Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique
In this study, Ni<sub>35</sub>Co<sub>35</sub>Cr<sub>12.6</sub>Al<sub>7.5</sub>Ti<sub>5</sub>Mo<sub>1.68</sub>W<sub>1.39</sub>Nb<sub>0.95</sub>Ta<sub>0.47</sub> high entropy alloy (HEA) was pre...
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MDPI AG
2023-03-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/5/2082 |
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| author | Zhipei Chen Xiaona Ren Peng Wang Jiangxiong Hu Changchun Ge |
| author_facet | Zhipei Chen Xiaona Ren Peng Wang Jiangxiong Hu Changchun Ge |
| author_sort | Zhipei Chen |
| collection | DOAJ |
| description | In this study, Ni<sub>35</sub>Co<sub>35</sub>Cr<sub>12.6</sub>Al<sub>7.5</sub>Ti<sub>5</sub>Mo<sub>1.68</sub>W<sub>1.39</sub>Nb<sub>0.95</sub>Ta<sub>0.47</sub> high entropy alloy (HEA) was prepared using mechanical alloying (MA) and spark plasma sintering (SPS) based on the unique design concept of HEAs and third-generation powder superalloys. The HEA phase formation rules of the alloy system were predicted but need to be verified empirically. The microstructure and phase structure of the HEA powder were investigated at different milling times and speeds, with different process control agents, and with an HEA block sintered at different temperatures. The milling time and speed do not affect the alloying process of the powder and increasing the milling speed reduces the powder particle size. After 50 h of milling with ethanol as PCA, the powder has a dual-phase FCC+BCC structure, and stearic acid as PCA inhibits the powder alloying. When the SPS temperature reaches 950 °C, the HEA transitions from a dual-phase to a single FCC phase structure and, with increasing temperature, the mechanical properties of the alloy gradually improve. When the temperature reaches 1150 °C, the HEA has a density of 7.92 g cm<sup>−3</sup>, a relative density of 98.7%, and a hardness of 1050 HV. The fracture mechanism is one with a typical cleavage, a brittle fracture with a maximum compressive strength of 2363 MPa and no yield point. |
| first_indexed | 2024-03-11T07:18:11Z |
| format | Article |
| id | doaj.art-072d771764b74c9185a07b6d22a6ef71 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T07:18:11Z |
| publishDate | 2023-03-01 |
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| record_format | Article |
| series | Materials |
| spelling | doaj.art-072d771764b74c9185a07b6d22a6ef712023-11-17T08:07:01ZengMDPI AGMaterials1996-19442023-03-01165208210.3390/ma16052082Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS TechniqueZhipei Chen0Xiaona Ren1Peng Wang2Jiangxiong Hu3Changchun Ge4Institute of Powder Metallurgy and Advanced Ceramics, University of Science & Technology Beijing, Beijing 100083, ChinaInstitute of Powder Metallurgy and Advanced Ceramics, University of Science & Technology Beijing, Beijing 100083, ChinaChina Machinery Institute of Advanced Materials (Zhengzhou) Co., Ltd., Zhengzhou 450001, ChinaInstitute of Powder Metallurgy and Advanced Ceramics, University of Science & Technology Beijing, Beijing 100083, ChinaInstitute of Powder Metallurgy and Advanced Ceramics, University of Science & Technology Beijing, Beijing 100083, ChinaIn this study, Ni<sub>35</sub>Co<sub>35</sub>Cr<sub>12.6</sub>Al<sub>7.5</sub>Ti<sub>5</sub>Mo<sub>1.68</sub>W<sub>1.39</sub>Nb<sub>0.95</sub>Ta<sub>0.47</sub> high entropy alloy (HEA) was prepared using mechanical alloying (MA) and spark plasma sintering (SPS) based on the unique design concept of HEAs and third-generation powder superalloys. The HEA phase formation rules of the alloy system were predicted but need to be verified empirically. The microstructure and phase structure of the HEA powder were investigated at different milling times and speeds, with different process control agents, and with an HEA block sintered at different temperatures. The milling time and speed do not affect the alloying process of the powder and increasing the milling speed reduces the powder particle size. After 50 h of milling with ethanol as PCA, the powder has a dual-phase FCC+BCC structure, and stearic acid as PCA inhibits the powder alloying. When the SPS temperature reaches 950 °C, the HEA transitions from a dual-phase to a single FCC phase structure and, with increasing temperature, the mechanical properties of the alloy gradually improve. When the temperature reaches 1150 °C, the HEA has a density of 7.92 g cm<sup>−3</sup>, a relative density of 98.7%, and a hardness of 1050 HV. The fracture mechanism is one with a typical cleavage, a brittle fracture with a maximum compressive strength of 2363 MPa and no yield point.https://www.mdpi.com/1996-1944/16/5/2082high entropy alloymechanical alloyingspark plasma sinteringcomposition designsuperalloy |
| spellingShingle | Zhipei Chen Xiaona Ren Peng Wang Jiangxiong Hu Changchun Ge Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique Materials high entropy alloy mechanical alloying spark plasma sintering composition design superalloy |
| title | Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique |
| title_full | Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique |
| title_fullStr | Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique |
| title_full_unstemmed | Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique |
| title_short | Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique |
| title_sort | microstructure and properties of nicocralti high entropy alloy prepared using ma sps technique |
| topic | high entropy alloy mechanical alloying spark plasma sintering composition design superalloy |
| url | https://www.mdpi.com/1996-1944/16/5/2082 |
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