Comparison of microstructure characterization methods by two-point correlation functions and reconstruction of 3D microstructures using 2D TEM images with high degree of phase clustering

Microstructural characterization methods and their performance in virtual microstructure reconstruction were investigated using two-phase Pebax/PBE membranes. In this study, the microstructural characteristics of two-phase Pebax/PBE membranes with random phase distribution were obtained from two-dimensional (2D) transmission electron microscopy (TEM) images to reconstruct three-dimensional (3D) virtual microstructures. The microstructural characteristics of the 2D TEM images with different volume fractions were expressed using a two-point correlation function (P₂) and cooccurrence correlation functions (CCFs), and the results were compared. Virtual 3D microstructures were reconstructed through a stochastic optimization process using CCFs obtained from 2D TEM images of the membranes. This study further investigated and evaluated the effects of phase clustering on probabilistic functions, namely, P₂ and CCFs. It is confirmed that CCFs accurately represent the characteristics of microstructures with a high degree of phase clustering and that virtual 3D samples can be effectively reconstructed using CCFs obtained from 2D images.