TY - JOUR
T1 - Plastic deformation of single crystals of the equiatomic Cr−Mn−Fe−Co−Ni high-entropy alloy in tension and compression from 10 K to 1273 K
AU - Kawamura, Marino
AU - Asakura, Makoto
AU - Okamoto, Norihiko L.
AU - Kishida, Kyosuke
AU - Inui, Haruyuki
AU - George, Easo P.
N1 - Funding Information:
This work was supported by Grants-in-Aid for Scientific Research on Innovative Areas on High Entropy Alloys through the grant number JP18H05450 and JP18H05451 , and in part by JSPS KAKENHI grant numbers JP18H01735 , JP18H05478 , JP19H00824 and by the Elements Strategy Initiative for Structural Materials (ESISM) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan grant number JPMXP0112101000 . EPG is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division and acknowledges the JSPS Fellowship for senior scientists that enabled a 2-month stay in HI's group at Kyoto University during which this work was conceived. The authors wish to thank Drs. Takashi Fukuda and Tomoyuki Kakeshita of Osaka University, Japan for providing their single-crystal growth facility.
Funding Information:
This manuscript has been co-authored by UT-Battelle, LLC under Contract No. DE-AC05–00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). This work was supported by Grants-in-Aid for Scientific Research on Innovative Areas on High Entropy Alloys through the grant number JP18H05450 and JP18H05451, and in part by JSPS KAKENHI grant numbers JP18H01735, JP18H05478, JP19H00824 and by the Elements Strategy Initiative for Structural Materials (ESISM) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan grant number JPMXP0112101000. EPG is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division and acknowledges the JSPS Fellowship for senior scientists that enabled a 2-month stay in HI's group at Kyoto University during which this work was conceived. The authors wish to thank Drs. Takashi Fukuda and Tomoyuki Kakeshita of Osaka University, Japan for providing their single-crystal growth facility.
Funding Information:
This manuscript has been co-authored by UT-Battelle, LLC under Contract No. DE-AC05–00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Publisher Copyright:
© 2020
PY - 2021/1/15
Y1 - 2021/1/15
N2 - The plastic deformation behavior of single crystals of the quinary, equiatomic Cr−Mn−Fe−Co−Ni high-entropy alloy (HEA) with the face-centered cubic structure has been investigated in tension and compression as a function of crystal orientation and temperature from 10 K to 1373 K. The critical resolved shear stress (CRSS) for {111}<110> slip at room temperature is 42−45 MPa. It does not depend much on crystal orientation (i.e., the Schmid law holds true) and the sense (tension vs. compression) of the applied load. The CRSS for {111}<110> slip increases with the decrease in temperature, without showing any significant inertia effects at cryogenic temperatures below 77 K. Extrapolation from the measured yield stresses down to 10 K yields a CRSS value at 0 K of 168 MPa. At cryogenic temperatures, the measured strain-rate sensitivity of flow stress is consistent with a very small activation volume. The concept of stress equivalence holds true both for the temperature dependence of CRSS and the stress dependence of activation volume, indicating that solid-solution hardening is the major strengthening mechanism. Deformation twinning occurs at 77 K but not at room temperature, resulting in higher tensile elongation to failure at 77 K than at room temperature. Deformation twinning at 77 K occurs at a shear stress of 378 MPa on conjugate (1¯1¯1) planes in the form of Lüders deformation after large plastic strain (about 85%) achieved by the stage I (easy glide) and stage II (linear work-hardening) deformation.
AB - The plastic deformation behavior of single crystals of the quinary, equiatomic Cr−Mn−Fe−Co−Ni high-entropy alloy (HEA) with the face-centered cubic structure has been investigated in tension and compression as a function of crystal orientation and temperature from 10 K to 1373 K. The critical resolved shear stress (CRSS) for {111}<110> slip at room temperature is 42−45 MPa. It does not depend much on crystal orientation (i.e., the Schmid law holds true) and the sense (tension vs. compression) of the applied load. The CRSS for {111}<110> slip increases with the decrease in temperature, without showing any significant inertia effects at cryogenic temperatures below 77 K. Extrapolation from the measured yield stresses down to 10 K yields a CRSS value at 0 K of 168 MPa. At cryogenic temperatures, the measured strain-rate sensitivity of flow stress is consistent with a very small activation volume. The concept of stress equivalence holds true both for the temperature dependence of CRSS and the stress dependence of activation volume, indicating that solid-solution hardening is the major strengthening mechanism. Deformation twinning occurs at 77 K but not at room temperature, resulting in higher tensile elongation to failure at 77 K than at room temperature. Deformation twinning at 77 K occurs at a shear stress of 378 MPa on conjugate (1¯1¯1) planes in the form of Lüders deformation after large plastic strain (about 85%) achieved by the stage I (easy glide) and stage II (linear work-hardening) deformation.
KW - Critical resolved shear stress
KW - Single crystals
KW - Strain-rate sensitivity
KW - Tensile and compressive mechanical properties
KW - Twinning
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U2 - 10.1016/j.actamat.2020.10.073
DO - 10.1016/j.actamat.2020.10.073
M3 - Article
AN - SCOPUS:85096222794
VL - 203
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
M1 - 116454
ER -