Anisotropy factors from texture and mechanical strain in Zircaloy-4 fuel sheaths

Abstract The crystallographic textures in Zircaloy-4 fuel sheathing in the as-manufactured condition and with simulated braze zones microstructures have been characterized by neutron diffraction at several different temperatures (100–1000 °C). The texture (ODF) data measured at 100 °C for these three sets of samples are used to calculate the Kearns numbers and the Hill’s anisotropy factors using SELFPOLY (a self-consistent polycrystalline model) to compare and correlate with previously obtained values from X-ray diffraction and mechanical strain tests on similar type of Zircaloy-4 fuel sheath materials. The results from SELFPOLY calculations showed the values for Kearns numbers to be similar to earlier data. It is found that the SELFPOLY calculated values for the Hill’s anisotropy factors showed some reasonable agreement with those from mechanical strain tests, when a texture-based parameter replacing the numerical value for the “stress-exponent, n” parameter and a pre-fixed set of values for the critical resolved shear stress (CRSS) for the three different slips systems (prism, basal, and pyramidal) are used in the calculations.