Anomalous mechanical strengths and shear deformation paths of Al2O3 polymorphs with high ionicity

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10364387" target="_blank" >RIV/00216208:11320/16:10364387 - isvavai.cz</a>

Alternative codes found

RIV/61989100:27740/16:10237916

Result on the web

<a href="http://dx.doi.org/10.1039/c5ra25796d" target="_blank" >http://dx.doi.org/10.1039/c5ra25796d</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c5ra25796d" target="_blank" >10.1039/c5ra25796d</a>

Result language

angličtina

Original language name

Anomalous mechanical strengths and shear deformation paths of Al2O3 polymorphs with high ionicity

Original language description

Alumina (Al2O3) formed by selective oxidization provides an effective way to protect aluminide alloys against corrosion for sustainable applications. Despite a broad interest and investigations on Al2O3 polymorphs such as alpha-Al2O3 and theta-Al2O3, their intrinsic mechanical strengths and atomic deformation mechanisms are not yet fully understood. In this research, density functional theory is used to show that the calculated shear moduli and mechanical strengths of theta-Al2O3 are substantially lower than those of alpha-Al2O3, and this explains why theta-Al2O3 is much weaker than alpha-Al2O3. An analysis of shear deformation paths and electronic structure indicates that the longest Al-O ionic bonds are responsible for the lattice instability of both polymorphs during shear, showing they have different anisotropic features. This study gives a novel view on the failure of thermally grown alpha-Al2O3 and theta-Al2O3, and it should help to improve the performance of thermal barrier coatings.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

RSC Advances

ISSN

2046-2069

e-ISSN

—

Volume of the periodical

6

Issue of the periodical within the volume

16

Country of publishing house

GB - UNITED KINGDOM

Number of pages

8

Pages from-to

12885-12892

UT code for WoS article

000369546100020

EID of the result in the Scopus database

2-s2.0-84956935392