Spall strength dependence on grain size and strain rate in tantalum

T. P. Remington, E. N. Hahn, S. Zhao, R. Flanagan, J. C.E. Mertens, S. Sabbaghianrad, T. G. Langdon, C. E. Wehrenberg, B. R. Maddox, D. C. Swift, B. A. Remington, Nikhilesh Chawla, M. A. Meyers

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We examine the effect of grain size on the dynamic failure of tantalum during laser-shock compression and release and identify a significant effect of grain size on spall strength, which is opposite to the prediction of the Hall-Petch relationship because spall is primarily intergranular in both poly and nanocrystalline samples; thus, monocrystals have a higher spall strength than polycrystals, which, in turn, are stronger in tension than ultra-fine grain sized specimens. Post-shock characterization reveals ductile failure which evolves by void nucleation, growth, and coalescence. Whereas in the monocrystal the voids grow in the interior, nucleation is both intra - and intergranular in the poly and ultra-fine-grained crystals. The fact that spall is primarily intergranular in both poly and nanocrystalline samples is a strong evidence for higher growth rates of intergranular voids, which have a distinctly oblate spheroid shape in contrast with intragranular voids, which are more spherical. The length of geometrically-necessary dislocations required to form a grain-boundary (intergranular) void is lower than that of grain-interior (intragranular) void with the same maximum diameter; thus, the energy required is lower. Consistent with prior literature and theory we also identify an increase with spall strength with strain rate from 6 × 106 to 5 × 107 s−1. Molecular dynamics calculations agree with the experimental results and also predict grain-boundary separation in the spalling of polycrystals as well as an increase in spall strength with strain rate. An analytical model based on the kinetics of nucleation and growth of intra- and intergranular voids and extending the Curran-Seaman-Shockey theory is applied which shows the competition between the two processes for polycrystals.

Original languageEnglish (US)
Pages (from-to)313-329
Number of pages17
JournalActa Materialia
Volume158
DOIs
StatePublished - Oct 1 2018

Fingerprint

Tantalum
Polycrystals
Strain rate
Nucleation
Grain boundaries
Spalling
Coalescence
Dislocations (crystals)
Molecular dynamics
Analytical models
Crystals
Kinetics
Lasers

Keywords

  • Grain size
  • Spall strength
  • Strain rate
  • Texture
  • Void growth

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Cite this

Remington, T. P., Hahn, E. N., Zhao, S., Flanagan, R., Mertens, J. C. E., Sabbaghianrad, S., ... Meyers, M. A. (2018). Spall strength dependence on grain size and strain rate in tantalum. Acta Materialia, 158, 313-329. https://doi.org/10.1016/j.actamat.2018.07.048

Spall strength dependence on grain size and strain rate in tantalum. / Remington, T. P.; Hahn, E. N.; Zhao, S.; Flanagan, R.; Mertens, J. C.E.; Sabbaghianrad, S.; Langdon, T. G.; Wehrenberg, C. E.; Maddox, B. R.; Swift, D. C.; Remington, B. A.; Chawla, Nikhilesh; Meyers, M. A.

In: Acta Materialia, Vol. 158, 01.10.2018, p. 313-329.

Research output: Contribution to journalArticle

Remington, TP, Hahn, EN, Zhao, S, Flanagan, R, Mertens, JCE, Sabbaghianrad, S, Langdon, TG, Wehrenberg, CE, Maddox, BR, Swift, DC, Remington, BA, Chawla, N & Meyers, MA 2018, 'Spall strength dependence on grain size and strain rate in tantalum', Acta Materialia, vol. 158, pp. 313-329. https://doi.org/10.1016/j.actamat.2018.07.048
Remington TP, Hahn EN, Zhao S, Flanagan R, Mertens JCE, Sabbaghianrad S et al. Spall strength dependence on grain size and strain rate in tantalum. Acta Materialia. 2018 Oct 1;158:313-329. https://doi.org/10.1016/j.actamat.2018.07.048
Remington, T. P. ; Hahn, E. N. ; Zhao, S. ; Flanagan, R. ; Mertens, J. C.E. ; Sabbaghianrad, S. ; Langdon, T. G. ; Wehrenberg, C. E. ; Maddox, B. R. ; Swift, D. C. ; Remington, B. A. ; Chawla, Nikhilesh ; Meyers, M. A. / Spall strength dependence on grain size and strain rate in tantalum. In: Acta Materialia. 2018 ; Vol. 158. pp. 313-329.
@article{0b3397a614434b6e8c65735d519b0d17,
title = "Spall strength dependence on grain size and strain rate in tantalum",
abstract = "We examine the effect of grain size on the dynamic failure of tantalum during laser-shock compression and release and identify a significant effect of grain size on spall strength, which is opposite to the prediction of the Hall-Petch relationship because spall is primarily intergranular in both poly and nanocrystalline samples; thus, monocrystals have a higher spall strength than polycrystals, which, in turn, are stronger in tension than ultra-fine grain sized specimens. Post-shock characterization reveals ductile failure which evolves by void nucleation, growth, and coalescence. Whereas in the monocrystal the voids grow in the interior, nucleation is both intra - and intergranular in the poly and ultra-fine-grained crystals. The fact that spall is primarily intergranular in both poly and nanocrystalline samples is a strong evidence for higher growth rates of intergranular voids, which have a distinctly oblate spheroid shape in contrast with intragranular voids, which are more spherical. The length of geometrically-necessary dislocations required to form a grain-boundary (intergranular) void is lower than that of grain-interior (intragranular) void with the same maximum diameter; thus, the energy required is lower. Consistent with prior literature and theory we also identify an increase with spall strength with strain rate from 6 × 106 to 5 × 107 s−1. Molecular dynamics calculations agree with the experimental results and also predict grain-boundary separation in the spalling of polycrystals as well as an increase in spall strength with strain rate. An analytical model based on the kinetics of nucleation and growth of intra- and intergranular voids and extending the Curran-Seaman-Shockey theory is applied which shows the competition between the two processes for polycrystals.",
keywords = "Grain size, Spall strength, Strain rate, Texture, Void growth",
author = "Remington, {T. P.} and Hahn, {E. N.} and S. Zhao and R. Flanagan and Mertens, {J. C.E.} and S. Sabbaghianrad and Langdon, {T. G.} and Wehrenberg, {C. E.} and Maddox, {B. R.} and Swift, {D. C.} and Remington, {B. A.} and Nikhilesh Chawla and Meyers, {M. A.}",
year = "2018",
month = "10",
day = "1",
doi = "10.1016/j.actamat.2018.07.048",
language = "English (US)",
volume = "158",
pages = "313--329",
journal = "Acta Materialia",
issn = "1359-6454",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Spall strength dependence on grain size and strain rate in tantalum

AU - Remington, T. P.

AU - Hahn, E. N.

AU - Zhao, S.

AU - Flanagan, R.

AU - Mertens, J. C.E.

AU - Sabbaghianrad, S.

AU - Langdon, T. G.

AU - Wehrenberg, C. E.

AU - Maddox, B. R.

AU - Swift, D. C.

AU - Remington, B. A.

AU - Chawla, Nikhilesh

AU - Meyers, M. A.

PY - 2018/10/1

Y1 - 2018/10/1

N2 - We examine the effect of grain size on the dynamic failure of tantalum during laser-shock compression and release and identify a significant effect of grain size on spall strength, which is opposite to the prediction of the Hall-Petch relationship because spall is primarily intergranular in both poly and nanocrystalline samples; thus, monocrystals have a higher spall strength than polycrystals, which, in turn, are stronger in tension than ultra-fine grain sized specimens. Post-shock characterization reveals ductile failure which evolves by void nucleation, growth, and coalescence. Whereas in the monocrystal the voids grow in the interior, nucleation is both intra - and intergranular in the poly and ultra-fine-grained crystals. The fact that spall is primarily intergranular in both poly and nanocrystalline samples is a strong evidence for higher growth rates of intergranular voids, which have a distinctly oblate spheroid shape in contrast with intragranular voids, which are more spherical. The length of geometrically-necessary dislocations required to form a grain-boundary (intergranular) void is lower than that of grain-interior (intragranular) void with the same maximum diameter; thus, the energy required is lower. Consistent with prior literature and theory we also identify an increase with spall strength with strain rate from 6 × 106 to 5 × 107 s−1. Molecular dynamics calculations agree with the experimental results and also predict grain-boundary separation in the spalling of polycrystals as well as an increase in spall strength with strain rate. An analytical model based on the kinetics of nucleation and growth of intra- and intergranular voids and extending the Curran-Seaman-Shockey theory is applied which shows the competition between the two processes for polycrystals.

AB - We examine the effect of grain size on the dynamic failure of tantalum during laser-shock compression and release and identify a significant effect of grain size on spall strength, which is opposite to the prediction of the Hall-Petch relationship because spall is primarily intergranular in both poly and nanocrystalline samples; thus, monocrystals have a higher spall strength than polycrystals, which, in turn, are stronger in tension than ultra-fine grain sized specimens. Post-shock characterization reveals ductile failure which evolves by void nucleation, growth, and coalescence. Whereas in the monocrystal the voids grow in the interior, nucleation is both intra - and intergranular in the poly and ultra-fine-grained crystals. The fact that spall is primarily intergranular in both poly and nanocrystalline samples is a strong evidence for higher growth rates of intergranular voids, which have a distinctly oblate spheroid shape in contrast with intragranular voids, which are more spherical. The length of geometrically-necessary dislocations required to form a grain-boundary (intergranular) void is lower than that of grain-interior (intragranular) void with the same maximum diameter; thus, the energy required is lower. Consistent with prior literature and theory we also identify an increase with spall strength with strain rate from 6 × 106 to 5 × 107 s−1. Molecular dynamics calculations agree with the experimental results and also predict grain-boundary separation in the spalling of polycrystals as well as an increase in spall strength with strain rate. An analytical model based on the kinetics of nucleation and growth of intra- and intergranular voids and extending the Curran-Seaman-Shockey theory is applied which shows the competition between the two processes for polycrystals.

KW - Grain size

KW - Spall strength

KW - Strain rate

KW - Texture

KW - Void growth

UR - http://www.scopus.com/inward/record.url?scp=85050975323&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85050975323&partnerID=8YFLogxK

U2 - 10.1016/j.actamat.2018.07.048

DO - 10.1016/j.actamat.2018.07.048

M3 - Article

AN - SCOPUS:85050975323

VL - 158

SP - 313

EP - 329

JO - Acta Materialia

JF - Acta Materialia

SN - 1359-6454

ER -