| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Multi-Principal Element Alloys II
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| Presentation Title |
Evolution of Hierarchical Nanotwins in the Annealed Mn-free FeCoNiCr High-entropy Alloy Subjected to Ex-situ Tensile Deformation at a Cryogenic Temperature |
| Author(s) |
Tsai-Fu Chung, Ching-Wen Yeh, Chih-Yuan Chen, Chien-Nan Hsiao, Cheng-Si Tsao, Jer-Ren Yang |
| On-Site Speaker (Planned) |
Tsai-Fu Chung |
| Abstract Scope |
In this work, the microstructures of annealed Mn-free Fe27Co24Ni23Cr26 high-entropy alloy were examined at different stages of the tensile deformation at -150 °C. First, boundaries of the primary and secondary deformation nanotwins can confine the movement of dislocations. In the matrix of grain, the intersected region of the deformation nanotwins easily intrigues the formation of tertiary deformation nanotwins. As the flow stress increases, the pre-existing annealing-nanotwins were first refined by the primary deformation nanotwins and further divided by the secondary deformation nanotwins, bringing about dynamic grain refinement. At the ultimate strength stage, the intersected deformation nanotwins within the matrix of annealing-nanotwins have been found. Moreover, the matrix of secondary deformation nanotwins is significantly refined by tertiary deformation nanotwins. It is suggested that twinning occurs first in the matrices of grains, enhancing the initial work-hardening; subsequent the hierarchical twinning takes place in pre-existing annealing-nanotwins, thereby promoting further straining. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Mechanical Properties, |