Influence of NaF on Crystallization and Machinability of Mica Glass Ceramics

• Published in: Synthesis and reactivity in inorganic, metal-organic, and nano-metal chemistry metal-organic, and nano-metal chemistry, 2012-08, Vol.42 (7), p.958-964
• Main Authors: Ghasemzadeh, M., Nemati, A., Hamnabard, Z., Baghshahi, S., Golikand, A. Nozad
• Format: Article
• Language: English
• Subjects: crystallization kinetics; glass ceramics; machinability; phlogopite; transparency
• ISSN: 1553-3174; 1553-3182
• DOI: 10.1080/15533174.2012.680105

Effect of NaF on crystallization kinetics, microstructure, and mechanical properties of mica glass ceramics were investigated by the differential thermal analysis (DTA), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and microhardness tests. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses are changed in the range of 235-246 KJ/mol, while the crystallization activation energies of samples with addition of NaF are changed in the range of 263-367 KJ/mol. The increase of crystallization temperature is helpful for the increase of aspect ratio, and the microstructure of the glass ceramics becomes interconnected, which contributes the improvement of the machinability of the glass ceramics. Microhardness (H v ), cutting energy (μ 1 ), and machinability parameter (m) can be used for estimating the machinability of mica glass ceramics. Transparency in the studied glass samples is assumed to occur due to the presence of crystallites with nano size.