Flow of a Viscoplastic Arsenic Selenide Melt in Circular-Cylindrical Channels

Abstract

The flow rate of molten arsenic selenide in circular-cylindrical channels was measured as a function of temperature and excess gas pressure over the melt with application to the fabrication of optical fibers by crucible methods. The channel diameter was 3.0, 4.2, and 4.5 mm, and the channel length was 120 mm. The temperature was varied from 285 to 320 ° C, and the excess pressure of the inert gas was up to 1.5 × 10 5 Pa. The results demonstrate that there is a threshold pressure for melt flow, suggesting that the melt is a viscoplastic fluid. The experimental data are interpreted in terms of the Shvedov-Bingham rheological model.