Determination of the Rate of Latent Heat Liberation in Binary Alloys

For the simulation of casting solidification, it is necessary to model the liberation of latent heat from the solidifying metal or alloy. The existing models use simplifying assumptions that result in loss of accuracy. In this paper, a numerical method based on the thermodynamics of solidification is presented to calculate the modified specific heat that can incorporate the liberation of latent heat into any numerical solution procedure and yield more accurate results. The cases of (1) equilibrium solidification and (2) nonequilibrium solidification based on Scheilʹs equation are used for calculating the fraction solid formed. The present method takes into account two important aspects namely: (1) the change in the fraction solid with decrease in temperature during solidification, and (2) the change in the composition of the solid formed during solidification. The calculated values of modified specific heat are compared with the results reported in literature.