Abstract
An equi-atomic single-fcc-phase CrMnFeCoNi high entropy alloy (HEA) shows much higher tensile properties at cryogenic temperature than at room temperature because of its fcc characteristics and abundant twinning at cryogenic temperature. In order to further improve the cryogenic-temperature tensile properties of single-fcc-phase HEAs, we propose non-equi-atomic Fe-rich VCrMnFeCoNi HEAs, and analyze the strengthening effects of the brittle intermetallic sigma (σ) phase. The σ phase is unintentionally obtained, but favorably shows a pronounced strengthening by its hardness and grain refinement effect due to grain-boundary pinning, which leads to high yield and tensile strengths of 0.76 GPa and 1.23 GPa, respectively, together with good ductility of 54%. This positive utilization of the σ phase is unexpected because its formation has been suppressed in typical HEAs. Our results demonstrate that the present Fe-rich VCrMnFeCoNi design and σ-phase strengthening has potential in high-strength HEA studies.
| Original language | English |
|---|---|
| Pages (from-to) | 403-410 |
| Number of pages | 8 |
| Journal | Materials Science and Engineering A |
| Volume | 724 |
| DOIs | |
| Publication status | Published - 2018 May 2 |
| Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the Future Material Discovery Project of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (MSIP) of Korea ( NRF-2016M3D1A1023383 ) and by Brain Korea 21 PLUS Project for Center for Creative Industrial Materials .
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Cryogenic
- High entropy alloy
- Mechanical property
- Sigma phase
- Thermodynamic calculation
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering