Livarski vestnik 62/2015 nr. 3
R.Döpp, Institute for Metallury, Technical University Clausthal, Germany
Izudin Dugić, Linnaeus University, Faculty of Technology, Department of Mechanical Engineering, Växjö, Sweden.
Peter Majerič*, Rebeka Rudolf*,***, Ivan Anžel*, Jelena Bogović**, Srečko Stopić**, Bernd Friedrich**, * Faculty of Mechanical Engineering, Maribor, Slovenia, **IME Institut für Metallurgische Prozesstechnik und Metallrecycling, RWTH Aachen, Germany, *** Zlatarna Celje d.d., Celje, Slovenia
Corinna H. Müller*, Axel Rudolph**, Andreas Bührig-Polaczek***, Sebastian F. Fischer***, * Georg Fischer Automotive AG, 8201 Schaffhausen, Switzerland, ** Georg Fischer GmbH, 40822 Mettmann, Germany, *** Foundry-Institute, RWTH Aachen University, 52072 Aachen, Germany
R.Döpp, Institute for Metallury, Technical University Clausthal, Germany
CONTRIBUTION TO WATERGLASS PROCESS FOR CORES AND MOULDS
Abstract
The water glass process with CO2 is known in Germany since about 1950. Although it has a lot of advantages, mainly no dangers concerning critical components during casting and solidification procedure, application in practice was relative small. Early promoters of the CO2 process were for example W. Schumacher, I. Bindernagel, G. Gettwert, F. Richarz and U. Kleinheyer in Germany, H. G. Levelink in the Netherlands, F. Hofmann in Switzerland, H. Sagmeister in Austria, I. L. Svensson in Sweden, F. W. Nield and D. Epstein in Great Britain, D. V. Atterton in USA, P. Doroshenko in Russia, last but not least L. Petržela and J. Gajdusek, P. Jelinek, C. Vančura, M. Julina and V. Slaveniček in the Czech Republic. In later times f. i. E. Flemming and H. Polzin in Freiberg were encouraging promoters and active cooperation partners for us in Clausthal. This is gratefully acknowledged. Thanks also to members of CIATF-WFO commission 1.6 Inorganic Binders for theoretical and practical assistance. Some examples concerning basic knowledge, progresses in procedure and properties of different sand-binder-mixtures, results of reclamation tests by application of a mechanical-pneumatic fluid-bed cleaner following P. Pohl will be discussed. The continuous aim is to reduce the former practical disadvantages and restrictions of sodium-silicate-CO2 process (f. i. fluidity and residual strength) systematically step by step. Many thanks to my main co-workers in Clausthal: R. Deike, H. Schneider, A. Alekassir, B. Xiao and G. Brümmer. Problems and successful results were published frequently. They are a contribution to the present revival and growing application of inorganic binder systems for ecological-environmental and economical production of cores and moulds for castings.
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Izudin Dugić, Linnaeus University, Faculty of Technology, Department of Mechanical Engineering, Växjö, Sweden.
WHITE CAST IRON FOR THE IMPELLERS
Abstract
High chromium white cast iron is commonly used in applications requiring excellent abrasion resistance, as central parts for pumps. Their excellent abrasion resistance is mainly due to their solidification microstructures. The specifications and requirements applied for the white cast iron components are among the most stringent used within the iron foundry branch. One of the problems for the production of these components can be cracks. Because of this reason there are just a few iron foundries in Sweden that are able to cast the required high quality white cast iron components. This work has been carried out in a foundry where an impeller for pumps has been analyzed. The project work has focused on reducing cracks on casting component in a production scale using different type of shell moulding sands. The experiments showed that the shell moulding sand had an important influence on the cracks.
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Peter Majerič*, Rebeka Rudolf*,***, Ivan Anžel*, Jelena Bogović**, Srečko Stopić**, Bernd Friedrich**, * Faculty of Mechanical Engineering, Maribor, Slovenia, **IME Institut für Metallurgische Prozesstechnik und Metallrecycling, RWTH Aachen, Nemčija, *** Zlatarna Celje d.d., Celje, Slovenia
NANOPARTICLES PREPARED FROM NITI ORTHODONTIC WIRE
Abstract
Nanoparticles were synthesized from NiTi orthodontic wire with the aerosol process Ultrasonic Spray Pyrolysis and characterized with TEM microscope equipped with EDX analysis and by zeta potential measurements. The shape memory effect of these nanoparticles has been surmised through the analysis of the obtained results and available literature. Investigation showed that on the nanoparticles the titanium volume had been oxidized, entrapping the nickel content inside the nanoparticle cores. Even though Ti oxides have inhibited the shape memory effect of the material somewhat, it probably does not eliminate this property. First tests have also been investigated using these nanoparticles in the electrospinning process for textile fabrication.
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Corinna H. Müller*, Axel Rudolph**, Andreas Bührig-Polaczek***, Sebastian F. Fischer***, * Georg Fischer Automotive AG, 8201 Schaffhausen, Switzerland, ** Georg Fischer GmbH, 40822 Mettmann, Germany, *** Foundry-Institute, RWTH Aachen University, 52072 Aachen, Germany
INFLUENCE OF THE INOCULATION BLOCK'S COMPOSITION AND GRAIN SIZE ON THE COST-EFFECTIVE INMOULD INOCULATION OF DUCTILE IRON
Abstract
The inoculation process is of particular importance for the production of safety-related components made of ductile iron. In case of an incomplete or missing ladle inoculation, the formation of a metastable structure has to be avoided by other means. In order to guarantee solidification with stable phases (e.g. graphite and not cementite), additional inoculant blocks are used at GF-production sites. An experimental device was installed to produce inoculant blocks made of loose inoculant and inorganic binder. The aim is to reduce costs and supplier dependence. The production and evaluation of inoculant blocks, made of four different granular inoculants with two distinct grain size distributions, are the main topics of the present study. The evaluation of the inoculation efficiency of the various inoculants is based on mechanical properties and microstructure analysis of the test specimens. The present study shows that the mechanical and metallographic properties of the test components achieved with self-made inoculant blocks are comparable with these using the standard inoculant block. Consequently, the commercially available product can be substituted.
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