scholarly journals Metastable Al–Si–Ni Alloys for Additive Manufacturing: Structural Stability and Energy Release during Heating

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 483 ◽  
Author(s):  
Tibor Bedo ◽  
Bela Varga ◽  
Daniel Cristea ◽  
Alexandra Nitoi ◽  
Andrea Gatto ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Melt Spinning ◽  
Practical Importance ◽  
Metal Alloys ◽  
Heating Process ◽  
Structural Development ◽  
Ni Alloys ◽  
Metastable Structures ◽  
High Cooling Rates ◽  
Manufacturing Technologies

Rapid solidification with high cooling rates of metal alloys determines both the improvement of mechanical properties, due to the finishing of the structure, as well as obtaining metastable structures in the form of supersaturated or amorphous/nano solid solutions, which could potentially confer the material outstanding properties. It is of particular interest to use the energies released during the heating stage for these materials, due to the potentially lower input energy required to melt/fuse these materials. This phenomenon could add to the development and diversification of additive manufacturing technologies. The paper presents results concerning the structural development and phase transformation of metastable structures from Al–Si–Ni-based alloys, obtained by melt spinning and atomization techniques. It was observed that the structural transformations occurring during the heating process, starting from metastable structures, generate significant amounts of energy. This is of practical importance in the use of metallic powders in additive manufacturing technology, due to potentially reduced energy input.

scholarly journals On the Features of Composite Coating, Based on Nickel Alloy and Aluminum–Iron Bronze, Processed by Direct Metal Deposition

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 957
Author(s):  
Eugene E. Feldshtein ◽  
Oleg Devojno ◽  
Marharyta Kardapolava ◽  
Nikolaj Lutsko ◽  
Justyna Patalas-Maliszewska
Keyword(s):  
Additive Manufacturing ◽  
Composite Coating ◽  
Ceramic Materials ◽  
Metal Substrate ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Metal Alloys ◽  
Aluminum Iron ◽  
Manufacturing Technologies ◽  
Intensive Development

In recent years, additive manufacturing technologies have become increasingly widespread with the most intensive development being direct metal deposition (DMD), alloys, and ceramic materials on a metal substrate. This study shows the possibilities of the effective formation of coatings, based on heterogeneous metal alloys (Ni-based alloy and Fe-Al bronze) deposited onto 1045 structural steel. Changes in the microhardness, the microstructure, and the tribological properties of the composite coating, depending on the laser spot speed and pitch during DMD processing, have been considered. It was revealed that if the components of the composite coating are chosen correctly, there are possible DMD conditions ensuring reliable and durable connection between them and with the substrate.

Assessing Printability Maps in Additive Manufacturing of Metal Alloys

2019 ◽  
Author(s):  
Luke Johnson ◽  
Mohamad Mahmoudi ◽  
Bing Zhang ◽  
Raiyan Seede ◽  
Janine T. Maier ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Metal Alloys

scholarly journals Fiber Formation and Structural Development of HBA/HNA Thermotropic Liquid Crystalline Polymer in High-Speed Melt Spinning

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Bo Seok Song ◽  
Jun Young Lee ◽  
Sun Hwa Jang ◽  
Wan-Gyu Hahm
Keyword(s):  
Mechanical Properties ◽  
Shear Rate ◽  
High Speed ◽  
Melt Spinning ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Fiber Formation ◽  
Structural Development ◽  
Thermotropic Liquid Crystalline Polymer

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.

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.

scholarly journals Adhesion Studies during Generative Hybridization of Textile-Reinforced Thermoplastic Composites via Additive Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3888
Author(s):  
Johanna Maier ◽  
Christian Vogel ◽  
Tobias Lebelt ◽  
Vinzenz Geske ◽  
Thomas Behnisch ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Polyamide 6 ◽  
Thermoplastic Composites ◽  
Efficient Production ◽  
Angle Measurements ◽  
Small Series ◽  
Contact Angle Measurements ◽  
Static Tensile ◽  
Pre Treatment ◽  
Manufacturing Technologies

Generative hybridization enables the efficient production of lightweight structures by combining classic manufacturing processes with additive manufacturing technologies. This type of functionalization process allows components with high geometric complexity and high mechanical properties to be produced efficiently in small series without the need for additional molds. In this study, hybrid specimens were generated by additively depositing PA6 (polyamide 6) via fused layer modeling (FLM) onto continuous woven fiber GF/PA6 (glass fiber/polyamide 6) flat preforms. Specifically, the effects of surface pre-treatment and process-induced surface interactions were investigated using optical microscopy for contact angle measurements as well as laser profilometry and thermal analytics. The bonding characteristic at the interface was evaluated via quasi-static tensile pull-off tests. Results indicate that both the bond strength and corresponding failure type vary with pre-treatment settings and process parameters during generative hybridization. It is shown that both the base substrate temperature and the FLM nozzle distance have a significant influence on the adhesive tensile strength. In particular, it can be seen that surface activation by plasma can significantly improve the specific adhesion in generative hybridization.

scholarly journals MODEL-BASED DESIGN OF AM COMPONENTS TO ENABLE DECENTRALIZED DIGITAL MANUFACTURING SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 2127-2136
Author(s):  
Olivia Borgue ◽  
John Stavridis ◽  
Tomas Vannucci ◽  
Panagiotis Stavropoulos ◽  
Harry Bikas ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Production Systems ◽  
Data Generation ◽  
Production Networks ◽  
Model Based ◽  
Manufacturing Technologies ◽  
Am Processes ◽  
Final Consumer

AbstractAdditive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy.

scholarly journals PoreAnalyzer—An Open-Source Framework for the Analysis and Classification of Defects in Additive Manufacturing

2021 ◽  
Vol 11 (13) ◽  
pp. 6086
Author(s):  
Nils Ellendt ◽  
Fabian Fabricius ◽  
Anastasiya Toenjes
Keyword(s):  
Additive Manufacturing ◽  
Open Source ◽  
Total Porosity ◽  
Shape Accuracy ◽  
Process Maps ◽  
Defect Type ◽  
Open Source Framework ◽  
New Material ◽  
High Cooling Rates

Additive manufacturing processes offer high geometric flexibility and allow the use of new alloy concepts due to high cooling rates. For each new material, parameter studies have to be performed to find process parameters that minimize microstructural defects such as pores or cracks. In this paper, we present a system developed in Python for accelerated image analysis of optical microscopy images. Batch processing can be used to quickly analyze large image sets with respect to pore size distribution, defect type, contribution of defect type to total porosity, and shape accuracy of printed samples. The open-source software is independent of the microscope used and is freely available for use. This framework allows us to perform such an analysis on a circular area with a diameter of 5 mm within 10 s, allowing detailed process maps to be obtained for new materials within minutes after preparation.

scholarly journals Influence of Deposition Patterns on Distortion of H13 Steel by Wire-Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 485
Author(s):  
Xufeng Li ◽  
Jian Lin ◽  
Zhidong Xia ◽  
Yongqiang Zhang ◽  
Hanguang Fu
Keyword(s):  
Additive Manufacturing ◽  
Temperature History ◽  
H13 Steel ◽  
Deposition Patterns ◽  
Field Distortion ◽  
Set Up ◽  
Manufacturing Technologies ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Wire Arc Additive Manufacturing

Wire-arc additive manufacturing (WAAM) has been considered as one of the potential additive-manufacturing technologies to fabricate large components. However, its industrial application is still limited by the existence of stress and distortion. During the process of WAAM, the scanning pattern has an important influence on the temperature field, distortion and final quality of the part. Four kinds of deposition patterns, including sequence, symmetry, in–out and out–in, were designed to deposit H13 steel in this study. An in situ measurement system was set up to record the temperature history and the progress of accumulated distortion of the parts during deposition. An S value was proposed to evaluate the distortion of the substrate. It was shown that the distortion of the part deposited by sequence was significantly larger than those of other parts. The distortion deposited by the out–in pattern decreased by 68.6% compared with sequence. The inherent strain method and strain parameter were introduced to expose the mechanism of distortion reduction caused by pattern variation.

Sign in / Sign up

Export Citation Format

Share Document