Premium
Evolution of Mullite Texture on Firing Tape‐Cast Kaolin Bodies
Author(s) -
Chen ChinYi,
Tuan WeiHsing
Publication year - 2002
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.1151-2916.2002.tb00232.x
Subject(s) - mullite , materials science , texture (cosmology) , scanning electron microscope , metakaolin , composite material , spinel , equiaxed crystals , mineralogy , phase (matter) , metallurgy , microstructure , ceramic , chemistry , compressive strength , image (mathematics) , artificial intelligence , computer science , organic chemistry
Kaolin undergoes a series of phase changes on heating to elevated temperature, proceeding through kaolin, metakaolin, γ‐Al 2 O 3 spinel, and mullite. The morphologic evolution of the kaolin–mullite reaction series was investigated in the present study. A highly textured kaolin green body was prepared by a tape‐casting technique, and the morphology evolution from kaolin flakes to mullite aciculars on firing from 450° to 1600°C was then monitored using X‐ray diffractometry and scanning electron microscopy. Equiaxed mullite nuclei first appeared at 1000°C; the aspect ratio of the mullite grains then increased with increased firing temperature. The mullite aciculars rearranged their orientation in a glassy phase until they impinged on each other. A highly textured mullite specimen was prepared by firing the kaolin tape at a temperature >1500°C.