| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
High-pressure Phase Transformation in Zirconium: Role of Slip Dislocations and Twinning |
| Author(s) |
Arul Kumar Mariyappan, T Yu, Y Wang, R McCabe, C Tome, Laurent Capolungo |
| On-Site Speaker (Planned) |
Arul Kumar Mariyappan |
| Abstract Scope |
Group-IV transition hexagonal-close-packed (HCP) α-phase Zr is widely used in nuclear and chemical industries. With an increase in pressure, the HCP α-phase transforms into a simple-hexagonal ω-phase. This ω-phase is significantly stiffer, more brittle, and more plastically anisotropic than the α-phase. Understanding the α-to-ω transformation is relevant for enhancing the applicability of transition metals. In this work, using X-ray synchrotron experiments, the role of slip-dislocations and twinning on the α-to-ω transformation is investigated. The high-pressure experiments reveal that pre-existing prismatic<a> dislocations and tensile-twins favor the transformation compared to pyramidal<c+a> dislocations and compression-twins. Further, neutron diffraction-based in-situ pressure-hold experiments are performed to understand the transformation kinetics. These experiments find that the transformation rate increases with the holding pressure. Detailed analysis of the experimental data in connection with the Avrami equation finds that the nucleation and migration rates of slip dislocations increase with the imposed pressure and thus accelerate the α-to-ω transformation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Characterization, Other |