scholarly journals Powder Application in Additive Manufacturing of Metallic Parts

10.5772/66874 ◽  
2017 ◽  
Author(s):  
Jan Džugan ◽  
Zbyšek Novy
Keyword(s):  
Additive Manufacturing ◽  
Metallic Parts

scholarly journals Design and Validation of Integrated Clamping Interfaces for Post-Processing and Robotic Handling in Additive Manufacturing

2021 ◽  
Author(s):  
Julian Ferchow ◽  
Dominik Kälin ◽  
Gokula Englberger ◽  
Marcel Schlüssel ◽  
Christoph Klahn ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Machining Process ◽  
Post Processing ◽  
Maximum Displacement ◽  
Build Time ◽  
Clean Interface ◽  
Tool Accessibility ◽  
Form Deviation ◽  
Metallic Parts ◽  
Subtractive Machining

Abstract Additive manufacturing (AM), particularly laser-based powder bed fusion of metals (LPBF), enables the fabrication of complex and customized metallic parts. However, 20–40% of the total manufacturing costs are usually attributed to post-processing steps. To reduce the costs of extensive post-processing, the process chain for AM parts has to be automated. Accordingly, robotic gripping and handling processes, as well as an efficient clamping for subtractive machining of AM parts, are key challenges. This study introduces and validates integrated bolts acting as a handling and clamping interface of AM parts. The bolts are integrated into the part design and manufactured in the same LPBF process. The bolts can be easily removed after the machining process using a wrench. This feasibility study investigates different bolt elements. The experiments and simulations conducted in the study show that a force of 250 N resulted in a maximum displacement of 12.5 µm. The milling results of the LPBF parts reveal a maximum roughness value, Ra, of 1.42 µm, which is comparable to that of a standard clamping system. After the bolt removal, a maximum residual height of 0.067 mm remains. Two case studies are conducted to analyze the form deviation, the effect of bolts on build time and material volume and to demonstrate the application of the bolts. Thus, the major contribution of this study is the design and the validation of standardized interfaces for robotic handling and clamping of complex AM parts. The novelties are a simple and clean interface removal, less material consumption, less support structure required and finally an achievement of a five-side tool accessibility by combining the interfaces with a three-jaw chuck.

Optimization of Metallic Powder Filaments for Additive Manufacturing Extrusion (MEX)

2021 ◽  
Author(s):  
Fábio Silva Cerejo ◽  
Daniel Gatões ◽  
Teresa Vieira
Keyword(s):  
Additive Manufacturing ◽  
Low Cost ◽  
Metallic Powder ◽  
Powder Injection ◽  
Layer By Layer ◽  
Powder Injection Moulding ◽  
Powder Particles ◽  
Powder Content ◽  
Metallic Parts ◽  
Am Processes

Abstract Additive manufacturing (AM) of metallic powder particles has been establishing itself as sustainable, whatever the technology selected. Material Extrusion (MEX) integrates the ongoing effort to improve AM sustainability, in which low-cost equipment is associated with a decrease of powder waste during manufacturing. MEX has been gaining increasing interest for building 3D functional/structural metallic parts because it incorporates the consolidated knowledge from powder injection moulding/extrusion feedstocks into the AM scope—filament extrusion layer-by-layer. Moreover, MEX as an indirect process can overcome some of the technical limitations of direct AM processes (laser/electron-beam-based) regarding energy-matter interactions. The present study reveals an optimal methodology to produce MEX filament feedstocks (metallic powder, binder and additives), having in mind to attain the highest metallic powder content. Nevertheless, the main challenges are also to achieve high extrudability and a suitable ratio between stiffness and flexibility. The metallic powder volume content (vol.%) in the feedstocks was evaluated by the critical powder volume concentration (CPVC). Subsequently, the rheology of the feedstocks was established by means of the mixing torque value, which is related to the filament extrudability performance.

scholarly journals Finite Element Modeling and Validation of Metal Deposition in Wire Arc Additive Manufacturing

2021 ◽  
pp. 61-66
Author(s):  
Akram Chergui ◽  
Nicolas Beraud ◽  
Frédéric Vignat ◽  
François Villeneuve
Keyword(s):  
Finite Element ◽  
Additive Manufacturing ◽  
Large Scale ◽  
Low Cost ◽  
Source Model ◽  
Metal Deposition ◽  
High Deposition Rate ◽  
Element Technique ◽  
Metallic Parts ◽  
Wire Arc Additive Manufacturing

AbstractWire arc additive manufacturing allows the production of metallic parts by depositing beads of weld metal using arc-welding technologies. This low-cost additive manufacturing technology has the ability to manufacture large-scale parts at a high deposition rate. However, the quality of the obtained parts is greatly affected by the various thermal phenomena present during the manufacturing process. Numerical simulation remains an effective tool for studying such phenomena. In this work, a new finite element technique is proposed in order to model metal deposition in WAAM process. This technique allows to gradually construct the mesh representing the deposited regions along the deposition path. The heat source model proposed by Goldak is adapted and combined with the proposed metal deposition technique taking into account the energy distribution between filler material and the molten pool. The effectiveness of the proposed method is validated by series of experiments, of which an example is detailed in this paper.

scholarly journals Additive manufacturing of powder components based on subtractive sintering approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Maricruz Henkel Carrillo ◽  
Geuntak Lee ◽  
Charles Maniere ◽  
Eugene A. Olevsky
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Ceramic Powder ◽  
High Density ◽  
Ease Of Use ◽  
Powder Particle Size ◽  
Proof Of Concept ◽  
Content Type ◽  
Novel Approach ◽  
Metallic Parts

Purpose The purpose of this work is to introduce a novel approach of using additive manufacturing (AM) to produce dense complex ceramic and metallic parts. Powder 3D printing has been gaining popularity due to its ease of use and versatility. However, powder-based methods such as Selective Laser Melting (SLM) and Sintering (SLS), utilizes high power lasers which generate thermal shock conditions in metals and are not ideal for ceramics due to their high melting temperature. Indirect additive manufacturing methods have been explored to address the above issues but have proven to be wasteful and time-consuming. Design/methodology/approach In this work, a novel approach of producing high density net-shaped prototypes using subtractive sintering (SS) and solvent jetting is developed. AM combined with SS (AM-SS) is a process that includes five simple steps. AM-SS can produce repeatable and reliable results as has been shown in this work. Findings As a proof-of-concept, a zirconia dental crown with a high density of 97% is fabricated using this approach. Microstructure and properties of the fabricated components are analyzed. Originality/value A major advantage of this method is the ability to efficiently fabricate high density parts using either metal powder and more importantly, ceramic powder which is traditionally difficult to densify using AM. Additionally, any powder particle size (including nano) and shape can be used which is not the case for traditional powder-based 3D printing.

scholarly journals Review of Powder Bed Fusion Additive Manufacturing for Metals

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1391
Author(s):  
Leila Ladani ◽  
Maryam Sadeghilaridjani
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Disruptive Technology ◽  
Powder Bed ◽  
Powder Particles ◽  
Metallic Parts ◽  
The Cost ◽  
Scientific Questions ◽  
Metal Additive

Additive manufacturing (AM) as a disruptive technology has received much attention in recent years. In practice, however, much effort is focused on the AM of polymers. It is comparatively more expensive and more challenging to additively manufacture metallic parts due to their high temperature, the cost of producing powders, and capital outlays for metal additive manufacturing equipment. The main technology currently used by numerous companies in the aerospace and biomedical sectors to fabricate metallic parts is powder bed technology, in which either electron or laser beams are used to melt and fuse the powder particles line by line to make a three-dimensional part. Since this technology is new and also sought by manufacturers, many scientific questions have arisen that need to be answered. This manuscript gives an introduction to the technology and common materials and applications. Furthermore, the microstructure and quality of parts made using powder bed technology for several materials that are commonly fabricated using this technology are reviewed and the effects of several process parameters investigated in the literature are examined. New advances in fabricating highly conductive metals such as copper and aluminum are discussed and potential for future improvements is explored.

scholarly journals A Review of Heat Treatments on Improving the Quality and Residual Stresses of the Ti–6Al–4V Parts Produced by Additive Manufacturing

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1006 ◽  
Author(s):  
Óscar Teixeira ◽  
Francisco J. G. Silva ◽  
Luís P. Ferreira ◽  
Eleonora Atzeni
Keyword(s):  
Fatigue Life ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Electron Beam Melting ◽  
Heat Treatments ◽  
High Melting Point ◽  
High Corrosion Resistance ◽  
Beam Source ◽  
Powder Bed ◽  
Metallic Parts

Additive manufacturing (AM) can be seen as a disruptive process that builds complex components layer upon layer. Two of its distinct technologies are Selective Laser Melting (SLM) and Electron Beam Melting (EBM), which are powder bed fusion processes that create metallic parts with the aid of a beam source. One of the most studied and manufactured superalloys in metal AM is the Ti–6Al–4V, which can be applied in the aerospace field due to its low density and high melting point, and in the biomedical area owing to its high corrosion resistance and excellent biocompatibility when in contact with tissues or bones of the human body. The research novelty of this work is the aggregation of all kinds of data from the last 20 years of investigation about Ti–6Al–4V parts manufactured via SLM and EBM, namely information related to residual stresses (RS), as well as the influence played by different heat treatments in reducing porosity and increasing mechanical properties. Throughout the report, it can be seen that the expected microstructure of the Ti–6Al–4V alloy is different in both manufacturing processes, mainly due to the distinct cooling rates. However, heat treatments can modify the microstructure, reduce RS, and increase the ductility, fatigue life, and hardness of the components. Furthermore, distinct post-treatments can induce compressive RS on the part’s surface, consequently enhancing the fatigue life.

A practical fabrication strategy for wire arc additive manufacturing of metallic parts with wire structures

2021 ◽  
Author(s):  
Ziping Yu ◽  
Zengxi Pan ◽  
Donghong Ding ◽  
Joseph Polden ◽  
Lei Yuan ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Complex Geometry ◽  
Free Form ◽  
Welding Parameter ◽  
High Deposition Rate ◽  
Manufacturing Strategy ◽  
Environmental Friendliness ◽  
Bead Modelling ◽  
Metallic Parts ◽  
Wire Arc Additive Manufacturing

Abstract Wire Arc Additive Manufacturing (WAAM) is well suited for the manufacture of sizeable metallic workpieces featuring medium-to-high geometrical complexity due to its high deposition rate, low processing conditions limit, and environmental friendliness. To enhance the current capability of the WAAM process for fabricating structures with complex geometry, this paper proposes a robot-based WAAM strategy adapted specifically for fabricating free-form parts with wire structures composed of multiple struts. Contributions in this work include: (i) The study of bead modelling, which establishes optimal welding parameter selection for the process; (ii) The novel manufacturing strategy, including the adaptive slicing methodology and height control system for accurately depositing every single strut; (iii) Detailed manufacturing procedures for multi-strut branch intersections as well as the collision-free path planning to control the overall fabrication process. To verify the effectiveness of this proposed WAAM approach, two complex wire structures were fabricated successfully, indicating the feasibility of the proposed fabrication strategy.

Thermal Modeling of Electron Beam Additive Manufacturing Process: Powder Sintering Effects

2012 ◽  
Author(s):  
Ninggang Shen ◽  
Kevin Chou
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
High Energy ◽  
Maximum Temperature ◽  
Beam Diameter ◽  
Moving Heat Source ◽  
Metal Powders ◽  
Melt Pool ◽  
Metallic Parts ◽  
Melt Pool Size

In recently developed Additive Manufacturing (AM) technologies, high-energy sources have been used to fabricate metallic parts, in a layer by layer fashion, by sintering and/or melting metal powders. In particular, Electron Beam Additive Manufacturing (EBAM) utilizes a high-energy electron beam to melt and fuse metal powders to build solid parts. EBAM is one of a few AM technologies capable of making full-density metallic parts and has dramatically extended their applications. Heat transport is the center of the process physics in EBAM, involving a high-intensity, localized moving heat source and rapid self-cooling, and is critically correlated to the part quality and process efficiency. In this study, a finite element model was developed to simulate the transient heat transfer in a part during EBAM subject to a moving heat source with a Gaussian volumetric distribution. The developed model was first examined against literature data. The model was then used to evaluate the powder porosity and the beam size effects on the high temperature penetration volume (melt pool size). The major findings include the following. (1) For the powder layer case, the melt pool size is larger with a higher maximum temperature compared to a solid layer, indicating the importance of considering powders for the model accuracy. (2) With the increase of the porosity, temperatures are higher in the melt pool and the molten pool sizes increase in the depth, but decrease along the beam moving direction. Furthermore, both the heating and cooling rates are higher for a lower porosity level. (3) A larger electron-beam diameter will reduce the maximum temperature in the melt pool and temperature gradients could be much smaller, giving a lower cooling rate. However, for the tested electron beam-power level, the beam diameter around 0.4 mm could be an adequate choice.

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