| Autor: |
Soon Hyung Hong, Taeyeong Kong, Byungchul Kang, Nguyen Huy Dan, Doan Dinh Phuong, Ho Jin Ryu |
| Rok vydání: |
2021 |
| Předmět: |
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| Zdroj: |
International Journal of Refractory Metals and Hard Materials. 100:105636 |
| ISSN: |
0263-4368 |
| DOI: |
10.1016/j.ijrmhm.2021.105636 |
| Popis: |
The effect of boron (B) addition on the microstructure and mechanical properties of a refractory high-entropy alloy (RHEA) was investigated. The Al0.1CrNbVMo RHEA was doped with 0.015 at.% of B by the powder metallurgical process, and its mechanical properties were compared with undoped RHEA. The microstructures of the undoped and doped RHEAs consisted of a single body-centered cubic matrix phase with homogeneously distributed Al2O3 inclusions. The doped B atoms segregated along grain boundaries and did not form any boride phases. Boron segregation at the grain boundaries was characterized by atom-probe tomography. Compared with the undoped RHEA, the B-doped RHEA showed improved yield strength of 2933 MPa (15% improvement) and ductility of 25.9% (26% improvement). Adding B transformed the fracture surface from intergranular to transgranular due to enhanced grain boundary cohesion induced by B segregation, which resulted in improved ductility. Quantitative analysis was conducted on the undoped and doped alloys to investigate the effect of B on yield strength. The improved yield strength resulting from B doping was attributed to the combined effects of Orowan, dislocation, and B interstitial strengthening. This work demonstrates that B doping of RHEAs is a promising way to overcome their limited room temperature ductility, while maintaining excellent strength. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect