Description of strengthening mechanism in layered ceramic composites

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F16%3A00448574" target="_blank" >RIV/68081723:_____/16:00448574 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.4028/www.scientific.net/KEM.665.93" target="_blank" >http://dx.doi.org/10.4028/www.scientific.net/KEM.665.93</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/www.scientific.net/KEM.665.93" target="_blank" >10.4028/www.scientific.net/KEM.665.93</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Description of strengthening mechanism in layered ceramic composites

Popis výsledku v původním jazyce

During the last years many researchers put so much effort to design layered structures combining layers of different materials in order to improve low fracture toughness and mechanical reliability of the ceramics. It has been proven, that an effective way is to create layered ceramics with strong bonded interfaces. After the cooling process from the sintering temperature, due to the different coefficients of thermal expansion of individual constituents of the composite, significant internal residual stresses are developed within the layers. These stresses can change the crack behaviour. This results to the higher value of so-called apparent fracture toughness, i.e. higher resistance of the ceramic laminate to the crack propagation. The contribution deals with a description of the specific crack behaviour in the layered alumina-zirconia ceramic composite and its strengthening mechanism. The main aim is to clarify crack behaviour in the compressive layer and provide computational tools for estimation of crack behaviour in the field of strong residual stresses. The crack propagation was investigated on the basis of linear elastic fracture mechanics. Finite element models were developed in order to obtain a stress distribution in the ceramic laminate containing a crack and to simulate crack propagation. The sharp change of the crack propagation direction was estimated using criterion based on the strain energy density factor. This change of the crack propagation direction and next crack propagation parallel to the materials interface is connected with higher energy consumption and represents the main reason for higher apparent fracture toughness of ceramic laminates with strong interfaces. Estimated crack behaviour is qualitatively in a good agreement with experimental observations.

Název v anglickém jazyce

Description of strengthening mechanism in layered ceramic composites

Popis výsledku anglicky

During the last years many researchers put so much effort to design layered structures combining layers of different materials in order to improve low fracture toughness and mechanical reliability of the ceramics. It has been proven, that an effective way is to create layered ceramics with strong bonded interfaces. After the cooling process from the sintering temperature, due to the different coefficients of thermal expansion of individual constituents of the composite, significant internal residual stresses are developed within the layers. These stresses can change the crack behaviour. This results to the higher value of so-called apparent fracture toughness, i.e. higher resistance of the ceramic laminate to the crack propagation. The contribution deals with a description of the specific crack behaviour in the layered alumina-zirconia ceramic composite and its strengthening mechanism. The main aim is to clarify crack behaviour in the compressive layer and provide computational tools for estimation of crack behaviour in the field of strong residual stresses. The crack propagation was investigated on the basis of linear elastic fracture mechanics. Finite element models were developed in order to obtain a stress distribution in the ceramic laminate containing a crack and to simulate crack propagation. The sharp change of the crack propagation direction was estimated using criterion based on the strain energy density factor. This change of the crack propagation direction and next crack propagation parallel to the materials interface is connected with higher energy consumption and represents the main reason for higher apparent fracture toughness of ceramic laminates with strong interfaces. Estimated crack behaviour is qualitatively in a good agreement with experimental observations.

Druh

D - Stať ve sborníku

CEP obor

JL - Únava materiálu a lomová mechanika

OECD FORD obor

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Projekt

<a href="/cs/project/GA15-09347S" target="_blank" >GA15-09347S: Role reziduálních napětí v životnosti keramických kompozitů</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název statě ve sborníku

Advances in Fracture and Damage Mechanics XIV

ISBN

978-3-03835-541-0

ISSN

1013-9826

e-ISSN

—

Počet stran výsledku

4

Strana od-do

93-96

Název nakladatele

Trans Tech Publications

Místo vydání

Zurich

Místo konání akce

Budva

Datum konání akce

21. 9. 2015

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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