Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners
To investigate the microstructure evolution and dynamic deformation behavior of a CoCrNi medium entropy alloy under an ultrahigh explosive loading rate, CoCrNi-shaped charged liners were fabricated and fired into steel targets. Targets with residual jet fragments were recovered for detailed microstr...
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MDPI AG
2022-05-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/12/5/811 |
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| author | Jian Chen Tian-Wei Liu Fu-Hua Cao Hai-Ying Wang Yan Chen Lan-Hong Dai |
| author_facet | Jian Chen Tian-Wei Liu Fu-Hua Cao Hai-Ying Wang Yan Chen Lan-Hong Dai |
| author_sort | Jian Chen |
| collection | DOAJ |
| description | To investigate the microstructure evolution and dynamic deformation behavior of a CoCrNi medium entropy alloy under an ultrahigh explosive loading rate, CoCrNi-shaped charged liners were fabricated and fired into steel targets. Targets with residual jet fragments were recovered for detailed microstructural analysis using scanning electrical microscopy, X-ray diffraction, electron backscattered diffraction, and transmission electron microscopy. The results indicate that the grain size was reduced by more than 3 times and grains were found to be equiaxed in the residual jet, which indicates that dynamic recrystallization (DRX) occurred during this extremely high strain rate and large plastic deformation. Furthermore, the content of Cr element in CoCrNi at the grain boundaries increased significantly after detonation deformation. The reduced grain sizes are believed to reduce the bulk diffusion path of Cr from grain interior into grain boundaries with the support of sufficient energy provided by the ultrahigh temperature. The enrichment of Cr at grain boundaries promotes the formation of nanosized Cr-rich precipitates with body-centered cubic (BCC) structures, which were found to be widely distributed along grain boundaries in the residual jet. These precipitates were considered obstacles for grain boundary movement and promotion of crack initiation along the grain boundaries, which might cause ductility loss of the CoCrNi-shaped charge jet and loss of penetration capability. |
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| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T03:25:09Z |
| publishDate | 2022-05-01 |
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| spelling | doaj.art-80686b6d8d944a42a5f5d165ad2ea7e72023-11-23T12:09:44ZengMDPI AGMetals2075-47012022-05-0112581110.3390/met12050811Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge LinersJian Chen0Tian-Wei Liu1Fu-Hua Cao2Hai-Ying Wang3Yan Chen4Lan-Hong Dai5State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaTo investigate the microstructure evolution and dynamic deformation behavior of a CoCrNi medium entropy alloy under an ultrahigh explosive loading rate, CoCrNi-shaped charged liners were fabricated and fired into steel targets. Targets with residual jet fragments were recovered for detailed microstructural analysis using scanning electrical microscopy, X-ray diffraction, electron backscattered diffraction, and transmission electron microscopy. The results indicate that the grain size was reduced by more than 3 times and grains were found to be equiaxed in the residual jet, which indicates that dynamic recrystallization (DRX) occurred during this extremely high strain rate and large plastic deformation. Furthermore, the content of Cr element in CoCrNi at the grain boundaries increased significantly after detonation deformation. The reduced grain sizes are believed to reduce the bulk diffusion path of Cr from grain interior into grain boundaries with the support of sufficient energy provided by the ultrahigh temperature. The enrichment of Cr at grain boundaries promotes the formation of nanosized Cr-rich precipitates with body-centered cubic (BCC) structures, which were found to be widely distributed along grain boundaries in the residual jet. These precipitates were considered obstacles for grain boundary movement and promotion of crack initiation along the grain boundaries, which might cause ductility loss of the CoCrNi-shaped charge jet and loss of penetration capability.https://www.mdpi.com/2075-4701/12/5/811shaped charge linerCoCrNiultrahigh strain ratenanosized precipitation |
| spellingShingle | Jian Chen Tian-Wei Liu Fu-Hua Cao Hai-Ying Wang Yan Chen Lan-Hong Dai Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners Metals shaped charge liner CoCrNi ultrahigh strain rate nanosized precipitation |
| title | Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners |
| title_full | Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners |
| title_fullStr | Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners |
| title_full_unstemmed | Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners |
| title_short | Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners |
| title_sort | deformation behavior and microstructure evolution of cocrni medium entropy alloy shaped charge liners |
| topic | shaped charge liner CoCrNi ultrahigh strain rate nanosized precipitation |
| url | https://www.mdpi.com/2075-4701/12/5/811 |
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