Livarski vestnik 63/2016 št. 1
H. Kerber 1), M. Riegler 1,2), G. Schindelbacher1), P. Schumacher1,2),1) Österreichisches Gießerei-Institut, Leoben, 2) Lehrstuhl für Gießereikunde, Montanuniversität Leoben, Austria
NEW POSSIBILITIES WITH IMPROVED GREEN SAND TESTING FACILITIES
Daniel MOLNAR1, Balazs SANDOR2, Jeno DUL3, 1 Associate professor, PhD, 2 PhD student, 3 Honorary Professor, Institute of Foundry Engineering, University of Miskolc
FLOWABILITY SIMULATION OF LIQUID METALS WITH DIFFERENT RHEOLOGICAL BEHAVIOUR
J. MEDVED1, S. KORES1, P. MRVAR1, A. KRIŽMAN2, M. VONČINA1, 1University of Ljubljana, Faculty of Natural Sciences and Engineering, 2University of Maribor
INFLUENCE OF ZR ADDITION ON AL ALLOYS PROPERTIES
Iztok Naglič1, Semjon Ilić2, Boštjan Markoli1, Matej Dolenec3, Blaž Leskovar1, Žan Filipič1, Matej Perhoč1, Jakob Kraner1, Matej Bizjak1, Božo Skela1, Luka Kelhar3, Špela Kozole1, David Gerčar1, Teja Ramšak1, 1University of Ljubljana, Faculty of Natural Sciences and Engineering, 2Livarstvo Krim d.o.o., 3Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
MODIFICATION OF ALSI7MG ALLOY CAST IN TO A SAND MOULD
H. Kerber 1), M. Riegler 1,2), G. Schindelbacher1), P. Schumacher1,2),1) Österreichisches Gießerei-Institut, Leoben, 2) Lehrstuhl für Gießereikunde, Montanuniversität Leoben, Austria
NEW POSSIBILITIES WITH IMPROVED GREEN SAND TESTING FACILITIES
Abstract
The quality of green sand moulds is paramount for the casting quality and reduction of surface defects. In most industrial environments hand driven machines which concepts were developed in the last century are still used. While these old fashioned apparatuses can help to maintain quality in a foundry no new additional information on the green sand quality will be obtained. This presentation will give information on the development of novel green sand testing facilities for compaction, pressure, as well as wet strength testing and gives comparison to values obtained by manually operated machines. Within the presentation concepts for granular systems will be introduced for the behaviour of green sands.
Daniel MOLNAR1, Balazs SANDOR2, Jeno DUL3, 1 Associate professor, PhD, 2 PhD student, 3 Honorary Professor, Institute of Foundry Engineering, University of Miskolc
FLOWABILITY SIMULATION OF LIQUID METALS WITH DIFFERENT RHEOLOGICAL BEHAVIOUR
Abstract
High pressure die casting is a near net shape process where turbulent filling and rapid solidification occurs under high pressure conditions. Alternative die casting technologies such as rheocasting have been developed in order to increase the quality of castings. The simulation of flowability and fillability is influenced by several factors such as temperature of the melt and the die, viscosity behaviour in the mushy zone, solid particle ratio and flow properties. Here a control volume model is developed to simulate the rheocasting process based on the commercial software NovaFlow&Solid. Several simulation trials were carried out to examine the flowability of normal AlSi7Mg alloy and its semisolid version.
J. MEDVED1, S. KORES1, P. MRVAR1, A. KRIŽMAN2, M. VONČINA1, 1University of Ljubljana, Faculty of Natural Sciences and Engineering, 2University of Maribor
INFLUENCE OF ZR ADDITION ON AL ALLOYS PROPERTIES
Abstract
In modern industrial practice standard casting alloys, including high-quality materials, do not satisfy the rigorous requirements for applications in different areas of technology. One of the most attractive systems for new casting alloy developers is the Al–Zn–Mg–Cu, which is the basic system for development of the strongest wrought alloys of the AA7075 type. Alloys with the zirconium addition have significant potential for the development of applications at elevated temperatures. In the process of optimizing the mechanical properties of aluminium alloys, the addition of the 0.1 – 0.25 % (mass fraction in this article) of Zr was suggested in order to enhance the formation of small precipitates of Al3Zr. In this article, about the alloys from Al-X-Zr systems, will be discussed using thermodynamic equilibrium calculations (Thermo-Calc), various thermal analysis, optical and scanning electron microscopy in order to identify the generated microstructures and corresponding properties.
Iztok Naglič1, Semjon Ilić2, Boštjan Markoli1, Matej Dolenec3, Blaž Leskovar1, Žan Filipič1, Matej Perhoč1, Jakob Kraner1, Matej Bizjak1, Božo Skela1, Luka Kelhar3, Špela Kozole1, David Gerčar1, Teja Ramšak1, 1University of Ljubljana, Faculty of Natural Sciences and Engineering, 2Livarstvo Krim d.o.o., 3Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
MODIFICATION OF ALSI7MG ALLOY CAST IN TO A SAND MOULD
Abstract
In this work the effect of commercial strontium and sodium (SIMODAL 77) modifiers in sand cast AlSi7Mg alloy were evaluated. Castings with different wall thickness were prepared to evaluate the effect of modifiers at different cooling rates. Light microscopy was used to assess the effect of eutectic silicon modification. It was found that 0.3 % (mass fraction in this article) of modifier SIMODAL 77 and between 0.02 and 0.03 % Sr effectively modified the eutectic silicon in AlSi7Mg alloy castings with wall thickness of 10 and 20 mm. Eutectic silicon was not fully modified when the wall thickness was 40 mm. Eutectic silicon remained modified after remelting in the case of strontium whilst sodium from SIMODAL 77 failed in this respect.