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Crystallization Kinetics and Mechanism of Low‐Dielectric, Low‐Temperature, Cofirable CaO‐B 2 O 3 ‐SiO 2 Glass‐Ceramics
Author(s) -
Chang ChiaRuey,
Jean JauHo
Publication year - 1999
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.1151-2916.1999.tb01992.x
Subject(s) - wollastonite , activation energy , crystallization , materials science , nucleation , dielectric , mineralogy , kinetics , thermal expansion , phase (matter) , crystal (programming language) , chemical engineering , analytical chemistry (journal) , thermodynamics , chemistry , composite material , chromatography , raw material , physics , optoelectronics , organic chemistry , quantum mechanics , engineering , computer science , programming language
The crystallization kinetics and mechanism of low‐dielectric, low‐temperature, cofirable CaO‐B 2 O 3 ‐SiO 2 glass‐ceramics were investigated. Crystalline phases formed during firing included calcium silicates (CaSiO 3 , Ca 3 Si 2 O 7 , Ca 2 SiO 4 ) and calcium borate (CaB 2 O 4 ), with crystalline wollastonite (CaSiO 3 ) the major phase. The crystallization kinetics of wollastonite followed an Avrami equation. The results of the present study showed an apparent activation energy of 200‐260 kJ/mol. Combined with the results of reduced growth rate (growth rate × viscosity) and thermal analysis, the rate‐controlling mechanism of crystallization appeared to be a two‐dimensional surface nucleation growth. As the amount of crystalline wollastonite increased, the dielectric constant decreased, but the thermal expansion coefficient remained relatively unchanged.