Influence of ZnO on the crystallization kinetics and properties of diopside-Ca-Tschermak based glasses and glass-ceramics

摘要

We report on the influence of ZnO on the structural, thermal, and crystallization behavior of the diopside-Ca-Tschermak based glasses, and on the processing, microstructure, and the properties of the sintered glass ceramics. Four glasses with nominal compositions of CaMg_(0.8)Al_(0.4)Si_(1.8)O_6, CaMg_(0.75)Zn_(0.05)Al_(0.4)Si_(1.8)O_6, CaMg_(0.70)Zn_(0.10)Al_(0.4)Si_(1.8)O_6, and CaMg_(0.60)Zn_(0.20)Al_(0.4)Si_(1.8)O_6 were obtained by melting at 1580 ℃ for 1 h. Structural and thermal behavior of the glasses was investigated by Fourier-transform infrared spectroscopy, density measurements, dilatometry, and differential thermal analysis. Nonisothermal crystallization kinetics has been employed to study the crystallization mechanism in the glasses. Sintering, crystallization, microstructure, and properties of the glass ceramics were investigated under nonisothermal heating conditions in the temperature range of 850-1000 ℃.