Pinning effect of reactive elements on adhesion energy and adhesive strength of incoherent Al2O3/NiAl interface

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F16%3A86099435" target="_blank" >RIV/61989100:27740/16:86099435 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1039/c6cp03609k" target="_blank" >http://dx.doi.org/10.1039/c6cp03609k</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c6cp03609k" target="_blank" >10.1039/c6cp03609k</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Pinning effect of reactive elements on adhesion energy and adhesive strength of incoherent Al2O3/NiAl interface

Popis výsledku v původním jazyce

The profound effects of reactive elements (REs) on the adhesion energy and adhesive strength of the alpha-Al2O3/beta-NiAl interface in thermal barrier coating (TBC) systems have attracted increasing attention because RE-doping has played a significant role in improving the thermal cycling lifetime of TBCs. However, the fundamental mechanism is, so far, not well understood due to the experimental difficulty and theoretical complexity in interface modelling. For this purpose, in the present study we have performed comprehensive density functional theory calculations and information targeted experiments to underline the origin of the surprising enhancement of interface adhesion, stability and mechanical strength of the alpha-Al2O3/beta-NiAl interface by different RE doping levels. Our results suggest that the interface failure firstly appears within the NiAl layer adjacent to the Al-terminated oxide under mechanical loading, while the formation of O-RE-Ni bond pairs at the interface can effectively hinder the interface de-cohesion, providing a higher mechanical strength. By comparing several typical REs, it is observed that Hf can emerge not only with the highest interface adhesion energy, but also the highest mechanical strength; in agreement with our experimental results. By continuously increasing the dopant concentration, the strengthening effect may increase correspondingly, but is limited by the solute solubility. These results shed light into the effect of REs on the stability and strength of the alpha-Al2O3/beta-NiAl interface, providing theoretical guidance for interface design via a combinational analysis of bond topology and electronic structure.

Název v anglickém jazyce

Pinning effect of reactive elements on adhesion energy and adhesive strength of incoherent Al2O3/NiAl interface

Popis výsledku anglicky

The profound effects of reactive elements (REs) on the adhesion energy and adhesive strength of the alpha-Al2O3/beta-NiAl interface in thermal barrier coating (TBC) systems have attracted increasing attention because RE-doping has played a significant role in improving the thermal cycling lifetime of TBCs. However, the fundamental mechanism is, so far, not well understood due to the experimental difficulty and theoretical complexity in interface modelling. For this purpose, in the present study we have performed comprehensive density functional theory calculations and information targeted experiments to underline the origin of the surprising enhancement of interface adhesion, stability and mechanical strength of the alpha-Al2O3/beta-NiAl interface by different RE doping levels. Our results suggest that the interface failure firstly appears within the NiAl layer adjacent to the Al-terminated oxide under mechanical loading, while the formation of O-RE-Ni bond pairs at the interface can effectively hinder the interface de-cohesion, providing a higher mechanical strength. By comparing several typical REs, it is observed that Hf can emerge not only with the highest interface adhesion energy, but also the highest mechanical strength; in agreement with our experimental results. By continuously increasing the dopant concentration, the strengthening effect may increase correspondingly, but is limited by the solute solubility. These results shed light into the effect of REs on the stability and strength of the alpha-Al2O3/beta-NiAl interface, providing theoretical guidance for interface design via a combinational analysis of bond topology and electronic structure.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

<a href="/cs/project/LM2015070" target="_blank" >LM2015070: IT4Innovations národní superpočítačové centrum</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

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Svazek periodika

neuveden

Číslo periodika v rámci svazku

33

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

22864-22873

Kód UT WoS článku

000382109300013

EID výsledku v databázi Scopus

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