A surprising proliferation of detwinning in beta-tin at extreme loading rates and other investigations in compression of condensed matter

ORAL

Abstract

Integrating data from dynamic compression experiments of condensed matter across three national laboratories has led to insight

and quantitative calibration of materials strength over many decades of loading rates. For many materials, a single strength model

(such as PTW) is sufficient to capture the flow-stress strain rate relationship which is monotonic. We show here that beta-tin, a

tetragonal metal, exhibits dramatic deviations from this behavior. Naive fitting to a single PTW model is insufficient to capture the

behavior; indeed, such resulting inferred flow stress versus strain exhibits a non-monotonic behavior. We suggest a resolution to this

by proposing that in beta-tin there are important Bauschinger effects arising from favorable conditions for twinning and detwinning.

A simple yield surface model when paired with PTW hardening captures the experimental data.

*This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore NationalLaboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLNL-JRNL-871188.Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia,LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s NationalNuclear Security Administration under Contract No. DE-NA0003525. This publication is based in part upon workperformed at the Dynamic Compression Sector at the Advanced Photon Source supported by the U.S. Department ofEnergy, National Nuclear Security Administration, under Award No. DE-NA0002442 and operated by WashingtonState University (WSU).

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Publication: Submitted article to scripta mat "A surprising proliferation of detwinning in -tin at extreme loading rates"

Presenters

  • William Joseph Schill

    • Lawrence Livermore National Laboratory

Authors

  • William Joseph Schill

    • Lawrence Livermore National Laboratory

  • Nathan R Barton

    • Lawrence Livermore National Laboratory