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Shape of MgAl 2 O 4 Grains in a CaMgSiAlO Glass Matrix
Author(s) -
Park SangYeup,
Choi Kyoon,
Kang SukJoong L.,
Yoon Duk N.
Publication year - 1992
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.1151-2916.1992.tb05470.x
Subject(s) - materials science , annealing (glass) , octahedron , grain boundary , matrix (chemical analysis) , crystallography , mineralogy , composite material , microstructure , chemistry , crystal structure
When sintered Al 2 O 3 is annealed with CaMgSiAlO glass at 1600°C, polyhedral MgAl 2 O 4 grains form and glass pockets are entrapped within the grains. After annealing for 13 h at 1600°C, the liquid pockets show a regular octahedron shape which is expected to represent the equilibrium shape. All grain surfaces in contact with the glass matrix show the same shape. The small grains, which must be shrinking, thus have the equilibrium shape, because their shrinkage shape is is identical to the equilibrium and growth shape. However, the octahedral shape also represents the growth shape for the growing large grains. The grains also form grain boundaries with neighboring grains.