Ab-initio and experimental study of phase stability of Ti-Nb alloys
| Autor: | G.A. Evangelakis, A. Gebert, D.G. Papageorgiou, N.T. Panagiotopoulos, Ch.E. Lekka, Matthias Bönisch, J. J. Gutiérrez Moreno, Jürgen Eckert, Mariana Calin |
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| Přispěvatelé: | Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]) |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Ab initio Electronic band 02 engineering and technology Crystal structure 01 natural sciences [SPI.MAT]Engineering Sciences [physics]/Materials Biomaterials symbols.namesake Phase stability 0103 physical sciences Materials Chemistry Titanium alloys Line (formation) 010302 applied physics Mechanical Engineering Fermi level Metals and Alloys Titanium alloy 021001 nanoscience & nanotechnology Antibonding molecular orbital Crystallography Mechanics of Materials symbols 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds Journal of Alloys and Compounds, Elsevier, 2017, 696, pp.481-489. ⟨10.1016/j.jallcom.2016.11.231⟩ |
| ISSN: | 0925-8388 |
| Popis: | International audience; A systematic theoretical and experimental study concerning the crystallographic structure and electronic properties of Ti-xNb (x < 50 at%) alloys is presented, aiming to enlighten the electronic origins of the beta-phase stability which is of high interest for the development of novel beta stabilized Ti-based alloys for biomedical applications. Both quantum-mechanical calculations and X-ray diffraction found several structural phases depending on Nb concentration. The ab-initio total energy results reveal that at low Nb contents the alpha' and omega phases are favoured while at Nb content > 18.75 at% the beta-phase is favoured against all other crystallographic structures in line with the experimental results. Interestingly, at high Nb content the alpha' and omega hexagonal phases become unstable due to the electronic band filling close to the Fermi level E-F, which is mainly due to Nb-p and Ti-d antibonding hybridizations. On the contrary, in the cubic beta-Ti-25Nb (at%) the depletion of the occupied electronic states at the EF occurs mainly due to Nbd and Ti-d bonding interactions, resulting in a stable beta-TiNb structure. These data could enlighten the electronic origin of the Ti-Nb phase stability, thus, may contribute to the design of beta stabilized low moduli Ti-based alloys suitable for load-bearing biomedical applications. (C) 2016 Elsevier B. V. All rights reserved. |
| Databáze: | OpenAIRE |
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