Crystallization,microstructure and mechanical behavior of titanium doped barium fluormica glass-ceramics

Crystallization, microstructure and mechanical behavior of TiO₂ doped barium fluorphlogopite glass-ceramics were systematically studied. TiO₂ was used as a doper nucleant in the BaO·4MgO·Al₂O₃·6SiO₂·2MgF₂ glass system. Melting technique was adopted to prepare the glass samples which were analyzed by differential thermal analysis (DTA), X-ray diffraction, scanning electron microscopy, and micro hardness indenter. The DTA study demonstrated that the crystallization exotherm of fluorphlogopite mica appeared in the temperature window of 886-903°C. In this investigation, four glass samples were prepared using 2 (MA1), 4 (MA2), 6 (MA3), and 8 (MA4) wt% of TiO_2. Glass transition (T_g) and peak crystallization (T_p) temperatures escalated with an increase in the TiO₂ content from 2 (MA1) to 4 wt% (MA2). However, beyond this value, T_g and T_p decreased with a surge in TiO₂ content from 6 (MA3) to 8 wt% (MA4). Nevertheless, with a gradual rise in the TiO₂ content, the crystals of the glass-ceramics became enlarged and subsequently exhibited mechanical properties, such as hardness, fracture toughness, and machinability. Therefore, in solid oxide fuel cell applications, TiO₂ is a promising nucleating agent to generate fluorphlogopite mica-based glass-ceramics.