scholarly journals An Innovative Approach on Directed Energy Deposition Optimization: A Study of the Process Environment’s Influence on the Quality of Ti-6Al-4V Samples

2020 ◽  
Vol 10 (12) ◽  
pp. 4212
Author(s):  
Alessandro Carrozza ◽  
Alberta Aversa ◽  
Federico Mazzucato ◽  
Mariangela Lombardi ◽  
Sara Biamino ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Environmental Factors ◽  
Grain Morphology ◽  
Point Of View ◽  
Gas System ◽  
Columnar Grain ◽  
Directed Energy ◽  
Manufacturing Technologies ◽  
Blown Powder ◽  
Process Atmosphere

Blown powder additive manufacturing technologies are not restricted to the use of a process chamber. This feature allows to build larger components with respect to conventional powder bed processes. This peculiarity is mostly promising for manufacturing large components or repairing/rebuilding parts of large systems. The main downside of using an open environment, even if a protective shielding gas system is adopted, is the lack of control of process atmosphere. This is particularly critical for titanium alloys which are very sensitive to oxygen/nitrogen pick-up; they have a detrimental effect on ductility, by causing embrittlement and possibly leading to the formation of cracks. It is then important to address how environmental factors, such as process atmosphere and platform temperature, impact not only on the processability but also on the final component properties, both from a compositional and mechanical point of view. The correlations between these environmental factors and microstructure, interstitials content, grain size, and hardness were investigated. Moreover, the Hall–Petch equation was then adopted to additive manufacturing microstructures, characterized by a columnar grain morphology, and used to further investigate the relationship intercurring between grains and hardness and how different microstructures might influence this correlation.

scholarly journals Wire Arc Additive Manufacturing: Review on Recent Findings and Challenges in Industrial Applications and Materials Characterization

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 939
Author(s):  
Mukti Chaturvedi ◽  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Luigi Renato Mistodie ◽  
Danut Mihailescu ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Integrity ◽  
Industrial Applications ◽  
Raw Material ◽  
Continuous Increase ◽  
Control Optimization ◽  
Modern Manufacturing ◽  
Directed Energy ◽  
Manufacturing Technologies ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is a fusion manufacturing process in which the heat energy of an electric arc is employed for melting the electrodes and depositing material layers for wall formation or for simultaneously cladding two materials in order to form a composite structure. This directed energy deposition-arc (DED-arc) method is advantageous and efficient as it produces large parts with structural integrity due to the high deposition rates, reduced wastage of raw material, and low consumption of energy in comparison with the conventional joining processes and other additive manufacturing technologies. These features have resulted in a constant and continuous increase in interest in this modern manufacturing technique which demands further studies to promote new industrial applications. The high demand for WAAM in aerospace, automobile, nuclear, moulds, and dies industries demonstrates compatibility and reflects comprehensiveness. This paper presents a comprehensive review on the evolution, development, and state of the art of WAAM for non-ferrous materials. Key research observations and inferences from the literature reports regarding the WAAM applications, methods employed, process parameter control, optimization and process limitations, as well as mechanical and metallurgical behavior of materials have been analyzed and synthetically discussed in this paper. Information concerning constraints and enhancements of the wire arc additive manufacturing processes to be considered in terms of wider industrial applicability is also presented in the last part of this paper.

Innovative approaches to designing and manufacturing a prosthetic thumb

2020 ◽  
pp. 030936462094971 ◽  
Author(s):  
Branko Štefanovič ◽  
Monika Michalíková ◽  
Lucia Bednarčíková ◽  
Marianna Trebuňová ◽  
Jozef Živčák
Keyword(s):  
Additive Manufacturing ◽  
3D Scanning ◽  
Metacarpal Bone ◽  
Point Of View ◽  
Dominant Hand ◽  
Fused Filament Fabrication ◽  
Conventional Methods ◽  
Manufacturing Technologies ◽  
The Right ◽  
Manufacturing Time

Case description: Conventional methods for producing custom prosthetic fingers are time-consuming, can be uncomfortable for the patient, and require a skilled prosthetist. The subject was a 40-year-old male with congenital absence of the thumb and related metacarpal bone on the right non-dominant hand, anomaly of the lengths of individual upper limb segments, and contracture of the elbow joint. This hand presentation made it impossible for him to perform thumb opposition, which is a very important function for common daily activities. Objective: The goal was to design an individual passive thumb prosthesis using free open-source software, 3D scanning technology, and additive manufacturing methods (i.e., fused filament fabrication). Study design: Case report. Treatment: Artificial thumb prostheses with two types of bases and fastening interfaces were designed and manufactured. One combination was chosen as the best alternative. Outcomes: The shape, positioning, firmness, and fastening of the prosthesis were compliant enough for the patient to be able to hold objects with his healthy fingers and artificial thumb. This innovative approach to fabrication of a custom thumb prosthesis provided considerable advantages in terms of custom sizing, manufacturing time, rapid production, iteration, comfort, and costs when compared to conventional methods of manufacturing a hand prosthesis. Conclusion: The methodology of designing and manufacturing a prosthetic thumb using 3D scanning and additive manufacturing technologies have been demonstrated to be adequate from a practical point of view. These technologies show potential for use in the practice of prosthetics.

scholarly journals Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Gianpaolo Savio ◽  
Stefano Rosso ◽  
Roberto Meneghello ◽  
Gianmaria Concheri
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Geometric Modeling ◽  
Solid Freeform Fabrication ◽  
Cellular Materials ◽  
Point Of View ◽  
Porous Scaffolds ◽  
Freeform Fabrication ◽  
Geometric Point ◽  
Manufacturing Technologies

Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed.

scholarly journals Additive manufacturing – digitally changing the global business landscape

2019 ◽  
Vol 28 (2) ◽  
pp. 174-188 ◽  
Author(s):  
Christina Öberg
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Design Methodology ◽  
Emerging Technology ◽  
Point Of View ◽  
Power Dependence ◽  
Power Struggle ◽  
Global Business ◽  
Content Type ◽  
Manufacturing Technologies

Purpose Additive manufacturing, that is, layer-based manufacturing technologies, is thought to change supply chain operations from global to local, while also affecting design processes and product structures. As this transformation happens, a power struggle among various actors relating themselves to additive manufacturing has emerged. The purpose of this paper is to discuss and explain the development of additive manufacturing from a power dependence point of view. Design/methodology/approach The paper is based on data collected from a number of seminars hosting a total of 620 industry experts representing 102 companies in the area, and reflecting every step of the supply chain. Findings The paper points out how measures to deal and create power imbalances occur also related to indirect parties, and how the disruptive character of the supply chain leads to exercised power. Originality/value The power struggle provides new insights into how an emerging technology is realised and the effect of protectionism on such attempts. Specifically related to additive manufacturing, the paper illustrates the business side from various actors’ point of view, which adds to technological perspectives on additive manufacturing, as well as studies viewing the supply chain from a bird’s-eye perspective.

scholarly journals Examination of possibilities of the strength modification in the case of FDM/FFF manufacturing technology

2020 ◽  
Vol 10 (2) ◽  
pp. 27-34
Author(s):  
Péter Ficzere ◽  
Norbert László Lukács
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Manufacturing Technology ◽  
Point Of View ◽  
Main Body ◽  
Generative Design ◽  
Mechanical Stiffness ◽  
Know How ◽  
3D Printed ◽  
Manufacturing Technologies

In many situations the result of the topology optimization or generative design can be manufactured only by additive manufacturing technologies. It is also important to know how the optimised shape behaves from the mechanical stiffness, the manufacturing technology and beneficial point of view. These two different goals can be combined and just the infill properties can be changed and optimised within the main body of 3D printed part.

scholarly journals A STRUCTURED APPROACH TO REDUCE DESIGN ITERATIONS IN ADDITIVE MANUFACTURING

2021 ◽  
Vol 1 ◽  
pp. 231-240
Author(s):  
Laura Wirths ◽  
Matthias Bleckmann ◽  
Kristin Paetzold
Keyword(s):  
Additive Manufacturing ◽  
Spare Parts ◽  
Design Guidelines ◽  
Final Part ◽  
Layer By Layer ◽  
Powder Bed ◽  
Batch Sizes ◽  
Manufacturing Technologies ◽  
Structured Approach ◽  
Design Freedom

AbstractAdditive Manufacturing technologies are based on a layer-by-layer build-up. This offers the possibility to design complex geometries or to integrate functionalities in the part. Nevertheless, limitations given by the manufacturing process apply to the geometric design freedom. These limitations are often unknown due to a lack of knowledge of the cause-effect relationships of the process. Currently, this leads to many iterations until the final part fulfils its functionality. Particularly for small batch sizes, producing the part at the first attempt is very important. In this study, a structured approach to reduce the design iterations is presented. Therefore, the cause-effect relationships are systematically established and analysed in detail. Based on this knowledge, design guidelines can be derived. These guidelines consider process limitations and help to reduce the iterations for the final part production. In order to illustrate the approach, the spare parts production via laser powder bed fusion is used as an example.

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