Use of Phase Diagrams to Predict Glass-Ceramic Assemblages

Therefore it would be sheer folly to attempt developing a glass-ceramic with a stable assemblage of cordierite (Mg2Al Si50jg) and P-eucryptite (LiAlSiO ), even though it would seem useful to have sudi a phase mixture to achieve a zero coefficient of thermal expansion in a high-temperature material. 

In summary, phase diagrams can determine the feasibility of coexistence of crystal species in glass-ceramics. They cannot, however, yield any information regarding such issues as nucleation, grain growth, or other kinetic phenomena. 

The microstructures of the glass-ceramics resemble well-known structures and phenomena in nature, science, technology, and daily life. In some cases, the microstructures that are discussed exhibit ultrafine crystal structures reminiscent of those of nanopowders. To help describe the appearance of certain microstructures, comparisons are made to the structure of a cell, cabbage head, or a house of cards. These examples are addressed in the following sections. The special properties produced by the specific designs will also be discussed in these sections. 

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