Extensive twinning was observed in specimens which had been subjected to a plane shock wave (about 45GPa peak pressure, 1.8 pulse duration). Transmission electron microscopy revealed twins in all four <042> directions, on the traces of {112} planes at (100) grain surfaces. Twins were also observed in the tail region of an explosively formed penetrator. However, these had very irregular shapes and seemed to be recovering. Due to these features and to the absence of twins in such studies of Ta, it was suggested that they were very sensitive to the temperature rise which was associated with post-detonation deformation. Some preliminary  in situ  heating experiments, that were performed at about 900C, produced some rather unusual so-called recovery microstructures which were thought to be related to deformation twinning.

S.Pappu, C.Kennedy, L.E.Murr, M.A.Meyers: Scripta Materialia, 1996, 35[8], 959-65