Expansion coefficient of high borosilicate glass

High borosilicate glass has a very low coefficient of thermal expansion, only about one-third of ordinary glass, which will reduce the impact of temperature gradient stress, thus having stronger fracture resistance, even if the temperature changes suddenly, high borosilicate glass is not easy to break. The shape deviation is very small, and when broken, high borosilicate glass will have large cracks instead of crushing into particles. At the same time, high borosilicate glass also has low dispersion and relatively low refractive index.
The linear expansion coefficient of high borosilicate glass G3.3 is (3.3, 0.1) ×10-6K-1, which is a kind of glass based on sodium oxide (Na2O), boron oxide (B2O3), and silicon dioxide (SIO2). The content of borosilicate in the glass is higher, which are boron (12.5~13.5) % and silicon (78~80) % respectively.