Livarski vestnik 60/2013 Nr. 1
Nadežda M. Talijan
University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12, 11000 Belgrade, Serbia
PROCESSING, PROPERTIES AND APPLICATION OF ADVANCED ELECTRICAL CONTACT MATERIALS
DUL, Jenö (ontdul@uni-miskolc.hu); LESKO, Zsolt(lesko.zsolt@gmail.com); JUHASZ, Borbala(juhaszboriska@gmail.com)
University of Miskolc, Department of Foundry Engineering
ANALYSIS OF THE THERMAL CONDITIONS OF DIE-CASTING TOOL
Jožef Medved, Maja Vončina, Grega Klančnik, Primož Mrvar
University of Ljubljana, Faculty of Natural Sciences and Engineering, Department for Materials and Metallurgy
THERMODYNAMIC MODELING AS A SUPPORT FOR OPTIMIZATION OF ALUMINIUM MATERIALS AND TECHNOLOGIES
Nadežda M. Talijan
University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12, 11000 Belgrade, Serbia
PROCESSING, PROPERTIES AND APPLICATION OF ADVANCED ELECTRICAL CONTACT MATERIALS
ABSTRACT
The presented study gives brief overview of the experimental results of investigations of different production technologies of silver-metal oxide electrical contact materials in relation: processing method - properties. The two most common routes of production internal oxidation/ingot metallurgy and powder metallurgy are demonstrated on the example of Ag- CdO and Ag-ZnO materials. For illustration of alternative processing routes that provide higher dispersion of metal-oxide particles in silver matrix more environmentally friendly Ag- SnO2 contact materials are used. Processing of electrical contact materials by mechanical mixing of starting powders in high energy ball mill is presented. The obtained experimental results of application of different methods of introduction of SnO2 nanoparticles in silver matrix such as conventional powder metallurgy mixing and template method are given and discussed in terms of their influence on microstructure and physical properties (density, hardness and electrical conductivity) of the prepared Ag-SnO2 electrical contact materials.
Keywords: silver-metal oxide contacts, SnO2 nanoparticles, processing, properties
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DUL, Jenö (ontdul@uni-miskolc.hu ); LESKO, Zsolt(lesko.zsolt@gmail.com ); JUHASZ, Borbala(juhaszboriska@gmail.com )
University of Miskolc, Department of Foundry Engineering
ANALYSIS OF THE THERMAL CONDITIONS OF DIE-CASTING TOOL
ABSTRACT
The heat balance of a casting cycle can be ensured in short times by annealing of the die-casting tool, by which the well-constructed and well-functioning cooling system can enhance productivity. Incorrect cooling, however, can lead to heat unbalance in die casting tool, thus causing the destruction of casting quality, reduction of the lifetime of die casting tool and irreversible production-reduction. Besides theoretical examination of construction and function of cooling system, the evaluation of effectively removed heat quantities has great importance. This paper presents an analysis of the function of the cooling system of a scraggy thin casting of AlSi9Cu3 alloy, in case of different cooling parameters. Based on the measured results of the inlet and outlet temperatures and the volume flow of cooling agents, the heat quantities belonging to the cooling circles are determined and an optimization of the cooling system is proposed. The findings of the analysis can be utilized for the construction and optimum operation of die-casting cooling systems.
Keywords: high pressure die-casting, effect of cooling and casting parameters
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Jožef Medved, Maja Vončina, Grega Klančnik, Primož Mrvar
University of Ljubljana, Faculty of Natural Sciences and Engineering, Department for Materials and
THERMODYNAMIC MODELING AS A SUPPORT FOR OPTIMIZATION OF ALUMINIUM MATERIALS AND TECHNOLOGIES
ABSTRACT
Thermodynamic characterization of castable Al-alloys with the predicted and experimental determined data will increase the basic understanding of Al-alloys that can be used as lightweight castings alternatives for real industrial applications. The new generation of the thermodynamic database is important for further development of new castings, applications, modeling etc. The various computational techniques exist to reduce the amount of experimental effort required for formation of data bases. Nevertheless, the experimenting is still needed to confirm or to optimize the already existent thermodynamic database. Using the different combinations of elements in specific temperature regions the information of which specific phase (solid solution, intermetallic compound) is formed is important. Determination of composition and types of phases, amount of phase and study of equilibrium and non-equilibrium processes, the characteristic temperatures for lightweight alloys was done. Thermal analysis provides us new information about thermodynamic properties, phase transitions and phase precipitation used further for database simulations in the castings. The aim of this work is to gain accurate thermodynamic properties of investigated alloys as a basis for other investigations and industrial applications.
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