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[ 1 ] Helfrich, A.; Klotz, S.; Zanger, F. & Schulze, V. (2017), „Machinability of Continuous-Discontinuous Long Fiber Reinforced Polymer Structures“. Procedia CIRP, Hrsg. Elsevier, S. 193-198.
Abstract:
In the present paper a new material system which combines the properties of continuous and discontinuous fibers (CoDiCoFRP) is investigated. The machinability and the induced damage effects of six material variations are investigated for a milling process at various cutting speeds and feed rates with an uncoated cemented carbide tool. The resulting forces and cutting torque were measured and analyzed for each material. After the milling process, the surface layers of the specimens were analyzed to quantify damage introduced during the milling process. The results show a strong influence of the material structure on the machining forces and damage.

[ 2 ] Fellmeth, A.; Zanger, F. & Schulze, V. (2017), „Kinematic Hardening of AISI 5120 During Machining Operations“. Procedia Cirp 58, Hrsg. Elsevier, S., S. 104-109.
Abstract:
Metal manufacturing processes like machining include complicated load cases and significant plastic deformation inside the manufactured component. The Finite-Element-Method (FEM) has been successfully applied to analyze machining processes. The plastic deformations during machining operations, especially of ductile materials, are a major part of the total deformation. If the deformation incorporates a large plastic deformation part with changing spatial directions, kinematic hardening should be considered, additionally to isotropic hardening. Previous work on the kinematic hardening of ARMCO iron revealed an almost near constant ratio of isotropic and kinematic hardening. The constant kinematic hardening ratio is revised and analyzed in tensile-compression tests with normalized AISI 5120. The FEM simulation results using the new material model of the kinematically hardening AISI 5120 are validated with experimental force measurement during orthogonal machining. The influence of kinematic hardening during machining operations is not the major influence, but still substantial.

[ 3 ] Götze, E.; Zanger, F. & Schulze, V. (2017), „Finish machining of laser beam melted parts“. Proceedings of the Special Interest Group meeting on Dimensional Accuracy and Surface Finish in Additive Manufacturing, Hrsg. Euspen Headquarters, S. 99-103.
Abstract:
The finish machining process of parts manufactured by laser beam melting is of high concern due to the lack of surface accuracy. Therefore, the focus of the work lies on the influence of the build-up direction of the parts and their effect on the finish machining process. The investigated process is drilling with a drill diameter of 6.8 mm and a drilling depth of 30 mm using lubrication. The investigations contain the materials stainless steel (1.4404), titanium (Ti6Al4V) and nickel-base alloy (IN718). Due to the difficulties of machining of nickel-base alloys a cemented carbide drill with a special nitride based coating is utilized for IN718. For the material Ti6Al4V and 1.4404 a cemented carbide drill with a TiAlN coating is chosen. During the experiments the feed rate was varied in the range of 0.1 mm/rev and 0.2 mm/rev. Additionally, the selection of the cutting speed varies for the different materials. For 1.4404 cutting speeds between 60 m/min and 100 m/min were chosen, for IN718 and Ti6Al4V more moderate cutting speeds between 25 m/min and 55 m/min were selected. The results provide the base for processing strategies. Therefore, the specimens are solely laser beam melted without post-processing like heat treatment. During the experiments the drilling forces and the resulting roughnesses are evaluated.

[ 4 ] Stähr, T.; Ungermann, F. & Lanza, G. (2017), „Scalable assembly for fuel cell production“. 7. WGP-Jahreskongress Aachen, 5.-6. Oktober 2017, Hrsg. Schmitt, R. & Schuh, G., S. 303-311.
Abstract:
The reduced time-to-market and multiple innovations lead to a rising number of emerging technologies and new products. Production systems for emerging technologies are subject to high stress from highly volatile influencing factors such as volume and variants. In order to react to these factors and to achieve cost-efficient production, companies need to establish scalable production systems. This paper introduces a methodology which supports the production planner with an iterative planning method for a scalable production system focussing on the scalability of the level of automation. The methodology consists of four steps. Its basis constitutes in a scenario analysis of the influencing factors for the production system. In the next step, alternative configurations of the production system are generated. From the different configurations, possible scaling paths are derived in accordance with the scenarios. The final step focusses on identifying the optimal scaling paths according to production cost and risk. The methodology will be demonstrated with the use case of fuel cell production within the European research project INLINE.

[ 5 ] Eschner, N.; Kopf, R.; Lieneke, T.; Künneke, T.; Berger, D.; Häfner, B.; Lanza, G. & Zimmer, D. (2017), „Kombination etablierter und additiver Fertigung“, ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, Band 112, S. 469-472. https://doi.org/10.3139/104.111751 [31.10.17].
Abstract:
Der Serieneinsatz der additiven Fertigung ist maßgeblich durch die hohen Kosten und der geringen Produktivität der Verfahren limitiert. Der hier vorgestellte Ansatz zeigt, wie die Wirtschaftlichkeit des Laser-Strahlschmelzens (LBM) durch die Kombination mit etablierten Fertigungsverfahren erhöht werden kann. Ziel ist es, nur solche Funktionsträger additiv zu fertigen, die einen höheren Kundennutzen bringen. Dazu werden Konstruktionsrichtlinien definiert, Prozessketten erarbeitet und eine Qualitätssicherung mittels Ultraschallüberwachung realisiert.

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