Calculation of the pressure derivative of elastic constants for non-cubic polycrystals

Abstract

The self-consistent T-matrix approach to evaluate the pressure derivative of the effective elastic constants of cubic polycrystals has been extended to non-cubic systems in this work. The purpose of the present work is to assess the different approximations resorted to and their inter-relations with respect to non-cubic polycrystals. The results are widely different from one another when based on the Voigt Reuss average T-matrix and self-consistent approximations for certain materials. These calculations may stimulate experimental observation in particular for some tetragonal polycrystals where the predictions differ even in sign. Finally, results were obtained for fourteen different polycrystalline substances belonging to hexagonal, trigonal, tetragonal and orthorhombic symmetries for which all the input data are available.