scholarly journals The Effect of Binder Loading on the Pore Size of 3D Printed PMMA

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1190
Author(s):  
Simon Riechmann ◽  
Odo Wunnicke ◽  
Arno Kwade
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Capillary Flow ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Powder Bed ◽  
Close Relationship ◽  
3D Printed ◽  
Binder Jetting ◽  
Pmma Powder

Binder jetting is known to produce porous objects by depositing the binder selectively layer by layer on a powder bed. In this study, the pore size of printed parts and the correlating mechanical properties are investigated on a commercially available PMMA powder binder system. Pore sizes are measured via capillary flow porometry and mechanical properties via tensile tests. Porometry indicates that the pore size stays at a constant level of 22 µm at 5 to 10 wt% binder loading before decreasing to 6 µm at loadings of 30 wt% or higher. The results were compared with the mechanical testing and related to the agglomerate strength model of Rumpf. The highlights of the article are the application of a binder jetted part as a filter and the identification of a close relationship between porosity and mechanical strength, similar to phenomena in agglomeration science.

scholarly journals Deterioration of the Mechanical Properties of FFF 3D-Printed PLA Structures

Inventions ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Asahi Yonezawa ◽  
Akira Yamada
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Test Piece ◽  
Tensile Tests ◽  
Poly Lactic Acid ◽  
Uniaxial Tensile ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Test Pieces ◽  
3D Printed

Poly(lactic acid) (PLA) is a biodegradable polymer material used for the fabrication of objects by fused filament fabrication (FFF) 3D printing. FFF 3D printing technology has been quickly spreading over the past few years. An FFF-3D-printed object is formed from melted polymer extruded from a nozzle layer-by-layer. The mechanical properties of the object, and the changes in those properties as the object degrades, differ from the properties and changes observed in bulk objects. In this study we evaluated FFF-3D-printed objects by uniaxial tensile tests and four-point flexural tests to characterize the changes of three mechanical properties, namely, the maximum stress, elastic modulus, and breaking energy. Eight types of test pieces printed directly by an FFF 3D printer using two scan patterns and two interior fill percentages (IFPs) were tested by the aforesaid methods. The test pieces were immersed in saline and kept in an incubator at 37 °C for 30, 60, or 90 days before the mechanical testing. The changes in the mechanical properties differed largely between the test piece types. In some of the test pieces, transient increases in strength were observed before the immersion degraded the strength. Several of the test piece types were found to have superior specific strength in the tests. The results obtained in this research will be helpful for the design of PLA structures fabricated by FFF 3D printing.

scholarly journals Metallization of Thermoplastic Polymers and Composites 3D Printed by Fused Filament Fabrication

Technologies ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 49
Author(s):  
Alessia Romani ◽  
Andrea Mantelli ◽  
Paolo Tralli ◽  
Stefano Turri ◽  
Marinella Levi ◽  
...  
Keyword(s):  
Physical Vapor Deposition ◽  
Test Sample ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Post Processing ◽  
Thermoplastic Polymers ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
3D Printed ◽  
Manufacturing Technologies

Fused filament fabrication allows the direct manufacturing of customized and complex products although the layer-by-layer appearance of this process strongly affects the surface quality of the final parts. In recent years, an increasing number of post-processing treatments has been developed for the most used materials. Contrarily to other additive manufacturing technologies, metallization is not a common surface treatment for this process despite the increasing range of high-performing 3D printable materials. The objective of this work is to explore the use of physical vapor deposition sputtering for the chromium metallization of thermoplastic polymers and composites obtained by fused filament fabrication. The thermal and mechanical properties of five materials were firstly evaluated by means of differential scanning calorimetry and tensile tests. Meanwhile, a specific finishing torture test sample was designed and 3D printed to perform the metallization process and evaluate the finishing on different geometrical features. Furthermore, the roughness of the samples was measured before and after the metallization, and a cost analysis was performed to assess the cost-efficiency. To sum up, the metallization of five samples made with different materials was successfully achieved. Although some 3D printing defects worsened after the post-processing treatment, good homogeneity on the finest details was reached. These promising results may encourage further experimentations as well as the development of new applications, i.e., for the automotive and furniture fields.

Modeling, Simulation and Experimental Validation of Heat Transfer During Selective Laser Melting

2015 ◽  
Author(s):  
Mohammad Masoomi ◽  
Xiang Gao ◽  
Scott M. Thompson ◽  
Nima Shamsaei ◽  
Linkan Bian ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Heat Fluxes ◽  
Transient Temperature ◽  
Thermal Gradients ◽  
Layer By Layer ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Bed

Selective Laser Melting (SLM), a laser powder-bed fusion (PBF-L) additive manufacturing method, utilizes a laser to selectively fuse adjacent metal powders. The powders are aligned in a bed that moves vertically to allow for layer-by-layer part construction-Process-related heat transfer and thermal gradients have a strong influence on the microstructural features, and subsequent mechanical properties, of the parts fabricated via SLM. In order to understand and control the heat transfer inherent to SLM, and to ensure high quality parts with targeted microstructures and mechanical properties, comprehensive knowledge of the related energy and mass transport during manufacturing is required. In this study, the transient temperature distribution within and around parts being fabricated via SLM is numerically simulated and the results are provided to aid in quantify the SLM heat transfer. In order to verify simulation output, and to estimate actual thermal gradients and heat transfer, experiments were separately conducted within a SLM machine using a substrate with embedded thermocouples. The experiments focused on characterizing heat fluxes during initial deposition on an initially-cold substrate and during the fabrication of a thin-walled structure built via stainless steel 17-4 powders. Results indicate that it is important to model heat transfer thorough powder bed as well as substrate.

Powder Bed Fusion of Biomedical Co-Cr-Mo and Ti-6Al-4V Alloys: Microstructure and Mechanical Properties

2019 ◽  
Vol 1151 ◽  
pp. 3-7 ◽  
Author(s):  
Eleonora Santecchia ◽  
Paolo Mengucci ◽  
Andrea Gatto ◽  
Elena Bassoli ◽  
Lucia Denti ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
X Ray Diffraction ◽  
Powder Bed ◽  
Mechanical Parts ◽  
Aided Design ◽  
Microscopy Techniques ◽  
High Degree

Powder bed fusion (PBF) is an additive manufacturing technique, which allows to build complex functional mechanical parts layer-by-layer, starting from a computer-aided design (CAD) model. PBF is particularly attractive for biomedical applications, where a high degree of individualization is required. In this work, the microstructure of two biomedical alloys, namely Co-Cr-Mo and Ti-6Al-4V, were studied by X-ray diffraction and electron microscopy techniques. Hardness and tensile tests were performed on the sintered parts.

scholarly journals Determination of Anisotropic Mechanical Properties for Materials Processed by Laser Powder Bed Fusion

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Even W. Hovig ◽  
Amin S. Azar ◽  
Frode Grytten ◽  
Knut Sørby ◽  
Erik Andreassen
Keyword(s):  
Mechanical Properties ◽  
Transversely Isotropic ◽  
Tensile Tests ◽  
Image Correlation ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed ◽  
Anisotropic Mechanical Properties ◽  
Anisotropic Elastic

Improving the success rate in additive manufacturing and designing highly optimized structures require proper understanding of material behaviour. This study proposes a novel experimental method by which anisotropic mechanical properties of additively manufactured materials can be assessed. The procedure is based on tensile testing of flat specimens, manufactured by laser powder bed fusion (LPBF) at different orientations relative to the build plate. In this study, the procedure was applied to the Inconel 718 alloy. Three identical specimen sets were built, each of which received complementary postprocessing treatments. The tensile tests were carried out on specimens with as-built surface finish. Digital image correlation was used to record the strain field evolution on two perpendicular surfaces of the tensile specimens under loading. An optimization algorithm is also proposed for determining the anisotropic elastic constants using only a few tensile test results. It was observed that both build orientation and postprocessing have strong influence on the anisotropic mechanical properties of the material. The effect of microstructure was also investigated and characterised. Consequently, three transversely isotropic compliance matrices were constructed, representing the effect of the different processing conditions.

scholarly journals Parameters Affecting the Mechanical Properties of Three-Dimensional (3D) Printed Carbon Fiber-Reinforced Polylactide Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2456
Author(s):  
Demei Lee ◽  
Guan-Yu Wu
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Bed Temperature ◽  
3D Printed ◽  
The Impact

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.

Wire + Arc Additive Manufacturing of Metals

2020 ◽  
pp. 106-126
Author(s):  
Krishna Kishore Mugada ◽  
Aravindan Sivanandam ◽  
Ravi Kumar Digavalli
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Manufacturing Sector ◽  
Manufacturing Processes ◽  
Deposition Rates ◽  
Direct Energy Deposition ◽  
Powder Bed ◽  
Direct Energy ◽  
Wire Arc Additive Manufacturing ◽  
Binder Jetting

Wire + Arc additive manufacturing (WAAM) processes have become popular because of their proven capabilities to produce large metallic components with high deposition rates (promoted by arc-based processes) compared to conventional additive manufacturing processes such as powder bed fusion, binder jetting, direct energy deposition, etc. The applications of WAAM processes were constantly increasing in the manufacturing sector, which necessitates an understanding of the process capability to various metals. This chapter outlines the significant outcomes of the WAAM process for most of the engineering metals in terms of microstructure and mechanical properties. Discussion on various defects associated with the processed components is also presented. Potential application of WAAM for different metals such as aluminum and its alloys, titanium, and steels was discussed. The research indicates that the components manufactured by the WAAM process have significant microstructural changes and improved mechanical properties.

Laser Welding of Laser Powder Bed Fusion Manufactured Inconel 718: Microstructure and Mechanical Properties

2021 ◽  
Vol 883 ◽  
pp. 234-241
Author(s):  
Timo Rautio ◽  
Jarmo Mäkikangas ◽  
Jani Kumpula ◽  
Antti Järvenpää ◽  
Atef Hamada
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed ◽  
Back Scattering ◽  
Solidification Crack

This paper focuses on the laser weldability of additively manufactured (AM) Inconel 718. The experiments of this research were conducted on different series of AM Inconel 718 alloy, i.e. as­-built, heat­ treated (HT), and HT after welding, and comprehensively characterized using optical microscope and electron back scattering diffraction (EBSD). The weld morphology and microstruc­tural evolution of the fusion zone were recorded. The mechanical properties of the welded AM Inconel 718 were evaluated by tensile tests and hardness measurements. It was found that solidification crack and micropore defects are induced in the as­built AM Inconel 718. However, defect­free weld was promoted in the HT alloy. The changes in hardness profiles and tensile strength under the experimen­tal parameters were further reported. Homogenous hardness of 500 HV across the weld was obtained when HT was applied after the LW.

Influence of nozzle temperature and volumetric filling on the mechanical properties of 3D-printed PEEK

2020 ◽  
Vol 62 (4) ◽  
pp. 351-356
Author(s):  
Danny Vogel ◽  
Volker Weißmann ◽  
Leo Rührmund ◽  
Harald Hansmann ◽  
Rainer Bader
Keyword(s):  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Bending Strength ◽  
Layer By Layer ◽  
Bending Properties ◽  
Filling Degree ◽  
Fused Deposition ◽  
3D Printed ◽  
Injection Molded ◽  
Nozzle Temperature

Abstract Fused deposition modeling is a layer-by-layer 3D printing technology used to additively manufacture polymers. A major benefit of 3D-printed polymers is the option of tailoring their mechanical properties by varying the process parameters. In addition, the present study investigates the influence of the filling degree (50 % or 100 %) and the nozzle temperature during manufacturing on the mechanical properties of 3D-printed poly-ether-ether-ketone (PEEK) material. PEEK samples were built either compact (filling degree 100 %) or closed-cell porous (filling degree 50 %), using three different nozzle temperatures (390 °C, 430 °C and 470 °C). In static bending tests, the bending properties were evaluated and compared with injection molded PEEK samples. Bending strength and modulus increased up to 21.1 %, when the nozzle temperature was increased and up to 40.8 % when the volumetric filling was altered. The results indicate that nozzle temperature and volumetric filling can be altered to tailor the bending properties of 3D-printed PEEK for particular applications. However, the mechanical properties of the 3D-printed samples determined in the current study could not achieve those of the properties of the injection molded PEEK.

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