Multi-impurities induced crystallization for fused silica glasses upon heating by contact with the corundum plate

Abstract

Under the thermal treatment, crystallization of fused silica glasses was observed and investigated in detail. Normally, the crystallization of the transparent fused silica glass does not occur with the temperature less than 1200°C even 1380°C. In this paper, cristobalite was present in fused silica by contacting with the corundum plate under the annealing temperature of 850°C. The cristobalite phase transformation from amorphous into polycrystal fused silica glasses was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The crystallization mechanism of the fused silica glass was investigated further. Energy dispersive spectroscopy (EDS) was used to detect impurities of the fused silica glass, and the elements, such as sodium, potassium, aluminum , have been observed. The thermal diffusion process of impurity elements from the corundum plate to the fused silica glass was verified with the X-ray photoelectron spectroscopy (XPS) technique. In view of impurity elements detected by EDS and XPS, multi-impurities induced crystallization of fused silica glasses has been quantitatively analyzed in detail. The research result in this paper can shed light on understanding the mechanism of crystallization and eliminate devitrification of the silica material with the thermal treatment.