Local segregation versus irradiation effects in high-entropy alloys

Steady-state conditions in a driven system

Leonie Koch, Fredric Granberg, Tobias Brink, Daniel Utt, Karsten Albe, Flyura Djurabekova, Kai Nordlund

Research output: Contribution to journalArticleScientificpeer-review

Abstract

We study order transitions and defect formation in a model high-entropy alloy (CuNiCoFe) under ion irradiation by means of molecular dynamics simulations. Using a hybrid Monte-Carlo/molecular dynamics scheme, a model alloy is generated which is thermodynamically stabilized by configurational entropy at elevated temperatures, but partly decomposes at lower temperatures by copper precipitation. Both the high-entropy and the multiphase sample are then subjected to simulated particle irradiation. The damage accumulation is analyzed and compared to an elemental Ni reference system. The results reveal that the high-entropy alloy—independent of the initial configuration—installs a certain fraction of short-range order even under particle irradiation. Moreover, the results provide evidence that defect accumulation is reduced in the high-entropy alloy. This is because the reduced mobility of point defects leads to a steady state of defect creation and annihilation. The lattice defects generated by irradiation are shown to act as sinks for Cu segregation.
Original languageEnglish
Article number105106
JournalJournal of Applied Physics
Volume122
Issue number10
Number of pages10
ISSN0021-8979
DOIs
Publication statusPublished - 14 Sep 2017
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 114 Physical sciences

Cite this

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title = "Local segregation versus irradiation effects in high-entropy alloys: Steady-state conditions in a driven system",
abstract = "We study order transitions and defect formation in a model high-entropy alloy (CuNiCoFe) under ion irradiation by means of molecular dynamics simulations. Using a hybrid Monte-Carlo/molecular dynamics scheme, a model alloy is generated which is thermodynamically stabilized by configurational entropy at elevated temperatures, but partly decomposes at lower temperatures by copper precipitation. Both the high-entropy and the multiphase sample are then subjected to simulated particle irradiation. The damage accumulation is analyzed and compared to an elemental Ni reference system. The results reveal that the high-entropy alloy—independent of the initial configuration—installs a certain fraction of short-range order even under particle irradiation. Moreover, the results provide evidence that defect accumulation is reduced in the high-entropy alloy. This is because the reduced mobility of point defects leads to a steady state of defect creation and annihilation. The lattice defects generated by irradiation are shown to act as sinks for Cu segregation.",
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Local segregation versus irradiation effects in high-entropy alloys : Steady-state conditions in a driven system. / Koch, Leonie; Granberg, Fredric; Brink, Tobias; Utt, Daniel; Albe, Karsten; Djurabekova, Flyura; Nordlund, Kai.

In: Journal of Applied Physics, Vol. 122, No. 10, 105106 , 14.09.2017.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Local segregation versus irradiation effects in high-entropy alloys

T2 - Steady-state conditions in a driven system

AU - Koch, Leonie

AU - Granberg, Fredric

AU - Brink, Tobias

AU - Utt, Daniel

AU - Albe, Karsten

AU - Djurabekova, Flyura

AU - Nordlund, Kai

PY - 2017/9/14

Y1 - 2017/9/14

N2 - We study order transitions and defect formation in a model high-entropy alloy (CuNiCoFe) under ion irradiation by means of molecular dynamics simulations. Using a hybrid Monte-Carlo/molecular dynamics scheme, a model alloy is generated which is thermodynamically stabilized by configurational entropy at elevated temperatures, but partly decomposes at lower temperatures by copper precipitation. Both the high-entropy and the multiphase sample are then subjected to simulated particle irradiation. The damage accumulation is analyzed and compared to an elemental Ni reference system. The results reveal that the high-entropy alloy—independent of the initial configuration—installs a certain fraction of short-range order even under particle irradiation. Moreover, the results provide evidence that defect accumulation is reduced in the high-entropy alloy. This is because the reduced mobility of point defects leads to a steady state of defect creation and annihilation. The lattice defects generated by irradiation are shown to act as sinks for Cu segregation.

AB - We study order transitions and defect formation in a model high-entropy alloy (CuNiCoFe) under ion irradiation by means of molecular dynamics simulations. Using a hybrid Monte-Carlo/molecular dynamics scheme, a model alloy is generated which is thermodynamically stabilized by configurational entropy at elevated temperatures, but partly decomposes at lower temperatures by copper precipitation. Both the high-entropy and the multiphase sample are then subjected to simulated particle irradiation. The damage accumulation is analyzed and compared to an elemental Ni reference system. The results reveal that the high-entropy alloy—independent of the initial configuration—installs a certain fraction of short-range order even under particle irradiation. Moreover, the results provide evidence that defect accumulation is reduced in the high-entropy alloy. This is because the reduced mobility of point defects leads to a steady state of defect creation and annihilation. The lattice defects generated by irradiation are shown to act as sinks for Cu segregation.

KW - 114 Physical sciences

U2 - 10.1063/1.4990950

DO - 10.1063/1.4990950

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JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

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ER -