Effects of composite nucleating agents on crystallization behavior and properties of fluorphlogopite glass-ceramics

Abstract

In this paper, fluorophlogopite glass-ceramics were prepared by the conventional melt-quenching and two-step treatment methods. The effects of composite nucleating agent (TiO2+ZrO2) and heat-treatment on crystallization behavior, microstructure and properties of glass-ceramics were systematically analyzed by DSC, XRD and SEM and other detection methods. The results show that TiO2 and ZrO2 promote glass microcrystallization by inducing phase separation. When the content of nucleating agent was 3 wt%, crystallinity of glass-ceramics crystallized at 1100 °C for 4 h reaches the highest (74.48%). At the same time, the Vickers hardness of glass-ceramic was the smallest, while the theoretical machinability was the best, reaching 0.1391. The prepared samples have low dielectric constant (8.3–8.7, 1 MHz), dielectric loss (0.4–1.2 × 10−3, 1 MHz) and high volume resistivity (3.66-4.02 × 1011 Ω•cm) at room temperature. It can be widely used in electronic instruments and chemical equipment that require high dimensional accuracy of components and good electrical insulation.