3D microstructure of magnesium potassium phosphate ceramics from X-ray tomography: new insights into the reaction mechanisms

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F19%3A00496962" target="_blank" >RIV/68378297:_____/19:00496962 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1007/s10853-018-3113-7" target="_blank" >https://doi.org/10.1007/s10853-018-3113-7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10853-018-3113-7" target="_blank" >10.1007/s10853-018-3113-7</a>

Jazyk výsledku

angličtina

Název v původním jazyce

3D microstructure of magnesium potassium phosphate ceramics from X-ray tomography: new insights into the reaction mechanisms

Popis výsledku v původním jazyce

Magnesium potassium phosphate ceramics are chemically bonded ceramics employed as biomaterials, in nuclear waste encapsulation and for concrete repair. The microstructure dictates material performance and depends on the raw mix composition. Synchrotron X-ray computed microtomography was employed to describe the 3D microstructure and its time evolution during hardening and gain insights into the reaction mechanisms. Any excess water with respect to the stoichiometry of the reaction brought about an increase in porosity, but, notably, a reduction in the average pore size. Crystals filled the water ‘pockets’ in the ceramic volume by growing larger, although less densely packed, increasing the complexity of the pore shape. Platelet over elongated crystal habit was favoured. Such a change in shape is likely related to a change in reaction mechanism, as crystallization from a gel-like amorphous precursor is hindered and progressively substituted by a through-solution mechanism. It is proposed that the time evolution of the microstructure is dictated by the balance between crystallization from amorphous precursor, prevailing in relatively ‘dense’ systems (with stoichiometric water or in low excess), and water segregation, prevailing at higher water contents. The former mechanism was shown to produce an increase in porosity with time, because of the density mismatch between the amorphous and the crystalline phase

Název v anglickém jazyce

3D microstructure of magnesium potassium phosphate ceramics from X-ray tomography: new insights into the reaction mechanisms

Popis výsledku anglicky

Magnesium potassium phosphate ceramics are chemically bonded ceramics employed as biomaterials, in nuclear waste encapsulation and for concrete repair. The microstructure dictates material performance and depends on the raw mix composition. Synchrotron X-ray computed microtomography was employed to describe the 3D microstructure and its time evolution during hardening and gain insights into the reaction mechanisms. Any excess water with respect to the stoichiometry of the reaction brought about an increase in porosity, but, notably, a reduction in the average pore size. Crystals filled the water ‘pockets’ in the ceramic volume by growing larger, although less densely packed, increasing the complexity of the pore shape. Platelet over elongated crystal habit was favoured. Such a change in shape is likely related to a change in reaction mechanism, as crystallization from a gel-like amorphous precursor is hindered and progressively substituted by a through-solution mechanism. It is proposed that the time evolution of the microstructure is dictated by the balance between crystallization from amorphous precursor, prevailing in relatively ‘dense’ systems (with stoichiometric water or in low excess), and water segregation, prevailing at higher water contents. The former mechanism was shown to produce an increase in porosity with time, because of the density mismatch between the amorphous and the crystalline phase

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/LO1219" target="_blank" >LO1219: Udržitelný pokročilý rozvoj CET</a><br>

Návaznosti

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

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Journal of Materials Science

ISSN

0022-2461

e-ISSN

—

Svazek periodika

54

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

3748-3760

Kód UT WoS článku

000452712800005

EID výsledku v databázi Scopus

2-s2.0-85056575816