Další formáty:
BibTeX
LaTeX
RIS
@article{1703497,
author = {Abdoshahi, Neda and SpoerkandErdely, Petra and Friak, Martin and Mayer, Svea and Šob, Mojmír and Holec, David},
article_location = {College Park, Maryland},
article_number = {10},
doi = {http://dx.doi.org/10.1103/PhysRevMaterials.4.103604},
keywords = {First-principles calculations; Phase transitions by order},
language = {eng},
issn = {2475-9953},
journal = {Physical Review Materials},
title = {Ab initio study of chemical disorder as an effective stabilizing mechanism of bcc-based TiAl( plus Mo)},
url = {https://doi.org/10.1103/PhysRevMaterials.4.103604},
volume = {4},
year = {2020}
}
TY - JOUR
ID - 1703497
AU - Abdoshahi, Neda - Spoerk-Erdely, Petra - Friak, Martin - Mayer, Svea - Šob, Mojmír - Holec, David
PY - 2020
TI - Ab initio study of chemical disorder as an effective stabilizing mechanism of bcc-based TiAl( plus Mo)
JF - Physical Review Materials
VL - 4
IS - 10
SP - 1-14
EP - 1-14
PB - American Physical Society
SN - 24759953
KW - First-principles calculations
KW - Phase transitions by order
UR - https://doi.org/10.1103/PhysRevMaterials.4.103604
L2 - https://doi.org/10.1103/PhysRevMaterials.4.103604
N2 - To shed a new light on the complex microstructural evolution in the Ti-Al-Mo system, we employ ab initio calculations to study bcc-fcc structural transformations of ordered beta(o)-TiAl(+Mo) and disordered beta-TiAl(+Mo) to ordered gamma-TiAl(+Mo) and hypothetically assumed disordered gamma(dis)-TiAl(+Mo) alloys, respectively. In particular, tetragonal (Bain's path) and trigonal transformations are combined with the concept of special quasirandom structures (SQS) and examined. Our calculations of the ordered phases show that the beta(o )-> gamma tetragonal transformation of TiAl is barrierless, i.e., proceeds spontaneously, reflecting the genuine structural instability of the beta(o) phase. Upon alloying of approximate to 7.4 at.% Mo, a small barrier between beta(o) and gamma-related local energy minima is formed. Yet a higher Mo content of approximate to 9 at.% leads to an opposite-direction barrierless transformation gamma -> beta(o )i.e., fully stabilizing the beta(o) phase. Considering the disordered phases, the beta(o)-Ti0.5Al0.5-xMox and gamma(dis)-Ti0.5Al0.5-xMox, are energetically very close. Importantly, for all here-considered compositions up to 11 at.% of Mo, a small energy barrier separates beta-TiAl(+Mo) and gamma(dis)-TiAl(+Mo) energy minima Finally, a trigonal path was studied as an alternative transformation connecting disordered beta and gamma(dis)-TiAl phases, but it turns out that it exhibits an energy barrier over 60 meV/at. which, in comparison to the Bain's path with 9 meV/at. barrier, effectively disqualifies the trigonal transformation for the TiAl system.
ER -
ABDOSHAHI, Neda, Petra SPOERK-ERDELY, Martin FRIAK, Svea MAYER, Mojmír ŠOB a David HOLEC. Ab initio study of chemical disorder as an effective stabilizing mechanism of bcc-based TiAl( plus Mo). \textit{Physical Review Materials}. College Park, Maryland: American Physical Society, 2020, roč.~4, č.~10, s.~1-14. ISSN~2475-9953. Dostupné z: https://dx.doi.org/10.1103/PhysRevMaterials.4.103604.
|
