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Microstructure and Kinetics of Crystallization of MgO‐Al 2 O 3 −Si0 2 Glass‐Ceramics
Author(s) -
ZDANIEWSKI WIESLAW A.
Publication year - 1978
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.1151-2916.1978.tb09278.x
Subject(s) - crystallization , nucleation , materials science , microstructure , cordierite , induction period , quartz , impurity , chemical engineering , mineralogy , crystal growth , crystallography , kinetics , ceramic , analytical chemistry (journal) , metallurgy , chemistry , chromatography , physics , organic chemistry , quantum mechanics , engineering
Quantitative X‐ray diffraction and microscopy were used to study the morphology development and overall crystallization rate between 900° and 990°C of MgO‐Al 2 O 3 −SiO 2 glasses with added ZrO, TiO 2 , CaF 2 , or CeO 2 . Three basic stages of micro‐structural development were distinguishable: I, an induction period, II, a spherulitic crystallization stage, and III, a final crystallization stage. The duration of the induction period, the crystallization rate of the high‐quartz solid solution, and the microstructures varied markedly with prior nucleation treatment and the type of modifier present in a glass of nearly equal silica content. The roles of major (high‐quartz ss , high cordierite) and of minor crystalline and liquid phases in textural development are discussed, and it is postulated that nucleants (ZrO 2 , TiO 2 ) act also as growth‐modifying “impurities” in crystal growth.