scholarly journals Polymer additive manufacturing of ABS structure: Influence of printing direction on mechanical properties

2019 ◽  
Vol 44 ◽  
pp. 288-298 ◽  
Author(s):  
H. Ramezani Dana ◽  
F. Barbe ◽  
L. Delbreilh ◽  
M. Ben Azzouna ◽  
A. Guillet ◽  
...  
2019 ◽  
Vol 809 ◽  
pp. 386-391 ◽  
Author(s):  
Patrick Striemann ◽  
Daniel Hülsbusch ◽  
Michael Niedermeier ◽  
Frank Walther

Generating serial components via additive manufacturing (AM) a deep understanding of process-related characteristics is necessary. The extrusion-based AM called fused layer manufacturing (FLM), also known as fused deposition modeling (FDM™) or fused filament fabrication (FFF) is an AM process for producing serial components. Improving mechanical properties of AM parts is done by adding fibers in the raw material to reinforce the polymer. The study aims to create a more detailed comprehension of FLM and process-related characteristics with their influence on the composite.Thereby, a short carbon fiber-reinforced polyamide (CarbonX™ Nylon, 3DXTECH, USA) with 12.5 wt.‑% fiber content, 7 μm fiber diameter, and 150 to 400 µm fiber length distribution was investigated. To separate process-related characteristics of FLM, reference specimens were fabricated via injection molding (IM) with single-batch material. For the mechanical characterization, quasi-static tensile tests were carried out in accordance to DIN 527‑2. Quality assessment including void content and void distribution was performed via micro-computed tomography (CT).The mechanical characterization clarifies effects on mechanical properties depending on process-related characteristics of FLM. CT scans show higher void contents of FLM specimens compared to IM specimens and void orientation dependent on printing direction. FLM shows process-related characteristics which generally strengthen mechanical properties of polymers. Nevertheless, tensile strength of FLM specimens decrease by more than 28% compared to quasi-homogenous IM specimens.


2021 ◽  
Vol 11 (16) ◽  
pp. 7336
Author(s):  
Shummaila Rasheed ◽  
Waqas Akbar Lughmani ◽  
Muhannad Ahmed Obeidi ◽  
Dermot Brabazon ◽  
Inam Ul Ahad

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.


2021 ◽  
Author(s):  
Dmitry Vysochinskiy ◽  
Naureen Akhtar ◽  
Tord Nordmo ◽  
Mathias Rabjerg Strand ◽  
Adrian Vyssios ◽  
...  

The additive manufacturing has initially gained popularity for production of non-loadbearing parts and components or in the fields where the material strength and ductility are less important such as modelling and rapid prototyping. But as the technology develops, availability of metal additive manufacturing naturally dictates the desire to use the produced components in load-bearing parts. This requires not-only a thorough documentation on the mechanical properties but also additional and independent research to learn the expected level of variation of the mechanical properties and what factors affect them. The presented paper investigates strength, ductility, hardness, and microstructure of the AlSi10Mg alloy produced by the selective laser melting (SLM). The mechanical properties were determined through a series of uniaxial tension tests and supplementary hardness tests and rationalized with the microstructure evolution with regard to printing direction and heat treatment. The paper also addresses the effect of surface roughness on the mechanical properties of the material, by comparing the machined and net shape tension samples. As expected, the as-manufactured AlSi10Mg-alloy appears to be a semi-brittle alloy, but its microstructure can be altered, and ductility increased by a proper heat-treatment. The effect of surface layer removal on the measured mechanical properties is of particular interest.


2020 ◽  
Vol 26 (3) ◽  
pp. 127-130
Author(s):  
Nassim Markiz ◽  
Eszter Horváth ◽  
Péter Ficzere

AbstractIn the recent years, additive manufacturing became an interesting topic in many fields due to the ease of manufacturing complex objects. However, it is impossible to determine the mechanical properties of any additive manufacturing parts without testing them. In this work, the mechanical properties with focus on ultimate tensile strength and modulus of elasticity of 3D printed acrylonitrile butadi-ene styrene (ABS) specimens were investigated. The tensile tests were carried using Zwick Z005 loading machine with a capacity of 5KN according to the American Society for Testing and Materials (ASTM) D638 standard test methods for tensile properties of plastics. The aim of this study is to investigate the influence of printing direction on the mechanical properties of the printed specimens. Thus, for each printing direction ( and ), five specimens were printed. Tensile testing of the 3D printed ABS specimens showed that the printing direction made the strongest specimen at an ultimate tensile strength of 22 MPa while at printing direction it showed 12 MPa. No influence on the modulus of elasticity was noticed. The experimental results are presented in the manuscript.


2017 ◽  
Vol 742 ◽  
pp. 482-489 ◽  
Author(s):  
Anselm Heuer ◽  
Pascal Pinter ◽  
Kay André Weidenmann

Additive manufacturing provides the ability to produce structural components featuring complex shapes in one step, compared to traditional methods of production. Therefore, additive manufacturing has recently gained attention for the direct production of parts. Using fibre reinforced filaments offers the opportunity to improve the mechanical properties of FFF printed components. In order to dimension them correctly, the mechanical properties of additive manufactured samples based on glass fibre reinforced filaments were determined. Additionally, the influence of extrusion paths resulting in a distinct fibre orientation were taken into account. Samples were produces by FFF-method (Fused Filament Fabrication) from three materials: Bulk ABS and short glass fibre reinforced ABS featuring 5 wt% and 10 wt% fibre content. Additionally, samples were printed in two different raster orientations of 0° and 90°. Three different sample types were manufactured in order to perform tension, flexural and impact tests. Prior to printing the samples, the slicer parameters were optimized for usage with the fibre reinforced filament. To determine the FOD (Fibre Orientation Distribution) and FLD (Fibre Length Distribution), the samples were scanned using a CT. Results show that fibre reinforced filaments used in this contribution can increase stiffness to 150 % of the bulk material in printing direction with a fibre weight content of 10 %. CT investigations have shown that the orientation of fibres is primary aligned to the printing path.


Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.


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