Author(s)

J Heger, J Stetina, F Kavicka, B Sekanina & P Ramik

Abstract

EUCOR, a corundo-badelleyit material, which is not only resistant to wear but also to extremely high temperatures, is seldom discussed in literature. The solidification and cooling of this ceramic material in a non-metallic mould is a very complicated problem of heat and mass transfer with a phase and structure change. Investigation of the temperature field, which can be described by the 3D Fourier equation, is not possible without the engagement of a numerical model of the temperature field of the entire system-comprising the casting, the mould and the surroundings. A temperature field had been investigated on a 350x200~400 m block casting-the so-called "stone"-with a riser of 400 mm using a numerical model with graphical input and output. The computation included the automatic generation of the network, and the successive display of the temperature field using iso-zones or iso-lines. The thermo physical properties of the cast, as well as the mould materials, were gathered and the initial derivation of the boundary conditions was conducted on all boundaries of the system. The initial measurements were conducted using thermocouples in a limited number of points. The paper provides results of the initial computation of the temperature field, which prove that the transfer of heat is solvable, and also that using the numerical model it is possible to optimise the technology of production of this ceramic material, which enhances its utilisation. The results are complemented with an approximated measurement of the chemical heterogeneity of EUCOR. This analysis was conducted using a program devised within the framework of the GA CR projects (No. 106/01/1464, 106/01N164and 106/99/0728) of the COST-OC.P3.20, the COST-OC526.10 and KONTAKT No. 2001/015 programmes.

Keywords