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Microstructure and properties of high alumina castables containing calcium alumino‐titanate
Author(s) -
Chen Jianwei,
Zhao Huizhong,
Zhang Han,
Li Zhengkun,
Zhang Jiaqin
Publication year - 2018
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13016
Subject(s) - materials science , microstructure , calcium titanate , scanning electron microscope , thermal expansion , sintering , composite material , porosity , grain growth , titanate , flexural strength , grain size , mineralogy , ceramic , chemistry
Calcium alumino‐titanate ( CAT )‐containing high alumina castables were prepared using bauxite, CAT , and α‐Al 2 O 3 as starting materials, and subsequently heat treated at various temperatures ranging from 1400°C to 1600°C. The thermo‐mechanical properties of the specimens as a function of the temperature were characterized in terms of linear shrinkage, bulk density, apparent porosity, cold crushing strength ( CCS ), modulus of rupture ( MOR ), residual ratio of MOR , and coefficient of thermal expansion ( CTE ). X‐ray diffraction ( XRD ) and scanning electron microscopy ( SEM ) were used to determine the phase composition and microstructural evolution, respectively. Sintering at temperatures between 1450 and 1500°C promoted normal grain growth, with the formation of a granular surface contact, and abnormal grain growth occurred at higher temperatures (≥ 1550°C). The cold strength of the specimen initially increased and subsequently decreased with temperature, whereas the residual ratio of MOR initially decreased with increasing temperature to 1550°C, then increased above 1550°C. In addition, the CTE of the specimen was only minimally influenced by the firing temperature.