Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy
As one of refractory high-entropy alloys (RHEAs), VNbMoTaW is considered to be a promising candidate for elevated-temperature application. However, its creep behavior is rarely reported. In the present work, the compressive creep behaviors of an equiatomic VNbMoTaW RHEA with a grain size of 138 ± 36...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-05-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423008359 |
| _version_ | 1827920204610404352 |
|---|---|
| author | Xun Shen Shengwei Xin Shuaijun Ding Yu He Weiguo Dong Baoru Sun Xuecheng Cai Tongde Shen |
| author_facet | Xun Shen Shengwei Xin Shuaijun Ding Yu He Weiguo Dong Baoru Sun Xuecheng Cai Tongde Shen |
| author_sort | Xun Shen |
| collection | DOAJ |
| description | As one of refractory high-entropy alloys (RHEAs), VNbMoTaW is considered to be a promising candidate for elevated-temperature application. However, its creep behavior is rarely reported. In the present work, the compressive creep behaviors of an equiatomic VNbMoTaW RHEA with a grain size of 138 ± 36 μm were well studied over an intermediate temperature range (973–1173 K) and under high applied stress (130–520 MPa). The stress exponent of the alloy is found to remain stable (∼1) at relatively low temperatures (973–1073 K), whereas a stress-dependent transition behavior occurs at high temperatures (1123–1173 K), i.e., the stress exponent of the alloy changes from ∼1 in the low stress region (130–390 MPa) to ∼ 4 in the high stress region (390–520 MPa). Meanwhile, the creep activation energy increases from 139 to 156 kJ mol−1 at low temperatures to 307–373 kJ mol−1 at high temperatures. The low stress exponent and low activation energy at low temperatures suggest that the creep is controlled by dislocation pipe diffusion. The low stress exponent and relatively high activation energy in the high-temperature low-stress region suggest that the creep is controlled by lattice diffusion. In the high-temperature high-stress region, the prevalent dislocations detected by the post-mortem microstructural observation, the high stress exponent, and high activation energy suggest that the creep deformation is controlled by a lattice diffusion mediated dislocation climb process. These findings provide a fundamental understanding of the creep behavior and deformation mechanism of VNbMoTaW, which can be applied to design advanced creep-resistant RHEAs. |
| first_indexed | 2024-03-13T04:09:16Z |
| format | Article |
| id | doaj.art-5792ae6421c643a584a60e769b389f3a |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-13T04:09:16Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-5792ae6421c643a584a60e769b389f3a2023-06-21T06:56:54ZengElsevierJournal of Materials Research and Technology2238-78542023-05-012447964807Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloyXun Shen0Shengwei Xin1Shuaijun Ding2Yu He3Weiguo Dong4Baoru Sun5Xuecheng Cai6Tongde Shen7Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaClean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of China; Corresponding author.Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaClean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaClean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaClean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaDepartment of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, HongKong, China; Corresponding author.Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of ChinaAs one of refractory high-entropy alloys (RHEAs), VNbMoTaW is considered to be a promising candidate for elevated-temperature application. However, its creep behavior is rarely reported. In the present work, the compressive creep behaviors of an equiatomic VNbMoTaW RHEA with a grain size of 138 ± 36 μm were well studied over an intermediate temperature range (973–1173 K) and under high applied stress (130–520 MPa). The stress exponent of the alloy is found to remain stable (∼1) at relatively low temperatures (973–1073 K), whereas a stress-dependent transition behavior occurs at high temperatures (1123–1173 K), i.e., the stress exponent of the alloy changes from ∼1 in the low stress region (130–390 MPa) to ∼ 4 in the high stress region (390–520 MPa). Meanwhile, the creep activation energy increases from 139 to 156 kJ mol−1 at low temperatures to 307–373 kJ mol−1 at high temperatures. The low stress exponent and low activation energy at low temperatures suggest that the creep is controlled by dislocation pipe diffusion. The low stress exponent and relatively high activation energy in the high-temperature low-stress region suggest that the creep is controlled by lattice diffusion. In the high-temperature high-stress region, the prevalent dislocations detected by the post-mortem microstructural observation, the high stress exponent, and high activation energy suggest that the creep deformation is controlled by a lattice diffusion mediated dislocation climb process. These findings provide a fundamental understanding of the creep behavior and deformation mechanism of VNbMoTaW, which can be applied to design advanced creep-resistant RHEAs.http://www.sciencedirect.com/science/article/pii/S2238785423008359VNbMoTaWRefractory high-entropy alloyCreep behaviorsStress-dependent transition behaviorLattice diffusionDislocation climb |
| spellingShingle | Xun Shen Shengwei Xin Shuaijun Ding Yu He Weiguo Dong Baoru Sun Xuecheng Cai Tongde Shen Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy Journal of Materials Research and Technology VNbMoTaW Refractory high-entropy alloy Creep behaviors Stress-dependent transition behavior Lattice diffusion Dislocation climb |
| title | Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy |
| title_full | Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy |
| title_fullStr | Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy |
| title_full_unstemmed | Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy |
| title_short | Intermediate-temperature creep behaviors of an equiatomic VNbMoTaW refractory high-entropy alloy |
| title_sort | intermediate temperature creep behaviors of an equiatomic vnbmotaw refractory high entropy alloy |
| topic | VNbMoTaW Refractory high-entropy alloy Creep behaviors Stress-dependent transition behavior Lattice diffusion Dislocation climb |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423008359 |
| work_keys_str_mv | AT xunshen intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT shengweixin intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT shuaijunding intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT yuhe intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT weiguodong intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT baorusun intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT xuechengcai intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy AT tongdeshen intermediatetemperaturecreepbehaviorsofanequiatomicvnbmotawrefractoryhighentropyalloy |