DYMAT 2009
Volume 2, 2009
DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
Page(s) 963 - 969
Section Micro-Structural Effects
Published online 15 September 2009
DYMAT 2009 (2009) 963-969
DOI: 10.1051/dymat/2009135

Influence of shockwave obliquity on deformation twin formation in Ta

G.T. (Rusty) Gray III, V. Livescu, E.K. Cerreta, T.A. Mason, P.J. Maudlin and J.F. Bingert

Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

Published online: 15 September 2009

Energetic loading subjects a material to a “Taylor wave” (triangular wave) loading profile that experiences an evolving balance of hydrostatic (spherical) and deviatoric stresses. While much has been learned over the past five decades concerning the propensity of deformation twinning in samples shock-loaded using “square-topped” profiles as a function of peak stress, achieved most commonly via flyer plate loading, less is known concerning twinning propensity during non-1-dimensional sweeping detonation wave loading. Systematic small-scale energetically-driven shock loading experiments were conducted on Ta samples shock-loaded with PETN that was edge detonated. Deformation twinning was quantified in post-mortem samples as a function of detonation geometry and radial position. In the edge detonated loading geometry examined in this paper, the average volume fraction of deformation twins was observed to increase with increasing shock obliquity. The results of this study are discussed in light of the formation mechanisms of deformation twins, previous literature studies of twinning in shocked materials, and modeling of the effects of shock obliquity on the stress tensor during shock loading.

© EDP Sciences 2009