Glass with low thermal expansion

摘要

The glass comprises in moles .% 50 - 90 SiO2, 0.5 - 30 Al2O3, 1.5. - 35 Cu2O + CuO and 0.5 - 20 ZnO. Specif. the glass produced has a linear expansion coefficient of 15 x 10-7 per degrees C (0 - 300 degrees C), and may be used to weld melted quartz to melted quartz or ceramics, ceramics to ceramics and melted silica to melted silica. It is used for astronomical mirrors.