Now showing 1 - 10 of 24
  • Publication
    Life cycle analysis results for engine blisk LCA
    Purpose - The aviation industry has seen consistent growth over the past few decades. To maintain its sustainability and competitiveness, it is important to have a comprehensive understanding of the environmental impacts across the entire life cycle of the industry, including materials, processes and resources; manufacturing and production; lifetime services; reuse; end-of-life; and recycling. One important component of aircraft engines, integral rotors known as Blisks, are made of high-value metallic alloys that require complex and resource-intensive manufacturing processes. The purpose of this paper is to assess the ecological and economical impacts generated through Blisk production and thereby identify significant ‘hot-spots’. Design/methodology/approach - This paper focuses on the methodology and approach for conducting a full-scale Blisk life cycle assessment (LCA) based on ISO 14040/44. Unlike previous papers in the European Aerospace Science Network series, which focused on the first two stages of LCA, this publication delves into the "life cycle impact assessment" and "interpretation" stages, providing an overview of the life cycle inventory modeling, impact category selection and presenting preliminary LCA results for the Blisk manufacturing process chain. Findings - The result shows that the milled titanium Blisk has a lower CO2 footprint than the milled nickel Blisk, which is less than half of the global warming potential (GWP) of the milled nickel Blisk. A main contributor to GWP arises from raw material production. However, no recycling scenarios were included in the analysis, which will be the topic of further investigations. Originality/value - The originality of this work lies in the detailed ecological assessment of the manufacturing for complex engine components and the derivation of hot spots as well as potential improvements in terms of eco-footprint reduction throughout the products cradle-to-gate cycle. The LCA results serve as a basis for future approaches of process chain optimisation, use of "greener" materials and individual process improvements.
  • Publication
    An optimization approach for a milling dynamics simulation based on Quantum Computing
    ( 2024-02-01) ;
    Danz, Sven
    ;
    Kienast, Pascal
    ;
    König, Valentina
    ;
    ;
    Since the machining of complex aerospace components, like integral compressor-rotors (blade integrated disks), is very cost-intensive, optimizing the process by means of process simulations is an active field of research. With the rise of Quantum Computing, a new instrument with high optimization potential is moving into focus. In this paper, a possible application of Quantum Computing for the machining simulation of multi-axis milling of thin-walled aerospace components is discussed. For this reason, a simulation framework used for the milling simulation is analyzed and each component is evaluated separately in relation to Quantum Computing. Parts of the Harrow, Hassidim, and Lloyd algorithm are proposed to enhance the Finite-Element simulation-based component, like the modal analysis for dynamics simulation. This algorithm can solve linear system problems with exponential speed-up over the classical method. The paper presents a roadmap on how the classical steps of a modal analysis for dynamics simulation could be replaced by quantum algorithms based on quantum phase estimation. The implementation of the first working steps is presented to validate this approach. The linear system problem, arising from the dynamics simulation, is analyzed in detail and a minimal value problem of linear coupled oscillators is derived.
  • Publication
    Machinability study in orthogonal cutting of additively manufactured Inconel 718 with specifically induced porosity
    ( 2024-02-01) ;
    Li, Yupeng
    ;
    Boseila, Jonas
    ;
    ; ;
    Schleifenbaum, Johannes Henrich
    In comparison to conventional manufacturing technologies, additive manufacturing (AM) offers great design freedom, the integration of functions into components, new lightweight design concepts and high material efficiency. In aerospace and turbomachinery, this technology is increasingly coming into focus, especially the laser-based powder bed fusion of metals (PBF-LB/M) process. PBF-LB/M is already used for some aerospace components, which are often exposed to high thermal and mechanical loads. Dependent on the component geometry, support structures are required for AM, which then usually have to be removed by machining. One suitable support structure is the use of material with specifically induced porosity. This ensures good heat dissipation and thus homogeneous component properties, high retention forces and short process times in PBF-LB/M. However, the machinability of porous, additively manufactured material has hardly been researched so far. One preliminary investigation of milling porous, additively manufactured Inconel 718, though, showed significantly poorer machinability of the porous material compared to the dense material. To further examine this phenomenon, this paper presents the results of fundamental machinability studies with porous, additively manufactured Inconel 718 in orthogonal cutting. The investigations with tungsten carbide cutting tools on a special fundamental test rig include the analysis of the cutting force, the chip geometry, the chip temperature and the surface quality. The research results provide explanations for the poorer machinability of the porous material and derived approaches for improving the machinability in future studies.
  • Publication
    Initial experiments to regenerate the surface of plasma-facing components by wire-based laser metal deposition
    ( 2024)
    Tweer, Jannik
    ;
    ; ;
    Dorow-Gerspach, Daniel
    ;
    Loewenhoff, Thorsten
    ;
    Wirtz, Marius
    ;
    Linsmeier, Christian
    ;
    ;
    Natour, Ghaleb
    Plasma-facing components (PFC) in nuclear fusion reactors are exposed to demanding conditions during operation. The combination of thermal loads, plasma exposure as well as neutron induced damage and activation limits the number of materials suitable for this application. Due to its properties, tungsten (W) is foreseen as plasma-facing material (PFM) for the future DEMOnstration power plant. It is considered suitable due to its exceptionally high melting point, excellent thermal conductivity, low tritium retention and low erosion resistance during plasma exposure. But even tungsten armored PFCs have a limited lifetime due to, among other factors, surface erosion and the resulting thickness reduction of the armor material. In-situ local deposition of tungsten by means of additive manufacturing (AM) could counteract surface erosion and thus increase the service life span of PFCs. After evaluation of the potential AM processes qualified for this task, the wire-based laser metal deposition (LMD-w) process was selected as the most suitable process. First trials were conducted to examine if it is possible to reliably deposit tungsten onto tungsten substrate using the LMD-w process. In these first studies, single welding beads were generated, and in later experiments, entire layers were created from several welding beads which are arranged next to each other. To ensure reproducibility of the results, the substrate temperature was kept constant. Further experiments aimed at the elimination or minimization of problems such as oxidation, occurrence of balling defects, porosity, cracking, surface waviness and insufficient connection to the substrate. To increase the welding bead quality, the input parameters like laser power, deposition velocity, wire feed rate, inert gas flow, as well as the wire position were optimized. Furthermore, stacking of several layers, as well as the remelting of an already created layer, were carried out and investigated. This study represents the first steps in testing the feasibility of an in-situ surface regeneration concept for PFCs.
  • Publication
    Blisk Specific Query Language (BLISQL) - An approach for domain specific data querying in Blisk Manufacturing
    Product lifecycle management (PLM) is constantly improved by a steadily growing amount of data collected along the product and process development chain. This data supports designing optimized geometries and manufacturing processes. For the optimization of the manufacturing process, data from process design and manufacturing are extracted and processed. The use of a query language is helpful to make the extraction more efficient. Query languages, referring to the specific domain of a component, simplify the formulation of the queries. We present an approach for domain specific data querying in blisk manufacturing based on the Resource Description Framework (RDF) using SPARQL.
  • Publication
    On the importance of domain expertise in feature engineering for predictive product quality in production
    Machine Learning (ML) offers significant potential for quality management in production with predictive analytics. Key aspects to building ML models are the selection and engineering of features from data. They allow the usage of relevant data for training ML models. Using the right features consequently improves the quality of the ML models. However, feature engineering requires knowledge of the data, data preprocessing techniques, algorithms, the domain, and use case. Hence, automatic feature engineering tools have become popular. In this paper, we investigate how domain experts and automatic tools compare for engineering features based on a time series dataset from production.
  • Publication
    Additiv gefertigte Gewindewerkzeuge aus HSS
    ( 2023-07-17)
    Tobias Kelliger
    ;
    Meurer, Markus
    ;
    Eine verlängerte Werkzeuglebensdauer bei der Gewindefertigung ist durch eine Neugestaltung der inneren Kühlschmierstoffzufuhr am Werkzeug möglich. Der Einsatz additiver Fertigungsverfahren wie dem Laser Powder Bed Fusion erlaubt die Fertigung innen liegender und komplexer Kanal- und Düsengeometrien. In umfangreichen Einsatztests konnten Prozesssicherheit und Potenziale additiv gefertigter Gewindeform- und Gewindeschneidwerkzeuge aus Schnellarbeitsstahl nachgewiesen werden.
  • Publication
    Cloud-based process design in a digital twin framework with integrated and coupled technology models for blisk milling
    ( 2022-12-19) ;
    Kienast, Pascal
    ;
    Vinogradov, Georg
    ;
    ;
    In this publication, the application of an implemented Digital Twin (DT) framework is presented by orchestration of CAM-integrated and containerized technology models carrying out FEM-coupled simulations for the finishing process of a simplified blade integrated disk (blisk) demonstrator. As a case study, the continuous acquisition, processing and usage of virtual process planning and simulation data as well as real machine and sensor data along the value chain is presented. The use case demonstrates the successful application of the underlying DT framework implementation for the prediction of the continuously changing dynamic behavior of the workpiece and according stable spindle speeds in the process planning phase as well as their validation in the actual manufacturing phase.
  • Publication
    Additively Manufactured Robot Gripper Blades for Automated Cell Production Processes
    The automation of cell production processes demands strict requirements with regard to sterility, reliability, and flexibility. Robots work in such environments as transporting devices for a huge variety of disposables, e.g., cell plates, tubes, cassettes, and other objects. Therefore, the blades of their grippers must be designed to hold all of these different materials in a stable, gentle manner, and in defined positions, which means that the blades require complex geometries. Furthermore, they should have as few edges as possible, so as to be easy to clean. In this report, we demonstrate how these requirements can be met by producing stainless steel robot grippers by additive manufacturing.
  • Publication
    Simulation of the Refractive Index Variation and Validation of the Form Deviation in Precisely Molded Chalcogenide Glass Lenses (IRG 26) Considering the Stress and Structure Relaxation
    Precise infrared (IR) optics are core elements of infrared cameras for thermal imaging and night vision applications and can be manufactured directly or using a replicative process. For instance, precision glass molding (PGM) is a replicative manufacturing method that meets the demand of producing precise and accurate glass optics in a cost-efficient manner. However, several iterations in the PGM process are applied to compensate the induced form deviation and the index drop after molding. The finite element method (FEM) is utilized to simulate the thermomechanical process, predicting the optical properties of molded chalcogenide lenses and thus preventing costly iterations. Prior to FEM modelling, self-developed glass characterization methods for the stress and structure relaxation of chalcogenide glass IRG 26 are implemented. Additionally, a ray-tracing method is developed in this work to calculate the optical path difference (OPD) based on the mesh structure results from the FEM simulation. The developed method is validated and conducted during the production of molded lenses.