Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization
This paper reports the microstructural evolution and mechanical properties of a low-density Al<sub>0.3</sub>NbTa<sub>0.8</sub>Ti<sub>1.5</sub>V<sub>0.2</sub>Zr refractory high-entropy alloy (RHEA) prepared by means of a combination of mechanical alloyi...
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MDPI AG
2021-10-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/19/5796 |
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| author | Larissa Moravcikova-Gouvea Igor Moravcik Vaclav Pouchly Zuzana Kovacova Michael Kitzmantel Erich Neubauer Ivo Dlouhy |
| author_facet | Larissa Moravcikova-Gouvea Igor Moravcik Vaclav Pouchly Zuzana Kovacova Michael Kitzmantel Erich Neubauer Ivo Dlouhy |
| author_sort | Larissa Moravcikova-Gouvea |
| collection | DOAJ |
| description | This paper reports the microstructural evolution and mechanical properties of a low-density Al<sub>0.3</sub>NbTa<sub>0.8</sub>Ti<sub>1.5</sub>V<sub>0.2</sub>Zr refractory high-entropy alloy (RHEA) prepared by means of a combination of mechanical alloying and spark plasma sintering (SPS). Prior to sintering, the morphology, chemical homogeneity and crystal structures of the powders were thoroughly investigated by varying the milling times to find optimal conditions for densification. The sintered bulk RHEAs were produced with diverse feedstock powder conditions. The microstructural development of the materials was analyzed in terms of phase composition and constitution, chemical homogeneity, and crystallographic properties. Hardness and elastic constants also were measured. The calculation of phase diagrams (CALPHAD) was performed to predict the phase changes in the alloy, and the results were compared with the experiments. Milling time seems to play a significant role in the contamination level of the sintered materials. Even though a protective atmosphere was used in the entire manufacturing process, carbide formation was detected in the sintered bulks as early as after 3 h of powder milling. Oxides were observed after 30 h due to wear of the high-carbon steel milling media and SPS consolidation. Ten hours of milling seems sufficient for achieving an optimal equilibrium between microstructural homogeneity and refinement, high hardness and minimal contamination. |
| first_indexed | 2024-03-10T06:56:13Z |
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| id | doaj.art-a034105264ce41d68cef082e9499deb2 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T06:56:13Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-a034105264ce41d68cef082e9499deb22023-11-22T16:27:13ZengMDPI AGMaterials1996-19442021-10-011419579610.3390/ma14195796Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process OptimizationLarissa Moravcikova-Gouvea0Igor Moravcik1Vaclav Pouchly2Zuzana Kovacova3Michael Kitzmantel4Erich Neubauer5Ivo Dlouhy6Institute of Materials Science and Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno, Czech RepublicInstitute of Materials Science and Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno, Czech RepublicCentral European Institute of Technology (CEITEC), Purkynova 123, 61200 Brno, Czech RepublicRHP-Technology GmbH, Forschungs- und Technologiezentrum, 2444 Seibersdorf, AustriaRHP-Technology GmbH, Forschungs- und Technologiezentrum, 2444 Seibersdorf, AustriaRHP-Technology GmbH, Forschungs- und Technologiezentrum, 2444 Seibersdorf, AustriaInstitute of Materials Science and Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno, Czech RepublicThis paper reports the microstructural evolution and mechanical properties of a low-density Al<sub>0.3</sub>NbTa<sub>0.8</sub>Ti<sub>1.5</sub>V<sub>0.2</sub>Zr refractory high-entropy alloy (RHEA) prepared by means of a combination of mechanical alloying and spark plasma sintering (SPS). Prior to sintering, the morphology, chemical homogeneity and crystal structures of the powders were thoroughly investigated by varying the milling times to find optimal conditions for densification. The sintered bulk RHEAs were produced with diverse feedstock powder conditions. The microstructural development of the materials was analyzed in terms of phase composition and constitution, chemical homogeneity, and crystallographic properties. Hardness and elastic constants also were measured. The calculation of phase diagrams (CALPHAD) was performed to predict the phase changes in the alloy, and the results were compared with the experiments. Milling time seems to play a significant role in the contamination level of the sintered materials. Even though a protective atmosphere was used in the entire manufacturing process, carbide formation was detected in the sintered bulks as early as after 3 h of powder milling. Oxides were observed after 30 h due to wear of the high-carbon steel milling media and SPS consolidation. Ten hours of milling seems sufficient for achieving an optimal equilibrium between microstructural homogeneity and refinement, high hardness and minimal contamination.https://www.mdpi.com/1996-1944/14/19/5796refractory complex concentrated alloysmicrostructuresmechanical alloyingspark plasma sinteringmechanical properties |
| spellingShingle | Larissa Moravcikova-Gouvea Igor Moravcik Vaclav Pouchly Zuzana Kovacova Michael Kitzmantel Erich Neubauer Ivo Dlouhy Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization Materials refractory complex concentrated alloys microstructures mechanical alloying spark plasma sintering mechanical properties |
| title | Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization |
| title_full | Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization |
| title_fullStr | Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization |
| title_full_unstemmed | Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization |
| title_short | Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization |
| title_sort | tailoring a refractory high entropy alloy by powder metallurgy process optimization |
| topic | refractory complex concentrated alloys microstructures mechanical alloying spark plasma sintering mechanical properties |
| url | https://www.mdpi.com/1996-1944/14/19/5796 |
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