About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
CALPHAD Modeling of Double Ordering |
Author(s) |
Yijia Gu, Kyaw Hla Saing Chak, Julia E. Medvedeva |
On-Site Speaker (Planned) |
Yijia Gu |
Abstract Scope |
The nonstoichiometric κ carbide is a critical strengthening phase in lightweight high-strength steel FeMnAlC alloy. However, current CALPHAD sublattice models are not able to predict the correct C concentration in κ carbide phase due to the incomplete description of the octahedral interstitial sites (for C and vacancy). A 4-sublattice model is developed to describe the κ carbide in FeMnAlC alloy. The transformation from γ (fcc) phase to κ carbide can thus be considered as two consecutive ordering processes. The first one is the L12 ordering and the second is the ordering of C and vacancy. In this study, DFT calculations were performed for the formation energies of the 64 endmembers for the Fe-Mn-Al-Si-C system. The 4-sublattice model is explored to assess the phase stabilities with different temperature and C concentration. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Phase Transformations, Modeling and Simulation |