Title: Elastic-plastic deformation of molybdenum single crystals shocked to 12.5 GPa: Crystal anisotropy effects

Abstract

Here, to understand crystal anisotropy effects on shock-induced elastic-plastic deformation of molybdenum (Mo), results from high-purity single crystals shocked along [110] and [111] orientations to an elastic impact stress of 12.5 GPa were obtained and compared with the [100] results previously reported [A. Mandal and Y. M Gupta, J. Appl. Phys. 121, 045903 (2017)]. Measured wave profiles showed a time-dependent response, and strong anisotropy was observed in the elastic wave attenuation with the propagation distance, elastic limits, shock speeds, and overall structure of the wave profiles. Resolved shear stresses on {110} $$\langle$$111$$\rangle$$ and {112} $$\langle$$111$$\rangle$$ slip systems provided insight into the observed anisotropy in elastic wave attenuation and elastic limits and showed that shear stresses, and not longitudinal stresses, are a better measure of strength in shocked single crystals. Under shock compression, resolved shear stresses at elastic limits were comparable to the Peierls stress of screw dislocations in Mo. Elastic wave attenuation was rapid when shear stresses were larger than the Peierls stress. Large differences in the elastic limits under shock and quasi-static loading are likely a consequence of the large Peierls stress value for Mo. Numerically simulated wave profiles, obtained using the dislocation-based plasticity model described in the [100] work, showed good agreement with all measured wave profiles but could not differentiate between the {110} $$\langle$$111$$\rangle$$ and {112} $$\langle$$111$$\rangle$$ slip systems. Overall, experimental results and corresponding numerical simulations for the three crystal orientations have provided a comprehensive insight into shock-induced elastic-plastic deformation of Mo single crystals, including the development of a continuum material model.

Authors:

Mandal, A.  ^[1];

• Search DOE PAGES for author "Mandal, A."
• Search DOE PAGES for ORCID "0000-0002-4116-0735"

Gupta, Y. M.  ^[2]

• Search DOE PAGES for author "Gupta, Y. M."
• Search DOE PAGES for ORCID "0000-0002-2669-3015"

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+ Show Author Affiliations

1. Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics, School of Mechanical and Materials Engineering
2. Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics, Dept. of Physics and Astronomy

Publication Date:

Thu Feb 07 00:00:00 EST 2019

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); 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:

1495157

Alternate Identifier(s):

OSTI ID: 1493763

Report Number(s):

LA-UR-18-28318
Journal ID: ISSN 0021-8979

Grant/Contract Number:  

89233218CNA000001; NA0002007

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 125; Journal Issue: 5; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; molybdenum; single crystal; plastic deformation; shock wave; crystal plasticity; dislocation slip; wave profile simulation; BCC; body-centered cubic