A transparent β-quartz glass ceramic is provided. The glass ceramic includes a primary crystal phase including a β-quartz solid solution, a secondary crystal phase including tetragonal ZrO.sub.2, and a lithium aluminosilicate amorphous phase. The glass ceramic may be ion exchanged utilizing molten nitrate salt baths. Methods for producing the glass ceramic are also provided.

A glass-ceramic that includes: SiO.sub.2 from 40 mol % to 80 mol %; Al.sub.2O.sub.3 from 3 mol % to 20 mol %; B.sub.2O.sub.3 from 3 mol % to 50 mol %; WO.sub.3 plus MoO.sub.3 from 1 mol % to 18 mol %; Fe.sub.2O.sub.3 plus MnO.sub.2 from 0.1 mol % to 2 mol %; and R.sub.2O from 0 mol % to 15 mol %. The R.sub.2O is one or more of Li.sub.2O, Na.sub.2O, K.sub.2O, Rb.sub.2O and Cs.sub.2O. Further, R.sub.2O—Al.sub.2O.sub.3 ranges from −12 mol % to +4 mol %.

Embodiments of a transparent glass-based material comprising a glass phase and a second phase that is different from and is dispersed in the glass phase are provided. The second phase may comprise a crystalline or a nanocrystalline phase, a fiber, and/or glass particles. In some embodiments, the second phase is crystalline. In one or more embodiments, the glass-based material has a transmittance of at least about 88% over a visible spectrum ranging from about 400 nm to about 700 nm and a fracture toughness of at least about 0.9 MPa.Math.m.sup.1/2, and wherein a surface of the glass-based material, when scratched with a Knoop diamond at a load of at least 5 N to form a scratch having a width w, is free of chips having a size of greater than 3w.

The present invention discloses a microcrystalline glass, a microcrystalline glass product, and a manufacturing method therefor. The main crystal phase of the microcrystalline glass comprises lithium silicate and a quartz crystal phase. The haze of the microcrystalline glass of the thickness of 0.55 mm is below 0.6%. The microcrystalline glass comprises the following components in percentage by weight: SiO.sub.2: 65-85%; Al.sub.2O.sub.3: 1-15%; Li.sub.2O: 5-15%; ZrO.sub.2: 0.1-10%; P.sub.2O.sub.5: 0.1-10%; K.sub.2O: 0-10%; MgO: 0-10%; ZnO: 0-10%. A four-point bending strength of the microcrystalline glass product is more than 600 Mpa.

Embodiments of a transparent glass-based material comprising a glass phase and a second phase that is different from and is dispersed in the glass phase are provided. The second phase may comprise a crystalline or a nanocrystalline phase, a fiber, and/or glass particles. In some embodiments, the second phase is crystalline. In one or more embodiments, the glass-based material has a transmittance of at least about 88% over a visible spectrum ranging from about 400 nm to about 700 nm and a fracture toughness of at least about 0.9 MPa.Math.m.sup.1/2, and wherein a surface of the glass-based material, when scratched with a Knoop diamond at a load of at least 5 N to form a scratch having a width w, is free of chips having a size of greater than 3w.

To provide an inorganic composition article containing at least one kind selected from α-cristobalite and α-cristobalite solid solution as a main crystal phase, in which by mass % in terms of oxide, a content of a SiO.sub.2 component is 50.0% to 75.0%, a content of a Li.sub.2O component is 3.0% to 10.0%, a content of an Al.sub.2O.sub.3 component is 5.0% or more and less than 15.0%, and a total content of the Al.sub.2O.sub.3 component and a ZrO.sub.2 component is 10.0% or more, and a surface compressive stress value is 600 MPa or more.

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, the oxidation protection system comprises a boron-glass layer formed on the composite substrate and a silicon-glass layer formed over the boron-glass layer. Each of the boron-glass layer and the silicon-glass layer include a glass former and a glass modifier.

A glass ceramic manufactured by sequentially performing the processes of melting and thermal decomposition, water quenching and sintering of a glass composite. The glass ceramic includes 38 wt % to 49 wt % CaO, 41 wt % to 52 wt % SiO.sub.2 and 0.1 wt % to 20 wt % P.sub.2O.sub.5. The glass composite includes a glass component and P.sub.2O.sub.5, and the glass component includes CaCO.sub.3 and SiO.sub.2 and does not include an alkali metal oxide. The melting and thermal composition temperature is from 1350° C. to 1650° C. The sintering temperature is from 750° C. to 1050° C. By the combination of CaO, SiO.sub.2 and P.sub.2O.sub.5 and the control of the contents of CaO, SiO.sub.2 and P.sub.2O.sub.5 within the aforementioned ranges, and the glass ceramic contains no alkali metal oxide, the glass ceramic has good mechanical strength and low cytotoxicity.

A transparent colored glass ceramic, in particular an LAS glass ceramic, suitable for use as a cooking surface is provided. The transparent colored glass ceramic includes high-quartz solid solution (HQ s.s.) as a main crystal phase and exhibits thermal expansion of −1 to +1 ppm/Kin the range from 20° C. to 700° C. The glass ceramic has from 3.0 to 3.6 percent by weight of lithium oxide (Li.sub.2O) as constituents and either is colored with 0.003 to 0.05 percent by weight of vanadium oxide (V.sub.2O.sub.5) or is colored with 0.003 to 0.25 percent by weight of molybdenum oxide (MoO.sub.3).

The present invention relates to inorganic fibres having a composition comprising: 65.7 to 70.8 wt % SiO.sub.2; 27.0 to 34.2 wt % CaO; 0.10 to 2.0 wt % MgO; and optional other components providing the balance up to 100 wt %,
wherein the sum of SiO.sub.2 and CaO is greater than or equal to 97.8 wt %; and the other components, when present, comprise no more than 0.80 wt % Al.sub.2O.sub.3; and wherein the amount of MgO and other components are configured to inhibit the formation of surface crystallite grains upon heat treatment at 1100° C. for 24 hours, wherein said surface crystallite grains comprise an average crystallite size in a range of from 0.0 to 0.90 μm.