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Low‐Temperature Transient Glass‐Phase Processing of Monoclinic SrAl2Si2O8
Author(s) -
Chinn Richard E.,
Haun Michael J.,
Kim Chan Young,
Price David B.
Publication year - 1998
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.1151-2916.1998.tb02623.x
Subject(s) - monoclinic crystal system , materials science , crystallization , aluminosilicate , dissolution , sintering , stoichiometry , pellets , phase (matter) , mineralogy , melting point , chemical engineering , analytical chemistry (journal) , metallurgy , composite material , crystallography , crystal structure , chemistry , organic chemistry , engineering , catalysis
The use of transient glass‐phase processing to lower the glass‐melting temperature and subsequent heat‐treatment temperature of stoichiometric SrAl 2 Si 2 O 8 to produce the stable monoclinic form has been described. Two nonstoichiometric, low‐melting, alumina‐deficient, strontium aluminosilicate compositions were melted, quenched, and milled into glass powders. B 2 O 3 was dissolved into one of the glass compositions to control the crystallization behavior. The glass powders were then wet‐mixed with enough alpha‐Al 2 O 3 powder so that the overall composition was that of stoichiometric SrAl 2 Si 2 O 8 (B 2 O 3 neglected). The four compositions were dry‐pressed into pellets and sintered in three processes. Glass‐alumina pellets with dissolved B 2 O 3 were densified via viscous‐phase sintering at 1100°C, followed by complete dissolution of the alumina and crystallization to ~100% monoclinic SrAl 2 Si 2 O 8 . Pellets without dissolved B 2 O 3 required considerably higher temperatures to form ~100% monoclinic SrAl 2 Si 2 O 8 in a modified process.