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Orientation and Grain Boundary Microstructure of Alumina in Al/Al 2 O 3 Composites Produced by Reactive Metal Penetration
Author(s) -
Murthy Varanasi S. R.,
Kawahara Koichi,
Saito Yasuko,
Matsuzaki Takashi,
Watanabe Tadao
Publication year - 2005
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.1551-2916.2005.00468.x
Subject(s) - grain boundary , materials science , crystallite , microstructure , composite material , composite number , metal , penetration (warfare) , penetration depth , metallurgy , optics , physics , operations research , engineering
The orientation and grain boundary microstructure of alumina in reactive metal penetration Al/Al 2 O 3 composites are studied using orientation imaging microscopy and the results are compared with those of sintered polycrystalline Al 2 O 3 . The interconnected Al 2 O 3 in the composite material is separated by Σ3 boundaries (twins) with a 60° rotation around the [0001] direction. A high frequency (∼100%) of Σ3 coincidence boundaries in composite alumina is remarkable since only ∼12% of boundaries in a sintered polycrystalline Al 2 O 3 are of special nature. The coincidence boundaries in the in situ alumina grow in a coherent and faceted manner.