. The models' robustness and generalizability were confirmed through validation on literature data across various printable materials and setups. These data-driven models can aid in optimizing parameters, generating variable width filaments, and printing non-planar layers. By linking print inputs to filament outputs, this comprehensive modeling approach advances 3DCP research for more reliable and versatile concrete printing. [ABSTRACT FROM AUTHOR]

The challenge of three‐dimensional (3D) printing by polymeric extrusion in tissue bioengineering is to control with precision the microarchitecture and porous interconnectivity of scaffolds, as well as search for models that allow and facilitate the development of personalized constructs that meet optimal characteristics for the regeneration of significant bone defects. In this study, anatomically accurate scaffolds were designed and printed to a critical size defect from a microtomography image of the rat calvaria. Different software is used to design a scaffold with exact anatomy. With Ultimaker Cura software, distinct printing parameters were standardized, permitting the printing of different types of pores and graded porosity scaffolds, with exact adaptation to the bone defect, utilizing a commercial 3D printer with a fused deposition modeling technique and compensating for the limitations of the method. The scaffolds were characterized by evaluating their mechanical properties and surface characteristics (pore size and porosity), employing scanning electron microscopy images, verifying that the size and shape of the pores were controlled, and evaluating cell viability and cell distribution on the 3D printed scaffold. Therefore, this work proves that by standardizing the printing parameters, it was possible to print a unique customized scaffold, controlling the shape and size of pores. [ABSTRACT FROM AUTHOR]

The advent of additive manufacturing also referred to as 3D printing, has brought about substantial changes in the industrial domain, as it possesses the capability to fabricate intricate items with enhanced cost‐efficiency and productivity. Fused Filament Fabrication (FFF) is a 3D printing process that has gained significant popularity due to its versatile capabilities and cost‐effectiveness. This paper investigates the impact of the printing parameters on the tensile characteristics of Triply Periodic Minimal Surface (TPMS) manufactured using FFF 3D printing. TPMS patterns have unique geometric properties and potential applications, making them an intriguing subject of study. The behavior of three different TPMS lattices with three printing parameters is investigated. Finding the best testing settings is done with the Taguchi method, and the data is analyzed with the Analysis of Variance (ANOVA) test. TPMS pattern was found to be the most effective parameter with 83.78%. While the highest strength was obtained in Schwarz diamond, the highest energy absorption was observed in the Gyroid structure. The contributions of printing parameters to tensile strength are line thickness, printing speed, and layer height, respectively. As line width and printing speed increase, both energy absorption and strength increase. Therefore, 0.40 mm line width and 60 mm/s printing speed give optimum values. When considered for energy absorption, the optimum value is 0.20 mm layer height, while when considered for strength, 0.10 mm layer height is the optimum value. The findings emphasize the importance of optimizing printing parameters for desired mechanical characteristics in 3D printed components and highlight the potential of TPMS structures in various applications. This research contributes to the growing knowledge in additive manufacturing and provides insights into optimizing FFF 3D printing for improved mechanical performance. [ABSTRACT FROM AUTHOR]

In this work we report the dramatic effects that changing the infill pattern has on the electrochemical performance of an additively manufactured electrode made from commercial filament. Electrodes were produced using six different slicing patterns and imaged to confirm how the infill pattern altered the working electrode surface. These electrodes were then electrochemically characterised against the near‐ideal outer sphere redox probe [Ru(NH3)6]3+, the common inner sphere probe [Fe(CN)6]3−, and then used for the electroanalytical determination of acetaminophen. It was found that changing the infill pattern had a dramatic effect on the electrochemical performance of the electrodes. Over the course of the manuscript, it can be seen that Aligned Rectilinear and Rectilinear infill patterns perform consistently well and offer good reproducibility. On the other hand, Concentric infill pattern had noticeably poor inter‐electrode reproducibility and the Hilbert Curve infill was one of the worst performing electrodes in many categories. For future work in this field, we recommend the infill pattern is always reported within the experimental section to allow other researchers to repeat work properly. Additionally, when optimising an electroanalytical sensing platform, we encourage researchers to optimise the infill pattern as it has direct influence on the analytical parameters. [ABSTRACT FROM AUTHOR]

Robocasting is an extrusion-based additive manufacturing (AM) process widely used to produce porous structures. It enables to build three-dimensional (3D) ceramic parts, thanks to computer numerical control of the filament deposition path onto a fabrication substrate. Despite its high potential, robocasting is much less explored than other AM techniques for producing dense parts. This work focused on the robocasting of dense alumina parts by varying the filament deposition path of an environmentally friendly paste. Taguchi method was used to establish a correlation between the printing parameters and the microstructural and mechanical properties of the sintered parts. Closed pores located between adjacent filaments were found to dictate crack propagation mechanisms, depending on the infill pattern. The optimal printing strategy led to 93% dense alumina samples having a flexural strength of 140 MPa, a Young's modulus of 355 GPa and a Poisson's ratio of 0.23. [ABSTRACT FROM AUTHOR]

This study explores the shape-morphing behavior of 4D-printed structures made from Polylactic Acid (PLA), a prominent bio-sourced shape-memory polymer. Focusing on the response of these structures to thermal stimuli, this research investigates how various printing parameters influence their morphing capabilities. The experimental approach integrates design and slicing, printing using fused deposition modeling (FDM), and a post-printing activation phase in a controlled laboratory environment. This process aims to replicate the external stimuli that induce shape morphing, highlighting the dynamic potential of 4D printing. Utilizing Taguchi's Design of Experiments (DoE), this study examines the effects of printing speed, layer height, layer width, nozzle temperature, bed temperature, and activation temperature on the morphing behavior. The analysis includes precise measurements of deformation parameters, providing a comprehensive understanding of the morphing process. Regression models demonstrate strong correlations with observed data, suggesting their effectiveness in predicting responses based on control parameters. Additionally, finite element analysis (FEA) modeling successfully predicts the performance of these structures, validating its application as a design tool in 4D printing. This research contributes to the understanding of 4D printing dynamics and offers insights for optimizing printing processes to harness the full potential of shape-morphing materials. It sets a foundation for future research, particularly in exploring the relationship between printing parameters and the functional capabilities of 4D-printed structures. [ABSTRACT FROM AUTHOR]

Despite the importance of process parameters in the printing of solid dosage forms using fused deposition modelling (FDM) technology, the field is still poorly explored. A design of experiment study was conducted to understand the complete set of process parameters of a custom developed FDM 3D printer and their influence on tablet disintegration time. Nine settings in the Simplify 3D printing process design software were evaluated with further experimental investigation conducted on the influence of infill percentage, infill pattern, nozzle diameter, and layer height. The percentage of infill was identified as the most impactful parameter, as increasing it parabolically affected the increase of disintegration time. Furthermore, a larger nozzle diameter prolonged tablet disintegration, since thicker extruded strands are generated through wider nozzles during the printing process. Three infill patterns were selected for in-depth analysis, demonstrating the clear importance of the geometry of the internal structure to resist mechanical stress during the disintegration test. Lastly, layer height did not influence the disintegration time. A statistical model with accurate fit (R2 = 0.928) and predictability (Q2 = 0.847) was created. In addition, only the infill pattern and layer height influenced both the uniformity of mass and uniformity of the disintegration time, which demonstrates the robustness of the printing process.

With the growing global need for housing and infrastructure, 3D concrete printing (3DCP) has emerged as an innovative construction method offering several potential benefits including design flexibility, speed, and sustainability. However, enhancing the reliability of 3DCP involves managing a variety of parameters that influence various aspects of the 3D printed structure. Process parameters like nozzle velocity, nozzle diameter, nozzle height, and material flow velocity have a major impact on the structural stability and filament shape. This project aimed to develop fast and accurate data-driven models for predicting and classifying filament shape based on process parameters. A print experiment systematically varied process parameters across 144 samples. The resulting filament geometry (width, height, contact width) was measured and classified by quality. Models were trained on this data to predict filament width, contact width, filament height, and classify filaments. These models can be utilized with any buildable material - a material with a high enough yield stress to bear the weight of upper layers without significant deformation. This condition does not restrict this study’s scope as it is a prerequisite for all 3DCP applications. The models’ robustness and generalizability were confirmed through validation on literature data across various printable materials and setups. These data-driven models can aid in optimizing parameters, generating variable width filaments, and printing non-planar layers. By linking print inputs to filament outputs, this comprehensive modeling approach advances 3DCP research for more reliable and versatile concrete printing.