Influence of anisotropy (crystallographic and microstructural) on spallation in Zr, Ta, HY-100 steel, and 1080 eutectoid steel

The purpose of this study is to quantify the influence of textural and microstructural anisotropy on spallation. This includes the influence of anisotropically-oriented MnS inclusion stringers in the HY-100 and 1080 steels on spallation, within two crystallographically-isotropic steels, and the influence of strong, anisotropic crystallographic texture in high-purity polycrystalline Ta and Zr materials to assess the role of texture on damage evolution and spallation responses. The effect of anisotropic crystallographic texture on the spallation response of Ta and Zr is shown to play a minimal role in the spallation response of each material, as seen in wave profile pull-back signals, compared to the effect of texture on the shock arrival time and the Hugoniot elastic limit that reflects strength in these two high-purity materials. In the case of both the 1080 and HY-100 steels, the influence of elongated MnS stringers, resident within the essentially crystallographically isotropic steels, was found to be dominated by the heterogeneous nucleation of damage orthogonal to the MnS stringers. Delamination between the pearlitic matrix microstructure and the MnS stringers in the 1080 steel, or inclusions and the martensitic matrix in the HY-100 steel, was seen to correlate to a lower pull-back signal during transverse loading than to that parallel to the stringer axis in each steel. © 2010 Springer Science+Business Media B.V.