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 Effects of Positioning Conditions on Material Properties In Powder bed Fusion Additive Manufacturing

2021 ◽  
Author(s):  
Mevlüt Yunus Kayacan ◽  
Nihat Yılmaz
Keyword(s):  
Additive Manufacturing ◽  
Material Properties ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cooling Rates ◽  
Powder Bed ◽  
Manufacturing Technologies ◽  
Average Size ◽  
Hardness Values

Abstract Among additive manufacturing technologies, Laser Powder Bed Fusion (L-PBF) is considered the most widespread layer-by-layer process. Although the L-PBF, which is also called as SLM method, has many advantages, several challenging problems must be overcome, including part positioning issues. In this study, the effect of part positioning on the microstructure of the part in the L-PBF method was investigated. Five Ti6Al4V samples were printed in different positions on the building platform and investigated with the aid of temperature, porosity, microstructure and hardness evaluations. In this study, martensitic needles were detected within the microstructure of Ti6Al4V samples. Furthermore, some twins were noticed on primary martensitic lines and the agglomeration of β precipitates was observed in vanadium rich areas. The positioning conditions of samples were revealed to have a strong effect on temperature gradients and on the average size of martensitic lines. Besides, different hardness values were attained depending on sample positioning conditions. As a major result, cooling rates were found related to positions of samples and the location of point on the samples. Higher cooling rates and repetitive cooling cycles resulted in microstructures becoming finer and harder.

scholarly journals Sensor-Based Additive Manufacturing Technologies

2021 ◽  
Vol 12 (3) ◽  
pp. 3513-3521
Keyword(s):  
Additive Manufacturing ◽  
Wearable Sensors ◽  
Sensor Technology ◽  
Layer By Layer ◽  
Environmental Sensors ◽  
Direct Energy Deposition ◽  
Powder Bed ◽  
Direct Energy ◽  
Building Components ◽  
Manufacturing Technologies

Additive manufacturing is the term that uses the CAD data to build components layer by layer; it is also termed layered manufacturing or 3D printing. The major advantage of additive manufacturing is the capability of building components without the use of molds or tools. Five major categories of AM processes include Powder Bed Fusion (PBF), Direct Energy Deposition (DED), Material Jetting (MJ), Binder Jetting (BJ), and Sheet Lamination (SL). The sensor may be defined as a device that responds to a physical stimulus and transmits a resulting impulse. Sensor technology has been widely adopted in advanced manufacturing, aerospace, biomedical and robotic applications. Commonly used sensors are temperature sensors, strain sensors, biosensors, environmental sensors, and wearable sensors, etc. Additive manufacturing technologies can fabricate sensors and microfluidic devices with less labor. This paper focuses on various sensors developed by additive manufacturing processes, and their practical application for the particular purpose is reviewed.

scholarly journals On The Relation Between Cooling Rate and Parts Geometry in Powder Bed Fusion Additive Manufacturing

2018 ◽  
Vol 1 (1) ◽  
pp. 223-231
Author(s):  
Nihat Yilmaz ◽  
Mevlüt Yunus Kayacan
Keyword(s):  
Additive Manufacturing ◽  
Cooling Rate ◽  
Solidification Process ◽  
Internal Stresses ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
Metal Powders ◽  
Powder Bed ◽  
Powder Particles ◽  
Manufacturing Technologies

Direct metal laser sintering (DMLS), one of the laser powder bed additive manufacturing technologies produces solid metal parts from 3-D CAD data, layer by layer, by melting/sintering and bonding metal powders with a focused laser beam. In this processes isn't complete melting of powder particles in micro melt pools as well as selective laser melting (SLM) and electron beam melting (EBM). Thus some different stress conditions and defects occur depending on the temperature changes during manufacturing. In this study, this problems is investigated aspect cooling rate. Cooling rate affects the solidification process in the melting (sintering) process such as casting, welding, laser assisted processes. Therefore, it also affect part quality and properties. In the scope of study, it is tried to explain how occurring the internal stresses and distortions differ depending on the cooling rates of geometrically different parts in additive manufacturing. The residual stresses and deformations are analyzed by FEA to see relation with geometry (volume, area) to cooling rate for Ti6Al4V materials. Cube shaped samples at 20, 40, 60, 80 and 100 mm edge dimensions have analysed by using FEA. Besides 10mm cube sample is manufactured as solid and verified both as experimental and numerical. Based on the FEA results, cooling rate values are changed from 1.67 to 16.67. In conclusion, the reasons of the problems occurring during laser powder bed fusion are investigated in terms of the cooling rate in relation with the samples geometry.

Digitalisierung von additiven Fertigungseinheiten/Digitalization of additive manufacturing units

2021 ◽  
Vol 111 (09) ◽  
pp. 633-637
Author(s):  
Maximilian Vogt ◽  
Julian Ulrich Weber ◽  
Vishnuu Jothi Prakash
Keyword(s):  
Additive Manufacturing ◽  
Feasible Solution ◽  
Spare Parts ◽  
Assistance System ◽  
Remote Locations ◽  
Assistance Systems ◽  
Mobile Manufacturing ◽  
Manufacturing Technologies

Additive Fertigungstechnologien erlauben die bedarfsgerechte Produktion von individuellen Ersatzteilen. Durch Einsatz mobiler Fertigungseinheiten lässt sich mithilfe dieser Verfahren die Resilienz von isolierten Produktionsstätten erhöhen. Um auch außerfachliches Personal zur Bedienung an entlegenen Einsatzorten zu befähigen, stellen digitale Assistenzsysteme eine mögliche Lösung dar. In diesem Beitrag wird ein solches Assistenzsystem zur Begleitung der manuellen Tätigkeiten beim roboterbasierten DED-Prozess in einer mobilen Fertigungseinheit diskutiert.   Additive manufacturing technologies enable the demand-driven production of individual spare parts. By using mobile manufacturing units, these processes can be used to increase the resilience of isolated production sites. In order to enable non-specialized personnel to operate at remote locations, digital assistance systems are a feasible solution. This paper discusses such an assistance system to accompany manual operations of the robot-based DED process in a mobile manufacturing unit.

Modeling and analysis of the on-demand spare parts supply using additive manufacturing

2019 ◽  
Vol 25 (3) ◽  
pp. 473-487 ◽  
Author(s):  
Yuan Zhang ◽  
Stefan Jedeck ◽  
Li Yang ◽  
Lihui Bai
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Spare Parts ◽  
Production Optimization ◽  
Arrival Process ◽  
Powder Bed Fusion ◽  
Content Type ◽  
Modeling And Analysis ◽  
Powder Bed ◽  
On Demand

PurposeDespite the widespread expectation that additive manufacturing (AM) will become a disruptive technology to transform the spare parts supply chain, very limited research has been devoted to the quantitative modeling and analysis on how AM could fulfill the on-demand spare parts supply. On the other hand, the choice of using AM as a spare parts supply strategy over traditional inventory is a rising decision faced by manufacturers and requires quantitative analysis for their AM-or-stock decisions. The purpose of this paper is to develop a quantitative performance model for a generic powder bed fusion AM system in a spare parts supply chain, thus providing insights into this less-explored area in the literature.Design/methodology/approachIn this study, analysis based on a discrete event simulation was carried out for the use of AM in replacement of traditional warehouse inventory for an on-demand spare parts supply system. Generic powder bed fusion AM system was used in the model, and the same modeling approach could be applied to other types of AM processes. Using this model, the impact of both spare parts demand characteristics (e.g. part size attributes, demand rates) and the AM operations characteristics (e.g. machine size and postpone strategy) on the performance of using AM to supply spare parts was studied.FindingsThe simulation results show that in many cases the AM operation is not as cost competitive compared to the traditional warehouse-based spare parts supply operation, and that the spare parts size characteristics could significantly affect the overall performance of the AM operations. For some scenarios of the arrival process of spare parts demand, the use of the batched AM production could potentially result in significant delay in parts delivery, which necessitates further investigations of production optimization strategies.Originality/valueThe findings demonstrate that the proposed simulation tool can not only provide insights on the performance characteristics of using AM in the spare parts supply chain, especially in comparison to the traditional warehousing system, but also can be used toward decision making for both the AM manufacturers and the spare parts service providers.

scholarly journals Laser powder bed fusion additive manufacturing of copper wicking structures: fabrication and capillary characterization

2021 ◽  
Author(s):  
Adnen Mezghani
Keyword(s):  
Additive Manufacturing ◽  
Performance Analysis ◽  
Heat Pipes ◽  
Manufacturing Processes ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Published Report ◽  
Secondary Manufacturing ◽  
Design Freedom

PurposeAn integral component in heat pipes (HPs) and vapor chambers (VCs) is a porous wicking structure. Traditional methods for manufacturing wicking structures within HPs and VCs involve secondary manufacturing processes and are generally limited to simple geometries. This work aims to leverage the unprecedented level of design freedom of laser powder bed fusion (LPBF) additive manufacturing (AM) to produce integrated wicking structures for HPs and VCs.Design/methodology/approachCopper wicking structures are fabricated through LPBF via partial sintering and via the formation of square, hexagonal and rectangular arrangements of micro-pins and micro-grooves, produced in multiple build directions. Wicks are characterized by conducting capillary performance analysis through the measurement of porosity, permeability and capillary rate-of-rise.FindingsCopper wicking structures were successfully fabricated with capillary performance, K/reff, ranging from 0.186–1.74 µm. The rectangular-arrangement micro-pin wick presented the highest performance.Originality/valueThis work represents the first published report on LPBF AM of copper wicking structures for HPs/VCs applications and represents foundational knowledge for fabricating complete assemblies of copper VCs and HPs through LPBF AM.

scholarly journals Investigation of microstructure and hardness of a rib geometry produced by metal forming and wire-arc additive manufacturing

2018 ◽  
Vol 190 ◽  
pp. 02005 ◽  
Author(s):  
Markus Hirtler ◽  
Angelika Jedynak ◽  
Benjamin Sydow ◽  
Alexander Sviridov ◽  
Markus Bambach
Keyword(s):  
Additive Manufacturing ◽  
Metal Forming ◽  
Batch Size ◽  
Unit Costs ◽  
Batch Sizes ◽  
Traditional Manufacturing ◽  
Manufacturing Technologies ◽  
Forming Tools ◽  
Wire Arc Additive Manufacturing ◽  
Am Processes

Within the scope of consumer-oriented production, individuality and cost-effectiveness are two essential aspects, which can barely be met by traditional manufacturing technologies. Conventional metal forming techniques are suitable for large batch sizes. If variants or individualized components have to be formed, the unit costs rise due to the inevitable tooling costs. For such applications, additive manufacturing (AM) processes, which do not require tooling, are more suitable. Due to the low production rates and limited build space of AM machines, the manufacturing costs are highly dependent on part size and batch size. Hence, a combination of both manufacturing technologies i.e. conventional metal forming and additive manufacturing seems expedient for a number of applications. The current study develops a process chain combining forming and additive manufacturing. First, a semi-finished product is formed with forming tools of reduced complexity and then finished by additive manufacturing. This research investigates the addition of features using AlSi12 created by Wire Arc Additive Manufacturing (WAAM) on formed EN-AW 6082 preforms. By forming, the strength of the material was increased, while this effect was partly reduced by the heat input of the WAAM process.

Additive Manufacturing of Nickel-Based Super Alloys for Aero Engine Applications

2020 ◽  
pp. 48-70
Author(s):  
Raja A. ◽  
Mythreyi O. V. ◽  
Jayaganthan R.
Keyword(s):  
Additive Manufacturing ◽  
Complex Geometry ◽  
Source Parameters ◽  
Raw Material ◽  
Layer By Layer ◽  
Powder Bed ◽  
Complex Design ◽  
Direct Energy ◽  
Second Phases ◽  
Metal Addition

Ni based super alloys are widely used in engine turbines because of their proven performance at high temperatures. Manufacturing these parts by additive manufacturing (AM) methods provides researchers a lot of creative space for complex design to improve efficiency. Powder bed fusion (PBF) and direct energy deposition (DED) are the two most widely-used metal AM methods. Both methods are influenced by the source, parameters, design, and raw material. Selective laser melting is one of the laser-based PBF techniques to create small layer thickness and complex geometry with greater accuracy and properties. The layer-by-layer metal addition generates epitaxial growth and solidification in the built direction. There are different second phases in the Ni-based superalloys. This chapter details the micro-segregation of these particles and its influence on the microstructure, and mechanical properties are dependent on the process influencing parameters, the thermal kinetics during the process, and the post-processing treatments.

scholarly journals Laser powder bed fusion additive manufacturing of copper wicking structures: fabrication and capillary characterization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adnen Mezghani ◽  
Abdalla R. Nassar ◽  
Corey J. Dickman ◽  
Eduardo Valdes ◽  
Raul Alvarado
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Heat Pipes ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Published Report ◽  
Secondary Manufacturing ◽  
Design Freedom

Purpose An integral component in heat pipes (HPs) and vapor chambers (VCs) is a porous wicking structure. Traditional methods for manufacturing wicking structures within HPs and VCs involve secondary manufacturing processes and are generally limited to simple geometries. This work aims to leverage the unprecedented level of design freedom of laser powder bed fusion (LPBF) additive manufacturing (AM) to produce integrated wicking structures for HPs and VCs. Design/methodology/approach Copper wicking structures are fabricated through LPBF via partial sintering and via the formation of square, hexagonal and rectangular arrangements of micro-pins and micro-grooves, produced in multiple build directions. Wicks are characterized by conducting capillary performance analysis through the measurement of porosity, permeability and capillary rate-of-rise. Findings Copper wicking structures were successfully fabricated with capillary performance, K/reff, ranging from 0.186–1.74 µm. The rectangular-arrangement micro-pin wick presented the highest performance. Originality/value This work represents the first published report on LPBF AM of copper wicking structures for HPs/VCs applications and represents foundational knowledge for fabricating complete assemblies of copper VCs and HPs through LPBF AM.

scholarly journals A 3D weaving infill pattern for fused filament fabrication

2021 ◽  
Author(s):  
Yuan Yao ◽  
Cheng Ding ◽  
Mohamed Aburaia ◽  
Maximilian Lackner ◽  
Lanlan He
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Repetitive Structure ◽  
Mechanical Linkage ◽  
Manufacturing Technologies ◽  
Dimensional Object ◽  
Anisotropy Of Mechanical Properties ◽  
3D Weaving

Abstract The Fused Filament Fabrication process is the most used additive manufacturing process due to its simplicity and low operating costs. In this process, a thermoplastic filament is led through an extruder, melted, and applied to a building platform by the axial movements of an automated Cartesian system in such a way that a three-dimensional object is created layer by layer. Compared to other additive manufacturing technologies, the components produced have mechanical limitations and are often not suitable for functional applications. To reduce the anisotropy of mechanical strength in fused filament fabrication (FFF), this paper proposes a 3D weaving deposit path planning method that utilizes a 5-layer repetitive structure to achieve interlocking and embedding between neighbor slicing planes to improve the mechanical linkage within the layers. The developed algorithm extends the weaving path as an infill pattern to fill different structures and makes this process feasible on a standard three-axis 3D printer. Compared with 3D weaving printed parts by layer-to-layer deposit, the anisotropy of mechanical properties inside layers is significantly reduced to 10.21% and 0.98%.

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