Details
| Original language | English |
|---|---|
| Article number | 063202 |
| Journal | Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films |
| Volume | 43 |
| Issue number | 6 |
| Early online date | 23 Sept 2025 |
| Publication status | Published - Dec 2025 |
Abstract
Refractory high entropy alloys (RHEAs) consisting of high melting point elements, such as Hf, Mo, Nb, Ta, Ti, Mo, and Zr, have shown promising mechanical properties and phase stability at elevated temperatures and, thus, received increasing attention over the last two decades. In the present study, employing experimental and computational methods, the microstructures and mechanical properties of seven different RHEAs, namely, Hf16.6Nb16.6Ta16.6Ti50 (HEA1), HfNbTaTiZr (HEA2), Hf27Nb12Ta10Ti23Zr28 (HEA3), Hf30Nb14Ta10Ti28Zr18 (HEA4), Hf12Nb16Ta35Ti29Zr8 (HEA5), HfMoTaTiZr (HEA6), and MoNbTaTiZr (HEA7) were compared. The nonequilibrium solidification curves calculated using CALPHAD demonstrated that Ta, Nb, and Mo tend to solidify first in the dendrite arms, while the liquid phase becomes enriched with Ti and Zr as solidification progresses. However, depending on the Ta content, Hf is proclaimed to solidify in dendrite arms or interdendritic regions, also supported by thorough experimental characterization. Furthermore, the addition of Mo was demonstrated to increase the hardness and strength of the alloys at the expense of ductility. Finally, HEA1, HEA3, HEA4, and HEA5 demonstrate excellent strength-ductility synergy at room and cryogenic temperatures (−80 °C), expanding their service temperature range, promoting their utility in a variety of industrial applications.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 43, No. 6, 063202, 12.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Comparison on microstructure and mechanical properties of refractory high entropy alloys of the Hf-Mo-Nb-Ta-Ti-Zr system
AU - Ozdemir, Huseyin Can
AU - Hinte, Christian
AU - Nazarahari, Alireza
AU - Barienti, Khemais
AU - Canadinc, Demircan
AU - Maier, Hans Jürgen
N1 - Publisher Copyright: © 2025 Author(s).
PY - 2025/12
Y1 - 2025/12
N2 - Refractory high entropy alloys (RHEAs) consisting of high melting point elements, such as Hf, Mo, Nb, Ta, Ti, Mo, and Zr, have shown promising mechanical properties and phase stability at elevated temperatures and, thus, received increasing attention over the last two decades. In the present study, employing experimental and computational methods, the microstructures and mechanical properties of seven different RHEAs, namely, Hf16.6Nb16.6Ta16.6Ti50 (HEA1), HfNbTaTiZr (HEA2), Hf27Nb12Ta10Ti23Zr28 (HEA3), Hf30Nb14Ta10Ti28Zr18 (HEA4), Hf12Nb16Ta35Ti29Zr8 (HEA5), HfMoTaTiZr (HEA6), and MoNbTaTiZr (HEA7) were compared. The nonequilibrium solidification curves calculated using CALPHAD demonstrated that Ta, Nb, and Mo tend to solidify first in the dendrite arms, while the liquid phase becomes enriched with Ti and Zr as solidification progresses. However, depending on the Ta content, Hf is proclaimed to solidify in dendrite arms or interdendritic regions, also supported by thorough experimental characterization. Furthermore, the addition of Mo was demonstrated to increase the hardness and strength of the alloys at the expense of ductility. Finally, HEA1, HEA3, HEA4, and HEA5 demonstrate excellent strength-ductility synergy at room and cryogenic temperatures (−80 °C), expanding their service temperature range, promoting their utility in a variety of industrial applications.
AB - Refractory high entropy alloys (RHEAs) consisting of high melting point elements, such as Hf, Mo, Nb, Ta, Ti, Mo, and Zr, have shown promising mechanical properties and phase stability at elevated temperatures and, thus, received increasing attention over the last two decades. In the present study, employing experimental and computational methods, the microstructures and mechanical properties of seven different RHEAs, namely, Hf16.6Nb16.6Ta16.6Ti50 (HEA1), HfNbTaTiZr (HEA2), Hf27Nb12Ta10Ti23Zr28 (HEA3), Hf30Nb14Ta10Ti28Zr18 (HEA4), Hf12Nb16Ta35Ti29Zr8 (HEA5), HfMoTaTiZr (HEA6), and MoNbTaTiZr (HEA7) were compared. The nonequilibrium solidification curves calculated using CALPHAD demonstrated that Ta, Nb, and Mo tend to solidify first in the dendrite arms, while the liquid phase becomes enriched with Ti and Zr as solidification progresses. However, depending on the Ta content, Hf is proclaimed to solidify in dendrite arms or interdendritic regions, also supported by thorough experimental characterization. Furthermore, the addition of Mo was demonstrated to increase the hardness and strength of the alloys at the expense of ductility. Finally, HEA1, HEA3, HEA4, and HEA5 demonstrate excellent strength-ductility synergy at room and cryogenic temperatures (−80 °C), expanding their service temperature range, promoting their utility in a variety of industrial applications.
UR - http://www.scopus.com/inward/record.url?scp=105016727753&partnerID=8YFLogxK
U2 - 10.1116/6.0004885
DO - 10.1116/6.0004885
M3 - Article
AN - SCOPUS:105016727753
VL - 43
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
SN - 0734-2101
IS - 6
M1 - 063202
ER -