An investigation into the crystallization of Dicor glass-ceramic

The crystallization of Dicor glass-ceramic was investigated, emphasizing the role of fluorine, and silicon tetrafluoride loss on the crystallization mechanism. Combined differential thermal analysis/thermogravimetric analysis (DTA/TGA) was used to observe the crystallization behavior of three particle sizes of the Dicor base glass obtained by crushing the ingots and sieving. DTA confirmed that, up to the melting endotherm, silicon tetrafluoride was lost from Dicor during its cramming cycle. The fact that the smallest particle size had the greatest weight loss suggests that this loss is a surface process. While the bulk of Dicor crystallized to fluormica, the surface crystallized to proto-enstatite, a fluoride-free phase.