Quartz glass is a single component of silica glass, usually divided into transparent quartz glass and opaque quartz glass (fused quartz). Transparent quartz glass has only a small amount of bubbles, and has high optical uniformity and transparency. It is made from crystal or silicon tetrachloride by high temperature melting. The content of SiO2 is above 99.95%, and that of high purity quartz glass is more than 99.999%. Opaque quartz glass is made from vein quartz and quartz sand by high temperature melting, containing more than 299.5% SiO2.

Because quartz glass is a network framework composed of pure (SiO4) tetrahedron, and the silicon oxygen bond is strong and the structure is tight, so the mechanical strength and heat resistance are very high, the coefficient of thermal expansion is very small, the chemical stability is also very good, at the same time, the viscosity is high, the softening point is also very high, because there is no interstitial cation in the network, so the density, conductivity and medium loss are small.

Mechanical properties The mechanical properties of quartz glass are better than that of hard glass and ceramics. The strength of the newly drawn defect free quartz glass fiber is 24100 × 106 Pa. the quartz tube and quartz glass equipment with small diameter can withstand great pressure. If there are macroscopic defects in quartz glass products, such as bubbles, foreign impurities, uneven melting and residual stress, their strength will be affected and reduced.

Mechanical properties of quartz glass failure pressure of quartz glass tube

The tensile strength of transparent quartz glass increases from room temperature to 900oc, and the impact strength shows the maximum.