Microstructure Evolution and Toughening Mechanism of a Nb-18Si-5HfC Eutectic Alloy Created by Selective Laser Melting
Abstract
:1. Introduction
2. Experimental
2.1. Preparation of Powders and SLM Processing
2.2. Determination of the Phase and Examination of the Microstructure
2.3. Mechanical Properties
3. Results
4. Discussion
4.1. Microstructure Evolution of Nb-18Si-5HfC Alloys during SLM
4.2. Toughening Mechanism of Nb-18Si-5HfC Alloys Prepared by SLM
5. Conclusions
- The dense Nb-18Si-5HfC alloys were successfully prepared by selective laser melting. The ultrafine microstructure modulation was achieved by adjusting the scanning speed from 600 mm/s to 1200 mm/s.
- When the scan speed was higher than 1000 mm/s, the fine diffuse hafnium carbide particles successfully distributed between the eutectic lamella, which resulted in improved indentation fracture toughness.
- The prepared Nb-18Si-5HfC alloy, at a scanning speed 1000 mm/s, had a maximum indentation fracture toughness of 20.7 MPa∙m1/2. The toughening was mainly attributable to the synergistic co-donation of the crack trapping by the refined discontinuous α-Nbss, and the crack deflection of the hafnium carbide particles by the formation of microcracks.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Processing Parameter (mm/s) | a (μm) | l (μm) | c (μm) | Hardness (GPa) | Elastic Modulus (GPa) | Fracture Toughness (MPa·m0.5) |
---|---|---|---|---|---|---|
600 | 20.9 | 10.2 | 41.2 | 4.82 | 123.6 | 7.4 |
800 | 20.9 | 12.1 | 32.9 | 6.48 | 142.9 | 8.6 |
1000 | 20.9 | 3.7 | 24.6 | 9.22 | 160.6 | 20.7 |
1200 | 20.9 | 4.5 | 25.4 | 13.83 | 230.5 | 17.3 |
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Yao, L.; Wang, L.; Song, X.; Cui, R.; Li, B.; Lv, Q.; Luo, L.; Su, Y.; Guo, J.; Fu, H. Microstructure Evolution and Toughening Mechanism of a Nb-18Si-5HfC Eutectic Alloy Created by Selective Laser Melting. Materials 2022, 15, 1190. https://doi.org/10.3390/ma15031190
Yao L, Wang L, Song X, Cui R, Li B, Lv Q, Luo L, Su Y, Guo J, Fu H. Microstructure Evolution and Toughening Mechanism of a Nb-18Si-5HfC Eutectic Alloy Created by Selective Laser Melting. Materials. 2022; 15(3):1190. https://doi.org/10.3390/ma15031190
Chicago/Turabian StyleYao, Longhui, Liang Wang, Xiaojiao Song, Ran Cui, Binqiang Li, Qi Lv, Liangshun Luo, Yanqing Su, Jingjie Guo, and Hengzhi Fu. 2022. "Microstructure Evolution and Toughening Mechanism of a Nb-18Si-5HfC Eutectic Alloy Created by Selective Laser Melting" Materials 15, no. 3: 1190. https://doi.org/10.3390/ma15031190