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Decomposition of Mullite by Silica Volatilization
Author(s) -
IWAI SHINICHI,
WATANABE TAKASHI,
MINATO ICHIRO,
OKADA KIYOSHI,
MORIKAWA HIDEKI
Publication year - 1980
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1980.tb10647.x
Subject(s) - corundum , mullite , electron microprobe , crucible (geodemography) , decomposition , volatilisation , scanning electron microscope , mineralogy , thermal decomposition , microanalysis , materials science , analytical chemistry (journal) , chromite , chemistry , metallurgy , ceramic , composite material , chromatography , computational chemistry , organic chemistry
Thermal decomposition of mullite into corundum was investigated using a high‐temperature X‐ray single‐crystal camera equipped with a gas‐flame furnace and by scanning electron microscopy and electron probe microanalysis (EPMA). When heated to ∼1750°C, mullite decomposed to corundum by the liberation of the SiO 2 component with topotaxial relations of:1 (310) mull ∥(001) cor ; [001] mull ∥[110] cor2 (130) mull ∥(001) cor ; [001] mull ∥[110] cor3 (110) mull ∥(001) cor ; [001] mull ∥[110] corThus, it was considered that, when mullite decomposed into corundum, their oxygen close‐packed planes were almost preserved. The SEM photographs showed that the crystals of the developed corundum are prismatic and ∼5 μm wide. The EPMA showed that the phase boundary between mullite and developed corundum is discontinuous.