Microstructure and normal grain growth in metals and ceramics. Part II. Experiment

Abstract

An extensive set of measurements on the grain growth and microstructure evolution of a series of high-density Ni-Zn ferrites annealed over periods ranging from 1/4 to 48 h is reported. A comparison of the data with predictions of the statistical multiple-lognormal theory of normal grain growth presented in Part I is made. The time invariance of the standard deviations of both the grain size and population of individual topological classes is confirmed, demonstrating that the scaling and stability of normal grain growth are critically related to the dispersion of the grain sizes and that at least two parameters are needed to characterize a given microstructure. A parabolic growth law for the median diameter in both two and three dimensions is confirmed as well as the predicted power law dependence of the growth constants for each class on the topological index. A series of sectioning experiments verifies the near equivalence of the planar and spatial size parameters.