Shi Ying glass has a small coefficient of thermal expansion of 5.5× 10 - 7 / ℃ and only 1 / 12 ~ 1 / 20 of ordinary glass. According to the standard, the sample is burned to 1200 ℃ and then thrown into cold water rapidly. No cracking is allowed after repeated for more than three times.  Shi Ying glass can also be made into material with zero expansion coefficient after adding appropriate amount of titanium, which has been applied in laser technology, astronomy and cutting-edge technology.

 Detailed information

 The expansion coefficient of transparent Shi Ying glass is a function of temperature: α 0, t = 1 / L0× ( lt - L0 ) / t in the formula: L0 = length at 0 ℃ lt = length at t ℃ t = viscosity of Shi Ying glass at temperature t ℃, thermal conductivity, specific heat and service temperature are shown in Table 9, 10, 11, 12, 13. Table 9 Viscosity of Shi Ying glass ( strain point, annealing point and softening point ) vs. temperature ( LG η, poise ) Crystal Shi Ying glass synthesizes Shi Ying glass strain point 14.51075 ℃ 25 1025 ℃ 25 ℃ annealing point 13.0140