Provided is a high-strength crystallized glass or substrate having a high visible light transmittance and a good color balance, which is suitable for use in protecting members of portable electronic devices, optical devices and the like. Provided is a crystallized glass comprising, in terms of mol % on an oxide basis: an SiO.sub.2 component of 30.0% or more and 70.0% or less, an Al.sub.2O.sub.3 component of 8.0% or more and 25.0%, an Na.sub.2O component of 0% or more and 25.0% or less, an MgO component of 0% or more and 25.0% or less, a ZnO component of 0% or more and 30.0% or less and a TiO.sub.2 component of 0% or more and 10.0% or less, the molar ratio [Al.sub.2O.sub.3/(MgO+ZnO)] having a value of 0.5 or more and 2.0 or less, and comprising one or more selected from RAl.sub.2O.sub.4, RTi.sub.2O.sub.5, R.sub.2TiO.sub.4, R.sub.2SiO.sub.4, RAl.sub.2Si.sub.2O.sub.8 and R.sub.2Al.sub.4Si.sub.5O.sub.18 as a crystal phase.

Embodiments of a glass-ceramic, glass-ceramic article or glass-ceramic window that includes 40 mol %SiO.sub.280 mol %; 1 mol %Al.sub.2O.sub.315 mol %; 3 mol %B.sub.2O.sub.350 mol %; 0 mol %R.sub.2O15 mol %; 0 mol %RO2 mol %; 0 mol %P.sub.2O.sub.53 mol %; 0 mol %SnO.sub.20.5 mol %; 0.1 mol %MoO.sub.315 mol %; and 0 mol %WO.sub.310 mol % (or 0 mol %<MoO.sub.315 mol %; 0.1 mol %WO.sub.310 mol %; and 0.01 mol %V.sub.2O.sub.50.2 mol %), wherein the WO.sub.3 (mol %) plus the MoO.sub.3 (mol %) is from 1 mol % to 19 mol %, and wherein R.sub.2O (mol %) minus the Al.sub.2O.sub.3 (mol %) is from 12 mol % to 4 mol %, are disclosed.

A glass-ceramic includes a silicate-containing glass and crystals within the silicate-containing glass. The crystals include non-stoichiometric tungsten and/or molybdenum sub-oxides, and the crystals are intercalated with dopant cations.

Embodiments of the present disclosure are directed to methods for inducing color change in glass and glass-ceramic articles. According to one embodiment, color change may be x-ray induced in glass or glass-ceramic articles. The method for x-ray inducing color change may include exposing the glass or glass-ceramic article to x-rays at a temperature of up to 200 C. to induce a colored area in the glass or glass-ceramic article. The glass or glass-ceramic article may comprise: 50-85 mole % SiO.sub.2; 5-25 mole % Al.sub.2O.sub.3; 0-15 mole % P.sub.2O.sub.5; 0-15 mole % B.sub.2O.sub.3; 5-25 mole % R.sub.2O, wherein R.sub.2OLi.sub.2O+Na.sub.2O+K.sub.2O.

A coated glass or glass ceramic substrate includes a substrate with a surface area and a coating on that surface area. The coating includes a glass matrix and IR-reflecting pigments. The IR-reflecting pigments have a TSR value of at least 20%, as determined according to ASTM G 173. The coating, at a wavelength of 1500 nm, exhibits a remission of at least 35%, as measured according to ISO 13468.

A glass-ceramic includes SiO.sub.2 from about 50 mol % to about 80 mol %, Al.sub.2O.sub.3 from about 0.3 mol % to about 15 mol %, B.sub.2O.sub.3 from about 5 mol % to about 40 mol %, WO.sub.3 from about 2 mol % to about 15 mol %, and R.sub.2O from about 0 mol % to about 15 mol %, wherein R.sub.2O is one or more of Li.sub.2O, Na.sub.2O, K.sub.2O, Rb.sub.2O and Cs.sub.2O. A difference in the amount of the R.sub.2O and the Al.sub.2O.sub.3 ranges from about 12 mol % to about 2.5 mol %.

The present invention relates to a glass ceramic for veneering a dental frame structure, wherein said glass ceramic is characterized by a high content of B.sub.2O.sub.3, to a process for the preparation thereof, and to the use thereof in the production of dental restorations.

Glass-ceramics exhibiting a Vickers indentation crack initiation threshold of at least 15 kgf are disclosed. These glass-ceramics may be ion exchangeable or ion exchanged. The glass-ceramics include a crystalline and amorphous phases generated by subjecting a thin precursor glass article to ceramming cycle having an average cooling rate in the range from about 10 C./minute to about 25 C./minute. In one or more embodiments, the crystalline phase may comprise at least 20 wt % of the glass-ceramics. The glass-ceramics may include -spodumene ss as the predominant crystalline phase and may 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.

The application relates to bond materials for a grinding wheel, in particular a glass ceramic and a preparation method thereof, and a bond for the composite grinding wheel. The glass ceramic is prepared from raw materials comprising kaolin, silica, diboron trioxide, lithium superoxide, albite, potassium feldspar, talc, dolomite, phosphorus pentoxide, and yttrium oxide. A glass ceramic composed entirely of microcrystalline phases is obtained from the glass prepared by the above raw materials at 900-1020 C., achieving a complete conversion of the glass phase at a low temperature. The application also provides a bond for a composite grinding wheel, comprising glass ceramic and glass with mass ratio of (20-50):(50-80), the glass phase having a low flow temperature and, together with the glass ceramic phase, forming encapsulation of the abrasive particles, realizing low-temperature sintering of the grinding wheel. Microcrystalline phase in the bond results in high mechanical strength for the obtained grinding wheel.

A glass-ceramic includes a silicate-containing glass and crystals within the silicate-containing glass. The crystals include non-stoichiometric tungsten and/or molybdenum sub-oxides, and the crystals are intercalated with dopant cations.