Numerical Processing of Cooling Curves to Obtain Growth Parameters During Eutectic Solidification

Abstract

ABSTRACTIn this work a methodology to measure kinetic parameters to describe grain growth during equiaxed eutectic solidification is proposed. This methodology includes the numerical processing of two cooling curves and requires input data concerning the number of grains per unit volume. In addition, free grain growth before impingement and an exponential dependence of the grain growth rate on undercooling are assumed. The evolution of solid fraction of the sample as a function of time is obtained by applying the Fourier thermal analysis (FTA) method. Information collected is processed numerically in order to find numerical values for the pre-exponential and exponential parameters that characterize the grain growth kinetics as a function of undercooling. To validate this methodology a mechanistic model that simulates the cooling and solidification of eutectic Al-Si alloy in a sand mold is used. The results suggest that this methodology can be used to measure the kinetic parameters of equiaxed growth from the numerical processing of cooling curves and grain density data.