Papers by Keyword: Eutectic Alloys

Abstract: Solidification simulation software was developed, for parts having rotational symmetry cast of eutectic alloys or pure metals. The software uses a finite differences mathematical model described in cylindrical coordinates. Unlike software in Cartesian coordinates, it allows the solidification simulation for three dimensional parts with rotational symmetry using 2D simulation. As result the effective simulation time is much smaller (tens or even hundreds of times) in comparison with simulation in Cartesian coordinates. Cylindrical coordinates have the advantage of allowing a precise reproduction of the round contour parts. The paper presents the experimental verification of the results provided by the software. Experimental verification is performed by thermal analysis. A cylindrical sample with a diameter D = 60 mm and length L = 150mm was cast. The part was cast in Al-Si eutectic alloy (ATSi12). The temperature variation inside casting was recorded in three points: in the center, at the distance 1/2R and on the part surface. The experimental results were compared with those determined by computer solidification simulation. The values for liquid alloy initial temperature and for landing eutectic temperature used in simulation were chose accordingly to those experimentally determined for each point separately. The temperature variation curves during casting cooling and solidification obtained by simulation are close to those experimentally determined. The curves approaching in the first part (cooling in liquid state and solidification) can be appreciated as very good. Small differences appear in the final of the curves in the cooling area after the complete solidification of the alloy in that point. The experiment revealed that the tested software provide accurate data on castings solidification (solidification time and temperature distribution). As result, the software developed by the authors from Transilvania University, can be used with enough accuracy for fundamental and applied researches related to castings solidification.

Abstract: Currently, Russia, India, China, France, South Korea, and Japan are actively pursuing liquid metal cooled applications such as liquid cooled metal nuclear reactor concepts. The liquid metal coolants being considered for these designs are sodium, lead and lead-bismuth eutectic; these designs utilize reactive and toxic materials at temperatures up to 1073 K for nuclear power plant operations and other similar applications. To simulate these systems with the actual coolant material requires a high level of safety systems. Use of these materials in university experimental laboratory settings is difficult due to the safety hazards and that lead (Pb) is a designated substance requiring special permission to use. Therefore, a less toxic and less reactive liquid metal that can be used to simulate liquid metal cooled flows will allow for a greater number of investigations and experimentation of liquid metal flow with regards to the field of thermal hydraulics. Good candidates for a liquid metal experimental fluid are alloys from the indium-bismuth-tin system such as Fields metal, which by weight percent is 51% indium, 32.5% bismuth and 16.5% tin and possesses a melting temperature of 333 K. However, the thermodynamic properties of Fields metal and similar alloys in their liquid state are not well described in literature. This work experimentally measures the specific heat of the eutectic alloys of theindium-bismuth-tin tertiary system using a differential scanning calorimeter technique and analyzes the results to determine if the thermodynamic properties of the system have sufficient scaling for experimental modeling applications. The results verify the melting temperatures of the alloys and establish a relationship between temperature and specific heat.