A Discussion of the Dynamic Specific Heat during Solidification

摘要

State-of-the-art solidification theory shows that the apparent latent heat of fusion decreases with increasing cooling rates, due to the creation of lattice defects. A portion of the defects condenses during and after solidification, releasing heat, causing the apparent specific heat to be dynamic. Experimental data on copper shows an increase and a maximum in the apparent specific heat at moderate cooling rates. An extension of the existing theory for dynamic specific heats is made. Previous models do not reproduce the maximum, nor do they reproduce the equilibrium value at low cooling rates. The presently derived model reproduces all essential features of the experimentally data. It also clearly shows that the effect at moderate cooling rates is significant and the tabulated values are not applicable for modelling casting.