Abstract
Refractory high-entropy alloys have recently emerged as promising candidates for high-temperature structural applications. However, their performance is compromised by the trade-off required between strength and ductility. Here, a novel W30Ta5(FeNi)65 refractory high-entropy alloy with an outstanding combination of strength and plasticity at both room and elevated temperatures is designed, based on the multi-phase transitions design strategy. The alloy comprises a body-centered cubic dendrite phase, a topologically close-packed μ rhombohedral phase, and a high-density coherent nano-precipitate γ″ phase with the D022structure (Ni3Ta type) embedded in a continuous face-centered cubic matrix. Owing to precipitation strengthening of D022, the yield stress of the alloy is determined as high as 1450 MPa, which is a significant improvement (∼100%) in comparison with the D022-free alloy, without a loss of ductility. This alloy exhibits an excellent high-temperature strength, with the yield strengths of 1300 MPa at 600 °C and 320 MPa at 1000 °C. Detailed microstructural characterization using transmission electron microscopy, high-angle annular dark-field imaging, and three-dimensional atom probe tomography analyses indicated that this superior strength–plasticity combination stems from the synergy of a multiple-phase structure. These results provide a new insight into the design of RHEAs and other advanced alloys.
Original language | English |
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Pages (from-to) | 85-95 |
Number of pages | 11 |
Journal | Journal of Materials Science and Technology |
Volume | 177 |
DOIs | |
Publication status | Published - 1 Apr 2024 |
Keywords
- D0 superlattice
- Multi-phase structure
- Precipitation strengthening
- Refractory high entropy alloy
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics
- Metals and Alloys
- Materials Chemistry