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Ultrasonic treatment (UST) and its effects, primarily cavitation and acoustic streaming, are useful for a high range of industrial applications, e.g., welding, filtering, cleaning or emulsification. In the metallurgy and foundry industry, UST can be used to modify a material’s microstructure by treating metal in the liquid or semi-solid state. Cavitation (formation, pulsating growth and implosion of tiny bubbles) and its shock waves, released during the implosion of the cavitation bubbles, are able to break forming structures and thus refine them. In this context, especially aluminium alloys are in the focus of the investigations. Aluminium alloys, e.g., A356, have a significantly wide range of industrial applications in automotive, aerospace and machine engineering, and UST is an effective and comparatively clean technology for its treatment. In recent years, the efforts for simulating the complex mechanisms of UST are increasing, and approaches for computing the complex cavitation dynamics below the radiator during high intensity ultrasonic treatment have come up. In this study, the capabilities of the established CFD simulation tool FLOW-3D to simulate the formation and dynamics of acoustic cavitation in aluminium A356 are investigated. The achieved results demonstrate the basic capability of the software to calculate the above-mentioned effects. Thus, the investigated software provides a solid basis for further development and integration of numerical models into an established software environment and could promote the integration of the simulation of UST in industry.
Eric Riedel; Niklas Bergedieck; Stefan Scharf. CFD Simulation Based Investigation of Cavitation Dynamics during High Intensity Ultrasonic Treatment of A356. Metals 2020, 10, 1529 .
AMA StyleEric Riedel, Niklas Bergedieck, Stefan Scharf. CFD Simulation Based Investigation of Cavitation Dynamics during High Intensity Ultrasonic Treatment of A356. Metals. 2020; 10 (11):1529.
Chicago/Turabian StyleEric Riedel; Niklas Bergedieck; Stefan Scharf. 2020. "CFD Simulation Based Investigation of Cavitation Dynamics during High Intensity Ultrasonic Treatment of A356." Metals 10, no. 11: 1529.
Energy consumption, greenhouse gas emissions, environmental impact levels, and the availability of materials as well as their sustainable usage are all topics of high current interest. The energy intensive processes of casting production such as heat treatment are particularly affected by the pursuit of sustainability. It has been estimated that up to 20% of the total energy demand in a non-ferrous foundry is required to provide the heat energy necessary during heat treatment processes. This paper addresses the application-oriented development of a sustainable configuration of the heat treatment process at the example of the aluminium-casting alloy A356 (AlSi7Mg0.3). Based on calculations of the physically necessary operating modes and under investigation of previous parameter recommendations, experimental studies were carried out to investigate the effects of various heat treatment parameters on the ultimate mechanical properties of the alloy. Since the achievable mechanical properties of the finished casting are decisive, the static and dynamic casting properties resulting from the heat treatment with optimized process parameters were compared with those of conventional process control. Significant optimization potential is shown for reducing the treatment time and thus lowering the energy consumption.
Stefan Scharf; Niklas Bergedieck; Eric Riedel; Hans Richter; Norbert Stein. Unlocking Sustainability Potentials in Heat Treatment Processes. Sustainability 2020, 12, 6457 .
AMA StyleStefan Scharf, Niklas Bergedieck, Eric Riedel, Hans Richter, Norbert Stein. Unlocking Sustainability Potentials in Heat Treatment Processes. Sustainability. 2020; 12 (16):6457.
Chicago/Turabian StyleStefan Scharf; Niklas Bergedieck; Eric Riedel; Hans Richter; Norbert Stein. 2020. "Unlocking Sustainability Potentials in Heat Treatment Processes." Sustainability 12, no. 16: 6457.
Ultrasonic treatment (UST), more precisely, cavitation and acoustic streaming, of liquid light metal alloys is a very promising technology for achieving grain and structure refinement, and therefore, better mechanical properties. The possibility of predicting these process phenomena is an important requirement for understanding, implementing, and scaling this technology in the foundry industry. Using an established (casting) computational fluid dynamics (CFD)-simulation tool, we studied the ability of this software to calculate the onset and expansion of cavitation and acoustic streaming for the aluminum alloy A356, partly depending on different radiator geometries. A key aspect was a holistic approach toward pressure distribution, cavitation, and acoustic streaming prediction, and the possibility of two- and (more importantly) three-dimensional result outputs. Our feasibility analysis showed that the simulation tool is able to predict the mentioned effects and that the results obtained are in good agreement with the results and descriptions of previous investigations. Finally, capabilities and limitations as well as future challenges for further developments are discussed.
Eric Riedel; Martin Liepe; Stefan Scharf. Simulation of Ultrasonic Induced Cavitation and Acoustic Streaming in Liquid and Solidifying Aluminum. Metals 2020, 10, 476 .
AMA StyleEric Riedel, Martin Liepe, Stefan Scharf. Simulation of Ultrasonic Induced Cavitation and Acoustic Streaming in Liquid and Solidifying Aluminum. Metals. 2020; 10 (4):476.
Chicago/Turabian StyleEric Riedel; Martin Liepe; Stefan Scharf. 2020. "Simulation of Ultrasonic Induced Cavitation and Acoustic Streaming in Liquid and Solidifying Aluminum." Metals 10, no. 4: 476.
The sustainable usage of our precious energy resources is one of the most challenging topics in current developments in the field of mechanical engineering. Apart from the use of a product, the requirements for reducing the impact of manufacturing activities are also increasing, not least because of their economic relevance. Energy-intensive processes, such as foundry industries, are particularly affected. In Aluminium foundries, in addition to the melting process and primary shaping, heat treatment is also of particular significance for an eco-oriented redesign of thermal processing operations. In consideration of the efficient use of energy-resources, this study focuses on the development of innovative plant technology for a sustainable heat treatment of aluminium components. In contrast to previously known solutions, the developed gas-heated furnaces (based on a newly designed burner system) can provide the necessary processing heat for the first time in an electrical control quality. Additionally, the control of the developed burner allows for the reliable utilization of hot air, and thus the effective reuse of waste heat. Conducted analyses and verifications of the prototype plant exhibit tremendous potential for reducing the energy consumption, for lowering costs (savings up to 70%) and CO2 emissions (reduction of 60%), without adversely affecting the quality of the components.
Stefan Scharf; Norbert Dischinger; Baris Ates; Ulrich Schlegel; Norbert Stein; Hagen Stein. New Plant-Technologies for Reducing Carbon Emissions and Costs in Heat Treatment Processes of Aluminium Castings. Procedia CIRP 2018, 69, 283 -287.
AMA StyleStefan Scharf, Norbert Dischinger, Baris Ates, Ulrich Schlegel, Norbert Stein, Hagen Stein. New Plant-Technologies for Reducing Carbon Emissions and Costs in Heat Treatment Processes of Aluminium Castings. Procedia CIRP. 2018; 69 ():283-287.
Chicago/Turabian StyleStefan Scharf; Norbert Dischinger; Baris Ates; Ulrich Schlegel; Norbert Stein; Hagen Stein. 2018. "New Plant-Technologies for Reducing Carbon Emissions and Costs in Heat Treatment Processes of Aluminium Castings." Procedia CIRP 69, no. : 283-287.
In der Produktion erfolgt die Materialisierung (Herstellung, Montage, Prüfung) des in der Produktentwicklung entstandenen Produkts anhand seiner Dokumente zur Herstellung, Nutzung und Verwertung. Die Produktion besteht aus der Fertigungssteuerung, der Materialwirtschaft, der Fertigung, der Logistik und dem Versand Sobald die Produktfreigabe erfolgt ist, führt die Fertigung auf Basis der Dokumente aus der Produktentwicklung alle Maßnahmen zur Erzeugung des Produkts durch. Dafür kommen unterschiedlichste Werkzeuge, Techniken und Verfahren zum Einsatz, die aufgrund der stetigen Weiterentwicklung der Grundbedürfnisse des Menschen laufend weiterentwickelt werden.
Bernhard Karpuschewski; Dr. Sven Jüttner; Dr. Rüdiger Bähr; Ingolf Behm; Dipl.-Wirtsch.-Ing. Stefan Scharf. Fertigungstechniken. Integrated Design Engineering 2014, 239 -285.
AMA StyleBernhard Karpuschewski, Dr. Sven Jüttner, Dr. Rüdiger Bähr, Ingolf Behm, Dipl.-Wirtsch.-Ing. Stefan Scharf. Fertigungstechniken. Integrated Design Engineering. 2014; ():239-285.
Chicago/Turabian StyleBernhard Karpuschewski; Dr. Sven Jüttner; Dr. Rüdiger Bähr; Ingolf Behm; Dipl.-Wirtsch.-Ing. Stefan Scharf. 2014. "Fertigungstechniken." Integrated Design Engineering , no. : 239-285.