VITROCRYSTALLINE MATERIAL Russian patent published in 2008 - IPC C03C10/12 

FIELD: manufacture of vitrocrystalline materials (glass ceramics) which are transparent in visible area of spectrum.

SUBSTANCE: proposed vitrocrystalline material contains the following constituents, mass-%: SiO₂, 45.0-65.0; Al₂O₃, 20.0-35.0; Li₂O, 3.2-5.0; P₂O₅, 4.0-10.0; TiO₂, 3.0-4.0; ZrO₂,1.0-2.8; CaO, 1.0-3.0; MgO, 0.5-2.8; As₂O₃, 0.5-1.5; Sb₂O₃, 0.3-1.0. Welding is carried out at temperature of 1570±10 C. Maximum solidification temperature is 760-800 C. Glass ceramic thus obtained is characterized by fine dispersed structure at size of crystals of 25-30 nm, high transparency and enhanced acid resistance. Thermal linear expansion coefficient of glass ceramics is practically equal to zero within temperature interval of from minus 20 to plus 40 C. Proposed vitrocrystalline material may be used for manufacture of precision optic article requiring stability of linear sizes at abrupt change in temperature.

EFFECT: ultra-low thermal linear expansion coefficient; enhanced transparency; enhanced thermal and chemical resistance; enhanced thermal stability of main properties and linear sizes at change of temperature.

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