Quantitative Indicators of Microstructure and Texture Heterogeneity in Polycrystalline System

The microstructural features of polycrystals determine numerous properties, whereas the evolution of crystallographic texture is responsible for the anisotropy of particular properties. Therefore, it is of crucial importance to find proper quantitative indicators, which reflect the nature of microstructure and texture characteristics. This is partially performed by the assessment of the average grain size and texture intensity that provide basic information on the microstructural features evolved; however, often, the basic quantitative indicators are not capable of revealing the complete microstructural state especially when the system is highly heterogeneous. This contribution presents various methods to assess the degree of microstructural heterogeneity, while the crystallographic aspect of microstructure evolution is characterized by several indicators of texture heterogeneity. Numerous synthetic microstructures with normal, lognormal, and bimodal grain size distributions as well as their combinations are analyzed to evaluate the applicability of the methods presented in this study. The quantitative indicators described in the frame of this contribution are likewise tested on experimentally observed microstructures. It is shown that the derived coefficients of microstructure heterogeneity correlate well with the standard deviation in grain size distribution, Gini, and Hoover coefficients, while the quantitative measures of texture heterogeneity are capable of revealing hidden aspects of microstructure evolution.