Study on preparation and properties of boron bismuth/fluorooxy glass and glass-ceramics

Boron-bismuth/fluorine-oxygen glass was prepared by the traditional high-temperature melting annealing method. By studying and analyzing the effects of B₂O₃ and CaF₂ on the density, molar volume, thermal expansion coefficient and glass softening temperature of these two component glasses, it can be gained a deeper understanding of the structure and performance of the glass system. As the B₂O₃ content in boron-bismuth glass increases, some [BO₃] triangles in the glass will transform into [BO₄] tetrahedrons, the glass network structure will shrink, and the thermal stability of the glass will increase. With the increase of CaF₂ content in fluorinated oxygen glass, the phenomenon of F⁻ replacing O⁻ occurs in the glass network structure, the breaking of the bridge oxygen bond makes the glass network loose, and the thermal stability of the glass decreases. To select the glass with good comprehensive performance and pre-formulate the corresponding heat treatment system are to obtain glass ceramics with good crystallinity.