Effect of Crystallographic Orientation, Grain Shape, and Elastic Anisotropy on X-ray Stress Factor in Polycrystals with Crystallographic Textures

The effects of grain shape, crystallographic texture, and elastic anisotropy on the X-ray stress factor in polycrystals were studied. Polycrystal models with <110> fiber textures, comprised of single crystals exhibiting four different elastic anisotropy factors, were prepared. Then, the effects of the degree of <110> orientation, elastic anisotropy, and shape of the grains on the X-ray stress factor were examined using a self-consistent method consisting of the effective-medium approximation and Eshelby's inclusion method. Also, the effects of the degree of <110> orientation and elastic anisotropy on the X-ray stress factors were analyzed using the Voigt and Reuss approximations. The analyses using the self-consistent method revealed that the degree of <110> orientation and elastic anisotropy of single crystal affect the dependence of the X-ray stress factor on the aspect ratio of spheroidal grains. The comparison of the analyses using the self-consistent method, Voigt and Reuss approximations revealed that there is a correlation between the aspect-ratio dependency of the X-ray stress factor and the difference between the X-ray stress factors calculated using the Voigt and Reuss approximations; when the difference between the X-ray stress factors calculated using the Voigt and Reuss approximations is large, the effect of the aspect ratio of the spheroidal grain on the X-ray stress factor is large.