WHITE, OPAQUE, ß-SPODUMENE/RUTILE GLASS-CERAMICS; ARTICLES COMPRISING THE SAME; AND METHODS FOR MAKING THE SAME

摘要

Crystallizable glasses, glass-ceramics, IXable glass-ceramics, and IX glass-ceramics are disclosed. The glass-ceramics exhibit beta-spodumene ss as the predominant crystalline phase. These glasses and glass-ceramics, in mole %, include: 62-75 SiO2; 10.5-17 Al2O3; 5-13 Li3O; 0-4 ZnO; 0-8 MgO; 2-5 TiO2; 0-4 B2O3; 0-5 Na2O; 0-4 K2O; 0-2 ZrO2; 0-7 P2O5; 0-0.3 Fe2O3; 0-2 MnOx; and 0.05-0.2 SnO2. Additionally, these glasses and glass-ceramics exhibit the following criteria: a. a ratio: [ Li 2 ⁢ O + Na 2 ⁢ O + K 2 ⁢ O + MgO + ZnO _ ] ⁢ [ Al 2 ⁢ O 3 + B 2 ⁢ O 3 ] between 0.7 to 1.5; b. a ratio: [ TiO 2 + SnO 2 _ ] ⁢ [ SiO 2 + B 2 ⁢ O 3 ] greater than 0.04. Furthermore, the glass-ceramics exhibit an opacity >=about 85% over the wavelength range of 400-700 nm for an about 0.8 mm thickness and colors an observer angle of 10° and a CIE illuminant F02 determined with specular reflectance included of a* between -3 and +3, b* between -6 and +6, and L* between 88 and 97.