About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Understanding Phase Stability and Diffusion Kinetics in Structurally Unstable Phases from First-principles |
Author(s) |
Sara Kadkhodaei |
On-Site Speaker (Planned) |
Sara Kadkhodaei |
Abstract Scope |
The phase diagram of numerous materials of technological importance features high temperature phases that exhibit phonon instabilities. Leading examples include shape-memory alloys, ferroelectric, refractory, and structural materials. In this talk I will introduce a new thermodynamic model for free energy calculation in these phases from first principles. This model efficiently explores the system’s ab-initio energy surface by partitioning it into piecewise polynomials around local minima, which is combined with a continuous yet constrained sampling in the vicinity of these local minima. I present the application of this model to the bcc phase of titanium as well as the austenite and martensite phases in NiTi and PtTi shape memory alloys. In addition, I will try to shed light on diffusion kinetics in dynamically stabilized phases based on a first-principles approach within the transition state theory. Finally, I introduce the implementation of the model as an open-access and fully automated software toolkit. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, High-Temperature Materials, |