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Study on the Influence of the Processing Speed in the Generation of Complex Geometries in Aluminium Matrix Composites by Electrochemical Precision Machining

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Procedia CIRP 2018年 68卷 713-718页

作者： Norbert Lehnert Gunnar Meichsner Matthias Hackert-Oschätzchen André Martin Andreas Schubert Professorship Micromanufacturing Technology Chemnitz University of Technology 09107 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology 09126 Chemnitz Germany

Currently, an increasing demand for lightweight materials with a high strength can be observed. Potential materials, which fulfil these requirements, are particle reinforced aluminium matrix composites (AMCs). AMCs consist of an aluminium matrix, which is reinforced by ceramic particles. In a consequence, AMCs offer a strength, which is comparable to steel, along with a density, which is comparable to light metals. In the Collaborative Research Centre SFB 692 at Chemnitz University of technology, AMCs are analysed under different research aspects. One of these aspects is the generation of complex geometries by Electrochemical Precision Machining (PECM). The investigated AMC consists of ENAW 2017, which is reinforced by 10% of SiC-particles. To achieve the desired complex geometry, the dissolution characteristic of the specific AMC was analysed. Furthermore, the achievable surface quality was characterised. Based on these fundamental results, processing strategies for generating complex geometries in AMCs by PECM were derived. In this study, the influence of the PECM processing speed on the resulting complex geometry is investigated. For that purpose, a model geometry based on a retarder was selected and realized. The resulting side gap and the front gap as a function of an increasing processing voltage and an increasing feed rate are presented. It can be stated that the side gap can be reduced by an increase in feed rate.

关键词： Electro chemical machining (ECM) Metal matrix composite Aluminium Silicon carbide

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Derivation of Guidelines for Reliable Finishing of Aluminium Matrix Composites by Jet Electrochemical Machining

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Procedia CIRP 2018年 68卷 471-476页

作者： Norbert Lehnert Matthias Hackert-Oschätzchen André Martin Andreas Schubert Professorship Micromanufacturing Technology Chemnitz University of Technology 09107 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology 09126 Chemnitz Germany

The Collaborative Research Centre SFB 692 at Chemnitz University of technology is focused on aluminium-based light-weight materials in safety-related parts and components. One field of activity are aluminium matrix composites (AMCs). Thereby, the manufacturing, the mechanical properties, the economic opportunities and challenges as well as the machinability are investigated. One of the research focusses is the finish-machining of AMCs by Jet Electrochemical Machining (Jet-ECM). Therefore, one objective is to achieve guidelines for reliable machining of AMCs by Jet-ECM. In a first step the dissolution characteristic of EN AW 2017 with 10% of SiC particles, which was manufactured within the SFB 692, was analysed by help of a microcapillary cell, applying a sodium nitrate electrolyte. Furthermore, Jet-ECM was used to generate point erosions using different pH-neutral electrolytes, namely NaNO 3 and NaCl. AMCs made of the aluminium alloy EN AW 2017 with 0%, 5% and 10% SiC particles were machined with a maximal voltage of 25 V. In the current study the parameter field is extended further. The dissolution characteristic by using the pH-neutral electrolyte sodium-bromide is analysed and the voltage range is set to 60 V. Those experiments show, that each electrolyte causes a specific dissolution characteristic. Based on the experimental data, guidelines for a reliable finishing of AMCs by Jet-ECM are derived. The resulting guidelines can be used to predict the depth of the point erosions as function of particle fraction, the applied voltage and the machining time, with respect to the used electrolyte. The statistical evaluation of the guidelines show, that the applied voltage and the machining time are the dominant factors to control the dimensions of the point erosions. Whereas the particle fraction has a minor effect on depth and width.

关键词： Electro chemical machining (ECM) Metal matrix composite Aluminium Silicon carbide

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Influence of pass reduction in cold rolling on damage evolution in deep drawing of rotationally symmetric cups

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IOP Conference Series: Materials Science and Engineering 2021年第1期1157卷

作者： M Nick C Liebsch M Müller IF Weiser G Hirt T Bergs Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University Campus-Boulevard 30 52074 Aachen Germany Institute of Metal Forming (IBF) of RWTH Aachen University Intzestr. 10 52072 Aachen Germany Fraunhofer Institute for Production Technology IPT Steinbachstr. 17 52074 Aachen Germany

Improvement of component performance by controlling the damage state after metal forming enables a reduction in sheet thickness and, consequently, in component weight and material cost. To establish methods for controlling damage in finished parts, the entire process chain from steelmaking and casting through hot and cold rolling to deep drawing must be considered. Previous research has shown that in hot rolling of an S355 steel, the influence of pass reduction on damage in the hot strip disappears when the accumulated pass reduction becomes large. However, the influence of cold rolling parameters on damage and specifically on its evolution in subsequent forming processes has not yet been systematically investigated. In the present work, specimens of the the mentioned S355 steel are cold rolled with two different pass reductions and heat treated to obtain a DP800 dual phase steel. These specimens are deep drawn into rotationally symmetric cups with variation of the drawing die radius. Sheet specimens and deep drawn cups are investigated using scanning electron microscopy to determine the respective void area fractions. While no influence of height reduction on the void area fraction after cold rolling is found, the void area fraction after deep drawing differs with variation of the pass reduction. This effect is connected to the formation of a larger number of small voids in the material rolled with a larger pass reduction.

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Enhancement and analysis of multidimensional characteristic diagrams for correction of TCP-displacements caused by thermal tool displacement

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Procedia CIRP 2018年 77卷 553-556页

作者： Matthias Putz Christian Oppermann Michael Bräunig Fraunhofer-Institute for Machine Tools and Forming Technology IWU 09126 Chemnitz Germany Chemnitz University of Technology 09010 Chemnitz Germany

In the present paper former developed characteristic diagram approaches for the correction of thermo-elastic TCP-displacements during cutting processes are extended. Input variables linked with the resulting deformations are estimated by Design of Experiments (DoE). Deformations are computed by means of FEA via the estimation of heat fluxes in the system workpiece – chip – tool – clamping device and the temperature field in tool and clamping device. Multidimensional characteristic diagrams are derived to enable real-time correction of tool paths within the machine tool control. These correction approaches are of crucial importance especially in the field of precision machining and difficult-to-cut material generating large heat amounts. With the obtained correction values the effect of the different cutting parameters on the TCP-displacement is investigated in a sensitivity analysis.

关键词： TCP-displacement Thermal error Characteristic diagramm machine Tool Sensitivity analysis Design of Experiments

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Development of a classification and generation approach for innovative technologies

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Procedia Manufacturing 2018年 21卷 798-805页

作者： A.P. Kuznetsov H.-J. Koriath Moscow State University of Technology “STANKIN” 127055 Moscow Russia Fraunhofer Institute for Machine Tools and Forming Technology IWU 09126 Chemnitz Germany

This paper considers the state of the art and analyses five existing classification principles for technological and manufacturing processes aiming at the part and product formation. The proposed energetic-information model describes the generation of technological schemes and processes, based on the system description for structural conversion, transfer and interaction of material, energy and information. Classification principles for technological processes and their structural description generate classes, types and procedures (methods). A generation procedure and mechanism for innovative technological processes is developed. Approved classification of manufacturing processes for DIN8580, NISTIR 7913, according to Todd, Paul De Garmo, by Ashby are particular cases of the proposed classification approach. The proposed approach and process classification system is forming an image of DIN8580. The classification, generation and analysis approach for manufacturing technologies applies for the creation of innovative procedures, manufacturing equipment and systems.

关键词： methods manufacturing processes technology classification

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A new simulation and optimization tool for calculating the attenuation of airborne and structure-borne sound of maritime silencers 47

A new simulation and optimization tool for calculating the a...

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47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018

作者： Lindner, Paul Schulze, Christian Hübelt, Jörn Georgi, Tom Troge, Jan Gesellschaft für Akustikforschung Dresden mbH Blumenstraße 80 Dresden01307 Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany

The acoustical impact of silencers is restricted by the influence of structure-borne sound. Thereby, excitation and radiation of structure-borne sound play an important role, as well as its transmission along the silencer system. In the design process of a silencer the influence of structure-borne sound on the damping effect is mostly considered by empirical estimations, which can cause an oversized construction. For calculating structure-borne sound in maritime silencers with their typical large dimensions, the application of statistical methods is a possible problem-solving approach. In this contribution, a new simulation and optimization tool is presented, considering the decreased damping effect of silencers due to structure-borne sound. The tool is based on Statistical Energy Analysis (SEA). Results of analytical and experimental SEA are compared. These results were obtained on downscaled silencers and have been transferred to real maritime silencers. Especially the SEA-parameters loss factor and coupling loss factor, airborne and structure-borne sound energies and the number of relevant modes are considered. Based on the measured damping of a silencer compared with numerical and statistical calculations, the capability for optimizing the design process of large silencers is shown. © INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering. All rights reserved.

关键词： Damping

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Ontology-based microservices architecture for industrial assistant systems 12

Ontology-based microservices architecture for industrial ass...

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Smart Systems Integration 2018 - 12th International Conference and Exhibition on Integration Issues of Miniaturized Systems

作者： Singer, Adrian Wenzel, Ken Müller, Jan Langer, Tino Putz, Matthias Digitalization in Production Germany Department Digitalization in Production Germany Automation and Monitoring Germany Head of Division Smart Factory - Digitalization and Automation Germany Institute Scientific Field Machine Tools Production Systems and Machining Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany

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Identification of modal parameters of machine tools during cutting by operational modal analysis

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Procedia CIRP 2018年 77卷 473-476页

作者： Jan Berthold Martin Kolouch Volker Wittstock Matthias Putz Technische Universität Chemnitz Professorship for Machine Tools and Forming Technology Reichenhainer Str. 70 09126 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology (IWU) Reichenhainer Str. 88 09126 Chemnitz Germany

The dynamic behaviour of machine tools differs between standstill and process state. Operational modal analysis (OMA) makes possible to identify modal parameter under process conditions. In this paper, it is shown, how far the assumption of a time-invariant behaviour as well as a broadband excitation can be fulfilled by exciting the machine with a cutting process. After describing the dynamic behaviour in the work space to determine a time-invariant tool path, a broadband excitation is generated by changing cutting parameters during milling. The modal parameters are identified by different OMA methods and compared to results of the experimental modal analysis.

关键词： machine Tool Dynamics Operational Modal Analysis

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forming 4.0: Smart machine components applied as a hybrid plain bearing and a tool clamping system

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Procedia Manufacturing 2019年 27卷 65-71页

作者： R. Kurth R. Tehel T. Päßler M. Putz K. Wehmeyer C. Kraft H. Schwarze Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany Berg & Co. GmbH Gildemeisterstraße 80 33689 Bielefeld Germany Technical University Clausthal Institute of Tribology and Energy Conversion Machinery Leibnizstraße 32 38678 Clausthal-Zellerfeld Germany

Higher process reliability as well as detailed information about the machine condition are necessary requirements for the manufacturing of complex geometric shapes with simultaneous increase of the machine availability and output rate. By implementing smart machine components it is possible to solve central challenges focusing on the investment-intensive field of forming technology. These components gather and evaluate machine and process data on decentralized spots with certain integrated sensors. Within this paper the potential benefits of those smart machine components are demonstrated using the example of an intelligent hybrid plain bearing and a smart tool holder. Focusing on the damage prevention of plain bearings, a load controlled journal bearing combining hydrodynamic and hydrostatic characteristics has been developed and tested by simulation. In addition, a smart hydraulic tool holder for upper dies has been successfully tested by simulations and experiments in order to investigate and demonstrate the potential for using the monitored clamping characteristics to increase the process transparency and the condition of the tool holder. As a result these smart machine components can be used additionally for a significant improvement of industry 4.0 tools such as digital twins of both process and machine.

关键词： industry 4.0 sensor integration plain bearing journal bearing tool clamping condition monitoring smart components process monitoring

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Target-oriented Analysis of Resource Consumption in Manufacturing Process Chains

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Procedia Manufacturing 2018年 21卷 462-467页

作者： A. Demmer N. Klingbeil F. Klocke M. Putz R. Schmitt T. Vollmer Fraunhofer-Institute for Production Technology IPT Steinbachstrasse 17 Aachen 52074 Germany Fraunhofer-Institute for Machine Tools and Forming Technology IWU Reichenhainer Strasse 88 Chemnitz 09126 Germany

Nowadays, manufacturing companies have to view their resource consumption as a cost driver in order to identify efficient and economical processes. Methodologies for investigating, assessing and comparing process chains are vital in order to gain an accurate insight into cost drivers over the course of the entire process chain [1]. Scrutiny of this nature enables cost drivers to be identified via the parameters process time, machine and staff costs in addition to costs related to energy, material and consumables. A review of the usage phase permits elevated costs during manufacture to be justified by reduced costs during operation. The allocation of costs to resources within individual cost-driving process steps ensures target-oriented derivation of improvement measures. The methodology has been designed to serve as basis for production planning, for example, with regard to (energy and resource) efficiency and applied to low-pressure turbine blades made of nickel-base alloys and titanium aluminide. A dedicated analysis of process chain costs provides an insight into the development of individual production costs. This information forms a basis on which to make decisions regarding output quantity or the most appropriate time for investment in new machines. In conjunction with the process chain comparison, this serves as a basis for the integration of the results obtained into a data base which allows the user to select a goal-oriented process chain selection. The data base can provide information regarding the organization of production chains in order to ensure that the product is manufactured accordingly to reduce resources, energy consumption, process times or overall costs.

关键词： Energy efficiency Manufacturing process Production planning

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