Crack behaviour and mechanical properties of thermally treated kaolin based ceramics: The influence of pore generating agents

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F20%3A00538536" target="_blank" >RIV/61389021:_____/20:00538536 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169131720302635?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169131720302635?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.clay.2020.105698" target="_blank" >10.1016/j.clay.2020.105698</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Crack behaviour and mechanical properties of thermally treated kaolin based ceramics: The influence of pore generating agents

Popis výsledku v původním jazyce

In this study, the crack behaviour of porous kaolin based ceramics was experimentally investigated. The samples (ceramic bodies) were fabricated with the inclusion of pore formers in determined proportions and subjected to heat treatment. Next, the apparent porosity of the samples was measured using the water immersion method. The values confirmed the increased porosity (up to 47%) for the samples with embedded pores. We speculated that the open pores on the surface of the samples which were quite evident, especially with styrofoam as pore formers, may also have penetrated through, hence the enhanced porosity values for the samples. Acoustic emission (AE) activity which reveals the formation of microcracks in the ceramics due to the different thermal expansion coefficients in the cooling stage was recorded for the samples. The first signals of AE counts appeared at 800 °C, where the compressive stresses between the different phases (particles with different coefficients of thermal expansion) led to an appearance of microcracks. By introducing porosity to the samples, the AE signals were less pronounced. This was evident for the samples with sawdust as pore formers, and it was inferred that in this sample, microcracking was suppressed. As a validation protocol for AE measurements, mechanical measurements on the produced samples were conducted through the indentation technique to obtain the fracture toughness of the samples. The results conformed to the observation made during AE measurements. The samples embedded with sawdust as porogens produced the highest fracture toughness of 4.77 MPa.m1/2 by reason of the suppression of microcracking after heat treatment.

Název v anglickém jazyce

Crack behaviour and mechanical properties of thermally treated kaolin based ceramics: The influence of pore generating agents

Popis výsledku anglicky

In this study, the crack behaviour of porous kaolin based ceramics was experimentally investigated. The samples (ceramic bodies) were fabricated with the inclusion of pore formers in determined proportions and subjected to heat treatment. Next, the apparent porosity of the samples was measured using the water immersion method. The values confirmed the increased porosity (up to 47%) for the samples with embedded pores. We speculated that the open pores on the surface of the samples which were quite evident, especially with styrofoam as pore formers, may also have penetrated through, hence the enhanced porosity values for the samples. Acoustic emission (AE) activity which reveals the formation of microcracks in the ceramics due to the different thermal expansion coefficients in the cooling stage was recorded for the samples. The first signals of AE counts appeared at 800 °C, where the compressive stresses between the different phases (particles with different coefficients of thermal expansion) led to an appearance of microcracks. By introducing porosity to the samples, the AE signals were less pronounced. This was evident for the samples with sawdust as pore formers, and it was inferred that in this sample, microcracking was suppressed. As a validation protocol for AE measurements, mechanical measurements on the produced samples were conducted through the indentation technique to obtain the fracture toughness of the samples. The results conformed to the observation made during AE measurements. The samples embedded with sawdust as porogens produced the highest fracture toughness of 4.77 MPa.m1/2 by reason of the suppression of microcracking after heat treatment.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Applied Clay Science

ISSN

0169-1317

e-ISSN

—

Svazek periodika

194

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

6

Strana od-do

105698

Kód UT WoS článku

000546204800001

EID výsledku v databázi Scopus

2-s2.0-85085840274