NUCLEATION PHENOMENA IN GLASS - CERAMIC MATERIALS.
Final scientific rept.,
OWENS-ILLINOIS INC TOLEDO OHIO CORPORATE RESEARCH
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The primary objective of the research was to obtain a more thorough understanding of the mechanisms and kinetics of nucleation, phase separation, and crystallization in glass-ceramic materials. Small-angle x-ray scattering was employed as the principal investigative technique, with the specimen preparation and instrumental techniques developed so as to allow quantitative scattering data to be obtained from phase separated glasses. Also, interpretive procedures to allow analyses of these data in terms of the above objective were developed. The kinetics of phase separation, particle growth, and crystallization in a glass-ceramic material containing ZrO2 as nucleant was studied at various temperatures by means of small-angle x-ray scattering, electron microscopy, and x-ray diffraction. It was found that a particle plus diffusion depletion zone model was adequate for analysis of the scattering data at low temperatures. In a study of amorphous phase separation in various Na2L.Si2 glasses the kinetics of both the early and later stages of phase separation were investigated with glass composition, heating temperature, and initial state of the glass as experimental parameters. However, agreement with various aspects predicted from the theory of spinodal decomposition was obtained, and it was possible to define several parameters measurable from scattering experiments which assist in the recognition of this particular mechanism. Author
- Ceramics, Refractories and Glass