Modeling High Strain Rate Plasticity in BCC Lead

ORAL

Abstract

High-energy lasers enable determination of metal strength at very high pressures. Here we consider the strength (flow stress) of lead in the high-pressure body-centered cubic (bcc) phase at a peak pressure of ∼400 GPa. Two previous models of Pb strength were built from the low-pressure fcc phase. Plasticity in bcc and fcc crystals can be very different. Experiments conducted at the National Ignition Facility have used ramp-compression to drive Rayleigh-Taylor instability and measured the ripple growth to infer strength in the bcc phase of lead and lead alloy [1]. We have developed an Improved Steinberg-Guinan model for bcc lead strength [2] using ab initio calculations of the shear modulus at pressure that agrees well with those experiments. The alloying, which increases strength 4x at ambient conditions, has no measurable effect at high-pressure.
[1] A. Krygier et al., Phys. Rev. Lett., to appear (2019).
[2] Robert E. Rudd et al., AIP Conf. Proc. 1979, 070027 (2018)

*This work was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

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Presenters

  • Robert Rudd

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

Authors

  • Robert Rudd

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • Lin H Yang

    • Lawrence Livermore Natl Lab

  • Andrew Krygier

    • Lawrence Livermore Natl Lab

  • Philip Powell

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • Damian Swift

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • Christopher Wehrenberg

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • James M McNaney

    • Lawrence Livermore Natl Lab

  • Hye-Sook Park

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • Peter Graham

    • AWE
    • Atomic Weapons Establishment