ENTHALPY AND LATENT HEAT CALCULATIONS DURING SOLIDIFICATION

ARES, ALICIA;; GUEIJMAN, SERGIO; SCHVEZOV, CARLOS

Campinas-SP. Brasil.

Congreso; INTERNATIONAL SCHOOL ON CRYSTAL GROWTH AND ADVANCED MATERIALS; 1999

UNICAMP-Sociedad Brasilera de Crecimiento de Cristales (SBCC

In the present report, a general method for the calculation of latent heat for metallic alloys based on first principles and simple calculations has been presented. Thermodynamics aspects related to solidification of binary alloys are considered. Such aspects are the solidification path, the solid fraction vs. temperature, and the enthalpy and the latent heat evolution. A thermodynamic model including the above phenomena is developed and the values of the associated parameters are calculated, particularly the enthalpy of the solid and liquid phases of the alloys in the mushy zone, as a function of temperature and alloy concentration. From the calculated enthalpies, the latent heat released during solidification, which is a key input parameter in any solidification model, can be readily obtained. The total integrated heat released for complete solidification of binary alloys calculated with the present model is in good agreement with reported data. The alloys considered are Lead-Tin, Aluminum-Copper, Aluminum-Magnesium, Zinc-Aluminum and Nickel-Zirconium in a range of concentrations. In the present report these results are presented and discussed.