scholarly journals Measurement and Modeling of Forces in Extrusion-Based Additive Manufacturing of Flexible Silicone Elastomer With Thin Wall Structures

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Jeffrey Plott ◽  
Xiaoqing Tian ◽  
Albert Shih
Keyword(s):  
Additive Manufacturing ◽  
Bending Moment ◽  
Volumetric Flow Rate ◽  
Prosthetic Hand ◽  
Thin Wall ◽  
Layer Height ◽  
Normal Forces ◽  
Wall Structures ◽  
Resistance Approach ◽  
Inner Diameter

Flexible thin wall silicone parts fabricated via extrusion-based additive manufacturing (AM) tend to deform due to the AM forces, limiting the maximum build height. The tangential and normal forces in AM were measured to investigate effects of three key process parameters (volumetric flow rate Q, nozzle tip inner diameter di, and layer height t) on the build height. The interaction between the nozzle tip and the extruded silicone bead is controlled to prevent interaction, flatten the top surface of the extruded silicone, or immerse the nozzle in the extruded silicone. Results show that tangential and normal forces in AM strongly depend on this interaction. Specifically, the AM forces remained low (less than 0.2 mN) if the nozzle tip did not contact the extruded silicone bead. Once the nozzle interaction with extruded silicone came into effect, the AM forces quickly grew to over 1 mN. The single wall tower configuration was developed to determine a predictive deflection resistance approach based on the measured AM forces and the resultant bending moment of inertia. This approach shows that a smaller di can produce taller towers, while a larger di is better at bridging and overhangs. These results are applied to the AM of a hollow thin wall silicone prosthetic hand.

scholarly journals Low-Roughness-Surface Additive Manufacturing of Metal-Wire Feeding with Small Power

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4265
Author(s):  
Bobo Li ◽  
Bowen Wang ◽  
Greg Zhu ◽  
Lijuan Zhang ◽  
Bingheng Lu
Keyword(s):  
Additive Manufacturing ◽  
High Surface ◽  
Deposition Process ◽  
High Energy ◽  
Width Ratio ◽  
Thin Wall ◽  
Small Power ◽  
High Surface Quality ◽  
Wall Structures ◽  
Wire Feed

Aiming at handling the contradiction between power constraint of on-orbit manufacturing and the high energy input requirement of metal additive manufacturing (AM), this paper presents an AM process based on small-power metal fine wire feed, which produces thin-wall structures of height-to-width ratio up to 40 with core-forming power only about 50 W. In this process, thermal resistance was introduced to optimize the gradient parameters which greatly reduces the step effect of the typical AM process, succeeded in the surface roughness (Ra) less than 5 μm, comparable with that obtained by selective laser melting (SLM). After a 10 min electrolyte-plasma process, the roughness of the fabricated specimen was further reduced to 0.4 μm, without defects such as pores and cracks observed. The ultimate tensile strength of the specimens measured about 500 MPa, the relative density was 99.37, and the Vickers hardness was homogeneous. The results show that the proposed laser-Joule wire feed-direct metal deposition process (LJWF-DMD) is a very attractive solution for metal AM of high surface quality parts, particularly suitable for rapid prototyping for on-orbit AM in space.

scholarly journals Study of the Mechanism of a Stable Deposited Height During GMAW-Based Additive Manufacturing

2020 ◽  
Vol 10 (12) ◽  
pp. 4322
Author(s):  
Hongyao Shen ◽  
Rongxin Deng ◽  
Bing Liu ◽  
Sheng Tang ◽  
Shun Li
Keyword(s):  
Additive Manufacturing ◽  
Low Cost ◽  
Gas Metal Arc Welding ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Deposition Process ◽  
High Deposition Rate ◽  
Thin Wall ◽  
Forming Process ◽  
Layer Height

Gas metal arc welding (GMAW)-based additive manufacturing has the advantages of a high deposition rate, low cost, the production of a compact and dense microstructure in the cladding layer, and good mechanical properties, but the forming process is unstable. The shape of the welding bead critically affects the layer height and dimensional accuracy of the parts manufactured, and it is difficult to control. A series of experiments were designed and the results indicated that when the value of the predefined layer height is set in a certain range and other parameters are held constant, the height of the thin wall produced by GMAW-based additive manufacturing is almost equal to the predefined layer height multiplied by the number of layers. This research work shows that during the GMAW process, the changes in the distance between the torch and the top surface of the part cause a variety of dry extensions of the electrode; furthermore, the changes lead to a variety in the heat input into the molten pool. Therefore, the dry extension of the electrode is the key factor influencing the geometry of the welding bead, especially the layer height, and it has a compensating effect that makes the actual layer height close to the predefined value. A three-dimensional numerical model was established to study the influence of the predefined layer height to the fluid flow and heat transfer behaviors during the weld-deposition process.

scholarly journals Innovation in additive manufacturing of parts from aluminium matrix composites

2018 ◽  
Vol 224 ◽  
pp. 01073 ◽  
Author(s):  
Tatiana Tarasova ◽  
Galina Gvozdeva ◽  
Riana Ableyeva
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Formation Process ◽  
Thin Wall ◽  
Matrix Composites ◽  
Modern Equipment ◽  
Minimal Width ◽  
Thin Walls ◽  
Wall Structures

The laser build-up cladding is a well-known technique for additive manufacturing tasks. Modern equipment for the laser cladding enables material to be deposited with the lateral resolution of about 100 μm and to manufacture miniature parts. In this paper the laser micro cladding process was investigated to produce miniature thin-wall parts of Al-based composites. Thin walls formation process by subsequent single tracks overlapping with vertical increment was investigated. The influence of the cladding parameters on the minimal width and the quality of the fabricated thin walls was examined. The thin walls with the minimal width of 140 μm and surface roughness Ra 1,5 μm were generated. Laser micro cladding potential to manufacture lattice-shaped structures of Al-Si composites was shown. Fabricated thin-wall structures can have application in different fields e.g. aviation, automotive and tooling industries.

scholarly journals A Multiaxis Tool Path Generation Approach for Thin Wall Structures Made with WAAM

2021 ◽  
Vol 5 (4) ◽  
pp. 128
Author(s):  
Matthieu Rauch ◽  
Jean-Yves Hascoet ◽  
Vincent Querard
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Tool Path ◽  
Tool Path Generation ◽  
Path Generation ◽  
Thin Wall ◽  
Process Data ◽  
Technical Data ◽  
Wall Structures ◽  
Wire Arc Additive Manufacturing

Wire Arc Additive Manufacturing (WAAM) has emerged over the last decade and is dedicated to the realization of high-dimensional parts in various metallic materials. The usual process implementation consists in associating a high-performance welding generator as heat source, a NC controlled 6 or 8 degrees (for example) of freedom robotic arm as motion system and welding wire as feedstock. WAAM toolpath generation methods, although process specific, can be based on similar approaches developed for other processes, such as machining, to integrate the process data into a consistent technical data environment. This paper proposes a generic multiaxis tool path generation approach for thin wall structures made with WAAM. At first, the current technological and scientific challenges associated to CAD/CAM/CNC data chains for WAAM applications are introduced. The focus is on process planning aspects such as non-planar non-parallel slicing approaches and part orientation into the working space, and these are integrated in the proposed method. The interest of variable torch orientation control for complex shapes is proposed, and then, a new intersection crossing tool path method based on Design For Additive Manufacturing considerations is detailed. Eventually, two industrial use cases are introduced to highlight the interest of this approach for realizing large components.

Optimization of thin-wall structures using hybrid gravitational search and Nelder-Mead algorithm

2016 ◽  
Vol 58 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Ali Rıza Yıldız ◽  
Enes Kurtuluş ◽  
Emre Demirci ◽  
Betul Sultan Yıldız ◽  
Selçuk Karagöz
Keyword(s):  
Thin Wall ◽  
Wall Structures ◽  
Gravitational Search ◽  
Nelder Mead Algorithm

scholarly journals Automated Reconditioning of Thin Wall Structures Using Robot-Based Laser Powder Coating

2020 ◽  
Vol 12 (4) ◽  
pp. 1477
Author(s):  
Shahram Sheikhi ◽  
Eduard Mayer ◽  
Jochen Maaß ◽  
Florian Wagner
Keyword(s):  
Laser Scanner ◽  
Powder Coating ◽  
Basic Knowledge ◽  
Thin Wall ◽  
Economic Potential ◽  
Financial Investment ◽  
Work Space ◽  
Wall Structures ◽  
Cad Cam ◽  
Relevant Component

Implementing digitalization in the field of production represents a major hurdle for some small- and medium-sized enterprises (SMEs) due to the ensuing demands on employees and, in some cases, the significant financial investment required. The RobReLas research project has developed a system whose purpose is to enable an economical solution to this dilemma for SMEs in the field of automated, robot-based reconditioning of components. A laser scanner was integrated in the robot’s control. The data generated by the scanner are used to mathematically describe the virtual area of the surface to be laser-treated. The scanner recognizes the relevant area within the robot’s predefined work space by defining the maximum length and width of the relevant component. The system then automatically applies predefined and qualified repair strategies in the virtual area. Tests on nickel-based blades demonstrated the system’s economic potential, showing a reduction in reconditioning time of about 70% compared to the conventional reconditioning method. The main advantage of the system is the fact that a basic knowledge of operating robots is sufficient for the attainment of repeatable results. Further, no additional CAD/CAM workstations are required for implementation.

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