About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Additive Manufacturing Modeling, Simulation, and Machine Learning: Microstructure, Mechanics, and Process
|
Presentation Title |
Phase Stability and Mechanical Properties of Ni-Al and Ni-Cr Binary Solid Solutions Using CASTEP Supercell Approach |
Author(s) |
Vielet Semakaleng Hilane, Maje Phasha, Marandela Mulaudzi, Josias Van der Merwe |
On-Site Speaker (Planned) |
Vielet Semakaleng Hilane |
Abstract Scope |
The structural properties, phase stability and elastic properties of Ni-Al and Ni-Cr compounds were systemically investigated using first principle calculations based on density functional theory. The calculations were calculated using CASTEP supercell approach with ultrasoft pseudopotential. The structures comprised of 16 and 32 atoms built using 2x2x2 BCC and FCC unit cells, respectively, were geometry optimized using cut-off energy of 500 eV with k-points of 8 x 8 x 8. The resulting predicted lattice constants were found to be in agreement with experimental trends and in accordance with the Vegard’s law for binary solid solutions in both Ni-Al and Ni-Cr systems. The calculated heat of formation for binary FCC Ni-Al solid solutions revealed higher thermodynamic stability as Al concentration increased whereas the solubility of Cr in Ni was less favourable and limited to less than 25 at.% at 0K. The elastic constants of these binary solid solutions were also calculated. |