Mathematical description of alloys solidification in a macro scale can be formulated using the one domain method (fixed domain approach). The energy equation corresponding to this model contains the parameter called a substitute thermal capacity (STC). The analytical form of STC results from the assumption concerning the course of the function fS = fS (T) describing the changes of solid state volumetric fraction and the temperature at the point considered. Between border temperatures TS , TL the function fS changes from 1 to 0. In this paper the volumetric fraction fS (more precisely fL = 1- fS ) is found using the simple models of macrosegregation (the lever arm rule, the Scheil model). In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy.

JO - Archives of Foundry Engineering L1 - http://so.czasopisma.pan.pl/Content/87122/PDF/19_paper.pdf L2 - http://so.czasopisma.pan.pl/Content/87122 IS - No 4 KW - Application of Information Technology to the Foundry Industry KW - solidification process KW - One Domain Method KW - Substitute Thermal Capacity KW - numerical methods ER - A1 - Mochnacki, B. PB - The Katowice Branch of the Polish Academy of Sciences JF - Archives of Foundry Engineering T1 - Definition of Alloy Substitute Thermal Capacity Using the Simple Macrosegregation Models UR - http://so.czasopisma.pan.pl/dlibra/docmetadata?id=87122 DOI - 10.2478/v10266-012-0117-7