IMPACT OF HETEROGENEOUS BOUNDARY NUCLEATION ON TRANSFORMATION KINETICS AND MICROSTRUCTURE

We examine quantitatively the impact of heterogenous nucleation on the temporal evolution of a phase transformation with particular emphasis on the correlation of nucleation site distribution and product phase microstructure. This is accomplished by investigating the spatial corr elations in the transforming system via the calculation of several non -equilibrium, n-point correlation Functions and thereby defining assoc iated transformation fractions and correlation lengths. Computer simul ations of transformations are also employed in order to validate the t heoretical description and to relate the microstructural features of t he evolving phase to relevant length and time scales in the problem. F inally, our findings are related to the results of experimental calori metric studies of phase formation in thin films. Copyright (C) 1997 Ac ta Metallurgica Inc.