Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

Filters

1
Reset filters

Settings
Now showing 1 - 10 of 16
No Thumbnail Available
Publication

Taxonomy for Biological Transformation Principles in the Manufacturing Industry

2023 , Berkhahn, Magda , Kremer, Gerald , Riedelsheimer, Theresa , Lindow, Kai , Stark, Rainer

Industry and research are seeking answers to current demands in industrial value creation, like resilience of production, sufficient product quality and sustainability of products and processes. A novel line of thought, seeking the accomplishment of those is the Biological Transformation (BT). BT describes the interweaving of biological modes of action, materials and organisms with engineering and information sciences. The conflation of disciplines from natural, technical and social sciences yields in a heterogeneous field of activities with ambiguous technical terms. An ascertainment of principles of BT is required to classify yet undifferentiated patterns in nature-based production, facilitating their systematic implementation in aiming for sustained solutions on current challenges. With increasing research in biomimetic, attempts arise to capture nature‑based activities in manufacturing through schematic classifications. Yet, basic semantics representing the effective principles of BT in the manufacturing industry is lacking. The goal of this publication is to introduce a taxonomy of Biological Transformation in manufacturing based on its core principles Bio Inspiration, Bio Integration and Bio Interaction. Within the research project BioFusion 4.0, the taxonomy was developed and applied to classify technology innovations. The paper presents the taxonomy, its development and application in use cases.

View
No Thumbnail Available
Publication

A study of the magnetohydrodynamic effect on keyhole dynamics and defect mitigation in laser beam welding

2022 , Meng, X. , Bachmann, M. , Artinov, A. , Rethmeier, Michael

In this paper, the highly transient keyhole dynamics, e.g., laser absorption, keyhole geometry, and fluctuation, etc., under a magnetic field are investigated using an experimental approach and multi-physical modeling. The model provides accurate predictions to the variation of penetration depth and weld pool profiles caused by the MHD effect, which is validated by the measurements of optical micrographs and in-situ metal/glass observation. The micro-X-ray computed tomography shows a remarkable reduction of keyhole-induced porosity with the magnetic field. The correlation between the porosity mitigation and the weld pool dynamics influenced by the magnetic field is built comprehensively. It is found that the magnetic field gives a direct impact on the laser energy absorption at the keyhole front wall by changing the protrusion movement. The porosity mitigation comes from multiple physical aspects, including keyhole stabilization, widening of the bubble floating channel, and the electromagnetic expulsive force. Their contributions vary according to the bubble size. The findings provide a deeper insight into the relationship between electromagnetic parameters, keyhole dynamics, and suppression of keyhole-relevant defects.

View
No Thumbnail Available
Publication

Revealing dynamic processes in laser powder bed fusion with in situ X-ray diffraction at PETRA III

2022 , Krohmer, E. , Schmeiser, F. , Wahlmann, B. , Rosigkeit, J. , Graf, G. , Spoerk-Erdely, P. , Clemens, H. , Staron, P. , Körner, C. , Reimers, W. , Uhlmann, Eckart

The high flux combined with the high energy of the monochromatic synchrotron radiation available at modern synchrotron facilities offers vast possibilities for fundamental research on metal processing technologies. Especially in the case of laser powder bed fusion (LPBF), an additive manufacturing technology for the manufacturing of complex-shaped metallic parts, in situ methods are necessary to understand the highly dynamic thermal, mechanical, and metallurgical processes involved in the creation of the parts. At PETRA III, Deutsches Elektronen-Synchrotron, a customized LPBF system featuring all essential functions of an industrial LPBF system, is used for in situ X-ray diffraction research. Three use cases with different experimental setups and research questions are presented to demonstrate research opportunities. First, the influence of substrate pre-heating and a complex scan pattern on the strain and internal stress progression during the manufacturing of Inconel 625 parts is investigated. Second, a study on the nickel-base superalloy CMSX-4 reveals the formation and dissolution of γ′ precipitates depending on the scan pattern in different part locations. Third, phase transitions during melting and solidification of an intermetallic γ-TiAl based alloy are examined, and the advantages of using thin platelet-shaped specimens to resolve the phase components are discussed. The presented cases give an overview of in situ X-ray diffraction experiments at PETRA III for research on the LPBF technology and provide information on specific experimental procedures.

View
No Thumbnail Available
Publication

Performance analysis of an adaptive cooling system with primary and secondary heat paths for linear direct drives in machine tools

2022 , Uhlmann, Eckart , Salein, S.

Machine tools subjected to high demands regarding productivity and accuracy are faced with the challenge that thermal losses influencing the accuracy negatively. Due to high requirements regarding thermal stability of precision related machine tool components, the focused linear direct drives (LDD) must be tempered by active cooling systems. In machine tools, a sufficient cooling capacity is available, but the cooling is insufficiently adjusted to the process and the individual demand of the heat-inducing as well as precision related components. With the intention to achieve a demand-oriented cooling, the use of thermoelectricity in machine tools is one research objective at the Institute for Machine Tools and Factory Management (IWF). Inspired by the concept of thermoelectric self-cooling (TSC)-systems for electronic devices, an Adaptive Cooling (AC)-system with thermoelectric generators (TEG) for LDD in machine tools is developed and experimentally investigated. In order to enhance the performance of AC-systems, in this research a reduction of the global thermal resistance is focused. A promising approach to achieve this goal is the division of the induced heat flow into a primary and a secondary heat path. For a model-based performance analysis of this approach, a system simulation is presented. To acquire experimental data for model validation, a test bench of the AC-system with primary as well as primary and secondary heat path is put into operation. The comparison of simulative and experimental determined data indicates a predominantly high model prediction accuracy. As a result, the implementation of a secondary heat path enables a reduction of the temperature on the upper surface of the heat source by 24.6% and thus a decrease of the global thermal resistance by 38.1%. Compared to the initial state of the AC-system only with primary heat path, the achieved thermal stability in the precision related machine tool component as well as the self-starting capability is improved.

View
No Thumbnail Available
Publication

Analyse und Nutzung von Aluminium-Bronze-Schleifstaub für das Laser-Pulver-Auftragsschweißen

2022-12 , Müller, Vinzenz , Marko, Angelina , Kruse, Tobias , Biegler, Max , Rethmeier, Michael

Die additive Fertigung verspricht ein großes Potenzial für den maritimen Sektor. Insbesondere Directed Energy Deposition (DED) Verfahren bieten die Möglichkeit, großvolumige maritime Bauteile wie Propellernaben oder -schaufeln herzustellen. Bei der Nachbearbeitung solcher Bauteile fällt in der Regel eine große Menge an Schleifabfällen an. Ziel des vorgestellten Projekts ist die Entwicklung einer nachhaltigen zirkulären AM-Prozesskette für maritime Komponenten auf Basis von Aluminiumbronze-Schleifresten. Dazu soll das Material wiederaufbereitet und anschließend als Rohmaterial für die Herstellung von Schiffspropellern im Laser-Pulver DED-Verfahren verwendet werden. In der vorliegenden Arbeit werden Schleifabfälle mittels dynamischer Bildanalyse untersucht und mit kommerziellem DED-Pulver verglichen. Anschließend werden Probengeometrien aus Schleifstaub gefertigt und durch metallographische Schliffe und REM/EDX analysiert.

View
No Thumbnail Available
Publication

OptTopo: Automated set-point optimization for coupled systems using topology information

2022 , Thiele, Gregor , Johanni, Theresa , Sommer, David , Eigel, Martin , Krüger, Jörg

The manufacturing sector has witnessed a rapid rise in the importance of energy-efficient operation. For finding optimal set-points for industrial facilities, optimization problems of increasing complexity occur. Key challenges are the leak of derivative information and the curse of dimensionality. For systematic reduction of the search-space by decomposition of the model, a methodology for the inclusion of topology knowledge in the optimization procedure is developed. An implementation of OptTopo (Optimization based on Topology), embedded in a testbed, demonstrates its advantages compared to popular out-of-the-box-optimization. OptTopo could be integrated in energy management software offering advanced set-point control for complex facilities.

View
No Thumbnail Available
Publication

Influence of superimposed low frequency oscillations on single-pass honing of long-chipping steel

2022 , Uhlmann, E. , Rozek, André

Single-pass honing is used as a finishing process to meet high demands regarding form and dimensional accuracy of drilled bores. The disadvantages of single-pass honing compared to the conventional long-stroke honing are high process forces and torques as well as an increased risk of chip space clogging of the abrasive stones. A significant reduction in process forces and torques can be achieved by superimposing the axial movement with oscillations. In this work the kinematic basics of different oscillation parameters and their effects on single-pass honing of long-chipping steel are analyzed. It can be concluded that by superimposing low frequency oscillations in single-pass honing, the process forces and torques as well as the specific energy consumption can be reduced significantly without a decline in surface quality and form accuracy.

View
No Thumbnail Available
Publication

Transferability of ANN-generated parameter sets from welding tracks to 3D-geometries in Directed Energy Deposition

2022-11-04 , Marko, Angelina , Bähring, Stefan , Raute, Maximilian Julius , Biegler, Max , Rethmeier, Michael

Directed energy deposition (DED) has been in industrial use as a coating process for many years. Modern applications include the repair of existing components and additive manufacturing. The main advantages of DED are high deposition rates and low energy input. However, the process is influenced by a variety of parameters affecting the component quality. Artificial neural networks (ANNs) offer the possibility of mapping complex processes such as DED. They can serve as a tool for predicting optimal process parameters and quality characteristics. Previous research only refers to weld beads: a transferability to additively manufactured three-dimensional components has not been investigated. In the context of this work, an ANN is generated based on 86 weld beads. Quality categories (poor, medium, and good) are chosen as target variables to combine several quality features. The applicability of this categorization compared to conventional characteristics is discussed in detail. The ANN predicts the quality category of weld beads with an average accuracy of 81.5%. Two randomly generated parameter sets predicted as “good” by the network are then used to build tracks, coatings, walls, and cubes. It is shown that ANN trained with weld beads are suitable for complex parameter predictions in a limited way.

View
No Thumbnail Available
Publication

Residual stress assessment during cutting tool lifetime of CVD-diamond coated indexable inserts

2022 , Uhlmann, E. , Hinzmann, Daniel

Insufficient coating adhesion limits reproducibility regarding tool lifetime as well as workpiece quality during the application of CVD-diamond coated cutting tools. Depending on the combination of tungsten carbide substrate material, coating thickness as well as coating morphology, individual residual stress conditions exist within CVD-diamond coated cutting tool specifications. The application of these tools is accompanied by coating delamination as primary cutting tool failure. The tool lifetime of the respective cutting tool composition depends on the corresponding residual stress condition until crack development within the CVD-diamond coating initiates tool failure. During external cylindrical turning of hypereutectic aluminium silicon alloy AlSi17Cu4Mg-T6 the residual stress condition of a CVD-diamond coated cutting tool is assessed along the cutting edge, the rake face as well as flank face throughout the respective tool lifetime. Consequently, the progression of the residual stress condition until cutting tool failure regarding coating delamination is observed. During the tool lifetime of the investigated CVD-diamond cutting tools, compressive residual stress ∆σR,c shifts to tensile residual stress ∆σR,t underneath the cutting edge corner. The approximated residual stress difference of ∆σR ≈ 5 GPa indicates stress peak relaxation processes, such as crack initiation, within the CVD-diamond coating.

View
No Thumbnail Available
Publication

Gear Wheel Finishing with Abrasive Brushing Tools to Improve the Surface Quality of Tooth Flanks for the Industrial Application

2022 , Gülzow, Bernhard , Uhlmann, Eckart

A high surface quality of tooth flanks can improve the service life and the performance of gears, as well as reduce acoustic emissions. However, high demands on the gear geometry pose a challenge for the finishing of tooth flank surfaces because the dimensional accuracy that can be achieved with modern grinding processes must not be impaired by the finishing process. A preceding study has shown fundamentally that profiled abrasive brushing tools can be used to improve the quality of individual tooth flank surfaces. Due to the integration into the grinding machine, it represents a promising alternative to common finishing applications. Before the process can be used in an industrial environment, process reliability and tool life must be examined. For this purpose, complete reference gearwheels (39 × 10) were finished with the brushing tools. It could be shown that the surface roughness can be reliably reduced by ΔRa ≈ 0.2 µm by using a single brush for an entire gearwheel without changing the gear geometry. In addition to the influence of the tool specifications on the work result, the influence of the initial roughness after grinding was considered in particular. It was found that the achievable surface roughness depends significantly on the depth of the grinding grooves, as these are retained as desired, while the roughness peaks are fully smoothed. Furthermore, a device for the machine-integrated profiling and dressing of brushing tools was successfully designed, implemented, and tested.

View