Transformation Mechanism of Fluormica to Fluoramphibole in Fluoramphibole Glass Ceramics

Abstract

During isothermal sintering at 820°C, the transformation mechanism of fluormica to fluoramphibole in powder compacts of fluormica and soda-lime glass was investigated using differential thermal analysis, infrared reflection spectrometry, X-ray diffraction, scanning electron microscopy, and so forth. Results show that an interaction between fluormica and glass occurred during isothermal heating; O2−, Na+, and Ca2+ions were diffused from glass to fluormica. This diffusion facilitates the transformation of the sheet structures of fluormica crystals to double-chain structures by the breakage of bridge oxygen bonds in the sheet. Subsequently, the broken two parallel double chains were rearranged by relative displacement along thec-axis direction of the fluormica crystal and were linked by Na+and Ca2+ions to form fluoramphibole. A crystallography model of fluormica-fluoramphibole transformation was established in this study.