Research on high-temperature wettability between SiO2Al2O3CaO MgO glass melt droplets and platinum rhodium alloy

Abstract The high-temperature contact angles, which is concern with high-temperature wettability, between the glass melt droplets and the wire-drawing bushing has important influence on the fiberglass drawing forming. The contact angles between SiO 2 Al 2 O 3 CaO MgO glass melt droplets and Platinum Rhodium alloys were studied by sessile droplets method under high temperature and high vacuum wetting testing system. The images of contact angles between the glass melt droplets and platinum alloys were taken by CMOS camera and the contact angles were analyzed. The results indicate that the trend of contact angles with temperature can be divided into three stages: a gentle wave stage, a sharp drop stage, and a slow drop stage. The first stage change temperature is about 1170 °C and the second is about 1340 °C. Combined with the DSC curve and the SiO 2 Al 2 O 3 CaO MgO quaternary phase diagram, these changes may be mainly caused by phase transitions of quartz. The temperature matching contact angles 90° is about 1265 °C. The contact angles for PtRh20 and ODS-PtRh20 have a little difference: when below 1300 °C, the contact angles for PtRh20 is lower than ODS-PtRh20. When above 1300 °C, there are not obvious differences, and ODS-PtRh20 is slightly lower.