ESTIMATION OF SOLUTE CONCENTRATION DISTRIBUTION ACCOMPANIED BY INTERDENTRITIC SOLIDIFICATION.

A peculiar break point in the coding curves was experimentally observed. This point my result from the rapid progress of solidification caused by the supercooling of interdendritic liquid. For studying the mechanism mathematical models for estimating the distribution of the solute concentration in the interdendritic liquid have been developed. The models are described for three cases where the liquid-solid interface is a plain, cylindrical surface, and spherical one. Two models for the second and the third cases, which represent the state of the liquid surrounded with the dendrite arms, show that the difference between the liquid concentrations at the liquid-solid interface and those at the midpoint of adjacent dendrites increase when the solid fraction increases at the constant ratio. By the use of the third model the measured temperatures where the break point occurs can be explained.