scholarly journals Laser Welding of AISI 316L Stainless Steel Produced by Additive Manufacturing or by Conventional Processes

2021 ◽  
Vol 5 (4) ◽  
pp. 136
Author(s):  
Morgane Mokhtari ◽  
Pierrick Pommier ◽  
Yannick Balcaen ◽  
Joel Alexis
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Laser Welding ◽  
Aisi 316L Stainless Steel ◽  
Powder Bed ◽  
Size Limitation ◽  
Common Technique ◽  
Cold Rolled ◽  
Manufacturing Techniques ◽  
Complex Parts

Among all the additive manufacturing techniques, Laser Powder Bed Fusion (LBPF), also called Selective Laser Melting (SLM), is the most common technique due to its high capability of building complex parts with generally improved mechanical properties. One of the main drawbacks of this technique is the sample size limitation, which depends on elaborating chamber dimensions. In this study, we investigate the viability of obtaining large parts with the laser welding of additive manufactured plates. A comparison of the microstructure and the tensile mechanical properties of SLM-welded plates and cold-rolled welded plates was performed. This paper shows the possibility of obtaining defect-free parts. Even if welding has a low impact on the microstructure of the SLM samples, fractures are located on the fusion zone, and a decrease in ductility of around 30% compared to the base metal is observed.

scholarly journals Current Status and Perspectives on Wire and Arc Additive Manufacturing (WAAM)

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1121 ◽  
Author(s):  
Tiago A. Rodrigues ◽  
V. Duarte ◽  
R.M. Miranda ◽  
Telmo G. Santos ◽  
J.P. Oliveira
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Three Dimensional ◽  
Current Status ◽  
Powder Bed ◽  
Significant Research ◽  
Manufacturing Techniques ◽  
Materials Used ◽  
Metallic Parts ◽  
General Perspective

Additive manufacturing has revolutionized the manufacturing paradigm in recent years due to the possibility of creating complex shaped three-dimensional parts which can be difficult or impossible to obtain by conventional manufacturing processes. Among the different additive manufacturing techniques, wire and arc additive manufacturing (WAAM) is suitable to produce large metallic parts owing to the high deposition rates achieved, which are significantly larger than powder-bed techniques, for example. The interest in WAAM is steadily increasing, and consequently, significant research efforts are underway. This review paper aims to provide an overview of the most significant achievements in WAAM, highlighting process developments and variants to control the microstructure, mechanical properties, and defect generation in the as-built parts; the most relevant engineering materials used; the main deposition strategies adopted to minimize residual stresses and the effect of post-processing heat treatments to improve the mechanical properties of the parts. An important aspect that still hinders this technology is certification and nondestructive testing of the parts, and this is discussed. Finally, a general perspective of future advancements is presented.

scholarly journals Study of the Microstructure and Mechanical Properties Obtained by Laser Boost in SLM Process for the Ti-64 Alloy

2021 ◽  
Vol 1016 ◽  
pp. 1611-1617
Author(s):  
Caroline Widomski ◽  
Denis Solas ◽  
François Brisset ◽  
Anne Laure Helbert ◽  
Thierry Baudin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Maximum Strength ◽  
Post Processing ◽  
Laser Melting ◽  
Melting Area ◽  
Microstructure And Mechanical Properties ◽  
Manufacturing Techniques ◽  
Complex Parts

Selective laser melting (SLM) is one of the new additive manufacturing techniques in which complex parts can be created directly by selectively melting layers of powder. If the productivity of the process is too fast, defects (porosity, partially melted powder, spatters …) are generated inside the fabricated parts and can deteriorate the mechanical properties of the product. A new Laser Boost strategy with a larger melting area and a productivity of 43.20 cm3/h has been compared to a Linear Classic strategy. Ti-64 alloy samples were elaborated with both strategies to study their influence on microstructure and mechanical properties. Laser Boost strategy leads to the formation of Ti-64 prior β grains that are larger than the Linear Classic strategy. Mechanical properties obtains are similar with both strategies with a maximum strength average around 1250MPa and an elongation at failure between 3 and 9%. A thermal post-processing by Hot Isostatic Pressure have been carried out on samples made by Laser Boost to increase the ductility of the material up to 15%.

scholarly journals Development of a 3D Printable and Highly Stretchable Ternary Organic-Inorganic Nanocomposite Hydrogel

2021 ◽  
Author(s):  
Chen Hu ◽  
Malik Haider ◽  
Lukas Hahn ◽  
Mengshi Yang ◽  
Robert Luxenhofer
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Nanocomposite Hydrogel ◽  
Highly Stretchable ◽  
Manufacturing Techniques ◽  
Advanced Applications

Hydrogels that can be processed with additive manufacturing techniques and concomitantly possess favorable mechanical properties are interesting for many advanced applications. However, the development of novel ink materials with high...

A printability assessment framework for fabricating low variability nickel-niobium parts using laser powder bed fusion additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bing Zhang ◽  
Raiyan Seede ◽  
Austin Whitt ◽  
David Shoukr ◽  
Xueqin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Uncertainty Quantification ◽  
Process Optimization ◽  
Powder Bed Fusion ◽  
Assessment Framework ◽  
Laser Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Analytical Thermal Model

Purpose There is recent emphasis on designing new materials and alloys specifically for metal additive manufacturing (AM) processes, in contrast to AM of existing alloys that were developed for other traditional manufacturing methods involving considerably different physics. Process optimization to determine processing recipes for newly developed materials is expensive and time-consuming. The purpose of the current work is to use a systematic printability assessment framework developed by the co-authors to determine windows of processing parameters to print defect-free parts from a binary nickel-niobium alloy (NiNb5) using laser powder bed fusion (LPBF) metal AM. Design/methodology/approach The printability assessment framework integrates analytical thermal modeling, uncertainty quantification and experimental characterization to determine processing windows for NiNb5 in an accelerated fashion. Test coupons and mechanical test samples were fabricated on a ProX 200 commercial LPBF system. A series of density, microstructure and mechanical property characterization was conducted to validate the proposed framework. Findings Near fully-dense parts with more than 99% density were successfully printed using the proposed framework. Furthermore, the mechanical properties of as-printed parts showed low variability, good tensile strength of up to 662 MPa and tensile ductility 51% higher than what has been reported in the literature. Originality/value Although many literature studies investigate process optimization for metal AM, there is a lack of a systematic printability assessment framework to determine manufacturing process parameters for newly designed AM materials in an accelerated fashion. Moreover, the majority of existing process optimization approaches involve either time- and cost-intensive experimental campaigns or require the use of proprietary computational materials codes. Through the use of a readily accessible analytical thermal model coupled with statistical calibration and uncertainty quantification techniques, the proposed framework achieves both efficiency and accessibility to the user. Furthermore, this study demonstrates that following this framework results in printed parts with low degrees of variability in their mechanical properties.

Variance Quantification of Different Additive Manufacturing Processes for Acoustic Meta Materials

2021 ◽  
Vol 263 (4) ◽  
pp. 2708-2723
Author(s):  
Manuel Bopp ◽  
Arn Joerger ◽  
Matthias Behrendt ◽  
Albert Albers
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Production Process ◽  
Laser Scanning ◽  
Mode Shapes ◽  
Manufacturing Processes ◽  
3D Laser Scanning ◽  
Fused Filament Fabrication ◽  
Manufacturing Techniques ◽  
Different Levels

Many concepts for acoustic meta materials rely on additive manufacturing techniques. Depending on the production process and material of choice, different levels of precision and repeatability can be achieved. In addition, different materials have different mechanical properties, many of which are frequency dependent and cannot easily be measured directly. In this contribution the authors have designed different resonator elements, which have been manufactured utilizing Fused Filament Fabrication with ABSplus and PLA, as well as PolyJet Fabrication with VeroWhitePlus. All structures are computed in FEA to obtain the calculated Eigenfrequencies and mode shapes, with the respective literature values for each material. Furthermore, the dynamic behavior of multiple instances of each structure is measured utilizing a 3D-Laser-Scanning Vibrometer under shaker excitation, to obtain the actual Eigenfrequencies and mode shapes. The results are then analyzed in regards to variance between different print instances, and in regards to accordance between measured and calculated results. Based on previous work and this analysis the parameters of the FEA models are updated to improve the result quality.

Channel design for 3D models with applications in powder-bed additive manufacturing

2019 ◽  
Vol 25 (9) ◽  
pp. 1536-1544
Author(s):  
Xiangzhi Wei ◽  
Xianda Li ◽  
Shanshan Wen ◽  
Yu Zheng ◽  
Yaobin Tian
Keyword(s):  
Additive Manufacturing ◽  
3D Model ◽  
3D Models ◽  
Linear Constraints ◽  
Channel Design ◽  
Channel Network ◽  
Content Type ◽  
Powder Bed ◽  
Shortest Network ◽  
Manufacturing Techniques

Purpose For any 3D model with chambers to be fabricated in powder-bed additive manufacturing processes such as SLM and SLS, powders are trapped in the chambers of the finished model. This paper aims to design a shortest network with the least number of outlets for efficiently leaking the trapped powders. Design/methodology/approach This paper proposes a nonlinear objective with linear constraints for solving the channel design problem and a particle swarm optimization algorithm to solve the nonlinear system. Findings Structural optimization for the channel network leads to fairly short channels in the interior of the 3D models and very few outlets on the model surface, which achieves the cleaning of the powders while causing almost the least changes to the model. Originality/value This paper reveals the NP-harness of computing the shortest channel network with the least number of outlets. The proposed approach helps the design of lightweight models using the powder-bed additive manufacturing techniques.

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