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Mullite Joining by the Oxidation of Malleable, Alkaline‐Earth‐Metal‐Bearing Bonding Agents
Author(s) -
Sandhage Kenneth H.,
Schmutzler Hans J.,
Wheeler Robert,
Fraser Hamish L.
Publication year - 1996
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.1151-2916.1996.tb08004.x
Subject(s) - mullite , materials science , aluminosilicate , ceramic , amorphous solid , composite material , metal , barium , compaction , mineralogy , metallurgy , crystallography , chemistry , biochemistry , catalysis
Metallic Ba‐Al‐Si bonding agents have been used to produce all‐ceramic, BaO‐Al 2 O 3 ‐SiO 2 bonds between plates of mullite (Al 6 Si 2 O 13 ). Ba‐Al‐Si tapes (200 (μm thick) were fabricated by compaction and rolling of mechanically alloyed powder. The Ba‐Al‐Si tapes were placed between mullite plates and then oxidized by heating to a peak temperature of 1230°C in air. The oxidized tapes strongly adhered to the mullite plates at 25° and 1000°C, as indicated by the fracture morphologies obtained from compressive shear tests. Electron microscopy (EPMA, TEM) revealed that the bulk of the oxidized Ba‐Al‐Si tapes (away from the interfaces with mullite) consisted largely of the compound BaAl 2 Si 2 O 8 , along with some BaSiO 3 and an amorphous, barium‐rich aluminosilicate. The interface between the oxidized bonding agent and bulk mullite consisted of a mixture of BaAl 2 Si 2 O 8 , Al 6 Si 2 O 13 , A1 2 O 3 , BaAl 2 O 4 , and an amorphous, barium‐bearing aluminosilicate.