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Dissolution of Alumina, Sintering, and Crystallization in Glass Ceramic Composites for LTCC
Author(s) -
Müller Ralf,
Meszaros Robert,
Peplinski Burkhard,
Reinsch Stefan,
Eberstein Markus,
Schiller Wolfgang A.,
Deubener Joachim
Publication year - 2009
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.1551-2916.2009.03089.x
Subject(s) - anorthite , wollastonite , materials science , crystallization , borosilicate glass , sintering , composite material , microstructure , scanning electron microscope , dissolution , gehlenite , devitrification , differential thermal analysis , ceramic , glass ceramic , phase (matter) , mineralogy , chemical engineering , diffraction , chemistry , raw material , physics , organic chemistry , optics , engineering
Sintering and microstructure evolution of alkali‐free calcium–alumo–borosilicate glass/α‐Al 2 O 3 composites (mean particle size ca. 2 μm) for low‐temperature cofired ceramics were studied during heating at 5 K/min by heating microscopy, thermal analysis (DTA), X‐ray diffraction (XRD), and electron microscopy (SEM). Composites fully densify at ≈830°C, not essentially influenced by the dissolution of alumina and glass crystallization. Thus wollastonite, as first crystalline phase, was detectable at 840°C. Above 900°C, a pronounced crystallization of anorthite is evident, reaching 60 wt% at 1050°C. Rietveld analyses of XRD data revealed that anorthite precipitates at the expenses of alumina, which declines from ≈33 to <10 wt%, and wollastonite, which fully declines from its maximum of ≈19 wt%. Based on XRD, we discuss the evolution of crystal mass fractions, the residual glass composition, the glass viscosity, and the effective shear viscosity of the composites under study during heating.