An opaque gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (Mg.sub.xZn.sub.1-x)Al.sub.2O.sub.4 where x is less than 1 and a second crystal phase includes at least one of tetragonal ZrO.sub.2, MgTa.sub.2O.sub.6, mullite, and cordierite. The glass ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

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 resin composition for inorganic molded article production use, which is provided with inorganic particles each containing amorphous SiO.sub.2 and a photocurable resin composition, in which the photocurable resin composition contains a photocurable resin precursor and a photopolymerization initiator, the content of the inorganic particles is 60% by mass or more with respect to the total amount of the photocurable resin composition and the inorganic particles and is 60% by mass or more with respect to the entire amount of the resin composition for inorganic molded article production use, and the viscosity of the composition for inorganic molded article production use is 10000 mPa.Math.s or less.

A known method for homogenizing glass includes the following steps: providing a cylindrical blank composed of the glass, having a cylindrical outer surface which extends between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and moving the shear zone along the longitudinal axis of the blank. To reduce the risk of cracks and fractures during homogenizing, it is proposed that a thermal radiation dissipator is used that at least partially surrounds the shear zone, the lateral dimension of which in the direction of the longitudinal axis of the blank is greater than the shear zone and smaller than the length of the blank, the thermal radiation dissipator being moved synchronously with the shear zone along the longitudinal axis of the blank.

Proppants and methods for their preparation are described herein. The proppants can be prepared by a process comprising (a) directing the molten slag material at a temperature above 1300 C. to an atomizing apparatus to output the molten slag material in the form of atomized droplets, (b) projecting the droplets of the molten slag material, wherein a substantial portion of the droplets at least partially solidifies in flight, (c) maintaining the at least partially solidified droplets at a temperature between 700 C. and 1300 C. to provide proppant particles having a crystalline phase; and (d) cooling the proppant particles to below 700 C. Methods for hydraulic fracturing of a well in a subterranean formation having a fracturing stress are also described herein.

Glass articles and methods for modifying a composition of a surface portion of the glass article are disclosed. The method includes heating the surface portion of the glass article with a laser beam to a temperature within a range of about 1100?C to about 2200?C such that the heating evaporates one or more metalloids and/or one or more alkali metals present at the surface portion, and modifies the composition of the surface portion such that the surface portion has a lower alkali metals concentration and/or a lower metalloids concentration as compared to a portion of the glass article that is not heated by the laser beam.

A glass-ceramic article having one or more crystalline phases; a residual glass phase; a compressive stress layer extending from a first surface to a depth of compression (DOC); a maximum central tension greater than 70 MPa; a stored tensile energy greater than 22 J/m.sup.2; a fracture toughness greater than 1.0 MPam; and a haze less than 0.2.

A precision extreme ultraviolet lithography (EUVL) component having an average coefficient of thermal expansion (CTE) in a range from 0 to 50? C. of at most 0?0.1?10.sup.?6/K, and a thermal hysteresis of <0.1 ppm at least in the temperature range from 19 to 25? C., and an index F of <1.2. F=TCL (0; 50? C.)/|expansion (0; 50? C)|, where TCL is a total change of length.

According to an embodiment, a cover glass includes a glass plate forming at least a portion of an electronic device, and a first coat layer deposited on a surface of the glass plate, the first coat layer at least partially including a network structure. The first coat layer includes silicon (Si), oxygen (O), and at least one impurity, and such that SiO bonds are 80% or more by weight of the first coat layer. A polysilazane-applied coat is laid over one surface of the reinforced glass plate, providing an elegant haze glass cover.

A method of manufacturing a bonded body includes a preparation step of interposing a sealing material containing glass between a highly thermal conductive substrate and a glass substrate, and a bonding step of forming a sealing layer by irradiating the sealing material with laser light. The bonding step includes a first heating step of preheating the sealing material at a temperature lower than a softening point of the sealing material or a temperature at which the sealing material is prevented from softening and flowing by irradiation with the laser light, and a second heating step of heating, after the first heating step, the sealing material at a temperature equal to or higher than the softening point of the sealing material or a temperature at which the sealing material softens and flows by irradiation with the laser light.