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Aluminoborate Glass‐Ceramics with Low Thermal Expansivity
Author(s) -
MacDowell John F.
Publication year - 1990
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.1151-2916.1990.tb07590.x
Subject(s) - materials science , ceramic , thermal expansion , barium , mineralogy , stoichiometry , microstructure , phase (matter) , strontium , hexagonal crystal system , strontium barium niobate , composite material , chemical engineering , analytical chemistry (journal) , crystallography , metallurgy , chemistry , optoelectronics , engineering , ferroelectricity , chromatography , organic chemistry , dielectric
The synthesis and properties of calcium, strontium, and barium aluminoborate glass‐ceramics are described in this paper. Glass powder compacts near the RO‐Al 2 O 3 ‐B 2 O 3 stoichiometry were sintered and crystallized below 1000°C to form dense glass‐ceramics containing RAI 2 B 2 O 7 as the principal phase. Thermal expansion coefficients as low as 6 × 10 −7 /°C, 15 × 10 −7 /°C, and 23 × 10 −7 /°C were measured on SrAl 2 B 2 O 7 , CaAl 2 B 2 O 7 , and BaAl 2 B 2 O 7 glass‐ceramics, respectively. Two forms of the ultra‐low‐expansion SrAl 2 B 2 O 7 were not previously reported in the literature and were indexed as cubic and hexagonal crystals. The unique radial spherulitic interbladed microstructures and other important properties of these glass‐generated ceramics are also revealed.