• Editors' Suggestion
  • Rapid Communication
  • Open Access

Search for vacancies in concentrated solid-solution alloys with fcc crystal structure

L. Resch, M. Luckabauer, N. Helthuis, N. L. Okamoto, T. Ichitsubo, R. Enzinger, W. Sprengel, and R. Würschum
Phys. Rev. Materials 4, 060601(R) – Published 22 June 2020
PDFHTMLExport Citation

Abstract

Single-phase concentrated solid-solution alloys (CSA), i.e., alloys without a principle alloying element but one randomly populated crystal structure, exhibit attractive material properties such as very high ductility at cryogenic temperatures, a gentle decrease of strength with temperature, or an unexpectedly high resistance against irradiation. For clarification of those observations assessment of atomic transport mechanisms including formation and migration of equilibrium point defects is indispensable. Positron annihilation lifetime spectroscopy measurements are performed to quantify the concentration of quenched-in thermal vacancies in fcc CSAs after quenching from temperatures close to their onset of melting. For various alloy compositions the concentration of quenched-in vacancies decreases with increasing entropy of mixing ΔSmix. Whereas alloys with three constituents in nonequimolar fractions (CrFeNi) exhibit vacancy concentrations in the 105 range, the studied alloys with four (CoCrFeNi) and five constituents (CoCrFeMnNi, AlCoCrFeNi) do not show a vacancy-specific positron lifetime. Therefore, the concentration of quenched-in vacancies must be in the range of 106 or less. It can be concluded that there is either only a vanishingly small fraction of vacancies present at temperatures near the onset of melting or the generated vacancies are inherently unstable.

  • Figure
  • Figure
  • Received 25 February 2020
  • Accepted 4 May 2020

DOI:https://doi.org/10.1103/PhysRevMaterials.4.060601

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

L. Resch1,*, M. Luckabauer2, N. Helthuis2, N. L. Okamoto3, T. Ichitsubo3, R. Enzinger1, W. Sprengel1, and R. Würschum1

  • 1Institute of Materials Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
  • 2Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
  • 3Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

  • *Corresponding author: l.resch@tugraz.at

Article Text

Click to Expand

Supplemental Material

Click to Expand

References

Click to Expand
Issue

Vol. 4, Iss. 6 — June 2020

Reuse & Permissions
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Materials

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×