TRANSPARENT GLASS CERAMIC AND METHOD OF ITS PRODUCTION Russian patent published in 2024 - IPC C03C10/02 C03C3/87 

FIELD: glass.

SUBSTANCE: invention relates to optical material science, particularly to a method of producing articles from glass and transparent glass ceramics. Transparent glass ceramic contains, mol.%: Na₂O 5.00–7.00, ZrO₂ 1.00–2.00, TiO₂ 5.00–6.00, MgO 8.00–10.00, Al₂O₃ 9.00–10.00, ZnO 18.00–20.00, SiO₂ 48.00–50.00. Method of producing transparent glass ceramic involves mixing a mixture of said components in a drum-type mixer and cooking in an electric furnace in corundum crucibles at temperature of 1,560±2 °C and holding duration of not less than 2 hours with mechanical mixing of glass mass at the stage of homogenisation and production of glass mass into metal mould. Annealing is performed at temperature of 610±2 °C for at least 4 hours and subsequent additional heat treatment. At the same time the subsequent additional heat treatment is carried out according to the two-stage mode. At the first stage at temperature of 780–800 °C for 2–4 hours. At the second stage at temperature of 850–950 °C for 10–20 hours. Additionally, ion exchange is carried out in molten potassium nitrate at temperature of 450±2 °C for 24–72 hours.

EFFECT: surface and volume hardening of transparent glass ceramic.

2 cl