938 results about "Fused quartz" patented technology

Embodiments of the present invention are directed to apparatuses and methods of making a micromachined resonator gyroscope, e.g. a disc resonator gyro (DRG), including one or more of the following novel features. Embodiments of the invention may comprise a triple-wafer stack gyroscope with an all fused quartz (or all silicon) construction for an electrical baseplate, resonator and vacuum cap. This can yield superior thermal stability over prior art designs. A typical resonator embodiment may include a centrally anchored disc with high aspect-ratio in-plane electrostatic drive and sense electrodes to create large capacitance. A silicon sacrificial layer may be employed for attaching a quartz resonator wafer to a quartz handle wafer for high aspect-ratio etching. In addition, embodiments of the invention may comprise a low thermal stress, wafer-level vacuum packaged gyroscope with on-chip getter. An ultra-thin conductive layer deposited on the quartz resonator may also be utilized for high Q.

A high silica glass composition comprising about 82 to about 99.9999 wt. % SiO₂ and from about 0.0001 to about 18 wt. % of at least one dopant selected from Al₂O₃, CeO₂, TiO₂, La₂O₃, Y₂O₃, Nd₂O₃, other rare earth oxides, and mixtures of two or more thereof. The glass composition has a working point temperature ranging from 600 to 2,000° C. These compositions exhibit stability similar to pure fused quartz, but have a moderate working temperature to enable cost effective fabrication of pharmaceutical packages. The glass is particularly useful as a packaging material for pharmaceutical applications, such as, for example pre-filled syringes, ampoules and vials.

The present invention discloses a process for making rare earth (RE) doped optical fibre by using RE oxide coated silica nanoparticles as the precursor materia, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc., the coated tubes were further processed into optical preforms by following MCVD technique and fiberised in desired configuration, the novelty lies in eliminating the step of the formation of porous soot layer at high temperature by CVD process inside a fused silica glass tube for formation of the core and also in the elemination of the incorporation of the rare earth ions into the porous soot layer following the solution doping technique or other conventional methods, the direct addition of RE oxides in the sol eliminates the formation of microcrystalites and clusters of rare earth ions and prevents change in composition including variation of RE concentration in the core which results in increase in the reproducibility and reliability of the process to a great extent, further the addition of Ge(OET)4 at ambient temperature in the silica sol reduces the quantity of GeCl4 which is required at high temperature to achieve the desired Numerical Aperture.

A high silica glass composition comprising about 92 to about 99.9999 wt. % SiO₂ and from about 0.0001 to about 8 wt. % of at least one dopant selected from Al₂O₃, CeO₂, TiO₂, La₂O₃, Y₂O₃, Nd₂O₃, other rare earth oxides, and mixtures of two or more thereof. The glass composition has a working point temperature ranging from 600 to 2,000° C. These compositions exhibit stability similar to pure fused quartz, but have a moderate working temperature to enable cost effective fabrication of pharmaceutical packages. The glass is particularly useful as a packaging material for pharmaceutical applications, such as, for example pre-filled syringes, ampoules and vials.

The invention belongs to the field of inorganic non-metallic materials, and relates to the improvement of technology for preparing a fused quartz ceramic crucible. The method for preparing the fused quartz ceramic crucible comprises the steps of mixing-pulping-adding catalyst and initiator-gelatinating-drying- sintering. In the method, multi-stage fused quartz powder is taken as a raw material to prepare the quartz ceramic crucible by gel casting. The quartz ceramic crucible can realize even mixing of multiple dimensioned materials; furthermore, the prepared crucible has uniform structure, controllable porosity as well as excellent thermal shock resistance and high temperature resistance and can meet the requirements of technique and production of polysilicon. In addition, the technique has simple process and no environmental pollution, and is suitable for commercial process.

Disclosed are process and apparatus for making high purity fused silica glass materials. The process involves depositing soot particles onto an essentially planar deposition supporting surface and modulation of motion of the soot-generating device relative to the deposition supporting surface to result in a low local soot density variation. The apparatus is designed to implement the planar deposition process. The invention makes it possible to produce fused silica glass without the use of potentially contaminating refractory bricks.

The invention discloses a preparation method of a large quartz ceramic crucible, which is formed based on the method of gel casting molding, and particularly comprises the following steps: a) taking fused quartz with purity of 99.0-99.9% according to the mass percent as a raw material, and carrying out granular grading on the grains of the fused quartz; b) uniformly mixing the raw material proportioned by the step a), adding gel solution, preparing into pulp in a ball mill or a blender; c) injecting or pressure-injecting the prepared pulp prepared by the step b) into a preheated metal mold, and taking out from the metal mold after the pulp is solidified into green bodies; d) naturally drying the green bodies; and e) putting the dried green bodies into a high-temperature furnace, baking toobtian the large quartz ceramic crucible. Raw material grain proportioning and the preparation method, optimized by the invention, can product the quartz ceramic crucible with larger overall dimension and thin wall for fusion of special glass, casting of polycrystalline and calcining of rear earth material.

The invention belongs to the field of refractory materials and discloses a preparation method of a fused silica refractory casting material unwetted by an aluminum liquid, which comprises the following step of: enhancing a ground substance by adopting 10-20wt% of white alundum powder, 4-8wt% of calcium aluminate cement, 3-5wt% of hydrated alumina compound binding agent, 4-10wt% of silicon oxide micropowder and 3-6wt% of alumina micropowder, wherein 60-70wt% of fused silica is used as a main material, BaSO4 and Na3AlF6 is adopted as a compound aluminum liquid anti-wetting agent with the addition of 1-6wt%, and additional 0.12wt% of trimeric sodium phosphate and additional 0.03wt% of sodium hexametahposphate are adopted as dispensing agents. The casting material prepared by using the method has high strength, is unwetted by the aluminum liquid, has the highest use temperature of 1000 DEG C and can be used as the refractory materials, such as an aluminum flowing groove of an aluminum smelting furnace and the like.

The invention relates to a method for preparing heat insulation tiles of a shuttle, which is mainly used in heat insulation of shuttles and aircraft heat insulation protecting field such as other aerospace, aviation, guided missile and the like, belonging to the special technical field. The method comprises the steps of matrix batching, shaping, sintering and implementing coating, and the matrix batching is prepared from the following components by weight percent: 50-95% of fused quartz glass fiber, 5-50% of alumina fiber, 0-5% of boron nitride and 0-3% of matrix assistant. The heat insulation tile in the invention has the advantages of high-temperature resistance, high strength, low density, low heat conduction and fine heat insulation effect.

The invention relates to a thermal shock resistant thin-walled cordierite honeycomb ceramics. The components of the thermal shock resistant thin-walled cordierite honeycomb ceramics comprise, by weight, 18-22 parts of bimodal alpha-alumina micro powder with the particle size of 3 mum, 0-10 parts of activated alumina micro powder with the particle size of 5 mum, 38-43 parts of talc with the particle size of 8 mum, 10-15 parts of flake kaolin with the particle size of 2 mum, 20-25 parts of calcined kaolin with the particle size of 2 mum, and 5-10 parts of fused quartz with the particle size of 5 mum. The preparation method comprises the following steps: (1) uniformly mixing the bimodal alpha-alumina micro powder and the activated alumina micro powder; (2) uniformly mixing the resulting mixture from the step (1) and a surfactant; (3) uniformly mixing the resulting mixture from the step (2) and the talc; (4) uniformly mixing the resulting mixture from the step (3) with the flake kaolin, the calcined kaolin, the fused quartz, a binder, a lubricant and water; (5) carrying out treatments of forming, drying, sintering and thermal insulation, and then cooling to the room temperature to obtain the thermal shock resistant thin-walled cordierite honeycomb ceramics. The thermal shock resistant thin-walled cordierite honeycomb ceramics of the present invention has advantages of high mechanical strength, moderate porosity, and low expansion coefficient. The thermal shock resistance of the thermal shock resistant thin-walled cordierite honeycomb ceramics is that: the thermal shock resistant thin-walled cordierite honeycomb ceramics does not crack in three tests at the temperature of 750 DEG C. The thermal shock resistant thin-walled cordierite honeycomb ceramics meets the European IV emission standard.

The invention discloses a low-dielectric high-temperature-resistant phosphate-silicon dioxide coating, with the mass percentage content between the components and the raw material as follows: 50-80% of percentage content of inorganic compound binder, 15-50% of high-temperature filler, 0.5-1.5 wt% of curing agent, 2-5 wt% of thickener, and 0.3-1.5wt% of surfactant; the inorganic compound binder is the mixture of aluminum phosphate or aluminium-chromium phosphate and silicon collosol; the high-temperature resistant filler is the mixture of fused quartz powder and refined quartz powder or alpha-Al2O3 power; the curing agent is MgO; the thickener is fumed silica; the surfactant is non-ionic surfactant. The phosphate binder is firstly prepared, followed by phosphate/silicon collosol compound binder; then the non-ionic surfactant and the high-temperature resistant filler are added to the compound binder, followed by the thickener and the curing agent, then the mixture is evenly mixed. The invention can be used for the surface protection of porous inorganic materials or non-porous inorganic materials and is typically used as wave-transparent material for aerospace crafts.

The invention discloses a method for repairing a fused quartz optical damage component, which belongs to the technical field of the optical material and the optical component, in particular to a method for repairing and processing laser damage of a fused quartz optical component. The method comprises the following steps: firstly adopting infrared carbon dioxide laser to carry out laser fusion repair on the damage part of the fused quartz optical damage component; and then carrying out annealing treatment on the fused quartz optical damage component subjected to laser fusion repair. The method can carry out complete repair on the fused quartz optical damage component and eliminate residual stress caused by the laser fusion repairing process. The fused quartz optical component repaired by the method can revert to the state of the ideal fused quartz optical component. And the method also can inhibit the increase of the damage points of the fused quartz optical component. The method can prolong the service life of the fused quartz optical component, greatly reduces operation cost and has the characteristics of strong process controllability, high repetitiveness and stable performance.

A method for using substantial quantities of silicon powders as charge and processing it to produce a high quality silicon ingots suitable for photovoltaic use is disclosed. In a fused silica crucible, silicon feedstock containing more than about 5% by weight silicon powder is charged. The crucible with the charged silicon feedstock is placed into a furnace chamber and a vacuum is drawn to remove air. The vacuum is applied slowly. Then, the furnace chamber is backfilled with argon gas and heated to form molten silicon. Afterward, the molten silicon is solidified and annealed to form a multicrystalline silicon ingot.

The present invention is directed to a method for making fused silica glass. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO2 is provided and introduced directly into the flame of a combustion burner, thereby forming finely divided amorphous soot. The amorphous soot is deposited on a receptor surface where, either substantially simultaneously with or subsequently to its deposition, the soot is consolidated into a body of fused silica glass. The invention further relates to an apparatus for forming fused silica from liquid, preferably halide-free, silicon-containing reactants which includes: a combustion burner which, in operation, generates a flame; an injector for supplying a liquid silicon-containing compound to the flame to convert the compound by thermal oxidative decomposition to a finely divided amorphous soot; and a receptor surface on which the soot is deposited.

The invention discloses a preparation method of a heat-resisting alloy sliding-block shell by investment casting. The preparation method is characterized in that: the method comprises a first step of preparing coating, wherein surface coating comprises silica sol and a refractory powder material is fused alumina; and transition layer coating and back layer coating comprise the silica sol and a refractory powder material is one selected from the fused quartz, kaolin clinker and bauxite clinker; a second step of coating a wax mould with the surface coating, scattering the sand material of the fused alumina, drying and repeating for 2 times; coating the surface layer with the transistion layer coating, scattering one of the fused quartz, the kaolin clinker and the bauxite clinker, drying, and repeating for 5 times; and finally coating with a back layer coating, scattering one of the fused alumina, the kaolin clinker and the bauxite clinker and drying; and a third step of dewaxing and calcinating; and the shell produced by the method has advantages of high room-temperature strength and high-temperature strength, good internal surface quality, high percent of pass, low production cost and good economic benefit.

A method of manufacturing a fused silica crucible by heating and melting a vitreous silica powder compact shaped into a mold using arc discharge of electrodes arranged around a rotation shaft of the mold, includes the steps of: arranging the electrodes in a ring shape, and setting a ratio W/R of a horizontal distance W between the electrode front end and the surface of the vitreous silica powder compact to a vitreous silica powder compact opening radius R, for at least a predetermined time during arc heating, to be in the range of 0.002 to 0.98.

A method to deposit a layer of harder thin film substrate onto a softer substrate. In particular, the present invention provides a method to deposit a layer of sapphire thin film on to a softer substrate e.g. quartz, fused silica, silicon and (toughen) glass. This combination is better than pure sapphire substrate.

The invention relates to a low dielectric, low expansion and low temperature co-fired ceramic material and a preparation method thereof. The method comprises the steps of a, mixing (60-80)wt% of borosilicate glass powder with (20-40)wt% of spherical fused quartz micro powder to obtain low-temperature co-fired ceramic powder, b, adding a solvent, an adhesive agent, a plasticizer and a dispersing agent to the low temperature co-fired ceramic powder, obtaining casting slurry, and preparing the casting ceramic slurry into a green ceramic tape, and c, placing the green ceramic tape into an electric furnace for sintering to form the low temperature co-fired ceramic material. According to the low dielectric, low expansion and low temperature co-fired ceramic material and the preparation method thereof, a high-purity superfine spherical fused quartz material is added to representative borosilicate glass, so that the dielectric constant and the thermal expansion coefficient of an LTCC (low temperature co-fired ceramic) substrate material are reduced, and the low temperature sintering of the spherical fused quartz material is achieved. The prepared low temperature co-fired ceramic material has the dielectric constant of 5.1(1MHz) and the thermal expansion coefficient of 4.2*10<-6>K<-1>, and has a good application prospect.

Fused silica glass having an internal transmittance of UV with 245 nm wavelength, being at least 95% at 10 mm thickness, a OH content of not larger than 5 ppm, and a content of Li, Na, K, Mg, Ca and Cu each being smaller than 0.1 ppm. Preferably the glass has a viscosity coefficient at 1215° C. of at least 10^11.5 Pa·s; and a Cu ion diffusion coefficient of not larger than 1×10⁻¹⁰ cm²/sec in a depth range of greater than 20 μm up to 100 μm, from the surface, when leaving to stand at 1050° C. in air for 24 hours. The glass is made by crystobalitizing powdery silica raw material; then, fusing the crystobalitized silica material in a non-reducing atmosphere. The glass exhibits a high transmittance of ultraviolet, visible and infrared rays, has high purity and heat resistance, and exhibits a reduced diffusion rate of metal impurities, therefore, it is suitable for various optical goods, semiconductor-production apparatus members, and liquid crystal display production apparatus members.

The invention discloses a composite bonded silicious hot repair material, which belongs to the technical field of refractory materials. The repair material comprises the following compositions in percentage by weight: 45 to 55 percent of silicious clinker aggregate, 8 to 12 percent of silicious clinker powder, 20 to 30 percent of natural silica powder, 8 to 12 percent of complex binder, 3 to 5 percent of plasticizer, and 1 to 1.5 percent of dispersant. The silicious clinker aggregate and the silicious clinker powder are waste main crown silica bricks (SiO2 is more than or equal to 95 percent) and fused quartz tubes or fused quartz wedges (SiO2 is more than or equal to 98 percent), SiO2 is more than or equal to 96 percent in natural silica, the complex binder is formed by compounding an SiO2 ceramic bond and a phosphorous acid (phosphate) chemical bond, the plasticizer is white clay or bentonite, and the dispersant is silica fume. The repair material is processed according to the particle size. The invention can satisfy various conditions proposed by hot repair of a kiln to the repair material, can also realize the aims of saving energy sources and increasing the service life of the kiln, and can also be used for filling or building positions which are not suitable for silica brick masonry during the cold repair at the same time.

The invention provides a method for improving the damage threshold of a fused quartz optical element. The method comprises the following steps of: performing cleaning, rinsing and spray cleaning on the fused quartz optical element by using a mixed solution including a cleaning agent micro-90 and water; and performing etching, rinsing and spray cleaning on the fused quartz optical element through a hydrofluoric acid aqueous solution. In the whole cleaning process, 40-270 kHz of multi-frequency ultrasonic waves are introduced for cleaning. The method provided by the invention can effectively passivate scratches in a sub-surface damage layer of the fused quartz optical element, and remove polishing scraps and polishing impurities in the scratches with different scales to stabilize a hydrofluoric acid etching process, prevent re-deposition of an etching byproduct, and stably promote the damage threshold of the element sharply.

The invention discloses a bandwidth adjustable liquid crystal terahertz wave plate based on a porous graphene transparent electrode. Sub-wavelength metal wire gratings are arranged on the inner side of a substrate of an incidence surface, porous graphene is arranged on the inner side of a substrate on an exit surface, and the two substrates made of fused quartz are sealed and combined to form a liquid crystal box. Two light-control orientation layers are sandwiched between the metal wire gratings and the porous graphene in the liquid crystal box, liquid crystal materials are sandwiched between the two light-control orientation layers, and the liquid crystal materials are terahertz electronic control large birefringence liquid crystal materials. Parallel orientation of liquid crystals is achieved in the liquid crystal box through the mode of light-control orientation, and a 45-degree included angle is formed between the orientation direction and the direction of the metal wire gratings. According to the bandwidth adjustable liquid crystal terahertz wave plate based on the porous graphene transparent electrode, the electronic control birefringence characteristic of the liquid crystals is used, phase delay of ordinary light and extraordinary light is regulated through voltage to correspond to specific wave plates with different frequencies, and the bandwidth adjustable liquid crystal terahertz wave plate has the advantages of being superwide in frequency band, capable of achieving automatic polarization, high in transmittance, large in modulation amount, rapid in response and the like and can be widely applied in the booming terahertz field.

The invention specifically relates to a production method for fine spherical silicon powder, which belongs to the technical field of inorganic nonmetal powder materials. The invention provides a novel high temperature gasification production method to overcome the problems of great investment, low output and high cost of a chemical method and the problems of a low spheroidization rate, low whiteness, coarse particles the like of a physical method in conventional production of fine spherical silicon powder at home and abroad. According to the method, natural crystal, quartz mineral, a silicon material, fused quartz and the like are used as raw materials; the raw materials are pretreated and then sent to a vaporizing furnace for high temperature gasification, and cooling and collection are carried out so as to obtain the micron-sized fine spherical silicon powder. With the production method provided by the invention, the fine spherical silicon powder with high quality, high purity and an amorphous form can be produced, an amorphous rate reaches 100%, and an average particle size is 0.1 to 0.3 [mu]m; exhaust gas, waste water and solid refuse are not produced in the process of production; and the production method has the advantages of small investment and high output and is applicable to large-scale industrial production.