About this Abstract |
Meeting |
2nd World Congress on High Entropy Alloys (HEA 2021)
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Symposium
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2nd World Congress on High Entropy Alloys (HEA 2021)
|
Presentation Title |
Microstructural and Mechanical Evolutions of a Ti-V-Nb-Ta Refractory High-entropy Alloy during Thermal Aging |
Author(s) |
Junliang Liu, Bo-Shiuan Li, Hazel Gardner, Guanze He, David Armstrong, Angus Wilkinson |
On-Site Speaker (Planned) |
Junliang Liu |
Abstract Scope |
The equiatomic Ti-V-Nb-Ta is one of the few single-phase BCC refractory high-entropy alloys (RHEA) which exhibits considerable potentials for applications in fast reactor environments. In this study, we have used a combination of state-of-the-art microscopes (Transmission Electron Microscopy, Transmission Kikuchi Diffraction, Electron Energy Loss Spectroscopy and Atom Probe Tomography) and nano-indentation technique to characterise the microstructural and mechanical evolutions of a Ti-V-Nb-Ta RHEA during diffusion annealing and thermal aging. Microstructural analysis shows the homogenisation of the as-cast alloy can be achieved when it underwent diffusion annealing at 1500°C for 72 hrs, with an increase of the hardness from 4.1 GPa to 5.1 GPa. However, the hardness of the homogenised alloy was observed to decrease with increasing aging time at 700°C. Based on the microstructural and microchemical analysis, a mechanism describing the age softening phenomenon via oxygen-assisted phase segregation in the Ti-V-Nb-Ta RHEA was proposed. |
Proceedings Inclusion? |
Undecided |