Ordered nitrogen complexes overcoming strength–ductility trade-off in an additively manufactured high-entropy alloy
| Autor: | Dandan Zhao, Quan Yang, Dawei Wang, Ming Yan, Pei Wang, Mingguang Jiang, Changyong Liu, Dongfeng Diao, Changshi Lao, Zhangwei Chen, Zhiyuan Liu, Yuan Wu, Zhaoping Lu |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Virtual and Physical Prototyping, Vol 15, Iss S1, Pp 532-542 (2020) |
| Druh dokumentu: | article |
| ISSN: | 1745-2759 1745-2767 17452759 |
| DOI: | 10.1080/17452759.2020.1840783 |
| Popis: | Strength and ductility were simultaneously enhanced in the additively manufactured CoCrFeMnNi high-entropy alloy by laser powder bed fusion (LBPF) under reactive N2 atmosphere. It was found that nitrogen atoms picked up during additive manufacturing line-up to form ordered nitrogen complexes (ONCs) in the octahedral interstitial position of the HEA matrix. Dislocation multiplication is then facilitated by the formation of ONCs during LPBF, leading to a higher dislocation density with smaller dislocation cells. Dislocation strengthening, combined with interstitial strengthening, endows the additively manufactured HEA with the yielding strength of 690 MPa, 15% higher than that of the counterparts fabricated under inert atmosphere. More interestingly, the ONCs stimulate dislocation nucleation and engender more heterogeneous microstructure, giving rise to an outstanding ductility of 15.3%, with an increment of 34%. As a result, the strength–ductility trade-off was successfully reversed by the nitrogen doping during LPBF under reactive atmosphere. |
| Databáze: | Directory of Open Access Journals |
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