Glass is usually divided into oxide glass and non-oxide glass according to its main components.There are few varieties and quantities of non-oxide glass, mainly sulfur glass and halide glass.The anions of sulfur glass are mostly sulfur, selenium, tellurium, etc., which can cut off short wavelength light and pass through yellow, red light, and near and far infrared light, with low resistance and switching and memory characteristics.Halide glass has low refractive index and low dispersion and is used as optical glass.
Oxide glass is divided into silicate glass, borate glass, phosphate glass and so on.Silicate glass refers to the basic component of SiO2 glass, its variety, wide use.Usually according to the different content of SiO2, alkali metal and alkaline earth metal oxide in glass, it can be divided into:
Quartz glass.SiO2 content is greater than 99.5%, low thermal expansion coefficient, high temperature resistance, good chemical stability, ultraviolet and infrared light penetration, high melting temperature, high viscosity, forming difficult.It is widely used in semiconductor, electric light source, optical communication, laser and other technologies and optical instruments.
High silica glass.Also known as Vycor glass, the main component is SiO2 content about 95%~98%, containing a small amount of B2O3 and Na2O, its properties are similar to quartz glass.
Sodium calcium glass.Mainly containing SiO2, 15% Na2O and 16% CaO, it is cheap, easy to form and suitable for mass production, accounting for 90% of practical glass.Can produce glass bottle, plate glass, utensils, bulbs and so on.
Lead silicate glass.The main components are SiO2 and PbO, with unique high refractive index and high volume resistance, and good wetting with metal, which can be used in the manufacture of bulb, vacuum tube core column, crystal glassware, flint optical glass, etc.Leaded glass containing large amounts of PbO blocks X-rays and gamma rays.
5. Aluminosilicate glass.SiO2 and Al2O3 as the main components, high softening deformation temperature, used for the production of discharge bulbs, high temperature glass thermometer, chemical combustion tube and glass fiber.
Borosilicate glass.SiO2 and B2O3 as the main components, with good heat resistance and chemical stability, for the manufacture of cooking utensils, laboratory instruments, metal welded glass.Borate glass with B2O3 as the main component, low melting temperature, can resist sodium vapor corrosion.Borate glass containing rare earth elements is a new kind of optical glass with high refractive index and low dispersion.Phosphate glass is mainly composed of P2O5 with low refractive index and low dispersion. It is used in optical instruments.