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Flexible tooling for impulse forming
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Procedia Manufacturing 27 (2019) 130–137 Procedia Manufacturing 00 (2017) 000–000
FlexibleICAFT/SFU/AutoMetForm tooling for impulse2018 formingwww.elsevier.com/locate/procedia ICAFT/SFU/AutoMetForm 2018 ICAFT/SFU/AutoMetForm 2018 a a
Flexible, H. tooling forBeckschwarte impulse forming L. Langstädtler Pegel , B. , M. Herrmanna, Flexible for C.tooling Schencka,b , B.impulse Kuhfussa,bforming Flexible a* tooling a for impulse forming a a L. Langstädtler , H. Pegel , B. Beckschwarte , M. Herrmann , 28-30 June Manufacturing Engineering Society International Conference 2017, MESIC 2017, a* a a University of Bremen – Bremen Institut for Mechanical Badgasteiner 1, 28359 Bremen, aGermany a,bEngeneering, a,b a, Str. L. Langstädtler , H. Pegel , B. Beckschwarte M. Herrmann , a* a a , B. Kuhfuss Mapex Center for Materials and Processing, Postbox 330440, 28334, Bremen, Germany 2017, Vigo Spain L. Langstädtler ,C. H.Schenck Pegel ,(Pontevedra), B. a,b Beckschwarte a,b M. Herrmann , C. Schencka,b, B. Kuhfussa,b C. Schenck , B. Kuhfuss University of Bremen – Bremen Institut for Mechanical Engeneering, Badgasteiner Str. 1, 28359 Bremen, Germany a*
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Mapexfor Center for Materials Processing, Postbox 330440, Bremen, Germany of Bremen – Bremen Institut forand Mechanical Engeneering, Badgasteiner Str. 1, 28359 Bremen, CostingUniversity models capacity optimization in28334 Industry 4.0:Germany Trade-off University of Bremen – Bremen Institut forand Mechanical Engeneering, Badgasteiner Str. 1, 28359 Bremen, Germany Mapex Center for Materials Processing, Postbox 330440, 28334 Bremen, Germany Abstract Mapex Center for Materials and Processing, Postbox 330440, 28334 Bremen, Germany between used capacity and operational efficiency a a
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With impulse forming technologies like electrohydraulic and electromagnetic forming, the punch in a stamping process is Abstractby an impulse that acts in a short period and provides high strain rates of over 1000 s-1. Beneath the advantages which replaced a a,* b b A. Santana , P. , A.have Zanin , R. Wernke Abstract are accompanied with high speed forming the usedAfonso dies and tools to withstand mainly dynamic loads. This enables the Abstract With impulse forming technologies likeflexibility electrohydraulic andforelectromagnetic forming, the punch in a different stampingaspects processlike is realization of new concepts to increase in tooling impulse forming. The flexibility covers a -1 University of Minho, 4800-058 Guimarães, . Beneath advantages which replaced by an forming impulse that acts in short period and provides high strain ratesPortugal offorming, over 1000 With impulse technologies like electrohydraulic and electromagnetic thes punch in athe stamping process is intrinsic geometrical adaptability ofathe punch, reduced demand for mechanical stiffness, rapid manufacturing of the dies due to b Unochapecó, 89809-000 Chapecó, Brazil With impulse technologies like electrohydraulic andtools electromagnetic forming, thes-1punch in loads. athe stamping process is are with high speed the used dies and have withstand dynamic This enables the . Beneath advantages which replaced by anofforming impulse that acts in forming a short period anddies provides high straintoSC, rates overmainly 1000 the accompanied usability alternative tool materials, modular and the opportunity ofofconsecutive or -1 parallel process combinations. replaced by an impulse that acts in a short period and provides high strain rates of over 1000 s . Beneath the advantages which realization of new concepts to increase flexibility in tooling for impulse forming. The flexibility covers different aspects like are accompanied with high speedare forming the by used dies andintools havesize to withstand dynamic Thisforming. enables The the These aspects of flexible tooling illustrated examples different scales for mainly sheet metal, tubeloads. and bulk are accompanied high speed the usedin dies and tools have to withstand mainly dynamic loads. This enables the intrinsic adaptability offorming the punch, for mechanical rapidefficiently. manufacturing of theaspects dies duelike to realization of newwith concepts to increase flexibility impulse covers different proposedgeometrical techniques allow cold forming of smallreduced seriestooling ordemand evenfor single parts forming. morestiffness, costThe and flexibility time realization of new concepts to increase flexibility in tooling for impulse forming. The flexibility covers different aspects like the usability of alternative tool materials, modular diesdemand and thefor opportunity consecutive parallel process combinations. intrinsic geometrical adaptability of the punch, reduced mechanicalofstiffness, rapidormanufacturing of the dies due to Abstract intrinsic geometrical adaptability of the punch, reduced for mechanical rapidmetal, of the dies dueThe to These aspects flexible tooling are illustrated by examples different size scales for sheet tube and bulk forming. the usability ofofalternative tool materials, modular diesdemand andinthe opportunity ofstiffness, consecutive ormanufacturing parallel process combinations. the usability ofofalternative toolforming materials, modular dies opportunity ofcost consecutive or parallel process proposed techniques allow cold of small or and even single parts more andsheet timemetal, efficiently. © 2018 The Authors. Published by B.V.byseries These aspects flexible tooling areElsevier illustrated examples inthe different size scales for tube and bulkcombinations. forming. The These ofaccess flexible arethe illustrated byseries examples in single different tube and bulk forming. The Under the concept of tooling "Industry 4.0", production processes willsize bescales pushed totime bemetal, increasingly interconnected, This isaspects an open article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) proposed techniques allow cold forming of small or even parts more costfor andsheet efficiently. proposed allow coldtime forming of small series or evenmuch single more partsofmore cost and efficiently.capacity information on a real basis and,ofnecessarily, efficient. In time this context, optimization Selection techniques and based peer-review under responsibility the scientific committee ICAFT/SFU/AutoMetForm 2018. © 2018 B.V. 2019 The Authors. Published by of Elsevier B.V. goes beyond the traditional aim capacity maximization, contributing also for organization’s profitability and value. This is an open accessPublished article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) (https://creativecommons.org/licenses/by-nc-nd/4.0/) license © 2018 The Authors. by Elsevier B.V. Keywords: Metal Forming; Die; Rapid Tooling Indeed, lean management and continuous improvement approaches suggest capacity optimization instead of © 2018 The Authors. Published by Elsevier B.V. under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. Selection This is an and openpeer-review access article under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) maximization. The study of capacity optimization and costing models is an important research topic that deserves This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility of the scientific committee This of ICAFT/SFU/AutoMetForm 2018. a mathematical contributions from both theRapid practical perspectives. paper presents and discusses Keywords: Metal Forming; Die; Toolingand theoretical
Nomenclature model forMetal capacity management based on different costing models (ABC and TDABC). A generic model has been Keywords: Forming; Die; Rapid Tooling Keywords: Metal Die; to Rapid Tooling developed and Forming; it was used analyze idle capacity and to design strategies towards the maximization of organization’s C capacity value. The trade-off capacity maximization vs operational efficiency is highlighted and it is shown that capacity eNomenclature extrusion depth Nomenclature optimization might hide operational EHF electrohydraulic forming inefficiency. C capacity Nomenclature © 2017 The Authors. Published by Elsevier B.V. loading energy E capacity eCC extrusion depth Peer-review under responsibility of the scientific committee of the Manufacturing Engineering Society International Conference C capacity EMF electromagnetic forming e extrusion depth forming EHF electrohydraulic 2017. eE extrusion depth input energy for each individual forming operation E i EHF electrohydraulic loading energy forming C EHF electrohydraulic forming stepwise energy E loading energy EstC EMF electromagnetic formingCapacity Management; Idle Capacity; Operational Efficiency Keywords: Cost Models; ABC; TDABC; loading energy E hEMF forming depthfor forming electromagnetic ECi input energy each individual forming operation EMF electromagnetic U loading voltage input energy for forming each individual forming operation Esti stepwise energy input energy for each individual forming operation initial sheet thickness sE i Introduction stepwise energy hE01. forming depth st stepwise energy Est hU forming depth loading voltage hU The cost forming depth of idle capacity is a fundamental information for companies and their management of extreme importance loading voltage s0 initial sheet thickness U loading voltage in production systems. In general, it is defined as unused capacity or production potential and can be measured sheet thickness s0 moderninitial s0 severalinitial in ways:sheet tonsthickness of production, available hours of manufacturing, etc. The management of the idle capacity * Paulo Afonso. Tel.: +351 253 510 761; fax: +351 253 604 741 E-mail address: [email protected] * Corresponding author. Tel.: +49421 218 64828; fax: +49421 218 98 64828 E-mail address: [email protected] 2351-9789 © 2017 The Authors. Published by Elsevier B.V. Peer-review under of the scientific of the218 Manufacturing * Corresponding author. Tel.: +49421 218 64828; fax: +49421 98 64828 Engineering Society International Conference 2017. 2351-9789 © 2019responsibility TheAuthors. Authors. Published bycommittee Elsevier 2351-9789 © 2018 The Published by Elsevier B.V.B.V. E-mail [email protected] This is an address: open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) * Corresponding author. Tel.: +49421 218BY-NC-ND 64828; fax: license +49421 218 98 64828 This is an open access article under the CC (https://creativecommons.org/licenses/by-nc-nd/4.0/) * Corresponding author. Tel.: +49421 218 64828;offax: 218committee 98 64828 of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility the+49421 scientific E-mail address: [email protected] Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018. 10.1016/j.promfg.2018.12.055 E-mail address: [email protected] 2351-9789 © 2018 The Authors. Published by Elsevier B.V. This is an open access under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) 2351-9789 © 2018 Thearticle Authors. Published by Elsevier B.V. 2351-9789 © 2018 Thearticle Authors. Published by Elsevier B.V. Selection peer-review under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. This is an and open access under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) This is an and openpeer-review access article under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018.
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1. Introduction Manufacturing processes have to meet increasing requirements, which are subject to constant change. One of these transformation processes is the trend towards smaller batch sizes and individual products. Already existing approaches of rapid prototyping like 3D printing offer a high degree of flexibility due to a rapid provision of the product. Conventional forming processes are limited in the ability to follow this trend due to the dependence on rigid tools that have to withstand high static loads and that have to be manufactured in time and cost intensive processes. Hence, for rapid manufacturing arises a new potential with a strategy that combines impulse-forming processes – where the dies are loaded and unloaded very quickly – with new tooling concepts. The combination of impulse forming and flexible tooling offers three different fields of flexibility for a rapid manufacturing, which are categorized into the aspects of die material, tool provision and process design. The first category includes approaches to apply new die materials such as wood, polymers or non-ferrous metals [1]. Previous work, however, is based on conventional forming processes, whereby disadvantages by these new materials were not compensated due to static loads. The second category concerning the die material is covered by a wide range of previous work, which spread from modular and adaptable tools [2-4] to completely new approaches of tool production [5,6]. In contrast to the new approaches in tool provision in the third category, the process design affects the flexibility of the manufacturing process itself. A well-known concept to increase flexibility by process design is the single point incremental forming [7]. Examples for changes in process design in impulse forming regarding flexibility are given in different researches for joining by forming [8-10], in [11] by shaping electromagnetic force distributions as well as in [12] by using multiple electrohydraulic pressure chambers to form sheet metals. 2. Impulse forming processes In this work, two impulse-forming processes were used to show the potential in terms of flexibility. Both variants were based on facilities to provide high peak electric currents. For this purpose, a capacitor bank was loaded with electric energy. This energy was short-circuited over either a wire or a working coil. The exploding wire initiated a shockwave in a fluid whereas the working coil emitted an electromagnetic pulse, see Fig. 1. Both, the shockwave and the electromagnetic pulse were used for forming. Although the physical mechanisms of contactless energy transmission to the deformed part differed, both techniques share advantages compared to mechanical stamping. Improved formability, reduced spring back and winkling and the obsolescence of lubricant based on mineral oils were gained by the high strain rates of more than 1000 s-1. This impulse forming features were investigated for several forming operations for sheet metal [13] as well as tube forming, cutting [14,15], joining [8,16-18], bulk forming [19] and embossing of optical microstructures [20].
Fig. 1. Impulse forming set-ups.
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Fig. 2. Examples of alternative die materials: (a) electrohydraulic forming with jelly bear as die (s0 = 200 µm, EC = 112 J) [21]; ((b) electromagnetic embossing with polylactide as die material (s0 = 200 µm, EC = 1250 J).
3. Die material In contrast to the quasi-static forming, the load of the part and die in impulse forming is applied as an impact. Hence, common rules for the design of dies like the demand for high (static) stiffness and high hardness are challenged. Alternative die materials were applied to metal forming. For example, forming of 200 µm thick aluminum sheet was successfully performed with a soft body (jelly bear) as die, Fig. 2-a. More results regarding alternative materials were presented in [21]. Furthermore, FDM-printed polylactide dies delivered excellent results; even embossing a structure in sub-millimeter scale was possible, Fig. 2-b. 4. Tool provision 4.1. Manufacturing of dies As a result of using alternative die materials, the manufacturing methods for forming dies can be challenged to increase flexibility. In contrast to the conventional milled/turned steel dies, alternative materials feature properties, which can be used for rapid manufacturing. In Fig. 3 examples are presented, which challenge provision time, costs and traditional tooling strategies. On the base of a low melting temperature, FDM-printing can be applied. Further casting of silicone or other materials can be used. This results in the ability to generate parts by molding the die with soft material and forming the part with this die and an impulse technology.
Fig. 3. Top-view on impulse forming dies - manufacturing for new die materials for impulse forming.
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extrusion direction Fig. 4. Extrusion with stacked dies: (a) extrusion depth e as a function of the energy ΣEst; (b) initial and extruded sample (Est = 250 J, 11 impulses).
4.2. Modular dies Besides the manufacturing, another challenge is the time and cost consuming assembling process. For EHF and EMF, the assembling process is less time consuming due to less tool parts like guiding elements between stamp and die. In addition, the form stability of assembled dies must only withstand the impulse load. In consequence, die designs with rather low form stability could be chosen for impulse forming, e.g. stacked dies without preloading. Such stacked dies, made of unhardened S355 steel disks, were designed on the ideas of reconfigurable tools [2-4]. The assembly was intended for incremental electrohydraulic bulk forming of micro samples. Within the CRC 1232 the process was introduced to characterize spherical micro samples while they are incrementally formed. By in-situ measurements of the incremental deformations by e.g. the extrusion depth e and comparison with simulated characteristic values, the material behavior is predicted with micro-samples. Several disks were stacked to build an extrusion die forming channel. By changing the order of the single disks, the channel geometry and the resulting deformation is varied. The samples (Fig. 4) were extruded in several incremental forming steps with an incremental energy Est. Such a procedure was only applicable through the flexible punch of EHF, which adapted to the channel geometry and followed the deformed sample through the high aspect ratio channel. In addition, preloading of the extrusion dies proved to be dispensable both in axial and in radial direction.
Fig. 5. Examples for die-less forming; (a) electrohydraulic free forming of a tube (EC = 200 J); (b) electromagnetic hemming of different sheet metals (EC = 800 J, bottom sheet was bended in advance) [16].
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5. Process Design 5.1 Die-less forming A further step in the generalization of shaping elements is to substitute the application of dies by the force distribution or the workpiece itself. In that case, the desired shape is only affected by the applied force pattern and interacting workpiece. By the ability to vary the local force on the workpiece by the coil shape in EMF and the shape and/or position of the explosion chamber during EHF, it is possible to work without a product specific die. An example is giving in Fig. 5a, where an electrohydraulic explosion chamber is placed on a tube applying a localized impulse. Due to the inertia of surrounding material in the tube wall, a corrugation is created. Further examples are electromagnetic hemming. During hemming, the inertia of the part enables joining with form closure [16], Fig. 5b. 5.2. Single-stage Due to the ability of the punch to adapt to different dies, a flexible process design is enabled by combining different processes in parallel. Sheet metal blanking and forming was performed simultaneously with a single impulse [21]. Alternative processes could also be realized with the same die by different impulse energies, Fig. 6. With lower charging energy, a bulge was formed in aluminum sheets, whereas a higher energy facilitated cutting. As a result of the locally controllable impulse, forming, embossing and cutting in the same die and step is enabled.
Fig. 6. Example process design (single-stage): energy dependent forming and cutting.
Fig.7. Example process design (incremental EHF tube forming) (a) metallic printed mandrel with partial thread; (b) formed aluminum tube with thread (16 subsequent impulses with Ei = 300 J, shifted impulse, shifted and turned mandrel).
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Fig.8. Feature based geometric decomposition of an optical component for sequential forming [22].
5.3. Multi-stage Even more flexibility is enabled when multiple impulses are performed in series either using the same or different dies for each forming step. If using the same die, this die can represent either the complete form or only a part of it. The complete form approach was successfully performed by electromagnetic incremental forming with coil shifting [23]. The partial form approach was realized by electrohydraulic incremental forming of a thread in a tube, Fig. 7. A localized shockwave was aligned with a 3D-printed metallic mandrel that represented only a part of the thread (thread pitch: 20 mm). After each impulse, the aluminum tube was shifted and rotated to form the full thread iteratively. In contrast, using different dies enabled scale and feature based forming, Fig. 8. An optical component with a convex base geometry and a deterministic optical microstructure at the surface was split in these two basic features. The features were formed sequentially by electromagnetic embossing [24] and electromagnetic bulging. Planar embossing dies were machined by ultra-precision diamond chiseling in optical quality [22]. The tool for the free forming step was a simple bore. By this strategy of feature separation, the complexity of die manufacturing was significantly decreased. The firstly embossed microstructure was unharmed by the following free forming step, Fig. 9.
Fig. 9. Electromagnetic forming of an optical component in to forming steps: (a) measured geometry; (b) comparison of a selected micro channel geometry.
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6. Conclusion In this study, impulse forming was introduced to rapid manufacturing by considering new flexible tooling strategies regarding the process properties. The aspects of flexible tooling for impulse forming were discussed and illustrated. Therefore, flexible tooling was defined in three categories – die material, tool provision and process design. The following statements could be deduced:
For impulse forming, new strategies for die design could be taken into account. Due to the impact on the dies, the dynamic behavior becomes more important than the static stiffness. Extrusion of micro parts was enabled by electrohydraulic multi-impulse forming due to the flexible punch and the possibility of high aspect ratios of the forming channels. Furthermore, the manufacturing of the dies was simplified by the possibility to apply modular dies that furthermore enable the design of more sophisticated channel geometries. Hence, the forming channels are usable for material testing. Other applications like conditioning of material properties by e.g. applying severe shear deformation and combining multiple forming stages within one die for micro part production become conceivable. Die geometries can be simplified by multistage forming resulting in flexibility of the forming process. The strategies of splitting the tool shape into simpler tools and controlled forming with basic tools can be pursued. Different process combinations are applicable. With the same die, various processes like forming, cutting and embossing can be realized by adapting the process forces. Consequently, with these features production processes can be established for rapid cold forming of sheet and bulk metals. Hence, forming of individual parts and small batch sizes in micro and meso-scale dimensions can be achieved efficiently with impulse forming technology.
In order to develop the full potential of rapid forming, it is necessary not only to develop the process chains but also to further develop the underlying impulse technologies and the necessary plant technology. In particular, the availability and efficiency of surge current systems and automation still pose significant hurdles. Acknowledgements The authors gratefully acknowledge the support by the German Research Foundation (DFG) for the sub-project D04 within the Collaborative Research Center CRC 1232 as well as the support for the project „Electromagnetic embossing of optical microstructures“. Furthermore the authors gratefully acknowledge the support by the German Federation of Industrial Research Associations (AiF) for the project „Entwicklung des Elektrohydroumformens zum partiellen und inkrementellen Umformen“ supported by the Federal ministry for Economic Affairs and Energy on the basis of a decision by the german Bundestag and the ZIM (Zentrales Innovationsprogramm Mittelstand). References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
M. Pinto, A.D. Santos, P. Teixeira, P.J. Bolt, Study on the usability and robustness of polymer and wood materials for tooling in sheet metal forming, Journal of Materials Processing Technology 202 (2008) 47-53. N. Nakajima, A Newly Developed Technique to Fabricate Complicated Dies and Electrodes with Wires, Bulletin of JSME 12 (1969) 1546-1554. B. Koc, S. Thangaswamy, Design and analysis of a reconfigurable discrete pin tooling system for molding of three-dimensional free-form objects, Robotics and Computer-Integrated Manufacturing 27 (2011) 335-348. E. Haas, R.C. Schwarz, J.M. Papazian, Design and Test of a Reconfigurable Forming Die, Journal of Manufacturing Processes 4 (2002) 77-85. D.H. Müller, H. Müller, Experiences using rapid prototyping techniques to manufacture sheet metal forming tools (2000). P.K.D.V. Yarlagadda, I.P. Ilyas, P. Christodoulou, Development of rapid tooling for sheet metal drawing using nickel electroforming and stereolithography processes, Journal of Materials Processing Technology 111 (2001) 286-294. P.A.F. Martins, N. Bay, M. Skjoedt, M.B. Silva, Theory of single point incremental forming, CIRP Annals 57 (2008) 247-252. C. Weddeling, S.T. Woodward, M. Marré, J. Nellesen, V. Psyk, A.E. Tekkaya, W. Tillmann, Influence of groove characteristics on strength of form-fit joints, Journal of Materials Processing Technology 211 (2011) 925-935. V. Psyk, C. Scheffler, M. Linnemann, D. Landgrebe, Process analysis for magnetic pulse welding of similar and dissimilar material sheet metal joints, Procedia Engineering 207 (2017) 353-358. J. Lueg-Althoff, J. Bellmann, S. Gies, S. Schulze, A.E. Tekkaya, E. Beyer, Influence of the flyer kinetics on magnetic pulse welding of tubes, Journal of Materials Processing Technology 262 (2018) 189-203. M. Ahemd, S.K. Phanthi, N. Ramakrishnan, A.K. Jha, A.H. Yegneswaran, R. Dasgutpta, S. Ahemd, Alternative flat coil design for electromagnetic forming using FEM, Transactions of Nonferrous Metals Society of China 21 (2011) 618-625. S.F. Golovashchenko, N.M. Bessonov, A.M. Ilinich, Two-step method of forming complex shapes from sheet metal, Journal of Materials Processing Technology 211 (2011) 875-885. V. Psyk, P. Kurka, S. Kimme, M. Werner, D. Landgrebe, A. Ebert, M. Schwarzendahl, Structuring by electromagnetic forming and by forming with an elastomer punch as a tool for component optimisation regarding mechanical stiffness and acoustic performance, Manufacturing Rev. 2 (2015) 23.
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[14] B. Kuhfuß, C. Schenck, P. Wilhelmi, L. Langstädtler, Magnetic Pulse Cutting of Micro Metal Foils, International Conference On Micromanufacturing (2013). [15] E. Uhlmann, M. Scholz, Zerteilen von Aluminiumblechen durch Impulsmagnetfelder, Proceedings of the 2. Kolloquium Elektromagnetische Umformung (2003). [16] L. Langstädtler, M. Herrmann, C. Schenck, B. Kuhfuss, Electromagnetic Joining of Thin Sheets by Adapted Pulses, KEM 767 (2018) 439-446. [17] P. Jimbert, I. Perez, I. Eguia, G.S. Daehn, Straight Hemming of Aluminum Sheet Panels Using the Electromagnetic Forming Technology: First Approach, KEM 344 (2007) 365-372. [18] T. Aizawa, M. Kashani, K. Okagawa, Application of magnetic pulse welding for aluminium alloys and SPCC steel sheet joints, Welding in the World 86 (2007). [19] L. Langstädtler, H. Pegel, M. Herrmann, C. Schenck, D. Stöbener, J.F. Westerkamp, A. Fischer, B. Kuhfuss, Electrohydraulic extrusion of spherical bronze (CuSn6) micro samples, Technische Universität Dortmund. [20] M. Kamal, J. Shang, V. Cheng, S. Hatkevich, G.S. Daehn, Agile manufacturing of a micro-embossed case by a two-step electromagnetic forming process, Journal of Materials Processing Technology 190 (2007) 41-50. [21] H. Pegel, L. Langstädtler, M. Herrmann, C. Schenck, B. Kuhfuss, Electrohydraulic sheet metal forming with flexible tools, MATEC Web Conf. 190 (2018) 12001. [22] E. Brinksmeier, L. Schönemann, Generation of discontinuous microstructures by Diamond Micro Chiseling, CIRP Annals 63 (2014) 49-52. [23] K. Guo, X. Lei, M. Zhan, J. Tan, Electromagnetic incremental forming of integral panel under different discharge conditions, Journal of Manufacturing Processes 28 (2017) 373-382. [24] L. Langstädtler, L. Schönemann, C. Schenck, B. Kuhfuss, Electromagnetic Embossing of Optical Microstructures, J. Micro Nano-Manuf 4 (2016) 21001.
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Published by B.V.byseries These aspects flexible tooling areElsevier illustrated examples inthe different size scales for tube and bulkcombinations. forming. The These ofaccess flexible arethe illustrated byseries examples in single different tube and bulk forming. The Under the concept of tooling "Industry 4.0", production processes willsize bescales pushed totime bemetal, increasingly interconnected, This isaspects an open article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) proposed techniques allow cold forming of small or even parts more costfor andsheet efficiently. proposed allow coldtime forming of small series or evenmuch single more partsofmore cost and efficiently.capacity information on a real basis and,ofnecessarily, efficient. In time this context, optimization Selection techniques and based peer-review under responsibility the scientific committee ICAFT/SFU/AutoMetForm 2018. © 2018 B.V. 2019 The Authors. Published by of Elsevier B.V. goes beyond the traditional aim capacity maximization, contributing also for organization’s profitability and value. This is an open accessPublished article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) (https://creativecommons.org/licenses/by-nc-nd/4.0/) license © 2018 The Authors. by Elsevier B.V. Keywords: Metal Forming; Die; Rapid Tooling Indeed, lean management and continuous improvement approaches suggest capacity optimization instead of © 2018 The Authors. Published by Elsevier B.V. under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. Selection This is an and openpeer-review access article under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) maximization. The study of capacity optimization and costing models is an important research topic that deserves This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility of the scientific committee This of ICAFT/SFU/AutoMetForm 2018. a mathematical contributions from both theRapid practical perspectives. paper presents and discusses Keywords: Metal Forming; Die; Toolingand theoretical
Nomenclature model forMetal capacity management based on different costing models (ABC and TDABC). A generic model has been Keywords: Forming; Die; Rapid Tooling Keywords: Metal Die; to Rapid Tooling developed and Forming; it was used analyze idle capacity and to design strategies towards the maximization of organization’s C capacity value. The trade-off capacity maximization vs operational efficiency is highlighted and it is shown that capacity eNomenclature extrusion depth Nomenclature optimization might hide operational EHF electrohydraulic forming inefficiency. C capacity Nomenclature © 2017 The Authors. Published by Elsevier B.V. loading energy E capacity eCC extrusion depth Peer-review under responsibility of the scientific committee of the Manufacturing Engineering Society International Conference C capacity EMF electromagnetic forming e extrusion depth forming EHF electrohydraulic 2017. eE extrusion depth input energy for each individual forming operation E i EHF electrohydraulic loading energy forming C EHF electrohydraulic forming stepwise energy E loading energy EstC EMF electromagnetic formingCapacity Management; Idle Capacity; Operational Efficiency Keywords: Cost Models; ABC; TDABC; loading energy E hEMF forming depthfor forming electromagnetic ECi input energy each individual forming operation EMF electromagnetic U loading voltage input energy for forming each individual forming operation Esti stepwise energy input energy for each individual forming operation initial sheet thickness sE i Introduction stepwise energy hE01. forming depth st stepwise energy Est hU forming depth loading voltage hU The cost forming depth of idle capacity is a fundamental information for companies and their management of extreme importance loading voltage s0 initial sheet thickness U loading voltage in production systems. In general, it is defined as unused capacity or production potential and can be measured sheet thickness s0 moderninitial s0 severalinitial in ways:sheet tonsthickness of production, available hours of manufacturing, etc. The management of the idle capacity * Paulo Afonso. Tel.: +351 253 510 761; fax: +351 253 604 741 E-mail address: [email protected] * Corresponding author. Tel.: +49421 218 64828; fax: +49421 218 98 64828 E-mail address: [email protected] 2351-9789 © 2017 The Authors. Published by Elsevier B.V. Peer-review under of the scientific of the218 Manufacturing * Corresponding author. Tel.: +49421 218 64828; fax: +49421 98 64828 Engineering Society International Conference 2017. 2351-9789 © 2019responsibility TheAuthors. Authors. Published bycommittee Elsevier 2351-9789 © 2018 The Published by Elsevier B.V.B.V. E-mail [email protected] This is an address: open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) * Corresponding author. Tel.: +49421 218BY-NC-ND 64828; fax: license +49421 218 98 64828 This is an open access article under the CC (https://creativecommons.org/licenses/by-nc-nd/4.0/) * Corresponding author. Tel.: +49421 218 64828;offax: 218committee 98 64828 of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility the+49421 scientific E-mail address: [email protected] Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018. 10.1016/j.promfg.2018.12.055 E-mail address: [email protected] 2351-9789 © 2018 The Authors. Published by Elsevier B.V. This is an open access under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) 2351-9789 © 2018 Thearticle Authors. Published by Elsevier B.V. 2351-9789 © 2018 Thearticle Authors. Published by Elsevier B.V. Selection peer-review under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. This is an and open access under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) This is an and openpeer-review access article under the CC BY-NC-ND licensecommittee (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection under responsibility of the scientific of ICAFT/SFU/AutoMetForm 2018. Selection and peer-review under responsibility of the scientific committee of ICAFT/SFU/AutoMetForm 2018.
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1. Introduction Manufacturing processes have to meet increasing requirements, which are subject to constant change. One of these transformation processes is the trend towards smaller batch sizes and individual products. Already existing approaches of rapid prototyping like 3D printing offer a high degree of flexibility due to a rapid provision of the product. Conventional forming processes are limited in the ability to follow this trend due to the dependence on rigid tools that have to withstand high static loads and that have to be manufactured in time and cost intensive processes. Hence, for rapid manufacturing arises a new potential with a strategy that combines impulse-forming processes – where the dies are loaded and unloaded very quickly – with new tooling concepts. The combination of impulse forming and flexible tooling offers three different fields of flexibility for a rapid manufacturing, which are categorized into the aspects of die material, tool provision and process design. The first category includes approaches to apply new die materials such as wood, polymers or non-ferrous metals [1]. Previous work, however, is based on conventional forming processes, whereby disadvantages by these new materials were not compensated due to static loads. The second category concerning the die material is covered by a wide range of previous work, which spread from modular and adaptable tools [2-4] to completely new approaches of tool production [5,6]. In contrast to the new approaches in tool provision in the third category, the process design affects the flexibility of the manufacturing process itself. A well-known concept to increase flexibility by process design is the single point incremental forming [7]. Examples for changes in process design in impulse forming regarding flexibility are given in different researches for joining by forming [8-10], in [11] by shaping electromagnetic force distributions as well as in [12] by using multiple electrohydraulic pressure chambers to form sheet metals. 2. Impulse forming processes In this work, two impulse-forming processes were used to show the potential in terms of flexibility. Both variants were based on facilities to provide high peak electric currents. For this purpose, a capacitor bank was loaded with electric energy. This energy was short-circuited over either a wire or a working coil. The exploding wire initiated a shockwave in a fluid whereas the working coil emitted an electromagnetic pulse, see Fig. 1. Both, the shockwave and the electromagnetic pulse were used for forming. Although the physical mechanisms of contactless energy transmission to the deformed part differed, both techniques share advantages compared to mechanical stamping. Improved formability, reduced spring back and winkling and the obsolescence of lubricant based on mineral oils were gained by the high strain rates of more than 1000 s-1. This impulse forming features were investigated for several forming operations for sheet metal [13] as well as tube forming, cutting [14,15], joining [8,16-18], bulk forming [19] and embossing of optical microstructures [20].
Fig. 1. Impulse forming set-ups.
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Fig. 2. Examples of alternative die materials: (a) electrohydraulic forming with jelly bear as die (s0 = 200 µm, EC = 112 J) [21]; ((b) electromagnetic embossing with polylactide as die material (s0 = 200 µm, EC = 1250 J).
3. Die material In contrast to the quasi-static forming, the load of the part and die in impulse forming is applied as an impact. Hence, common rules for the design of dies like the demand for high (static) stiffness and high hardness are challenged. Alternative die materials were applied to metal forming. For example, forming of 200 µm thick aluminum sheet was successfully performed with a soft body (jelly bear) as die, Fig. 2-a. More results regarding alternative materials were presented in [21]. Furthermore, FDM-printed polylactide dies delivered excellent results; even embossing a structure in sub-millimeter scale was possible, Fig. 2-b. 4. Tool provision 4.1. Manufacturing of dies As a result of using alternative die materials, the manufacturing methods for forming dies can be challenged to increase flexibility. In contrast to the conventional milled/turned steel dies, alternative materials feature properties, which can be used for rapid manufacturing. In Fig. 3 examples are presented, which challenge provision time, costs and traditional tooling strategies. On the base of a low melting temperature, FDM-printing can be applied. Further casting of silicone or other materials can be used. This results in the ability to generate parts by molding the die with soft material and forming the part with this die and an impulse technology.
Fig. 3. Top-view on impulse forming dies - manufacturing for new die materials for impulse forming.
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extrusion direction Fig. 4. Extrusion with stacked dies: (a) extrusion depth e as a function of the energy ΣEst; (b) initial and extruded sample (Est = 250 J, 11 impulses).
4.2. Modular dies Besides the manufacturing, another challenge is the time and cost consuming assembling process. For EHF and EMF, the assembling process is less time consuming due to less tool parts like guiding elements between stamp and die. In addition, the form stability of assembled dies must only withstand the impulse load. In consequence, die designs with rather low form stability could be chosen for impulse forming, e.g. stacked dies without preloading. Such stacked dies, made of unhardened S355 steel disks, were designed on the ideas of reconfigurable tools [2-4]. The assembly was intended for incremental electrohydraulic bulk forming of micro samples. Within the CRC 1232 the process was introduced to characterize spherical micro samples while they are incrementally formed. By in-situ measurements of the incremental deformations by e.g. the extrusion depth e and comparison with simulated characteristic values, the material behavior is predicted with micro-samples. Several disks were stacked to build an extrusion die forming channel. By changing the order of the single disks, the channel geometry and the resulting deformation is varied. The samples (Fig. 4) were extruded in several incremental forming steps with an incremental energy Est. Such a procedure was only applicable through the flexible punch of EHF, which adapted to the channel geometry and followed the deformed sample through the high aspect ratio channel. In addition, preloading of the extrusion dies proved to be dispensable both in axial and in radial direction.
Fig. 5. Examples for die-less forming; (a) electrohydraulic free forming of a tube (EC = 200 J); (b) electromagnetic hemming of different sheet metals (EC = 800 J, bottom sheet was bended in advance) [16].
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5. Process Design 5.1 Die-less forming A further step in the generalization of shaping elements is to substitute the application of dies by the force distribution or the workpiece itself. In that case, the desired shape is only affected by the applied force pattern and interacting workpiece. By the ability to vary the local force on the workpiece by the coil shape in EMF and the shape and/or position of the explosion chamber during EHF, it is possible to work without a product specific die. An example is giving in Fig. 5a, where an electrohydraulic explosion chamber is placed on a tube applying a localized impulse. Due to the inertia of surrounding material in the tube wall, a corrugation is created. Further examples are electromagnetic hemming. During hemming, the inertia of the part enables joining with form closure [16], Fig. 5b. 5.2. Single-stage Due to the ability of the punch to adapt to different dies, a flexible process design is enabled by combining different processes in parallel. Sheet metal blanking and forming was performed simultaneously with a single impulse [21]. Alternative processes could also be realized with the same die by different impulse energies, Fig. 6. With lower charging energy, a bulge was formed in aluminum sheets, whereas a higher energy facilitated cutting. As a result of the locally controllable impulse, forming, embossing and cutting in the same die and step is enabled.
Fig. 6. Example process design (single-stage): energy dependent forming and cutting.
Fig.7. Example process design (incremental EHF tube forming) (a) metallic printed mandrel with partial thread; (b) formed aluminum tube with thread (16 subsequent impulses with Ei = 300 J, shifted impulse, shifted and turned mandrel).
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Fig.8. Feature based geometric decomposition of an optical component for sequential forming [22].
5.3. Multi-stage Even more flexibility is enabled when multiple impulses are performed in series either using the same or different dies for each forming step. If using the same die, this die can represent either the complete form or only a part of it. The complete form approach was successfully performed by electromagnetic incremental forming with coil shifting [23]. The partial form approach was realized by electrohydraulic incremental forming of a thread in a tube, Fig. 7. A localized shockwave was aligned with a 3D-printed metallic mandrel that represented only a part of the thread (thread pitch: 20 mm). After each impulse, the aluminum tube was shifted and rotated to form the full thread iteratively. In contrast, using different dies enabled scale and feature based forming, Fig. 8. An optical component with a convex base geometry and a deterministic optical microstructure at the surface was split in these two basic features. The features were formed sequentially by electromagnetic embossing [24] and electromagnetic bulging. Planar embossing dies were machined by ultra-precision diamond chiseling in optical quality [22]. The tool for the free forming step was a simple bore. By this strategy of feature separation, the complexity of die manufacturing was significantly decreased. The firstly embossed microstructure was unharmed by the following free forming step, Fig. 9.
Fig. 9. Electromagnetic forming of an optical component in to forming steps: (a) measured geometry; (b) comparison of a selected micro channel geometry.
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6. Conclusion In this study, impulse forming was introduced to rapid manufacturing by considering new flexible tooling strategies regarding the process properties. The aspects of flexible tooling for impulse forming were discussed and illustrated. Therefore, flexible tooling was defined in three categories – die material, tool provision and process design. The following statements could be deduced:
For impulse forming, new strategies for die design could be taken into account. Due to the impact on the dies, the dynamic behavior becomes more important than the static stiffness. Extrusion of micro parts was enabled by electrohydraulic multi-impulse forming due to the flexible punch and the possibility of high aspect ratios of the forming channels. Furthermore, the manufacturing of the dies was simplified by the possibility to apply modular dies that furthermore enable the design of more sophisticated channel geometries. Hence, the forming channels are usable for material testing. Other applications like conditioning of material properties by e.g. applying severe shear deformation and combining multiple forming stages within one die for micro part production become conceivable. Die geometries can be simplified by multistage forming resulting in flexibility of the forming process. The strategies of splitting the tool shape into simpler tools and controlled forming with basic tools can be pursued. Different process combinations are applicable. With the same die, various processes like forming, cutting and embossing can be realized by adapting the process forces. Consequently, with these features production processes can be established for rapid cold forming of sheet and bulk metals. Hence, forming of individual parts and small batch sizes in micro and meso-scale dimensions can be achieved efficiently with impulse forming technology.
In order to develop the full potential of rapid forming, it is necessary not only to develop the process chains but also to further develop the underlying impulse technologies and the necessary plant technology. In particular, the availability and efficiency of surge current systems and automation still pose significant hurdles. Acknowledgements The authors gratefully acknowledge the support by the German Research Foundation (DFG) for the sub-project D04 within the Collaborative Research Center CRC 1232 as well as the support for the project „Electromagnetic embossing of optical microstructures“. Furthermore the authors gratefully acknowledge the support by the German Federation of Industrial Research Associations (AiF) for the project „Entwicklung des Elektrohydroumformens zum partiellen und inkrementellen Umformen“ supported by the Federal ministry for Economic Affairs and Energy on the basis of a decision by the german Bundestag and the ZIM (Zentrales Innovationsprogramm Mittelstand). References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
M. Pinto, A.D. Santos, P. Teixeira, P.J. Bolt, Study on the usability and robustness of polymer and wood materials for tooling in sheet metal forming, Journal of Materials Processing Technology 202 (2008) 47-53. N. Nakajima, A Newly Developed Technique to Fabricate Complicated Dies and Electrodes with Wires, Bulletin of JSME 12 (1969) 1546-1554. B. Koc, S. Thangaswamy, Design and analysis of a reconfigurable discrete pin tooling system for molding of three-dimensional free-form objects, Robotics and Computer-Integrated Manufacturing 27 (2011) 335-348. E. Haas, R.C. Schwarz, J.M. Papazian, Design and Test of a Reconfigurable Forming Die, Journal of Manufacturing Processes 4 (2002) 77-85. D.H. Müller, H. Müller, Experiences using rapid prototyping techniques to manufacture sheet metal forming tools (2000). P.K.D.V. Yarlagadda, I.P. Ilyas, P. Christodoulou, Development of rapid tooling for sheet metal drawing using nickel electroforming and stereolithography processes, Journal of Materials Processing Technology 111 (2001) 286-294. P.A.F. Martins, N. Bay, M. Skjoedt, M.B. Silva, Theory of single point incremental forming, CIRP Annals 57 (2008) 247-252. C. Weddeling, S.T. Woodward, M. Marré, J. Nellesen, V. Psyk, A.E. Tekkaya, W. Tillmann, Influence of groove characteristics on strength of form-fit joints, Journal of Materials Processing Technology 211 (2011) 925-935. V. Psyk, C. Scheffler, M. Linnemann, D. Landgrebe, Process analysis for magnetic pulse welding of similar and dissimilar material sheet metal joints, Procedia Engineering 207 (2017) 353-358. J. Lueg-Althoff, J. Bellmann, S. Gies, S. Schulze, A.E. Tekkaya, E. Beyer, Influence of the flyer kinetics on magnetic pulse welding of tubes, Journal of Materials Processing Technology 262 (2018) 189-203. M. Ahemd, S.K. Phanthi, N. Ramakrishnan, A.K. Jha, A.H. Yegneswaran, R. Dasgutpta, S. Ahemd, Alternative flat coil design for electromagnetic forming using FEM, Transactions of Nonferrous Metals Society of China 21 (2011) 618-625. S.F. Golovashchenko, N.M. Bessonov, A.M. Ilinich, Two-step method of forming complex shapes from sheet metal, Journal of Materials Processing Technology 211 (2011) 875-885. V. Psyk, P. Kurka, S. Kimme, M. Werner, D. Landgrebe, A. Ebert, M. Schwarzendahl, Structuring by electromagnetic forming and by forming with an elastomer punch as a tool for component optimisation regarding mechanical stiffness and acoustic performance, Manufacturing Rev. 2 (2015) 23.
8
L. Langstädtler et al. / Procedia Manufacturing 27 (2019) 130–137 Author name / Procedia Manufacturing 00 (2018) 000–000
137
[14] B. Kuhfuß, C. Schenck, P. Wilhelmi, L. Langstädtler, Magnetic Pulse Cutting of Micro Metal Foils, International Conference On Micromanufacturing (2013). [15] E. Uhlmann, M. Scholz, Zerteilen von Aluminiumblechen durch Impulsmagnetfelder, Proceedings of the 2. Kolloquium Elektromagnetische Umformung (2003). [16] L. Langstädtler, M. Herrmann, C. Schenck, B. Kuhfuss, Electromagnetic Joining of Thin Sheets by Adapted Pulses, KEM 767 (2018) 439-446. [17] P. Jimbert, I. Perez, I. Eguia, G.S. Daehn, Straight Hemming of Aluminum Sheet Panels Using the Electromagnetic Forming Technology: First Approach, KEM 344 (2007) 365-372. [18] T. Aizawa, M. Kashani, K. Okagawa, Application of magnetic pulse welding for aluminium alloys and SPCC steel sheet joints, Welding in the World 86 (2007). [19] L. Langstädtler, H. Pegel, M. Herrmann, C. Schenck, D. Stöbener, J.F. Westerkamp, A. Fischer, B. Kuhfuss, Electrohydraulic extrusion of spherical bronze (CuSn6) micro samples, Technische Universität Dortmund. [20] M. Kamal, J. Shang, V. Cheng, S. Hatkevich, G.S. Daehn, Agile manufacturing of a micro-embossed case by a two-step electromagnetic forming process, Journal of Materials Processing Technology 190 (2007) 41-50. [21] H. Pegel, L. Langstädtler, M. Herrmann, C. Schenck, B. Kuhfuss, Electrohydraulic sheet metal forming with flexible tools, MATEC Web Conf. 190 (2018) 12001. [22] E. Brinksmeier, L. Schönemann, Generation of discontinuous microstructures by Diamond Micro Chiseling, CIRP Annals 63 (2014) 49-52. [23] K. Guo, X. Lei, M. Zhan, J. Tan, Electromagnetic incremental forming of integral panel under different discharge conditions, Journal of Manufacturing Processes 28 (2017) 373-382. [24] L. Langstädtler, L. Schönemann, C. Schenck, B. Kuhfuss, Electromagnetic Embossing of Optical Microstructures, J. Micro Nano-Manuf 4 (2016) 21001.