Title: Elastic-plastic deformation of molybdenum single crystals shocked along [100]

Abstract

To understand the elastic-plastic deformation response of shock-compressed molybdenum (Mo) – a body-centered cubic (BCC) metal, single crystal samples were shocked along the [100] crystallographic orientation to an elastic impact stress of 12.5 GPa. Elastic-plastic wave profiles, measured at different propagation distances ranging between ~0.23 to 2.31 mm using laser interferometry, showed a time-dependent material response. Within experimental scatter, the measured elastic wave amplitudes were nearly constant over the propagation distances examined. These data point to a large and rapid elastic wave attenuation near the impact surface, before reaching a threshold value (elastic limit) of ~3.6 GPa. Numerical simulations of the measured wave profiles, performed using a dislocation-based continuum model, suggested that {110}<111> and/or {112}<111> slip systems are operative under shock loading. In contrast to shocked metal single crystals with close-packed structures, the measured wave profiles in Mo single crystals could not be explained in terms of dislocation multiplication alone. A dislocation generation mechanism, operative for shear stresses larger than that at the elastic limit, was required to model the rapid elastic wave attenuation and to provide a good overall match to the measured wave profiles. However, the physical basis for this mechanism was not established for the high-purity singlemore » crystal samples used in this study. As a result, the numerical simulations also suggested that Mo single crystals do not work harden significantly under shock loading in contrast to the behavior observed under quasi-static loading.« less

Authors:

Mandal, A.  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-4116-0735"

Gupta, Y. M. ^[1]

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+ Show Author Affiliations

1. Washington State Univ., Pullman, WA (United States)

Publication Date:

Tue Jan 24 00:00:00 EST 2017

Research Org.:

Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP)

OSTI Identifier:

1342518

Grant/Contract Number:  

NA0002007

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 121; Journal Issue: 4; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE