47results about How to "Low thermal shock resistance" patented technology

The invention relates to a production method of a large-size graphite electrode which comprises the components in percentage by weight: 76-79 percent of calcined petroleum coke, 21-24 percent of medium-high temperature modified asphalt and the balance of filling material with the diameter of 0.075-2 mm, wherein the calcined petroleum coke comprises the following components in percentage by weight: not more than 4 percent of granules with the diameter of more than 12 mm, 6-10 percent of granules with the diameter of 8-13 mm, 13-17 percent of granules with the diameter of 4-8 mm, 9-13 percent of granules with the diameter of 2-4 mm and 30-32 percent of powder with the diameter of not more than 0.075 mm according to the particle size distribution; and the coking value of the modified asphalt is over 55 percent and the softening point is 95-100 DEG C. After the raw materials are mixed according to the proportion, the large-size graphite electrode is produced by adopting a conventional process, wherein the mixing temperature is 160-165 DEG C and the thicker lumpiness during the die-filling is less than 40 mm. A huge-size electrode with the diameter of over 960 mm can be produced by adopting the production method of the large-size graphite electrode; meanwhile, the electrode has low resistivity and good conduction property and can bear strong current, thereby enabling the unit consumption and the electricity consumption to be greatly lowered and saving the production cost.

The invention discloses a ceramic side sealing plate for twin-roll thin-strip continuous casting. The ceramic side sealing plate is characterized by comprising the following chemical components in percentage by mass: 40-75% of hexagonal boron nitride powder, 10-45% of Si3N4 powder, 10-30% of zirconia-mullite powder, 3-15% of TiN powder and 0.5-10% of additive, wherein the additive is one or a combination of several of Y2O3, industrial Al2O3, MgO and light magnesium carbonate. The side sealing plate has high temperature resistance, high strength, thermal shock resistance and low heat conductivity by developing the novel formula of the novel side sealing plate and adjusting a preparation method of the novel side sealing plate.

The invention relates to a petalite heat-resistant ceramic wok. The petalite heat-resistant ceramic wok is prepared by firing the following raw materials in parts by weight: 45 to 65 parts of petalite, 15 to 40 parts of spodumene, 12 to 20 parts of quartz, 15 to 20 parts of kaolin, 6 to 9 parts of talc, 5 to 8 parts of microcrystalline ceramic powder, 1 to 3 parts of halloysite nanotubes, 0.5 to 1part of nanometer tungsten carbide powder, 0.5 to 1 part of nanometer technetium oxide powder, 0.3 to 0.5 part of polyacrylamide. The petalite heat-resistant ceramic wok utilizes the cheaper petaliteas a main raw material, and the prepared petalite heat-resistant ceramic wok has good thermal shock resistance, good crack resistance, good wear resistance and good thermal conductivity.

The invention discloses an unfired brick with light weight and high intensity. The invention contains the components in quality percent as below: 40 to 60 percent of corundum hollow ball, 30 to 45 percent of high bauxite, 8 to 15 percent of high alumina cement and 18 to 22 percent of adscititious modified sodium silicate binder. The figuration bricks and the abnormal bricks with required size are made by adopting the vibration moulding method and being dried with 110 DEG C, wherein, the cubage thickness of the samples is 1.1 to 1.5 g/cm3, the normal temperature pressure compressive strength is more than or equal to 15Mpa, and the using temperature is 1500 DEG C. The unfired brick with light weight and high intensity can be widely used in varied heat engineering devices which are needed to be heat insulated and heat preserved. The invention has the advantages of large strength, high refractability and good heat preserving as well as heat insulating capacities, thereby being able to greatly reduce the energy consumption. Moreover, the invention having convenient preparation and simple technique is useful for the cost saving.

The invention discloses a boron nitride ceramic side seal plate for continuous thin-strip casting. The boron nitride ceramic side seal plate is characterized by comprising the following chemical components by mass percent: 20%-75% of hexagonal boron nitride, 10%-55% of aluminum nitride powder, 5%-40% of magnesium aluminate spinel, 5%-20% of mullite and 0.5%-15% of an additive, wherein the additive is selected from one or combination of several of MgAlON, AlON, CaAl4O7, CaZrO3 and CaTiO3. The boron nitride ceramic side seal plate manufactured by adopting novel ceramic formula and preparation method is relatively high in density, fire-resistant degree and rupture strength, so that the side seal plate is fully ensured to be not softened in a use process. Meanwhile, the side seal plate is low in heat conduction rate and good in thermal shock resistance, so that the side seal plate can well resist the thermal shock of molten steel in the use process and the service life of the side seal plate is prolonged.

The invention discloses a sealing gasket covered with carbon-fiber covering yarn. The sealing gasket comprises two mixed padding layers, a reinforcing fiber layer and a carbon-fiber covering yarn layer, wherein the reinforcing fiber layer is located between the two mixed padding layers, and the carbon-fiber covering yarn layer is arranged at the outer side of the sealing gasket in a covering manner. The sealing gasket is made of polytetrafluoroethylene, nitrile rubber, graphite, natural rubber, coke powder, vermiculite powder, barite powder, aramid fibers and glass fibers, and therefore the sealing gasket has the beneficial effects of being quite low in friction coefficient, quite good in high temperature stability and heat shock resistance, quite high in strength and heat conductivity coefficient, low in expansion coefficient, quite high in electrical resistivity, resistant to corrosion and capable of allowing microwaves or infrared rays to permeate and the like, the natural rubber is quite high in elasticity, and therefore the sealing gasket is quite good in elasticity and plasticity; the periphery of the sealing gasket is covered with the carbon-fiber covering yarn layer, and therefore the sealing gasket has the beneficial effects of being quite high in acid resistance, alkali resistance, corrosion resistance and abrasion resistance; and in addition, the sealing gasket is subjected to vulcanization treatment, so that the sealing gasket is durable and not prone to aging.

The invention relates to a graphene-based metal abrasion intelligent repair material and a preparation method thereof. The repair material provided by the invention consists of the following components according to weight and volume: 5 to 10 g of graphene, 30 to 150 g of serpentine powder, 20 to 40 g of molybdenum powder, 15 to 55 g of rare earth powder, 90 to 210 g of copper powder, 35 to 95 g of nickel powder and 1000 to 2000 ml of 100N base oil. The preparation method comprises the steps of putting the serpentine powder into a plastic ware, rinsing with hot water at the temperature of 80 to 90 DEG C and enabling the water to naturally evaporate; putting the serpentine powder, the molybdenum powder, the rare earth powder, the copper powder and the nickel powder into drying equipment, and drying at the temperature of 110 to 130 DEG C for 100 to 130 minutes, wherein the water content of each of the serpentine powder, the molybdenum powder, the rare earth powder, the copper powder and the nickel powder is less than 2 percent after drying; putting the dried powder into a homogenizer, stirring at the stirring speed of 2000 to 3000 revolutions per minute, adding the base oil after stirring, and continuously stirring for 1 to 10 hours to obtain a colloidal mixture; and putting the colloidal mixture into an ultrasonic dispersing instrument to perform dispersion.

The invention belongs to the technical field of fingerprint identification and relates to magnetic fingerprint revealing powder and a preparation method and application thereof. The magnetic fingerprint revealing powder is composed of magnetic powder and developing powder, and a chemical formula of the magnetic fingerprint revealing powder is Ma(BN)b, wherein M refers to the magnetic powder selected from at least one of Fe powder, Co power, Ni powder, Fe3O4 or Fe78Si9B13 amorphous powder, B refers to the developing powder, a and b refer to atom percentage contents of corresponding elements, a is larger than or equal to 50 and smaller than or equal to 88.9, b is larger than or equal to 11.1 and smaller than or equal to 50, and the amount of a and b is 100. Compared with the prior art, the magnetic fingerprint revealing powder not only has the advantages of easiness in raw material acquisition, simplicity in preparation, stability in performance, easiness in storage and the like but also has no toxic or side effect on users and has a most prominent advantage that high-precision reveal of fingerprints on the surfaces of various objects in dry or humid environment can be realized. Therefore, the preparation process is simplified on the premise of high revealing precision of the magnetic fingerprint revealing powder, and the magnetic fingerprint revealing powder is widely applicable to various complicated environments and has an extremely high practical application value.

The invention relates to the technical field of thermal insulation materials, and particularly discloses a preparation method of nanowire reinforced silicon nitride foamed ceramic composite silicon dioxide aerogel and a product thereof. Ceramic slurry containing silicon powder, water, a sintering aid and protein powder is cured, formed and dried to prepare a green body; the green body is embedded into silicon nitride powder, and nitrogen sintering is perfromed to obtain nanowire reinforced silicon nitride foamed ceramic; and the nanowire reinforced silicon nitride foamed ceramic is further put into SiO2 sol, vacuum impregnation, gelling, solution replacement and drying are performed to obtain the nanowire reinforced silicon nitride foamed ceramic composite silicon dioxide aerogel. According to the preparation method, the steps of the nanowire reinforced foamed ceramic are simplified, the silicon dioxide aerogel and the ceramic are connected more tightly due to the existence of the nanowire, the aerogel is prevented from falling off, the service life of the material is prolonged, and large-scale production is promoted.

The invention discloses a thermal barrier coating with good light resistance and thermal shock resistance. After added aluminum powder is roasted and modified at a high temperature, oxidation resistance of a ceramic phase and permeability of matrix metal can be improved; in a spraying process, part of particles are molten insufficiently in plasma jet flow, are slightly weak in deformation degree while hitting against the matrix, and are liable to form a porous structure which is lapped together, thereby improving heat insulation property of the coating; secondly, by virtue of a modification method, Y<3+> and Ce<4+> in a zirconium dioxide crystal lattice substitute Zr<4+>, so that oxygen vacancy and local stress field are generated, phonon scattering in the crystal lattice is increased, and thermal conductivity is obviously reduced; moreover, atomic weight of a solute atom Ce is much larger than that of Y, so that scattering intensity of phonons in a product disclosed by the invention can be remarkably improved, thereby reducing the thermal conductivity; and the prepared coating is high in surface hardness, good in toughness, not liable to crack and layer, has the characteristics of good light resistance, good thermal shock resistance and the like, and has a wider application.

The invention discloses a preparation method of a high-temperature resistant and anti-abrasion-and-corrosion gradient coating used for a circulating fluidized bed boiler. The preparation method includes the steps that firstly, sand blasting roughening is performed on the surface of a circulating fluidized bed boiler part; secondly, the surface subjected to sand blasting roughening is washed with acetone and ethyl alcohol successively and is dried; thirdly, a NiCrBSi intermediate coating is sprayed on the roughened and cleaned surface in a plasma spraying manner, then Cr3C2-NiCr-BN-Si3N4 particles are sprayed in a plasma spraying manner, and the conditions of a plasma spraying process includes that the main gas pressure is 0.7-1.0 MPa, the auxiliary gas pressure is 0.6-0.9 MPa, the main air flow is 1300-1800 l/h, the auxiliary air flow is 900-1100 l/h, the arc current is 450-600 A, the arc voltage is 85-100 V, the powder feeding gas pressure is 0.2-0.4 MPa, the powder feeding gas flow is 280-400 l/h, the spraying distance is 100-150 mm, the spraying speed is 2-3 kg/h, and the coating thickness is 1-2.5 mm. The coating can be resistant to high temperature corrosion and high temperature abrasion and corrosion when used for the circulating fluidized bed boiler, and the coating is firm and cannot fall.

The invention discloses a method for strengthening the performance of a complex-phase refractory material by a pre-calcination sintering microwave two-step method. The method comprises the following steps of: step 1, mixing ferronickel slag, magnesite clinker and chromium trioxide, carrying out ball milling to obtain a mixture, adding a magnesium chloride solution into the mixture, carrying out compression molding to obtain green pellets, and drying the green pellets, putting the dried green pellets into a microwave reactor, and pre-calcining the green pellets for 5-40 minutes at the temperature of 1100-1250 DEG C to obtain a pre-calcined blank; and 2, further performing microwave sintering on the pre-calcined blank obtained in the step 1 so as to obtain the complex-phase refractory material, the temperature of the microwave sintering ranging from 1,300 DEG C to 1,350 DEG C, and the temperature time of the microwave sintering is shorter than or equal to 20 min. With the method adopted,the high-performance complex-phase refractory material with the compressive strength of 183.4 to 206.6 MPa, the refractoriness of 1845 to 1873 DEG C, the volume density of 3.16 to 3.61 g/cm <3> and the apparent porosity of 1.2 to 1.7 percent is obtained. The method has the advantages of high resource utilization rate, high product additional value, low production cost, environmental friendliness,simple process and the like.

The invention relates to the field of chip heat sink, in particular to a chip heat sink, a preparation method thereof and a DBC substrate assembly. The chip heat sink comprises an upper end cover, a co-fired laminated heat dissipation structure and a lower end cover, wherein the lower end cover is provided with a coolant inlet and a coolant outlet; the material of the co-fired laminated heat dissipation structure is oxygen-free copper; and the material of the upper end cover and the lower end cover is oxygen-free copper and/or copper-containing alloy. Also disclosed are a method for manufacturing a chip heat sink and a DBC substrate assembly including the chip heat sink of any structure described above. The chip heat sink of the invention has good cold and heat shock resistance, heat conductivity and seal property of the chip heat sink, the cost of the chip heat sink of the invention is low, and the preparation process is easy to operate and realize.

The invention discloses a manufacturing method of a high-purity tantalum oxide body crucible. The technical scheme of the manufacturing method is as follows: carrying out proportioning on high-puritytantalum oxide powder, and carrying out granulation, pressing, drying, high-temperature sintering, annealing, polishing and finishing. The method has the advantages of reasonable process and low manufacturing cost, and the obtained product has the advantages of high strength, good purity, low water absorption, good thermal shock resistance, small deformation, almost no defects of cracking and thelike, long service period and high durability.