Abstract: PbO-B₂O₃ glasses were melted and solidified through drop shaft experiment to explore the phase-separation of the glasses under different gravity conditions. XRD was conducted to determine the phase of samples after phase-separation. The distribution of elements in different samples was compared through EDS analysis and the microstructures were observed by SEM. Results show that both Pb-rich phase and B-rich phase consistently exist in all the glasses no matter how different the gravity level is. For the sample of phase-separation happened under high gravity, the size of separated Pb-rich phase in the top of the sample is much smaller than that in the bottom of the sample, and the homogeneization of elements is the worst due to the difference in density between Pb-rich phase and B-rich phase.

Key words: lead-borate glass, phase-separation, gravity