Parametric process optimization to improve the accuracy and mechanical properties of 3D printed parts

MRS Advances ◽  
2018 ◽  
Vol 4 (24) ◽  
pp. 1383-1392
Author(s):  
Amirhossein Hakamivala ◽  
Amirali Nojoomi ◽  
Alieh Aminian ◽  
Arghavan Farzadi ◽  
Noor Azuan Abu Osman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Response Surface Methodology ◽  
Vertical Direction ◽  
Dimensional Accuracy ◽  
Efficient Design ◽  
Dimensional Error ◽  
Higher Dimensional ◽  
3D Printed ◽  
Cost Efficient

ABSTRACTInvestigating the mechanical properties and dimensional accuracy of 3D printed parts is an important step towards achieving optimum printing conditions. This condition, which leads to the fabrication of parts with appropriate mechanical properties and accuracy, is achieved by studying the effect of different process parameters on the final structure. In this work, Response Surface Methodology (RSM) was employed to design specified experiments to investigate the effects of layer thickness, printing orientation and delay, on the compressive strength and dimensional error of the parts. The results show that an increase in the delay time in X orientation results in better binder spreading and uniformity followed by improvement in the compression strength. Furthermore, more binder spreads in the vertical direction leads to the higher dimensional error in the Z direction. The results proved that the RSM provides a time and cost-efficient design to print the prototypes with optimum strength and dimensional error.

Enhancement of the Compressive Strength of 3D-Printed Polylactic Acid(PLA) by Controlling Internal Pattern

2021 ◽  
Vol 1023 ◽  
pp. 75-81
Author(s):  
Aappo Mustakangas ◽  
Atef Hamada ◽  
Antti Järvenpää
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Polylactic Acid ◽  
Optical Microscope ◽  
Fused Filament Fabrication ◽  
Loading Direction ◽  
Compressive Flow ◽  
3D Printed ◽  
Cost Efficient ◽  
Loading Axis

Cost-efficient 3D-printing can create a lot of new opportunities in engineering as it enables rapid prototyping of models and functional parts. In the present study, Polylactic acid (PLA) cubic specimens with different types of infill patterns (IPs), rectilinear, grid and cuboid, were additively manufactured by Fused Filament Fabrication 3D-printing. The PLA cubes are fabricated with one perimeter and different IPs density (10, 20, and 30%). Subsequently, the compressive strengths of the PLA materials were measured in two loading directions, i.e., the layers building direction is parallel (PD) to the loading axis and perpendicular (ND) to the loading direction. An optical microscope was used to examine the deformed IPs in both loading directions. The compressive flow stress curves of the PLA cubes infilled with rectilinear and grid patterns exhibited strong fluctuations with lower compressive strengths in the loading direction along ND. The PLA with 30% grid IP revealed a superior strength of ~12 kN in the loading direction along PD. On the contrary, the same material exhibited a worst compressive strength 3 kN along ND.

scholarly journals Comparison of Dental Stone Models and Their 3D Printed Acrylic Replicas for the Accuracy and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4066
Author(s):  
Marta Czajkowska ◽  
Ewa Walejewska ◽  
Łukasz Zadrożny ◽  
Monika Wieczorek ◽  
Wojciech Święszkowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Impact Strength ◽  
Physical Properties ◽  
Diagnostic Tool ◽  
Medical Records ◽  
Diagnostic Value ◽  
Dental Models ◽  
3D Printed ◽  
The Impact

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces. The mechanical properties of acrylic and stone samples, specifically the impact strength, shore D hardness, and flexural and compressive strength were investigated according to ISO standards. The matching of models’ surfaces was the highest on the level of peaks of cusps (average lack of deviations, 0.21 mm) and the lowest on the level of all teeth surfaces (average lack of deviations, 0.64 mm). Acrylic samples subjected to mechanical testing, as expected, showed higher mechanical properties as compared to the specimens made of dental stone. In the present study we demonstrated that 3D printed acrylic models could be ideal representatives in the case of use as a diagnostic tool and as a part of medical records. The acrylic samples exhibited not only higher mechanical properties, but also showed better accuracy comparing to dental stone.

scholarly journals Additive Manufacturing of Bone Scaffolds Using PolyJet and Stereolithography Techniques

2021 ◽  
Vol 11 (16) ◽  
pp. 7336
Author(s):  
Shummaila Rasheed ◽  
Waqas Akbar Lughmani ◽  
Muhannad Ahmed Obeidi ◽  
Dermot Brabazon ◽  
Inam Ul Ahad
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Dimensional Accuracy ◽  
Human Bone ◽  
Compression Tests ◽  
3D Scaffold ◽  
Bone Scaffolds ◽  
3D Printed ◽  
Printing Direction ◽  
Printing Techniques

In this study, the printing capability of two different additive manufacturing (3D printing) techniques, namely PolyJet and micro-stereolithography (µSLA), are investigated regarding the fabrication of bone scaffolds. The 3D-printed scaffold structures are used as supports in replacing and repairing fractured bone tissue. Printed bone scaffolds with complex structures produced using additive manufacturing technology can mimic the mechanical properties of natural human bone, providing lightweight structures with modifiable porosity levels. In this study, 3D scaffold structures are designed with different combinations of architectural parameters. The dimensional accuracy, permeability, and mechanical properties of complex 3D-printed scaffold structures are analyzed to compare the advantages and drawbacks associated with the two techniques. The fluid flow rates through the 3D-printed scaffold structures are measured and Darcy’s law is applied to calculate the experimentally measured permeability. The Kozeny–Carman equation is applied for theoretical calculation of permeability. Compression tests were performed on the printed samples to observe the effects of the printing techniques on the mechanical properties of the 3D-printed scaffold structures. The effect of the printing direction on the mechanical properties of the 3D-printed scaffold structures is also analyzed. The scaffold structures printed with the µSLA printer demonstrate higher permeability and mechanical properties as compared to those printed using the PolyJet technique. It is demonstrated that both the µSLA and PolyJet printing techniques can be used to print 3D scaffold structures with controlled porosity levels, providing permeability in a similar range to human bone.

scholarly journals Influence of curing age on high-temperature properties of additive manufactured geopolymer mortar

2020 ◽  
Vol 218 ◽  
pp. 03019
Author(s):  
Xiaohong Yin ◽  
Xiaodong Wang ◽  
Yuan Fang ◽  
Zhu Ding
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Flexural Strength ◽  
High Temperature Properties ◽  
Before And After ◽  
3D Printed ◽  
Curing Age

Some researches have been conducted on the application of geopolymer in 3D printing. However, there is no publication about the high-temperature properties of 3D printed geopolymer made from fly ash, slag, and metakaolin. This paper presents the experimental research on the mechanical properties of 3D printed geopolymer after being exposed to elevated empratures. The effects of curing age on high-temperature properties are analyzed. The heating temperasures were 300 °C, 600 °C, and 900 °C, and the holding time was one hour. After exposure to temperatures, the flexural strength of 3D printed geopolymer exhibited different change trends with increasing curing age for different exposure temperatures. Before and after exposure to elevated temperature, the 3D printed geopolymer experienced significant anisotropic compressive strengths. The change trends of compressive strength at different exposure temperatures wit hincreasing curing ages were different from each other on different loading directions.

scholarly journals Evaluation of the Mechanical Properties of a 3D-Printed Mortar

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4104 ◽  
Author(s):  
Hojae Lee ◽  
Jang-Ho Jay Kim ◽  
Jae-Heum Moon ◽  
Won-Woo Kim ◽  
Eun-A Seo
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Nozzle Height ◽  
Number Of Layers ◽  
3D Printed ◽  
Bond Strengths ◽  
Physical Impact ◽  
Direct Tensile ◽  
Direct Tensile Strength ◽  
Tensile Bond Strengths

The mechanical properties of 3D-printed mortars are determined in terms of their compressive and direct tensile bond strengths. To determine such properties using existing methods, a preliminary experiment was conducted. The compressive strength of the printed mortar was compared to mold-casted specimens and it was found that the compressive strength decreased by ~30%. Among the fabrication variables, an increase in nozzle height negatively influenced the direct tensile bond strength. For the same conditions and age, the direct tensile strength decreased by as much as 16–29% when the number of layers increased from 2 to 6. When the specimens were fabricated using a specially designed stainless steel frame and core drill, followed by extraction and the application of physical impact, the 28 days compressive strength of the specimen decreased by ~50%.

scholarly journals Additive Manufacturing of PLA-Based Composites Using Fused Filament Fabrication: Effect of Graphene Nanoplatelet Reinforcement on Mechanical Properties, Dimensional Accuracy and Texture

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 799 ◽  
Author(s):  
Miguel Caminero ◽  
Jesús Chacón ◽  
Eustaquio García-Plaza ◽  
Pedro Núñez ◽  
José Reverte ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Impact Strength ◽  
Dimensional Accuracy ◽  
Fused Filament Fabrication ◽  
Graphene Nanoplatelet ◽  
Graphene Composite ◽  
General Terms ◽  
3D Printed ◽  
Composite Samples

Fused filament fabrication (FFF) is a promising additive manufacturing (AM) technology due to its ability to build thermoplastics parts with advantages in the design and optimization of models with complex geometries, great design flexibility, recyclability and low material waste. This technique has been extensively used for the manufacturing of conceptual prototypes rather than functional components due to the limited mechanical properties of pure thermoplastics parts. In order to improve the mechanical performance of 3D printed parts based on polymeric materials, reinforcements including nanoparticles, short or continuous fibers and other additives have been adopted. The addition of graphene nanoplatelets (GNPs) to plastic and polymers is currently under investigation as a promising method to improve their working conditions due to the good mechanical, electrical and thermal performance exhibited by graphene. Although research shows particularly promising improvement in thermal and electrical conductivities of graphene-based nanocomposites, the aim of this study is to evaluate the effect of graphene nanoplatelet reinforcement on the mechanical properties, dimensional accuracy and surface texture of 3D printed polylactic acid (PLA) structures manufactured by a desktop 3D printer. The effect of build orientation was also analyzed. Scanning Electron Microscope (SEM) images of failure samples were evaluated to determine the effects of process parameters on failure modes. It was observed that PLA-Graphene composite samples showed, in general terms, the best performance in terms of tensile and flexural stress, particularly in the case of upright orientation (about 1.5 and 1.7 times higher than PLA and PLA 3D850 samples, respectively). In addition, PLA-Graphene composite samples showed the highest interlaminar shear strength (about 1.2 times higher than PLA and PLA 3D850 samples). However, the addition of GNPs tended to reduce the impact strength of the PLA-Graphene composite samples (PLA and PLA 3D850 samples exhibited an impact strength about 1.2–1.3 times higher than PLA-Graphene composites). Furthermore, the addition of graphene nanoplatelets did not affect, in general terms, the dimensional accuracy of the PLA-Graphene composite specimens. In addition, PLA-Graphene composite samples showed, in overall terms, the best performance in terms of surface texture, particularly when parts were printed in flat and on-edge orientations. The promising results in the present study prove the feasibility of 3D printed PLA-graphene composites for potential use in different applications such as biomedical engineering.

scholarly journals Effect of layer printing delay on mechanical properties and dimensional accuracy of 3D printed porous prototypes in bone tissue engineering

2015 ◽  
Vol 41 (7) ◽  
pp. 8320-8330 ◽  
Author(s):  
Arghavan Farzadi ◽  
Vicknes Waran ◽  
Mehran Solati-Hashjin ◽  
Zainal Ariff Abdul Rahman ◽  
Mitra Asadi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Dimensional Accuracy ◽  
3D Printed

Mechanical isotropy and postcure shrinkage of polydimethylsiloxane printed with digital light processing

2020 ◽  
Vol 26 (8) ◽  
pp. 1447-1452
Author(s):  
Dong Sung (Danny) Kim ◽  
Jakkrit Suriboot ◽  
Chin-Cheng Shih ◽  
Austin Cwiklik ◽  
Melissa A. Grunlan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Design Methodology ◽  
Good Accuracy ◽  
Dimensional Accuracy ◽  
Dimensional Error ◽  
Digital Light Processing ◽  
Content Type ◽  
Post Exposure ◽  
Exposure Conditions

Purpose This paper aims to investigate the printability of photocurable PDMS with digital light processing (DLP) in terms of dimensional accuracy, mechanical properties, isotropy and postcure shrinkage. Design/methodology/approach The photocurable PDMS was made from methacrylated PDMS-macromer and 2,4,6-Trimethylbenzoyldi-Phenylphosphinate (TPO-L) photoinitiator. The PDMS was printed using different orientations, sizes and post-exposure conditions and then evaluated by tensile test and microscope to determine the printability. Findings Printed parts show good accuracy and low shrinkage, but high directionality in modulus, ductility and strength. The dimensional error is less than 2% and the shrinkage rates are less than 0.52%. In contrast, the modulus varies between 0.87 and 0.96 MPa depending on print orientation, elongation varies from 34.7% to 66.4% and strength varies from 0.23 to 0.49 MPa. Originality/value This study quantitatively characterizes the printability of photo curable PDMS with DLP, which has not been reported elsewhere. This paper also discusses the challenges of PDMS printing for future advancement.

Mechanical Performance Analysis of ULTEM 9085 in a Heated, Irradiated Environment

2018 ◽  
Author(s):  
Matthew B. Ng ◽  
Sean N. Brennan
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Radiation Environment ◽  
Inspection System ◽  
Control Group ◽  
Inspection Systems ◽  
3D Printed ◽  
Cost Efficient

This paper investigates the thermal and radiation performance of 3D-printed ULTEM materials following ASTM standard D638. ULTEM is a thermoplastic in the polyetherimide (PEI) family that is regularly used as a high-grade material for 3D printing. This material has similar properties to polyether ether ketone (PEEK), which is another thermoplastic that has strong mechanical properties at elevated temperature conditions. While PEEK has stronger mechanical properties, ULTEM is significantly more cost efficient to acquire and process via 3D printing. Also, most 3D printers are unable to utilize PEEK because of the significantly higher temperature requirements this material imposes on a 3D printer. This work is motivated by the need to rapidly deploy robotic inspection systems within a nuclear canister environment, which exposes the material to temperatures up to 170°C (340°F), and radiation levels of 270 Gy/hr (27 krad/hr), which are significantly beyond that of conventional 3D-printed parts. The design analysis was performed via an experiment consisting of three treatment groups of dogbone ULTEM test pieces. After tensile testing all of the pieces, the material properties were compared to those of the control group. These results allow manufacturers to select a more cost-effective material to build parts to operate in such a harsh high-temperature, high-radiation environment, which could include applications in both space systems and nuclear inspection robotics. Specifically, the results were used to guide the development of a robust robotic inspection system for the Nuclear Energy University Program (NEUP) by replacing complex parts with easily-fabricated 3D-printed ULTEM pieces.

Assessing the Mechanical Properties of 3D Printed Bio-Inspired Structures and Integrating Them Into a Product

2021 ◽  
Author(s):  
Binjamin Perelman ◽  
Vishal S. Sharma
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Sandwich Panel ◽  
Permanent Deformation ◽  
Design Feature ◽  
Honeycomb Structure ◽  
The Novel ◽  
Cell Radius ◽  
Enamel Structure ◽  
3D Printed

Abstract The Honeycomb structure is one of the most common natural structures used in sandwich panel cores. The Enamel structure’s mechanical properties were compared to the Honeycomb structure’s mechanical properties to investigate if the Enamel structure can improve the compressive strength, stiffness and energy absorption capabilities of sandwich panel cores and potentially replace the common Honeycomb structure. Also, the optimal cellular configurations for the Honeycomb and Enamel structures were explored. Indeed, it was found the Enamel structure can potentially replace the Honeycomb structure and a wall thickness of 1.2 mm and a wall length/cell radius of 8.14 mm will maximize the natural structures mechanical properties. Furthermore, it was found that both the natural structures have good compressive strength. Therefore, the natural structures with their optimal cellular configurations were integrated into a novel automobile floor mat to ensure the mat possesses good compressive strength to resist failure or permanent deformation. Moreover, the novel automobile floor mat has a design feature that offers an efficient debris capturing and removal system that adds value to the automobile floor mat.

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