scholarly journals STEP-NC Based Squashing Slicing Algorithm for Multi-Material and Multi-Directional Additive Process

Author(s):  
Jumyung Um ◽  
Joung min Park ◽  
Ian Anthony Stroud

The paper describes problems with the current additive manufacturing chain before considering additive manufacturing as part of a modern manufacturing chain. Additive manufacturing can be used for near net-shape for finishing, for repair or for adding special features which cannot be made with traditional manufacturing. This paper describes how STEP-NC deals with these different scenarios in terms of accuracy, multi-material and variation of slice direction. The possibilities of multi-material objects also raises questions about the design of such objects and how these need to be handled by an advanced controller. The paper also describes non-planar slicing. Curved direction and cylindrical direction are shown to improve the accuracy of curved structure additive manufacturing. STEP-NC using boundary representation has better capability of depicting complex internal structures for additive processes. By using exact model of the final product represented by STEP-NC, the paper demonstrates improvements in data size reduction, slicing accuracy, and precise manipulation of internal structure.

2021 ◽  
Vol 11 (18) ◽  
pp. 8292
Author(s):  
Jumyung Um ◽  
Joungmin Park ◽  
Ian Anthony Stroud

Even though additive manufacturing is receiving increasing interest from aerospace, automotive, and shipbuilding, the legacy approach using tessellated form representation and cross-section slice algorithm still has the essential limitation of its inaccuracy of geometrical information and volumetric losses of final outputs. This paper introduces an innovative method to represent multi-material and multi-directional layers defined in boundary-representation standard model and to process complex sliced layers without missing volumes by using the proposed squashing operation. Applications of the proposed method to a bending part, an internal structure, and an industrial moulding product show the assurance of building original shape without missing volume during the comparison with the legacy method. The results show that using boundary representation and te squashing algorithm in the geometric process of additive manufacturing is expected to improve the inaccuracy that was the barrier of applying additive process to various metal industries.


Author(s):  
Keshavamurthy R. ◽  
Vijay Tambrallimath ◽  
Prabhakar Kuppahalli ◽  
Sekhar N.

Growth of nature is an additive process that gives sustainable existence to the structures developed; on the other hand, traditional manufacturing techniques can be wasteful as they are subtractive. Additive manufacturing produces almost nil waste and accordingly preserves raw materials resulting in cost reduction for the procurement of the same. It will also cut down on the carbon emissions that are usually generated from industrial manufacturing. Additive printed objects are lighter as well, making them more efficient, especially when used in the automobile and aerospace industry. Further, the intrinsic characteristics and the promising merits of additive manufacturing process are expected to provide a solution to improve the sustainability of the process. This chapter comprehensively reports on various additive manufacturing processes and their sustainable applications for green technology. The state of the art, opportunities, and future, related to sustainable applications of additive manufacturing have been presented at length.


2015 ◽  
Vol 809-810 ◽  
pp. 369-374 ◽  
Author(s):  
George Răzvan Buican ◽  
Gheorghe Oancea ◽  
Camil Lancea ◽  
Mihai Alin Pop

Nowadays Additive Manufacturing, and in particular Selective Laser Melting (SLM ), is being used more and more. The SLM manufacturing process has been subjects to a lot of studies in order to improve the manufacturing parameters. In this paper are presented some researches on the internal structure of the manufactured parts with two layer thickness: 30[μm] and 50[μm]. The internal structure of parts manufactured on SLM machine is obtained as images with a microscope. On the images each grain of the internal structures is painted in a different color and grouped according to its shape. All data about grains are analyzed by the means of statistical methods. The two manufacturing strategies, 30[μm] and 50[μm] layer thickness, generate parts that have slightly different internal structures. Thus, from the point of views of internal structure and manufacturing time, the strategy with 50[μm] layer thickness can be used because it generates a lowering in manufacturing costs and increases the overall productivity.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 939
Author(s):  
Mukti Chaturvedi ◽  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Luigi Renato Mistodie ◽  
Danut Mihailescu ◽  
...  

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiktoria Maria Wojnarowska ◽  
Jakub Najowicz ◽  
Tomasz Piecuch ◽  
Michał Sochacki ◽  
Dawid Pijanka ◽  
...  

Purpose Chicken orthoses that cover the ankle joint area are not commercially available. Therefore, the main purpose of this study is to fabricate a customised temporary Ankle–Foot Orthosis (AFO) for a chicken with a twisted ankle using computer-aided design (CAD) and three-dimensional (3D) printing. The secondary objective of the paper is to present the specific application of Additive Manufacturing (AM) in veterinary medicine. Design/methodology/approach The design process was based on multiple sketches, photos and measurements that were provided by the owner of the animal. The 3D model of the orthosis was made with Autodesk Fusion 360, while the prototype was fabricated using fused deposition modelling (FDM). Evaluation of the AFO was performed using the finite element method. Findings The work resulted in a functional 3D printed AFO for chicken. It was found that the orthosis made with AM provides satisfactory stiffen and a good fit. It was concluded that AM is suitable for custom bird AFO fabrication and, in some respects, is superior to traditional manufacturing methods. It was also concluded that the presented procedure can be applied in other veterinary cases and to other animal species and other parts of their body. AM provides veterinary with a powerful tool for the production of well-fitted and durable orthoses for animals. Research limitations/implications The study does not include the chicken's opinion on the comfort or fit of the manufactured AFO due to communication issues. Evaluation of the final prototype was done by the researchers and the animal owner. Originality/value No evidence was found in the literature on the use of AM for chicken orthosis, so this study is the first to describe such an application of AM. In addition, the study demonstrates the value of AM in veterinary medicine, especially in the production of devices such as orthoses.


2021 ◽  
Author(s):  
Enrique Ariza Galván ◽  
Isabel Montealegre Meléndez ◽  
Cristina Arévalo Mora ◽  
Eva María Pérez Soriano ◽  
Erich Neubauer ◽  
...  

Plasma metal deposition (PMD®) is a promising and economical direct energy deposition technique for metal additive manufacturing based on plasma as an energy source. This process allows the use of powder, wire, or both combined as feedstock material to create near-net-shape large size components (i.e., >1 m) with high-deposition rates (i.e., 10 kg/h). Among the already PMD® processed materials stand out high-temperature resistance nickel-based alloys, diverse steels and stainless steels commonly used in the industry, titanium alloys for the aerospace field, and lightweight alloys. Furthermore, the use of powder as feedstock also allows to produce metal matrix composites reinforced with a wide range of materials. This chapter presents the characteristics of the PMD® technology, the welding parameters affecting additive manufacturing, examples of different fabricated materials, as well as the challenges and developments of the rising PMD® technology.


2021 ◽  
Author(s):  
Kohei Kobayashi ◽  
Noriyuki Kodera ◽  
Taishi Kasai ◽  
Yuhei O Tahara ◽  
Takuma Toyonaga ◽  
...  

ABSTRACTMycoplasma mobile, a parasitic bacterium, glides on solid surfaces, such as animal cells and glass by a special mechanism. This process is driven by the force generated through ATP hydrolysis on an internal structure. However, the spatial and temporal behaviors of the internal structures in living cells are unclear. In this study, we detected the movements of the internal structure by scanning cells immobilized on a glass substrate using high-speed atomic force microscopy (HS-AFM). By scanning the surface of a cell, we succeeded in visualizing particles, 2 nm in hight and aligned mostly along the cell axis with a pitch of 31.5 nm, consistent with previously reported features based on electron microscopy. Movements of individual particles were then analyzed by HS-AFM. In the presence of sodium azide, the average speed of particle movements was reduced, suggesting that movement is linked to ATP hydrolysis. Partial inhibition of the reaction by sodium azide enabled us to analyze particle behavior in detail, showing that the particles move 9 nm right, relative to the gliding direction, and 2 nm into the cell interior in 330 ms, then return to their original position, based on ATP hydrolysis.IMPORTANCEThe Mycoplasma genus contains bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide by a special mechanism linked to their infection and survival. The special machinery for gliding can be divided into surface and internal structures that have evolved from rotary motors represented by ATP synthases. This study succeeded in visualizing the real-time movements of the internal structure by scanning from the outside of the cell using an innovative high-speed atomic force microscope, and then analyzing their behaviors.


2018 ◽  
Vol 190 ◽  
pp. 02005 ◽  
Author(s):  
Markus Hirtler ◽  
Angelika Jedynak ◽  
Benjamin Sydow ◽  
Alexander Sviridov ◽  
Markus Bambach

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.


2021 ◽  
Author(s):  
Angela Serra ◽  
Martina Malarco ◽  
Alessandro Musacchio ◽  
Giulio Buia ◽  
Pietro Bartocci ◽  
...  

Abstract Additive manufacturing (AM hereinafter) is revolutionizing prototyping production and even small-scale manufacturing. Usually it is assumed that AM has lower environmental impact, compared to traditional manufacturing processes, but there have been no comprehensive environmental life-cycle assessment studies confirming this, especially for the gas turbines (GT hereinafter) and turbomachinery sector. In this study the core processes performed at Baker Hughes site in Florence are considered, together with the powder production via atomization process to describe the overall environmental impact of a GT shroud produced through additive manufacturing and comparing it with traditional investment casting production process. Particular attention is given to materials production and logistics. The full component life cycle starts from the extraction of raw materials during mining, their fusion and, as said, the atomization process, the powders are transported to the gas turbines production site where they are used as base material in additive manufacturing, also machining and finishing processes are analyzed as they differ for a component produced by AM respect to one produced by traditional investment casting. From the analysis of the data obtained, it emerges that the AM process has better performances in terms of sustainability than the Investment casting (IC hereinafter), highlighted above all by a decrease in greenhouse gas emissions (GHG hereinafter) of over 40%.


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