On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry

Thurston, Keli V. S.; Hohenwarter, Anton; Laplanche, Guillaume; George, Easo P.; Gludovatz, Bernd; Ritchie, Robert O.

doi:10.1016/j.intermet.2019.04.012

Title: On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry

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Abstract

Deformation-induced nanoscale twinning is one of the mechanisms responsible for the excellent combination of strength and fracture toughness of the single-phase, face-centered cubic CrMnFeCoNi (Cantor) alloy, especially at cryogenic temperatures. In this work, we use a novel, modified dogbone geometry that allows the sampling of varying stress and strain regions within a single tensile specimen to characterize the onset of twinning in CrMnFeCoNi at 293 K, 198 K and 77 K. Electron backscatter diffraction (EBSD) and backscattered electron (BSE) imaging revealed the presence of deformation nano-twins in regions of the samples that had experienced plastic strains of ~25% at 293 K, ~16% at 198 K, and ~8% at 77 K, which are similar to the threshold strains described by Laplanche et al. (Acta Mater. 118, 2016, 152–163). From these strains we estimate that the critical tensile stress for the onset of twinning in this alloy is on the order of 750 MPa.

Authors:

Thurston, Keli V. S. ^[1]; Hohenwarter, Anton ^[2]; Laplanche, Guillaume ^[3];

^[4]; Gludovatz, Bernd ^[5]; Ritchie, Robert O. ^[1]

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Austrian Academy of Sciences, Leoben (Austria)
Ruhr Univ., Bochum (Germany)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Univ. of New South Wales, Sydney, NSW (Australia)

Publication Date:: Thu May 09 00:00:00 EDT 2019

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; German Research Foundation (DFG)

OSTI Identifier:: 1543214

Grant/Contract Number:: AC05-00OR22725; AC02-05-CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Intermetallics

Additional Journal Information:: Journal Volume: 110; Journal Issue: C; Journal ID: ISSN 0966-9795

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; High-entropy alloys; Deformation twinning; Twinning stress; Critical twinning strain

Citation Formats


                    Thurston, Keli V. S., Hohenwarter, Anton, Laplanche, Guillaume, George, Easo P., Gludovatz, Bernd, and Ritchie, Robert O. On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry.  United States: N. p., 2019. 
Web.  doi:10.1016/j.intermet.2019.04.012.

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                    Thurston, Keli V. S., Hohenwarter, Anton, Laplanche, Guillaume, George, Easo P., Gludovatz, Bernd, & Ritchie, Robert O. On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry.  United States.  https://doi.org/10.1016/j.intermet.2019.04.012

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                    Thurston, Keli V. S., Hohenwarter, Anton, Laplanche, Guillaume, George, Easo P., Gludovatz, Bernd, and Ritchie, Robert O. Thu .  
"On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry".  United States.  https://doi.org/10.1016/j.intermet.2019.04.012.  https://www.osti.gov/servlets/purl/1543214.

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@article{osti_1543214,

  title        = {On the onset of deformation twinning in the CrFeMnCoNi high-entropy alloy using a novel tensile specimen geometry},

  author       = {Thurston, Keli V. S. and Hohenwarter, Anton and Laplanche, Guillaume and George, Easo P. and Gludovatz, Bernd and Ritchie, Robert O.},

  abstractNote = {Deformation-induced nanoscale twinning is one of the mechanisms responsible for the excellent combination of strength and fracture toughness of the single-phase, face-centered cubic CrMnFeCoNi (Cantor) alloy, especially at cryogenic temperatures. In this work, we use a novel, modified dogbone geometry that allows the sampling of varying stress and strain regions within a single tensile specimen to characterize the onset of twinning in CrMnFeCoNi at 293 K, 198 K and 77 K. Electron backscatter diffraction (EBSD) and backscattered electron (BSE) imaging revealed the presence of deformation nano-twins in regions of the samples that had experienced plastic strains of ~25% at 293 K, ~16% at 198 K, and ~8% at 77 K, which are similar to the threshold strains described by Laplanche et al. (Acta Mater. 118, 2016, 152–163). From these strains we estimate that the critical tensile stress for the onset of twinning in this alloy is on the order of 750 MPa.},

  doi          = {10.1016/j.intermet.2019.04.012},

  journal      = {Intermetallics},

  number       = C,

  volume       = 110,

  place        = {United States},

  year         = {Thu May 09 00:00:00 EDT 2019},

  month        = {Thu May 09 00:00:00 EDT 2019}

}

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