About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Defects and Interfaces: Modeling and Experiments
|
Presentation Title |
Understanding the Interface Strain Induced hcp→bcc Phase Transformation in Nanolaminate Mg |
Author(s) |
Kevin Jacob, Krishna Yaddanapudi, Manish Jain, Sid Pathak |
On-Site Speaker (Planned) |
Kevin Jacob |
Abstract Scope |
We tackle some fundamental questions, originally suggested by the late Dr. Richard(Dick) Hoagland, related to the hcp-to-bcc pseudomorphic phase transformation of Mg in Nb/Mg nanolaminates. Interest in pseudomorphic bcc Mg stems from its unique mechanical properties, such as a 50% improvement in strength and 2X ductility as compared to traditional hcp Mg. However critical questions remain, such as the difference between the experimentally observed 7-8 nm critical layer thickness for stabilizing the pseudomorphic bcc Mg phase vs. 4.2 nm from DFT, or 5 nm from thermodynamic calculations. We investigate the following questions: (a) What are the operative mechanisms that control the critical layer thickness of pseudomorphic bcc Mg in a Nb/Mg nanolaminate? Can the above discrepancy be explained by considering the effects of the bottom vs. top Nb layers separately in a Nb/Mg multilayered structure? (b) What would be the effects of the Nb volume fraction on the resultant structure? |
Proceedings Inclusion? |
Planned: |
Keywords |
Phase Transformations, Thin Films and Interfaces, Characterization |