Ab initio study of chemical disorder as an effective
stabilizing mechanism of bcc-based TiAl( plus Mo)

J 2020

Ab initio study of chemical disorder as an effective stabilizing mechanism of bcc-based TiAl( plus Mo)

ABDOSHAHI, Neda; Petra SPOERK-ERDELY; Martin FRIAK; Svea MAYER; Mojmír ŠOB et. al.

Základní údaje

Originální název

Ab initio study of chemical disorder as an effective stabilizing mechanism of bcc-based TiAl( plus Mo)

Autoři

ABDOSHAHI, Neda; Petra SPOERK-ERDELY; Martin FRIAK; Svea MAYER; Mojmír ŠOB (203 Česká republika, garant, domácí) a David HOLEC

Vydání

Physical Review Materials, College Park, Maryland, American Physical Society, 2020, 2475-9953

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10302 Condensed matter physics

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 3.989

Kód RIV

RIV/00216224:14310/20:00117220

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1103/PhysRevMaterials.4.103604

UT WoS

000576705800004

EID Scopus

2-s2.0-85094142110

Klíčová slova anglicky

First-principles calculations; Phase transitions by order

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 3. 5. 2021 14:09, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

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.

Návaznosti

LM2015085, projekt VaV

Název: CERIT Scientific Cloud (Akronym: CERIT-SC)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, CERIT Scientific Cloud

LM2018140, projekt VaV

Název: e-Infrastruktura CZ (Akronym: e-INFRA CZ)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, e-Infrastruktura CZ

LQ1601, projekt VaV

Název: CEITEC 2020 (Akronym: CEITEC2020)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, CEITEC 2020

90042, velká výzkumná infrastruktura

Název: CESNET II

Citovat

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). Physical Review Materials. College Park, Maryland: American Physical Society, 2020, roč. 4, č. 10, s. 1-14. ISSN 2475-9953. Dostupné z: https://doi.org/10.1103/PhysRevMaterials.4.103604.

@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 = {https://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://doi.org/10.1103/PhysRevMaterials.4.103604.

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