Nucleation of Crystals in Sodium-Calcium-Silicate Glasses of the Metasilicate Section

Nucleation of crystals in sodium-calcium-silicate glasses of the quasi-binary metasilicate section CaO center dot SiO2-Na2O center dot SiO2 has been investigated by the development method. The maximal stationary rate of crystal nucleation in the composition range Na2O center dot 2CaO center dot 3SiO(2)-Na2O center dot CaO center dot 2SiO(2) increases substantially with the increase of the sodium oxide content. It was assumed that in this range, along with nucleation of crystals of solid solutions based on Na2O center dot 2CaO center dot 3SiO(2), nucleation of crystals 2Na(2)O center dot CaO center dot 3SiO(2) could occur as well. Nucleation of crystals of the above two phases in glass of the composition 28.4Na(2)O center dot 21.2CaO center dot 50.4SiO(2) (mol %) from the middle of the range Na2O center dot CaO center dot 2SiO(2)-2Na(2)O center dot CaO center dot 3SiO(2) has been studied.