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Title: Yielding of tantalum at strain rates up to 10{sup 9 }s{sup −1}

Abstract

We have used a 45 μJ laser pulse to accelerate the free surface of fine-grained tantalum films up to peak velocities of ∼1.2 km s{sup −1}. The films had thicknesses of ∼1–2 μm and in-plane grain widths of ∼75–150 nm. Using ultrafast interferometry, we have measured the time history of the velocity of the surface at different spatial positions across the accelerated region. The initial part of the histories (assumed to correspond to the “elastic precursor” observed previously) exhibited measured strain rates of ∼0.6 to ∼3.2 × 10{sup 9 }s{sup −1} and stresses of ∼4 to ∼22 GPa. Importantly, we find that elastic amplitudes exhibit little variation with strain rate for a constant peak surface velocity, even though, via covariation of the strain rate with peak surface velocity, they vary with strain rate. Furthermore, by comparison with data obtained at lower strain rates, we find that amplitudes are much better predicted by peak velocities rather than by either strain rate or sample thickness.

Authors:
; ; ; ; ;  [1]
  1. Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Publication Date:
OSTI Identifier:
22590473
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; FILMS; INTERFEROMETRY; LASERS; PEAKS; PRESSURE RANGE GIGA PA; STRAIN RATE; STRAINS; STRESSES; SURFACES; TANTALUM; THICKNESS; VELOCITY

Citation Formats

Crowhurst, Jonathan C., E-mail: crowhurst1@llnl.gov, Armstrong, Michael R., E-mail: armstrong30@llnl.gov, Gates, Sean D., Zaug, Joseph M., Radousky, Harry B., and Teslich, Nick E. Yielding of tantalum at strain rates up to 10{sup 9 }s{sup −1}. United States: N. p., 2016. Web. doi:10.1063/1.4960796.
Crowhurst, Jonathan C., E-mail: crowhurst1@llnl.gov, Armstrong, Michael R., E-mail: armstrong30@llnl.gov, Gates, Sean D., Zaug, Joseph M., Radousky, Harry B., & Teslich, Nick E. Yielding of tantalum at strain rates up to 10{sup 9 }s{sup −1}. United States. doi:10.1063/1.4960796.
Crowhurst, Jonathan C., E-mail: crowhurst1@llnl.gov, Armstrong, Michael R., E-mail: armstrong30@llnl.gov, Gates, Sean D., Zaug, Joseph M., Radousky, Harry B., and Teslich, Nick E. 2016. "Yielding of tantalum at strain rates up to 10{sup 9 }s{sup −1}". United States. doi:10.1063/1.4960796.
@article{osti_22590473,
title = {Yielding of tantalum at strain rates up to 10{sup 9 }s{sup −1}},
author = {Crowhurst, Jonathan C., E-mail: crowhurst1@llnl.gov and Armstrong, Michael R., E-mail: armstrong30@llnl.gov and Gates, Sean D. and Zaug, Joseph M. and Radousky, Harry B. and Teslich, Nick E.},
abstractNote = {We have used a 45 μJ laser pulse to accelerate the free surface of fine-grained tantalum films up to peak velocities of ∼1.2 km s{sup −1}. The films had thicknesses of ∼1–2 μm and in-plane grain widths of ∼75–150 nm. Using ultrafast interferometry, we have measured the time history of the velocity of the surface at different spatial positions across the accelerated region. The initial part of the histories (assumed to correspond to the “elastic precursor” observed previously) exhibited measured strain rates of ∼0.6 to ∼3.2 × 10{sup 9 }s{sup −1} and stresses of ∼4 to ∼22 GPa. Importantly, we find that elastic amplitudes exhibit little variation with strain rate for a constant peak surface velocity, even though, via covariation of the strain rate with peak surface velocity, they vary with strain rate. Furthermore, by comparison with data obtained at lower strain rates, we find that amplitudes are much better predicted by peak velocities rather than by either strain rate or sample thickness.},
doi = {10.1063/1.4960796},
journal = {Applied Physics Letters},
number = 9,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
  • Abstract not provided.
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