Influence of crystallographic anisotropy on the Hopkinson fracture “spallation” of zirconium

Abstract

The influence of texture on the spallation (Hopkinson fracture) of low-symmetry metals (e.g. Zr, U, or Sn) has seen limited study. In this study, the Hopkinson fracture of annealed, high-purity Zr has been probed as a function of crystallographic texture. The quasi-static yield strength of the Zr studied is ≈2.5x higher in the plate's through-thickness direction compared to that measured in-plane due to a pronounced basal texture. The pullback signals of each orientation shocked to 5 GPa were found to be insensitive to the texture, although the HEL's and the soft-recovered, incipiently-spalled samples exhibited differences in their damage evolution. The VISAR wave profiles were modeled using a 3-D finite-volume method (FVM) continuum code. The VISAR, post-spallation metallographic observations, and modeling analysis are discussed with reference to the HEL and texture.

Frontiers in Anisotropic Shock-Wave Modeling

“…Also, Gupta (74) presented experimental data for shock propagation along the 111 crystallographic direction in single-crystal LiF, with the observed elastic response up to 30 kbar experimental bounds and including shock propagation data along the 100 , 110 , and 111 directions (Gupta [75]). The dynamic elevated-temperature elastic properties of single-crystals and polycrystalline aluminum were studied by employing a laser pulse technique to produce propagating stress pulses in slender rods (Swearengen et al [76] For many years, it has been assumed in the shock-wave community that the response of materials to high intensity shock loading is isotropic, and only recently has anisotropy in the shock response attracted the attention of researchers (e.g., Gupta [75], Dick and Ritchie [78], Gray III et al [25,26]). It was shown in an investigation of cold rolled and annealed zirconium (see Gray III et al [25]) that the value of stresses varies in different directions in the quasi-static test and plate impact test.…”

“…The dynamic elevated-temperature elastic properties of single-crystals and polycrystalline aluminum were studied by employing a laser pulse technique to produce propagating stress pulses in slender rods (Swearengen et al [76] For many years, it has been assumed in the shock-wave community that the response of materials to high intensity shock loading is isotropic, and only recently has anisotropy in the shock response attracted the attention of researchers (e.g., Gupta [75], Dick and Ritchie [78], Gray III et al [25,26]). It was shown in an investigation of cold rolled and annealed zirconium (see Gray III et al [25]) that the value of stresses varies in different directions in the quasi-static test and plate impact test. Gray III et al (26) showed that under shock loading conditions (one-dimensional strain space), the variation of the Hugoniot elastic limit (HEL) or the yield strength of annealed zirconium was consistent with the quasi-static experimental data.…”

“…The impact loading of anisotropic materials is a subject that has received considerable attention for both low and high velocity in the recent monographs on composite materials (e.g., Abrate [8], Reid and Zhou [9], Ryan et al [10]) and in recent research papers on composite materials (e.g., Hereil et al [11], Bordzilovsky et al [12], Dandekar et al [13], Espinosa et al [14], Millett et al [15], Aktaş et al [16], Hazell and Appleby-Thomas [17], García-Castillo et al [18], Tekalur et al [19]), research papers on metals (e.g., Butcher [20], Johnson and Barker [21], Stevens and Tuler [22], Rosenberg et al [23,24], Gray III et al [25,26], Rubin [27]), and research papers on single crystals (e.g., Winey and Gupta [28][29][30]). …”

Influence of Microstructural Anisotropy on the Spallation of 1080 Eutectoid Steel

“…Strong crystallographic texture in high-purity zirconium has been shown to lead to anisotropic damage evolution during tensile loading resulting in ellipsoidal-shaped ductile dimples following isotropic void nucleation (3,8). Anisotropic damage evolution has been shown to control the quasi-static fracture response and ballistic impact resistance due to second-phase (elongated MnS stringers) initiation processes in HY-100 and armor steel, respectively (5,6).…”

“…While the influence of crystallographic texture on metal plasticity has seen in-depth study over the last 40 years (1), the role of anisotropy (due to texture or morphology) on fracture remains poorly understood (2,3). The effects of anisotropy on fracture can be: 1) atomistic in nature on a single-crystal level, such as the role of crystallographic orientation on cleavage fracture (4, 2) microstructural anisotropy (5, 6) due to microscopic directionality (grain shape, etc.…”