Temperature dependence of misfit strains of δ-hydrides of zirconium

In situ synchrotron X-ray diffraction study of hydrides in Zircaloy-4 during thermomechanical cycling

“…To understand the above experimental observations, the following is known regarding the stress state within the hydrides. Upon precipitation and owing to their anisotropic transformation strain [37,[41][42][43] and (primarily) to the plate-like shape of the hydrides, the internal stresses within the precipitated hydride platelets are not only compressive but such that the in-plane stress components exceed the stress component normal to the platelet [44,45], as shown schematically in Figure 9a. As will be described below, the resulting anisotropic strain state within the precipitated hydrides is such that the d-spacing of planes parallel to the hydride face exceeds the spacing of those planes aligned with the plate edges within the hydrides after precipitation.…”

Measurement and modeling of strain fields in zirconium hydrides precipitated at a stress concentration

“…However, it was important that the reference d-spacing come from the same experimental setup, as different equipment and calibration used to obtain hydride dspacing in other X-ray experiments found in the literature have an effect on the measured value. Unfortunately, using 'far-field' hydrides as a reference obscures the influence of the initial strain state of the hydrides, which is expected to be compressive due to the volume misfit strains generated in the hydride during precipitation [30,35]. This effect is evident when looking at the line plots in the experimental results.…”

Properties of Bulk Zirconium Hydrides

“…Recently, Singh et al [26] evaluated the temperature and composition dependence of these differences using data provided by Douglass [12] for the temperature dependence of the lattice parameters in a-Zr and by Yamanaka et al [31,32] for the temperature dependence and hydrogen composition dependence of the lattice parameter in d-hydride. Singh et al [26] focused on the temperature dependence of the lattice parameters for a single d-hydride phase composition of r ffi 1:66. Their results are reproduced in Fig.…”