PREPARATION OF Al₂O₃-CaAl₁₂O₁₉-ZrO₂ COMPOSITE CERAMIC MATERIAL BY THE HYDRATION AND SINTERING OF Ca₇ZrAl₆O₁₈-REACTIVE ALUMINA MIXTURE

Autor: Dominika Madej, Jacek Szczerba
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Ceramics-Silikáty, Vol 60, Iss 1, Pp 27-33 (2016)
Druh dokumentu: article
ISSN: 0862-5468
1804-5847
DOI: 10.13168/cs.2016.0004
Popis: Ceramic material of composition belonging to the Al₂O₃-CaAl₁₂O₁₉-ZrO₂ compatibility field was obtained as a result of hydration and sintering of the mixture of Al₂O₃ and Ca₇ZrAl₆O₁₈ powders. The hydrated Al₂O₃- Ca₇ZrAl₆O₁₈ mixture products were studied by XRD, DTA-TG-EGA and FT-IR after 14 days of curing and hydration at 50°C. C₃AH₆, Al(OH)₃ and CaZrO₃ compounds were formed upon hydration. CaZrO₃ and the lime-rich calcium aluminates formed as transient phases during hydration and dehydration processes were converted to CA6 and ZrO₂ in the presence of an excess of Al₂O₃ during sintering at 1500°C. The Al₂O₃-based dense refractory composite material was investigated by XRD, FT-IR, SEM-EDS and mercury porosimetry. The sintered ceramic microstructure consists of a homogeneous distribution of zirconia grains in an alumina matrix reinforced with the calcium hexaaluminate phase. The presence of Al₂O₃, CaAl₁₂O₁₉ and ZrO₂ in the synthesized material was confirmed by XRD and FT-IR techniques. By applying the mercury intrusion porosimetry technique, the heterogeneous pore size distribution of the refractory composite material was determined.
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