Abstract:
Moulded bodies made of quartz glass with at least one surface region of tranparent quartz glass, whose free surfaces are smooth and which have a superficial microroughness of less than 8 mu m, are already known. To facilitate production of such a body having a simple structure, cost-effectively and without the need for the stocking or separate production of auxiliary components, it will consist of a core body, the base material of which is at least 99.9 % chemically pure and has a cristobalite content of no more than 1 %; is impermeable to gases, opaque, and porous, has a virtually constant direct spectral transmission in the wavelength range lambda = 190 nm - lambda = 2.650 nm of below 10 % for 1 mm of thickness, and has a density of at least 2.15 g/cm . The transparent surface region is formed from the base material which is heat treated at a temperature in excess of 1.650 DEG C, is at least 0.5 mm thick and has a direct spectral transmission of at least 60 % in the wavelength range lambda = 600 nm - lambda = 2.650 nm for 1 mm of thickness. The invention also relates to process for manufacturing a moulded body of this type from quartz glass.
Abstract:
A process for the manufacture of a synthetic silica product by vapour-phase oxidation of a silica precursor material in a flame not less than 60 % of the silica in the deposited product being derived by oxidation of: (A) one or more straight chain volatile silicon compounds of the general formula: R3Si.O(SiR2O)n.SiR3 and/or (B) one or more cyclic volatile silicon compounds of the general formula: SinOn(R)2n. Doped or undoped fume powder, porous silica soot or fully densified bodies made by the process are also claimed.
Abstract:
A method for manufacturing a quartz glass substrate with a coating formed includes: surface roughening for a base surface of the quartz glass substrate, on which the sprayed coating is formed; and a heating treatment of heating the substrate after the surface roughening. The base surface is 0.9 μm or more and 5.0 μm or less in arithmetic mean roughness (Ra) in the surface roughening. The heating treatment is performed at a temperature that is equal to or higher than a strain point (temperature at which the viscosity reaches 1013.5 Pa·sec) of the quartz glass.
Abstract:
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 ZrO2, 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.
Abstract:
Systems and methods for forming a permanent plug in a subterranean formation include providing a solution of colloidal silica and pumping the colloidal silica into a bore of a subterranean well so that the colloidal silica penetrates pores of the subterranean formation. The colloidal silica within the pores of the subterranean formation is dehydrated to form a glass-like material within the pores of the subterranean formation.
Abstract:
Alkali-free glasses are disclosed having (in weight %) 50≦SiO2≦80%, 2≦Al2O3≦17%, 8≦B2O3≦36%, and greater than or equal to 2% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO. The alkali-free glasses can have a surface layer with greater than 0.2 weight % N. Such alkali-free glasses are achieved by nitriding processes and exhibit increased strength, scratch resistance and chemical durability.
Abstract:
To provide opaque quartz glass having no water absorbing properties and being excellent in infrared light shielding properties, and a method for its production. In the production of opaque quartz glass of the present invention, a fine amorphous silica powder and a pore forming agent are mixed, then molded and heated at a predetermined temperature, to obtain opaque quartz glass wherein contained pores are closed pores, the average pore size of pores is from 5 to 20 μm, and the content density of pores is high, whereby the heat shielding properties are high.
Abstract:
A method for producing synthetic quartz glass by fusion of SiO2 granulate involves synthesizing amorphous SiO2 primary particles, granulating the amorphous SiO2 primary particles to form an open-pore SiO2 granulate, sintering the open-pore SiO2 granulate by heating in a sintering atmosphere at a sintering temperature and for a sintering period to form a densified SiO2 granulate, and melting the densified SiO2 granulate at a melting temperature to form the synthetic quartz glass. To provide an inexpensive production of low-bubble transparent components of quartz glass despite the use of still open-pore SiO2 granulate, the sintering atmosphere, sintering temperature and sintering duration are adjusted such that the densified SiO2 granulate still comprises open pores but manifests a material-specific infrared transmission T1700 at a wavelength of 1700 nm. This transmission is in the range of 50-95% of the infrared transmission T1700 of quartz glass granules of the same material.
Abstract:
The synthetic amorphous silica powder of the present invention is characterized in that it comprises a synthetic amorphous silica powder obtained by applying a spheroidizing treatment to a silica powder, and by subsequently cleaning and drying it so that the synthetic amorphous silica powder has an average particle diameter D50 of 10 to 2,000 μm; wherein the synthetic amorphous silica powder has: a quotient of 1.00 to 1.35 obtained by dividing a BET specific surface area of the powder by a theoretical specific surface area calculated from the average particle diameter D50; a real density of 2.10 to 2.20 g/cm3; an intra-particulate porosity of 0 to 0.05; a circularity of 0.75 to 1.00; and a spheroidization ratio of 0.55 to 1.00.
Abstract:
Alkali-free glasses are disclosed having (in weight %) 50≦SiO2≦80%, 2≦Al2O3≦17%, 8≦B2O3≦36%, and greater than or equal to 2% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO. The alkali-free glasses can have a surface layer with greater than 0.2 weight % N. Such alkali-free glasses are achieved by nitriding processes and exhibit increased strength, scratch resistance and chemical durability.
Abstract translation:公开了无碱玻璃,其重量百分比为50%,SiO 2和N 100; 80%,2%,Al 2 O 3和N 2; 17%,8%和10%; B 2 O 3和N 3; 36%,并且大于或等于2%且小于或等于 CaO,MgO,BaO,SrO或ZnO中的至少一种。 无碱玻璃可以具有大于0.2重量%N的表面层。这种无碱玻璃通过渗氮工艺实现,并且显示出增加的强度,耐划伤性和化学耐久性。