First principles calculation of phase diagrams of V-Nb, V-Ta and Nb-Ta alloys
- Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India)
We report the solid state phase diagram of V-Nb, V-Ta and Nb-Ta alloys computed by combining the density functional theory total energies with the cluster expansion and Monte Carlo techniques. From the computed phase diagrams, we find that V-Nb and Nb-Ta alloys form continuous series of solid solutions and the solid solution phase is stable down to ambient temperatures, consistent with experiments. The calculated bcc V-Ta phase diagram exhibits complete miscibility. Since the current cluster expansion ignore V{sub 2}Ta phase, the chemical interaction due to relatively large electronegativity difference, which cause the ordering of V{sub 2}Ta phase from the bcc solid solution, appears to manifest by making the solid solution phase remain stable for the complete concentration range, down to ambient temperatures, perhaps with some short-range-order. This work further demonstrates the dominant role of constituent strains in the accurate calculation of phase diagram of alloys of constituents with significant size mismatches.
- OSTI ID:
- 22004155
- Journal Information:
- AIP Conference Proceedings, Vol. 1447, Issue 1; Conference: 56. DAE solid state physics symposium 2011, Kattankulathur, Tamilnadu (India), 19-23 Dec 2011; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Specific heat measurements in superconducting and normal state Ta-Nb-V ternary solid solutions
Thermodynamic description of the Ti-Mo-Nb-Ta-Zr system and its implications for phase stability of Ti bio-implant materials