Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization
Abstract
:1. Introduction
2. Materials and Methods
2.1. Mechanical Alloying and Sintering
2.2. Characterization
3. Results
3.1. Phase Prediction
3.2. Microstructural and Morphological Characterization of the Powders
3.3. Microstructural Characterization of Refractory High-Entropy Alloy Bulks
3.4. Mechanical Properties
4. Discussion
4.1. Influence of the Milling Time on the Properties of the Powders
4.2. Characterization of the RHEA Bulks
4.3. Mechanical Properties
5. Conclusions
- Longer milling times used for powder preparation for mechanical alloying produce more refined microstructures in the bulks.
- Powder homogeneity increases with the milling time, while a sufficient state is achieved after 10h of milling.
- Longer milling times lead to an increase in the total amount of oxides, carbides dispersed and iron in the matrix, compared to the non-milled state due to contamination.
- Carbide formation in the sintered RHEAs was observed after 3 h of powder milling, while oxides were detected after 30 h despite the fact that the fabrication was entirely performed using protective atmospheres. These could potentially positively contribute to the strength of the material.
- The extent of contamination is a function of the powder milling time, positively increasing with increasing milling time.
- Milling for 10 h provides the best balance between sufficient microstructural refinement, homogeneity, high hardness and minimal contamination.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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1 h | 3 h | 5 h | |||||||
---|---|---|---|---|---|---|---|---|---|
a [Å] | c [Å] | wt.% | a [Å] | c [Å] | wt.% | a [Å] | c [Å] | wt.% | |
BCC1 | 3.30 | - | 56.2 | 3.31 | - | 58.6 | 3.31 | - | 87.7 |
BCC2 | 3.03 | - | 2.9 | 3.03 | - | 3.3 | 3.03 | - | 0.4 |
HCP1 | 3.23 | 5.14 | 23.1 | 3.24 | 5.14 | 20.7 | 3.24 | 5.13 | 10.8 |
HCP2 | 2.95 | 4.68 | 17.8 | 2.95 | 4.68 | 17.4 | 2.94 | 4.68 | 1.1 |
10 h | 20 h | 30 h | |||||||
BCC1 | 3.31 | - | 94.3 | 3.31 | - | 100.0 | 3.32 | - | 100.0 |
HCP1 | 3.24 | 5.13 | 4.9 | - | - | - | - | - | - |
HCP2 | 2.95 | 4.68 | 0.8 | - | - | - | - | - | - |
40 h | 50 h | ||||||||
BCC1 | 3.32 | - | 100.0 | 3.33 | - | 100.0 |
BCC1 | BCC2 | ZrC (Fm-3m) | TiO2 (I41/amd) | ||||||
---|---|---|---|---|---|---|---|---|---|
a | wt.% | A | wt.% | a | wt.% | a | c | wt.% | |
Bulk 3 h | 3.32 | 98.0 | - | - | 4.62 | 2.0 | - | - | - |
Bulk 10 h | 3.32 | 52.7 | 3.30 | 43.3 | 4.62 | 4.0 | - | - | - |
Bulk 30 h | 3.32 | 74.6 | 3.29 | 20.7 | 4.61 | 4.3 | 3.80 | 9.56 | 0.4 |
Bulk 50 h | 3.31 | 88.7 | - | - | 4.60 | 6.8 | 3.79 | 9.55 | 4.5 |
(at.%) | Bulk 3 h (BCC1) | Bulk 10 h (BCC1) | Bulk 30 h (BCC1) | Bulk 50 h (BCC1) |
---|---|---|---|---|
Al | 5.4 ± 0.2 | 6.1 ± 0.1 | 6.0 ± 0.2 | 6.1 ± 0.1 |
Ti | 29.4 ± 1.2 | 31.0 ± 0.2 | 30.3 ± 0.1 | 29.8 ± 0.3 |
V | 3.9 ± 0.6 | 4.0 ± 0.4 | 4.5 ± 0.1 | 4.8 ± 0.1 |
Zr | 18.9 ± 1.2 | 20.5 ± 0.3 | 19.3 ± 0.3 | 20.5 ± 0.1 |
Nb | 23.0 ± 0.8 | 20.2 ± 0.1 | 19.9 ± 0.1 | 19.7 ± 0.3 |
Ta | 19.4 ± 1.2 | 18.3 ± 0.1 | 18.3 ± 0.1 | 18.0 ± 0.3 |
Fe | - | - | 1.8 ± 0.1 | 2.2 ± 0.1 |
Sample | Hardness (HV 0.2) | Elastic Modulus (NHT) (GPa) | Penetration Depth (NHT) (nm) |
---|---|---|---|
Bulk 3 h | 592.9 ± 21.0 | 134.7 ± 1.0 | 911.9 ± 5.2 |
Bulk 10 h | 641.8 ± 9.4 | 136.6 ± 1.2 | 861.3 ± 4.9 |
Bulk 30 h | 670.3 ± 12.3 | 137.2 ± 0.7 | 843.4 ± 6.3 |
Bulk 50 h | 675.7 ± 9.8 | 138.7 ± 0.8 | 842.6 ± 3.6 |
Elastic Modulus (NHT) (GPa) | Elastic Modulus (US) (GPa) | Poisson Ratio (US) [-] | Shear Modulus (US) (GPa) |
---|---|---|---|
136.6 | 136.0 | 0.326 | 53 |
Composition | Vickers Hardness (HV) | Preparation | Reference |
---|---|---|---|
Al0.3NbTa0.8Ti1.5V0.2Zr | 676 | PM—as-sintered: Milling 50 h SPS: 1200 °C—15 min | This work |
W0.7(TaTiCrV)0.3 | 671 | PM—as-sintered: Milling 3 h SPS: 1600 °C—10 min | [21] |
Al0.3NbTa0.8Ti1.5V0.2Zr | 670 | PM—as-sintered: Milling 30 h SPS: 1200 °C—15 min | This work |
Al0.3NbTa0.8Ti1.5V0.2Zr | 642 | PM—as-sintered: Milling 10 h SPS: 1200 °C—15 min | This work |
FeNiCrCo0.3Al0.7 | 624 | PM: as-sintered: Milling 45 h SPS: 1000 °C—8 min | [36] |
Al0.3NbTa0.8Ti1.5V0.2Zr | 593 | PM—as-sintered: Milling 3 h SPS: 1200 °C—15 min | This work |
HfTaTiNbZr | 592 | PM—as-sintered: Milling 1 h SPS: 1300 °C—10 min | [1,37] |
Al0.75FeNiCrCo | 577 | PM—as-sintered: Milling 45 h SPS: 1000 °C—8 min | [38] |
HfNbTaTiVZr | 558 | As-cast (Arc melting) | [1,39] |
MoNbTaVW | 535 | As-cast (Arc melting) | [40] |
W0.9(TaTiCrV)0.1 | 480 | PM—as-sintered: Milling 3 h SPS: 1600 °C—10 min | [21] |
NbTaTiVW | 447 | As-cast (Arc melting) | [41] |
Al0.6NiFeCr | 431 | PM—as-sintered: Milling 38 h SPS: 1000 °C—1 h | [42] |
HfNbTaTiZr | 390 | As-cast (Arc melting) | [43] |
NbTiVZr | 335 | Annealed (Arc melting) | [1,44] |
NbTaTiV | 298 | As-cast (Arc melting) | [41] |
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Moravcikova-Gouvea, L.; Moravcik, I.; Pouchly, V.; Kovacova, Z.; Kitzmantel, M.; Neubauer, E.; Dlouhy, I. Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization. Materials 2021, 14, 5796. https://doi.org/10.3390/ma14195796
Moravcikova-Gouvea L, Moravcik I, Pouchly V, Kovacova Z, Kitzmantel M, Neubauer E, Dlouhy I. Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization. Materials. 2021; 14(19):5796. https://doi.org/10.3390/ma14195796
Chicago/Turabian StyleMoravcikova-Gouvea, Larissa, Igor Moravcik, Vaclav Pouchly, Zuzana Kovacova, Michael Kitzmantel, Erich Neubauer, and Ivo Dlouhy. 2021. "Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization" Materials 14, no. 19: 5796. https://doi.org/10.3390/ma14195796
APA StyleMoravcikova-Gouvea, L., Moravcik, I., Pouchly, V., Kovacova, Z., Kitzmantel, M., Neubauer, E., & Dlouhy, I. (2021). Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization. Materials, 14(19), 5796. https://doi.org/10.3390/ma14195796