Fused Deposition Modeling Technique Research Articles

Testing of Different Scanning Protocols Used for Precise 3D-printing of Mandibular Models.

Multidetector computed tomography (MDCT) is often necessary to manufacture 3D-printed medical models (MMs) required for mandibular restoration due to trauma or malignant tumor. Although cone-beam computed tomography (CBCT) is a preferable method of mandibular imaging, additional scanning is often unjustified. To test whether a single radiologic protocol could be used for mandibular reconstructions, the human mandible was scanned with 6 MDCT and 2 CBCT protocols and later 3D-printed using a fused-deposition modelling technique. Then, we assessed linear measures on the mandible and compared them with MDCT/CBCT digital scans and 3D-printed MMs. Our data revealed that CBCT0.25 was the most precise protocol for manufacturing 3D-printed mandibular MMs, which is expected considering its voxel size. However, we noted that CBCT0.35 and Dental2.0H60s MDCT protocols were of comparable accuracy, indicating that this MDCT protocol could be a single radiologic protocol used to scan both donor and recipient regions required for mandibular reconstruction.

Study on the Mechanical Behavior of a Dual-Density Hybrid Lattice Structure under Quasi-Static and Dynamic Compressions.

The dual-phase lattice structure composed of the matrix phase (MP) and the reinforcement phase (RP) is a novel hybrid lattice showing excellent energy absorption ability. However, the mechanical behavior of the dual-phase lattice structure under dynamic compression and the enhancement mechanism of the reinforcement phase have not been widely studied with the increase in compression speed. Based on the design requirements of dual-phase lattice materials, this paper combined octet-truss cell structures with different porosities, and the dual-density hybrid lattice specimens were fabricated via the fused deposition modeling technique. Under quasi-static and dynamic compressive loadings, the stress-strain behavior, energy absorption capacity, and deformation mechanism of the dual-density hybrid lattice structure were studied. The results showed that the quasi-static-specific energy absorption of the dual-density hybrid lattice structure was significantly higher than that of the single-density Octet lattice, and with the increase in compression strain rate, the effective specific energy absorption of the dual-density hybrid lattice structure also increased. The deformation mechanism of the dual-density hybrid lattice was also analyzed, and the deformation mode changed from an inclined deformation band to a horizontal deformation band when the strain rate changed from 10-3 s-1 to 100 s-1.

Experimental and numerical investigation of 3D-Printed bone plates under four-point bending load utilizing machine learning techniques

The fused deposition modeling (FDM) technique is widely used to produce components for various applications and has the potential to revolutionize orthopedic research through the production of custom-fit and readily available biomedical implants. The properties of FDM-produced implants are significantly influenced by processing parameters, with layer thickness being a crucial parameter. This study investigated the effect of layer thickness on the flexural properties of Polylactic Acid (PLA) bone plate implants produced by the FDM technique. Experimental results showed that the flexural strength is inversely proportional to the layer thickness due to the variation of voids in the specimens. A 3D finite element (FE) model was developed using Abaqus/Explicit software by incorporating the Gurson-Tvergaard (GT) porous plasticity model to predict the elastoplastic and damage behavior of specimens with different layer thicknesses. The characterization of the elastoplastic and GT parameters was done using a tensile test and by the calibration of a machine learning algorithm. It was shown that the FE model was able to predict the flexural behavior of 3D-printed solid plates with a maximum error of 6.13% in the maximum load. The optimal layer height was found to be 0.1 mm, providing both high flexural strength and adequate bending stiffness.

Comparison of wear and mechanical properties of cast and 3D printed CuSn10 bronze alloy

Abstract This paper aims to provide a comparison between properties of CuSn10 bronze alloy produced by two methods: FDM (fused deposition modelling) and casting. Wear behavior, mechanical performance and microstructure of CuSn10 alloy produced by FDM and casting methods were determined and compared. 3D printed parts were sintered at 875 °C for 5 h and casting was done at 1200 °C. The amount of porosity was determined by the metallographic cross-sectional examination. Vicker’s hardness, wear and tensile properties of samples were determined. As a result, the porosity value of the CuSn10 alloy produced by the FDM technique was determined as 5.07 ± 0.53%. Tensile strength values were 233.75 ± 18.48 MPa and 349.04 ± 5.10 MPa for CuSn10 alloys produced by FDM and casting methods respectively. While adhesive wear occurs in both production methods, it was observed that the FDM method reduced the wear resistance.

The impact of the mechanical properties of 3D Prints produced by the Fused Deposition Modelling technique on proper selection for selected application

The impact of the mechanical properties of 3D Prints produced by the Fused Deposition Modelling technique on proper selection for selected application

Application and evaluation of fused deposition modeling technique in customized medical products

The fused deposition modeling (FDM) technique has enormous potential for developing customized medical products with complicated structures. In this study, the application of the FDM technique to three medical products was investigated, and the risk factors affecting product quality were evaluated. For FDM-printed matrix and reservoir preparations, special attention should be paid to spacing width reduction and layered coating thickness. Therefore, spacing printing fidelity and interlayer bonding strength was established as unique indexes to characterize the effectiveness and safety of FDM-printed medicine. For FDM-printed orthopedic implants, layer height affected the dimensional deviation of surface morphology, which could be digitally evaluated. Moreover, internal structure affected the biomechanical behavior, which could be investigated using in silico simulation. The results reveal the broad application of FDM technology in customized medical products and might help to establish scientific and reasonable evaluation systems for them.

An Experimental Effort on Impact Properties of Polylactic Acid Samples Manufactured by Additive Manufacturing

Additive manufacturing (AM) has been highly popular in recent years and the number of scientific efforts on this useful manufacturing way has increased day by day. Up to now, the majority of the studies accumulated on the physical and mechanical properties of the three-dimensional (3D) printed specimens. In this paper, the impact properties of the additively manufactured polylactic acid (PLA) parts were addressed in detail. All specimens were manufactured by way of fused deposition modeling (FDM). After the manufacturing, hardness and surface roughness measurements were carried out to probe the effectiveness of the offered FDM technique. In order to detect impact features of the PLA specimens, Charpy v-notch impact tests were conducted and the influence of the notch angle was examined. As for the manufacturing parameters, the factor of infill density was altered and its effects on the impact behaviors of the specimens were established. Furthermore, micro and macro damage analyses were performed elaboratively on tested PLA specimens to comprehend the main mechanism of deformation better.

ANNbased prediction of the absorption characteristics of additive manufactured glycol‐modified polyethylene terephthalate nanocomposites reinforced with short‐carbon fibers and nanoclay fillers

AbstractIn this research work, an artificial neural network (ANN) based data driven prediction technique is proposed to evaluate the absorption characteristics of glycol‐modified polyethylene terephthalate (PETG) polymer nanocomposites reinforced with short carbon fibers (SCFs) and organically modified montmorillonite (OMMT) nanoclay (NC) fillers. The specimens are fabricated through additive manufacturing routine. The data points owing to the absorption of PETG nanocomposites are collected with the aid of the experimentation, which are then used to train the ANN model using Levenberg–Marquardt backward propagation algorithm. Different variants of PETG nanocomposites are prepared using various weight percentages of NC (1%, 3%, and 5%) and SCFs (5%, 10%, and 15%). The required filaments were prepared with the aid of compounding and extrusion processes. The specimens were printed using the fused deposition modeling technique. Further, the absorption behavior of these nanocomposites when exposed to distilled water, salt solution, and sugar solution has been experimentally studied following the ASTM D570 standard. The individual and combined effects of reinforcing OMMT‐NC and SCFs in the PETG matrix are also studied. The experimental results suggest that the absorption characteristics of PETG nanocomposites are significantly affected by the NC and SCFs reinforcements. The outcomes of this work will aid the design/material engineers in making a good trade‐off between the mechanical and absorption properties of the proposed PETG nanocomposites.

Development of sustainable 3D printing filaments using recycled/virgin ABS blends: Processing and characterization

AbstractWaste plastic exposed to the environment creates problems and is of significant concern for all life forms. To reuse the waste plastic in a well‐organized manner and make it more productive, extrusion‐based additive manufacturing, specially fused deposition modeling technique, can be an effective way. Hence, the primary objective of this work is to reuse ABS waste for developing sustainable three‐dimensional printing filaments. A mixed feedstock processing approach is used to develop filaments, in which recycled ABS is blended with virgin ABS in weight ratio of 10%–50%. The rheological and thermo‐mechanical properties of the extruded filaments were examined. Results indicated that increasing extrusion temperature from 190°C to 195°C produced significant physical changes in ABS blends. There is a breakdown of styrene acrylonitrile and butadiene component in ABS which causes strain hardening and material stiffening. The Young's modulus, yield strength and ultimate tensile strength of 80% RABS/20% VABS filament were found to be 2329, 34.814 and 40.82 MPa, respectively, which is close to VABS filament. The novel filament produced from recycled/virgin ABS blends has the capability to replace commercially available ABS filaments for fabricating high‐quality plastic parts through an additive manufacturing routine.

Surface Optimization of Components Obtained by Fused Deposition Modeling for Air-Plasma-Sprayed Ceramic Coatings

Additive manufacturing is an emerging disruptive 3D printing technology that is stimulating innovations in design and engineering, materials, and manufacturing thanks to the prospects of reducing cost and waste and increasing efficiency; in doing so, it presents the potential to have marked industrial, economic, and societal impacts. Thermoplastic polymers show some ideal characteristics for the most common additive manufacturing methods, and this aids in the improvement of the design accuracy and reliability and makes inroads for the customized manufacturing of high-design-flexibility polymer parts. Despite this, this material family is strongly sensitive to temperature, and one of the viable ways of limiting this weak point is surface coating with thermal barriers. The focus of this work was the optimization of an additive manufacturing process for producing thermoplastic components and to improve the adhesion of a thermal barrier coating on their surface. In detail, flat plate specimens of ULTEM 1010 were obtained by the fused deposition modeling technique by varying two significant surface parameters, the enhanced visible rasters and the visible raster air gap; then, their surfaces were covered by a thin ceramic coating by an air plasma spray system. A micro-geometric analysis that was conducted using a confocal microscope and the coating thickness measurements highlighted that a global larger roughness value, the presence of more flat peaks with a large area, and the complexity of the texture can be considered as supporting factors for improving the mechanical gripping and allowing a uniform adhesion of the coating powders on the thermoplastic substrate.

Shear Test Characterization of 3D Printed Polyamide Reinforced Carbon Fiber Composites

The issue of delamination occurring on PACF materials is a structural application failure due to poor mechanical strength. The bonding process of composite materials between layers using fused deposition modeling (FDM) printing affects the tensile strength of the material. The main objective of this study was to study the shear strength of polyamide reinforced carbon composite (PACF) materials by using shear test method and to study the effect of fractured or delamination surfaces during shear testing. In this study, PACF material was printed using FDM technique through Ultimate S3 machine. A total of 20 printed PACF specimens underwent a semi-overlapping adhesion process using Loctite E-20HP epoxy adhesive which required curing for 24 hours at room temperature. Shear test methods were performed on PACF composite specimens using Universal Testing Machine. Furthermore, PACF samples were conducted experiments to determine the physical properties of the composites of the material as well as Scanning Electron Microscopy (SEM) experiments through fractured or eliminated surfaces. Based on the results obtained, the PACF material has a high shear tensile strength compared to that of epoxy adhesives with an average rate of 1.6 MPa respectively. This is may due to the low curing temperature and the thick epoxy layer. It was observed that the FDM printing method produces a porous print layer that can facilitate delamination to occur.

On the Pin-Bearing Strength of Additively Manufactured Polymer Parts

Due to the wide scope of applications of additive manufacturing (AM) in making final products, the mechanical strength of AM parts has become very important. Therefore, different tests are being developed to determine the structural integrity of three-dimensional printed components. In this respect, the pin-bearing test is designed to evaluate the response of a fastener, plate, and hole to stress. In this study, two different polymer materials were used to fabricate the samples utilizing the fused deposition modeling technique. Since the specimen width and hole diameter have effects on the pin-bearing strength and structural integrity of the parts, we prepared the specimens with four hole diameters to determine the influence of this ratio. A series of tensile tests were performed, and the stiffness and pin-bearing strength of additively manufactured specimens were determined. The preferred bearing failure mode was observed in several tested specimens. Subsequently, a scanning electron microscope investigation was conducted on the damaged area of the examined specimens to obtain insights into the damage mechanisms and failure behavior of the aforementioned specimens. We used digital image correlation technique to determine the strain field of dumbbell-shaped test coupons. The results of this research can be utilized for new designs of AM parts with a higher mechanical strength.

Deformation and failure of additively manufactured Voronoi foams under dynamic compressive loadings

Additive manufacturing (AM) enables the design and fabrication of foams with intricate cell architectures for enhanced mechanical performances in blast and impact mitigation applications. Although the crushing response of AM foams has been studied recently, there is limited research on their failure behaviours under dynamic loading. This work investigates the response of AM Voronoi foams under compressive loadings through a combined experimental and numerical effort, with the emphasis on the failure behaviour and its modelling. Voronoi foams with uniform and graded density distributions were fabricated via the Fused Deposition Modeling technique. Quasi-static (0.001 s−1) and low-speed impact (50 s−1) tests were carried out to quantify the mechanical response and to characterise the deformation and failure behaviours. Computational models of the Voronoi foams were built in ABAQUS and validated with the experiment to provide insights into the dynamic fracture behaviours. Results showed that although failure plays a minor role in the quasi-static loading case, dynamic compressive loading can yield complex fracture behaviours involving cell-wall buckling, cell-wall rupturing, large-scale shattering and shear band localisation, resulting in significant stress softening and strong stress fluctuations during the post-yield response. Consequently, the load-bearing and energy absorbing capacities materially deteriorated when transiting from quasi-static to dynamic loading conditions. The results reported in this work provide valuable guidance on the design of AM foams under dynamic loadings.

Evaluation of energy absorption enhancement of additively manufactured polymer composite lattice structures

The unique compressive behaviour of lattice cubic structures as well as their high specific strength and significant energy absorbing characteristics makes them an attractive solution for crashworthiness applications. Hence in this research study, the crashworthiness behaviour and energy absorbing characteristics of the thermoplastic polymer composite lattice cubic structures were experimentally investigated under quasi-static compression. Four design patterns such as Cuboctahedron, Kelvin cell, Truncated cube in square and dividend square geometrics were considered and fabricated through fused deposition modelling technique. The proposed structures were additively manufactured with four different thermoplastic polymer based filament materials and their influence on the crashworthiness characteristics were investigated experimentally. The obtained results revealed that the PLA-CF based KC configuration exhibited SEA of 2.50 kJ g−1 and the maximum value of CFE is 84.91% for PETG-CF based KC configuration. Furthermore, the experimental results indicated that the proposed thermoplastic polymer composite based lattice cubic structures are potentially a suitable component for crashworthiness applications owing to their significant energy absorption ability.

Characterisation of 3D printed meta-structure PLA substrate for patch antenna applications in S-Band

ABSTRACT A novel approach for the dielectric characterisation of 3D printed substrates in S-band applications of patch antennas with different infill percentages is presented in this paper. The meta-structure substrate design has been 3D printed with a fused deposition modelling technique using bio-sourced material poly-lactic acid (PLA). Combining different infill patterns changes the dielectric parameters, and hence, the RF(Radio-Frequency) performance of the design. To validate the usefulness of this approach, the Taguchi sampling technique is used, where nine samples of a meta-structure substrate were designed to determine the dielectric properties of the substrate. The ring resonator technique is used for measuring the dielectric constant and loss tangent of the fabricated substrates. All nine meta-structure substrate shows varying dielectric properties, which can be used for tuning of RF characteristics of the patch antenna. The measured permittivity of various substrate structures ranges between 2.39 and 2.71. The concept of propagation delay is chosen as the selective parameter for the fabrication of the antenna. The results of antenna simulation and fabrication were mapped closely. The proposed meta-structure design antenna resonates at 2.43 GHz with an S 11 of −26.60 dB. Gain enhancement of 5% is seen in the selected meta-structure design compared with the simple (solid) structure. This meta-structure substrate design approach using different patterns is simple, scalable and can be realised in other 3D printed antenna applications.

Preliminary Study on Mechanical Properties of 3D-Printed Carbon-PLA Filament with Different Printing Orientation for SUAV Wings Application

This article focuses on the production of tensile test (ASTM D638-03) specimens using fused deposition modelling technique as preliminary study for preparation of 3D-printed SUAV wings. Carbon-PLA (nylon 6/66 copolymer adding with 20% of carbon fiber) was used as 3D filament. There were 7 printing orientations: 0o, 15o, 30o, 45o, 60o, 75o, and 90o based on tensile axis with 3 specimens for each direction (21 specimens in total). Printing parameters were set using open-source slicing application CURA. It was found delamination and fracture outside the gauge length causing high deviation of the mechanical properties value. So, the result of the testing test seems like do not comply with theoretical aspect of relationship between fiber orientation and tensile properties of composite materials. Taking care of printing parameters and increasing the number of specimens has an opportunity to achieve high precision results since precise data is crucial as a starting point for the development of SUAV wings.

Finite Element Analysis in the Balancing Phase for an Open Source Transfemoral Prosthesis with Magneto-Rheological Damper

The article presents a finite element simulation for the stress analysis of a transfemoral prosthesis with damping for a 100 kg person in the balancing phase. The maximum force is exerted at this stage when the person supports his or her whole body on a single foot. Materials used included stainless steel and polymer matrix composites, for which mechanical testing was performed. The study applied the SolidWorks simulation software tools, where material properties were specified for each part that composes the prosthesis and considered loads, the fastenings, and the meshing. The simulation resembles the manufacturing process for each component, including the sole built by the novel composite fused deposition modeling technique. As a result of the simulation, the stress, displacement fields, and safety factor are obtained. Analysis of the safety factor indicates that the components can withstand the loads imposed. Finally, a fatigue analysis indicated that the most critically loaded component lasts at least 294,107 cycles at maximum constant loading.

Effects of Post-UV-Curing on the Flexural and Absorptive Behaviour of FDM-3D-Printed Poly(lactic acid) Parts

In this study, the effects of the post-ultraviolet-curing process on the flexural, absorptive, and morphological properties of poly(lactic acid) specimens produced using a fused deposition modelling technique 3D printer were experimentally investigated. In this direction, 15, 30, 45, and 60 min post-UV-curing processes were applied to poly(lactic acid) three-point bending and absorption specimens produced at 190 and 200 °C. Three-point bending tests and morphological analyses were applied after the post-ultraviolet-curing process, and absorption tests were applied by immersing the post-ultraviolet-cured specimens in a distilled water bath for 1-, 3-day, and 1-, 2-, and 4-week exposure times. The changes in flexural strain properties for each experimental parameter were also simulated by the computer-aided finite element analysis and compared with the experimental results. It was observed that the post-ultraviolet-curing process increased the flexural strength of the poly(lactic acid) specimens produced at both 190 and 200 °C with the same increasing trend up to 30 min of exposure, and the most significant increase was determined in the specimens that were subjected to post-ultraviolet-curing for 30 min. Although the flexural strengths of the post-ultraviolet-cured specimens were higher than the non-cured specimens in all conditions, it was detected that they tended to decrease after 30 min.

Process parameter optimisation of fused deposition modelling for augmenting the strength of nylon-aramid PMC’s

In mechanical parts and components, the strength of the material plays a vital role for its effective functioning. For certain individual materials, the enhancement on its quality of strength must be performed at the initial development stage and can rarely be performed using post processing techniques. 3-D printed Polymer Matrix Composites (PMC’s) are one such material. The current research focuses on augmenting the strength of nylon-aramid PMC’s, using Fused Deposition Modelling (FDM) 3-D printing technique. The 3-D printed material was tested according to ASTM standards for mechanical properties such as compression, tensile, flexural and impact strength. Since the association amongst the mechanical properties and the processing parameters of FDM is challenging to verify, an effort was attempted to obtain an empirical formula using the Taguchi Technique of Optimisation. The influencing processing parameters in the FDM technique, such as infill part, layer thickness, print temperature, raster angle, infill pattern style and density were optimised using Taguchi analysis combined with Multi-Response Performance Index (MPI), to enhance the Tensile, Flexural, Impact and Compression Strength, thereby augmenting the total strength of the FDM component. Thedevelopment of the FDM component used these optimised levels again. The mechanical properties were validated according to the ASTM standards of testing. The optimisation technique using T-DoE indicated that the similarity between the computed values from the regression equation and the measured with minimalistic deviations. The research concluded that for a print temperature of 300 °C, layer thickness of 0.4 mm, raster angle of 90°, infill part density of 90 %, and having a rectilinear style of infill pattern, provided an optimal levels of process parameters for augmenting the strength of 3-D printed Nylon-Aramid PMC’s.

A study in EDM electrode manufacturing using additive manufacturing

Electrode can be manufacture by conventional as well as non-conventional processes like Thermal spraying and Additive manufacturing (AM). In AM mostly Fused Deposition Modeling (FDM) and Laser Sintering (LS) are used. The selection of a proper manufacturing process has a very vital role when it comes to output characteristics of Electrodes. In this paper Authors have reviewed LS and FDM based EDM tool manufacturing processes. The purpose of this study is to present significant findings about effective EDM electrode manufacturing using LS and FDM. It was concluded that, the RP made tool electrode can be used where higher surface finish are desired and MRR and TWR can be neglected. The electrode manufactured using FDM techniques promising results for rough cutting and semi-finishing cut in EDM operations.