Direction Dependent Grain-Interaction Models for the Diffraction Stress Analysis of Thin Films

摘要

The well-known grain-interaction models for the description of the macroscopic elastic behaviour of polycrystalline specimens, for example the models due to Voigt and Reuss, may be applied to bulk specimens, but they are generally not suitable for thin films because they imply macroscopic elastic isotropy of the body. A thin film is usually at most transversely elastically isotropic, even in the absence of texture. A recently elaborated, alternative model for grain-interaction in thin films, adopting grain-interaction assumptions first given by Vook and Witt (J. Appl. Phys. 7, 2169 (1965)), is able to predict the transversely isotropic elastic behaviour. Although this model is more appropriate for thin films than traditional models, it still imposes extreme grain-interaction assumptions, which are in general not compatible with the true elastic behaviour of real specimens. In this paper a more general approach to grain-interaction in thin films is proposed.