Mechanical properties of 3D printed material with binder jet technology and potential applications of additive manufacturing in seismic testing of structures

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

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EFFECT OF EXTRUSION PROCESS PARAMETERS ON MECHANICAL PROPERTIES OF 3D PRINTED PLA PRODUCT

Journal of Mechanical Engineering and Mechatronics ◽

10.33021/jmem.v6i2.1573 ◽

2021 ◽

Vol 6 (2) ◽

pp. 119

Author(s):

Nanang Ali Sutisna ◽

Rakha Amrillah Fattah

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Fused Deposition Modeling ◽

Extrusion Process ◽

Experimental Procedure ◽

Fused Deposition ◽

Novel Approach ◽

Deposition Modeling ◽

3D Printed ◽

3D Digital Models

The method of producing items through synchronously depositing material level by level, based on 3D digital models, is named Additive Manufacturing (AM) or 3D-printing. Amongs many AM methods, the Fused Deposition Modeling (FDM) technique along with PLA (Polylactic acid) material is commonly used in additive manufacturing. Until now, the mechanical properties of the AM components could not be calculated or estimated until they've been assembled and checked. In this work, a novel approach is suggested as to how the extrusion process affects the mechanical properties of the printed component to obtain how the parts can be manufactured or printed to achieve improved mechanical properties. This methodology is based on an experimental procedure in which the combination of parameters to achieve an optimal from a manufacturing experiment and its value can be determined, the results obtained show the effect of the extrusion process affects the mechanical properties.

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DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels

Polymers ◽

10.3390/polym12081655 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1655 ◽

Cited By ~ 4

Author(s):

Giuseppe Melilli ◽

Irene Carmagnola ◽

Chiara Tonda-Turo ◽

Fabrizio Pirri ◽

Gianluca Ciardelli ◽

...

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Carboxymethyl Cellulose ◽

Biomedical Applications ◽

Digital Light Processing ◽

Chemically Modified ◽

Significant Step ◽

3D Printed ◽

Biomedical Field

The development of new bio-based inks is a stringent request for the expansion of additive manufacturing towards the development of 3D-printed biocompatible hydrogels. Herein, methacrylated carboxymethyl cellulose (M-CMC) is investigated as a bio-based photocurable ink for digital light processing (DLP) 3D printing. CMC is chemically modified using methacrylic anhydride. Successful methacrylation is confirmed by 1H NMR and FTIR spectroscopy. Aqueous formulations based on M-CMC/lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator and M-CMC/Dulbecco’s Modified Eagle Medium (DMEM)/LAP show high photoreactivity upon UV irradiation as confirmed by photorheology and FTIR. The same formulations can be easily 3D-printed through a DLP apparatus to produce 3D shaped hydrogels with excellent swelling ability and mechanical properties. Envisaging the application of the hydrogels in the biomedical field, cytotoxicity is also evaluated. The light-induced printing of cellulose-based hydrogels represents a significant step forward in the production of new DLP inks suitable for biomedical applications.

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Superior Mechanical Behavior and Fretting Wear Resistance of 3D-Printed Inconel 625 Superalloy

Applied Sciences ◽

10.3390/app8122439 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2439 ◽

Cited By ~ 8

Author(s):

Yong Gao ◽

Mingzhuo Zhou

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Wear Resistance ◽

Additive Manufacturing ◽

High Hardness ◽

Fretting Wear ◽

Inconel 625 ◽

3D Printed ◽

Inconel 625 Superalloy ◽

Electron Beam Selective Melting

Additive manufacturing (AM) nickel-based superalloys have been demonstrated to equate or exceed mechanical properties of cast and wrought counterparts but their tribological potentials have not been fully realized. This study investigates fretting wear behaviors of Inconel 625 against the 42 CrMo4 stainless steel under flat-on-flat contacts. Inconel 625 is prepared by additive manufacturing (AM) using the electron beam selective melting. Results show that it has a high hardness (335 HV), superior tensile strength (952 MPa) and yield strength (793 MPa). Tribological tests indicate that the AM-Inconel 625 can suppress wear of the surface within a depth of only ~2.4 μm at a contact load of 106 N after 2 × 104 cycles. The excellent wear resistance is attributed to the improved strength and the formation of continuous tribo-layers containing a mixture of Fe2O3, Fe3O4, Cr2O3 and Mn2O3.

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Additive Manufacturing of Bone Scaffolds Using PolyJet and Stereolithography Techniques

Applied Sciences ◽

10.3390/app11167336 ◽

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.

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Property Analysis of Photo-Polymerization-Type 3D-Printed Structures Based on Multi-Composite Materials

Applied Sciences ◽

10.3390/app11188545 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8545

Author(s):

So-Ree Hwang ◽

Min-Soo Park

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Composite Materials ◽

3D Printing ◽

Bending Test ◽

3D Printer ◽

Complex Structures ◽

Photo Polymerization ◽

Anisotropic Structures ◽

3D Printed

Additive manufacturing, commonly called 3D printing, has been studied extensively because it can be used to fabricate complex structures; however, polymer-based 3D printing has limitations in terms of implementing certain functionalities, so it is limited in the production of conceptual prototypes. As such, polymer-based composites and multi-material 3D printing are being studied as alternatives. In this study, a DLP 3D printer capable of printing multiple composite materials was fabricated using a movable separator and structures with various properties were fabricated by selectively printing two composite materials. After the specimen was fabricated based on the ASTM, the basic mechanical properties of the structure were compared through a 3-point bending test and a ball rebound test. Through this, it was shown that structures with various mechanical properties can be fabricated using the proposed movable-separator-based DLP process. In addition, it was shown that this process can be used to fabricate anisotropic structures, whose properties vary depending on the direction of the force applied to the structure. By fabricating multi-joint grippers with varying levels of flexibility, it was shown that the proposed process can be applied in the fabrication of soft robots as well.

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Comparison between Tests and Simulations Regarding Bending Resistance of 3D Printed PLA Structures

Polymers ◽

10.3390/polym13244371 ◽

2021 ◽

Vol 13 (24) ◽

pp. 4371

Author(s):

Dorin-Ioan Catana ◽

Mihai-Alin Pop ◽

Denisa-Iulia Brus

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Process Parameters ◽

Bending Stress ◽

Test Results ◽

Printing Process ◽

Simulation Process ◽

Bending Resistance ◽

3D Printed

Additive manufacturing is one of the technologies that is beginning to be used in new fields of parts production, but it is also a technology that is constantly evolving, due to the advances made by researchers and printing equipment. The paper presents how, by using the simulation process, the geometry of the 3D printed structures from PLA and PLA-Glass was optimized at the bending stress. The optimization aimed to reduce the consumption of filament (material) simultaneously with an increase in the bending resistance. In addition, this paper demonstrates that the simulation process can only be applied with good results to 3D printed structures when their mechanical properties are known. The inconsistency of printing process parameters makes the 3D printed structures not homogeneous and, consequently, the occurrence of errors between the test results and those of simulations become natural and acceptable. The mechanical properties depend on the values of the printing process parameters and the printing equipment because, in the case of 3D printing, it is necessary for each combination of parameters to determine their mechanical properties through specific tests.

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Effect of Porosity and Crystallinity on 3D Printed PLA Properties

Polymers ◽

10.3390/polym11091487 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1487 ◽

Cited By ~ 19

Author(s):

Yuhan Liao ◽

Chang Liu ◽

Bartolomeo Coppola ◽

Giuseppina Barra ◽

Luciano Di Maio ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Additive Manufacturing ◽

3D Printing ◽

Polylactic Acid ◽

Complex Geometry ◽

Fused Filament Fabrication ◽

3D Printed ◽

Physical Changes ◽

Crystalline Forms

Additive manufacturing (AM) is a promising technology for the rapid tooling and fabrication of complex geometry components. Among all AM techniques, fused filament fabrication (FFF) is the most widely used technique for polymers. However, the consistency and properties control of the FFF product remains a challenging issue. This study aims to investigate physical changes during the 3D printing of polylactic acid (PLA). The correlations between the porosity, crystallinity and mechanical properties of the printed parts were studied. Moreover, the effects of the build-platform temperature were investigated. The experimental results confirmed the anisotropy of printed objects due to the occurrence of orientation phenomena during the filament deposition and the formation both of ordered and disordered crystalline forms (α and δ, respectively). A heat treatment post-3D printing was proposed as an effective method to improve mechanical properties by optimizing the crystallinity (transforming the δ form into the α one) and overcoming the anisotropy of the 3D printed object.

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Mechanical Properties of 3D Printed Biomimicked Composites

Volume 12: Materials: Genetics to Structures ◽

10.1115/imece2018-86309 ◽

2018 ◽

Author(s):

Seyed M. Allameh ◽

Roger Miller ◽

Hadi Allameh

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Soft Materials ◽

Structural Composites ◽

Home Building ◽

Complex Shapes ◽

3D Printed ◽

Bend Tests ◽

Point Bend

Additive manufacturing technology has significantly matured over the last two decades. Recent progress in 3D printing has made it an attractive choice for fabricating complex shapes out of select materials possessing desirable properties at small and large scales. The application of biomimetics to the fabrication of structural composites has been shown to enhance their toughness and dynamic shear resistance. Building homes from bioinspired composites is possible if the process is automated. This can be achieved through additive manufacturing where layers of hard and soft materials can be deposited by 3D printing. This study examines mechanical properties of reinforced concrete fabricated by 3D printing. Preliminary results of 4-point bend tests are presented and the implications of 3D-printed home building on current conventional construction practices are discussed.

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Study of Printing Orientation on Mechanical Properties in Additive Manufacturing Process

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2019-11997 ◽

2019 ◽

Author(s):

Peyman Honarmandi ◽

Hongbin Xu

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Young’S Modulus ◽

Manufacturing Process ◽

Young's Modulus ◽

Innovative Technology ◽

Build Orientation ◽

Fused Deposition ◽

3D Printed

Abstract Additive manufacturing (AM) is an innovative technology that creates parts by adding small portions of materials layer by layer, which frees designers to create parts that were not possible to manufacture with subtractive manufacturing processes previously. This led to wide-spread popularity of 3D-printing technology. In this technology. fused deposition modeling (FDM) is the most affordable one in the market now. Therefore, it is vital to understand how the print orientation, which can be customized very easily, affects the mechanical properties of the prints to maximize the strength of the product. This paper aims to present the methodology and results of the experimental characterization of the acrylonitrile butadiene styrene (ABS) 3D-printed part. Tensile characterization of ABS was performed to analyze anisotropic nature of 3D-printed parts caused by its unique manufacturing process. Specimens were printed with six different configurations: four raster ([45/−45], [30/−60], [15/−75] and [0/90]) and three build orientations (0 or flat, 45, and 90 degrees with respect to the build plate, all printed in [45/−45] raster orientation). Dogbone tensile specimens were printed and pulled using the tensile test machine. The young’s modulus, yield strength, ultimate strength, strain at failure, breaking strength were found for each configuration. As the build orientation angle increased and the raster orientation goes from [45/−45] to [0/90], mechanical properties decreased steadily except the Young’s modulus. For build orientation, Young’s modulus decreased first then increased as angle increased, and for the raster orientation, there was no statistically significant difference as raster changed from [45/−45] to [0/90]. Overall, [45/−45] flat configuration is the strongest and the most stable configuration.

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