716results about How to "Improve flexural strength" patented technology

The invention discloses a fiber foamed concrete and a preparation method thereof. The fiber foamed concrete comprises the following raw materials in parts by weight: 5290 parts of cement, 4965 parts of water, 1.361 part of foaming solution, 1.2964 part of fly ash and 10 parts of fiber. The preparation method comprises the following steps: proportionally weighing the components; sequentially adding the cement and fly ash into a stirrer, proportionally weighing the water, uniformly stirring the mixture by the stirrer, and adding the fiber; preparing and adding the foaming solution; gradually adding the foam into the mixture, and continuously stirring until all the components are uniformly mixed; pouring the mixture into a mold on which lubricating oil is brushed, and curing in a curing chamber; after 24 hours, removing the mold; and respectively curing for 3 days, 7 days and 28 days for experimental detection. The fiber foamed concrete has the advantages of favorable thermal insulation property, favorable compression resistance and favorable bending resistance, and is applicable to a railway bed strengthening layer.

The invention relates to the technical field of carbon fiber reinforced ceramic matrix composites, in particular to a sintering process of a surface-modified short carbon fiber reinforced ceramic matrix composite, which comprises the following steps: surface modification treatment of short carbon fibers, preparation of a ceramic matrix material, mixing of the short carbon fibers and ceramic powder, compression molding and sintering. In the invention, the process is not only suitable for various ceramic matrixes such as aluminum oxide, silicon carbide, silicon nitride, zirconium oxide and the like, but also can flexibly adjust process parameters such as oxidizing agent types, coupling agent treatment time, ceramic powder particle size, forming pressure, sintering temperature and the like, so that customized preparation with different application requirements is realized; the prepared composite material has extremely high toughness, wear resistance and high-temperature resistance, and shows a wide application prospect.

The invention relates to the technical field of electronic ceramic materials, and particularly discloses a high-purity aluminum oxide ceramic substrate and a preparation process thereof. The high-purity aluminum oxide ceramic substrate is prepared from the following raw materials in parts by weight: 0.20 to 0.25 part of magnesium oxide, 0.35 to 0.55 part of zirconium oxide, 1.2 to 1.5 parts of dispersing agent, 60 to 65 parts of ethanol, 99.7 to 99.8 parts of aluminum oxide, 12 to 15 parts of adhesive, 6 to 9 parts of plasticizer and 50 to 55 parts of n-butyl alcohol, the adhesive is a mixture of polyvinyl butyral, water glass and modified paraffin. The prepared high-purity aluminum oxide ceramic substrate has excellent chemical stability and mechanical strength, and the obtained aluminum oxide ceramic substrate has better density, mechanical property and thermal stability by mixing various raw material components, and is not easy to break when subjected to bending load.

The invention relates to the technical field of high polymer materials, and particularly discloses a high-strength polypropylene composite material for a filter plate and a preparation method of the high-strength polypropylene composite material. The preparation method of the polypropylene composite material comprises the following steps: uniformly mixing polypropylene, polyimide, maleic anhydride grafted polypropylene, nylon 6, a maleic anhydride grafted styrene-butadiene-styrene copolymer, aminated calcium carbonate, modified glass fiber, an antioxidant and a lubricant according to a mass ratio of 100: (12-18): (2-5): (1-2): (3-5): (3-7): (6-10): (0.2-0.5): (0.1-0.3), carrying out melt blending, extruding, cooling, granulating, and carrying out extrusion molding to obtain the polypropylene composite material. Through the synergistic effect of the nano calcium carbonate and the glass fibers, the mechanical property of polypropylene is improved, all the raw materials are crosslinked to form a uniform network structure, more energy is absorbed when a matrix is impacted by external force, and it is guaranteed that the filter pressing plate is not damaged when deforming under the high-temperature and high-pressure conditions; the obtained polypropylene composite material is high in strength, good in heat resistance and excellent in comprehensive performance.

The invention relates to the technical field of concrete preparation, in particular to fiber-reinforced building solid waste recycled aggregate concrete and a preparation method thereof.The preparation method comprises the following preparation steps that S1, recycled coarse aggregate, slag, fly ash and river sand are mixed and stirred according to the proportion, and a cement mixture is obtained; s2, calcining the cement mixture for 2-3 hours to obtain cement clinker; s3, cement clinker, modified fibers, modified graphene oxide and tetrasodium iminodisuccinate are mixed according to the proportion and then poured into a stirrer to be stirred for 5-6 min; and S4, adding water into the stirrer according to the proportion, continuously stirring for 6-10 minutes, and taking out to obtain the fiber-reinforced building solid waste recycled aggregate concrete. According to the invention, the polystyrene fiber and the concrete are connected more tightly by using the modified fiber, and the polystyrene fiber can be subjected to multiple reactions with components in the concrete in an alkaline environment of the concrete to form a stable network structure, so that mechanical indexes such as crack resistance and breaking strength of the concrete are improved.

The invention discloses a high-performance special ceramic material and a preparation process thereof, and the preparation process comprises the following steps: proportioning tungsten carbide, ternary boride, titanium nitride, molybdenum, nickel, silicon, cobalt and other raw materials with nano silicon carbide whiskers according to a ratio, carrying out ball milling treatment, adding a forming agent, and continuing ball milling and granulation; and then, carrying out compression molding on the ceramic powder, carrying out liquid phase sintering in a CO atmosphere, and cooling to room temperature to obtain the high-performance special ceramic material. The Mo3NiB3 ternary boride is introduced, so that the hardness and impact resistance of the ceramic material can be improved, the interface bonding force between a ceramic matrix and a reinforcing phase is enhanced, and the bending strength is improved; the nano silicon carbide whiskers are subjected to nickel plating treatment, so that the interface bonding force can be improved, microcracks are reduced, and the strength and toughness of the ceramic material are enhanced; by optimizing the sintering process and adopting a staged heating mode, grain growth can be controlled, and the density and mechanical properties of the ceramic material are effectively improved.

The invention relates to a design method for the mix proportion of carbonized 3D printing concrete and the carbonized 3D printing concrete. Carbon dioxide is introduced into cement-based printing slurry, the introduction amount of the carbon dioxide is controlled, and when the carbon dioxide is introduced into the cement-based printing slurry, the use amount of magnesium chloride is calculated according to the content of a carbonization reaction product CaCO3 and the proportion of calcite to aragonite in a required concrete mixture. Magnesium chloride and carbon dioxide are added into the cement-based printing slurry at the same time for full reaction, and finally the 3D printing concrete material is prepared. By adding magnesium chloride and generating aragonite type calcium carbonate, the thixotropic behavior of the material is improved, the constructability of the cement slurry is higher, the orientation of the nano-scale aragonite fibers is arranged according to the printing direction, the reinforcing and toughening effects are excellent, and the bending resistance, bending resistance and compressive strength are all improved.

The invention discloses a high-impermeability curing agent for sandy soil and a preparation method, the high-impermeability curing agent comprises the following components by mass: 30-50 parts of a solid waste-based sulfur aluminum iron series cementing material; 10 to 30 parts of slag powder; 5-30 parts of ordinary Portland cement; 5-20 parts of desulfurized gypsum; and 1-10 parts of silica fume. A curing agent system further strengthens the hydration effect and the cementing performance of the cementing material, and a formed crystal-colloid composite hydration product system contributes to the stable and compact microstructure of the cured sandy soil, so that the impermeability and the mechanical property of the sandy soil can be greatly improved; the comprehensive application of solid waste raw materials such as desulfurized gypsum and mineral powder is realized, and the stacking cost of solid wastes and the influence on the environment are reduced.

The invention belongs to the technical field of low-temperature co-fired ceramics, and particularly relates to a high-density and high-strength LTCC (Low Temperature Co-fired Ceramic) raw ceramic chip as well as a preparation method and application thereof. The preparation method comprises the steps that stacking phase powder and filling phase powder in raw materials are fully mixed and then subjected to tape casting, the equivalent particle size ratio of the stacking phase powder to the filling phase powder is 1: (0.4-0.8), and the volume ratio of the stacking phase powder to the filling phase powder is 1: (0.15-0.45). The high-density and high-strength LTCC raw ceramic chip is used for preparing a low-temperature co-fired ceramic substrate. According to the technical scheme provided by the invention, the raw ceramic chip raw materials can be tightly arranged after being fully mixed through the inorganic powder with different particle sizes and matching the dosage ratio of the inorganic powder to the raw ceramic chip raw materials, and low porosity in the sintered substrate is realized on the basis of not changing the substrate raw material composition or crystal whiskers; and therefore, the bending strength is improved, and other properties are not influenced.

The invention provides microcrystalline cast stone and a preparation method and application thereof. According to the preparation method of the microcrystalline cast stone, adopted raw materials comprise 35-70 wt% of vanadium-titanium magnet tailings; wherein the content of TiO2 in the vanadium-titanium magnet tailings is not lower than 0.9 wt%, and / or the content of Fe2O3 is not lower than 9.8 wt%, and / or the raw materials further comprise a nucleating agent not higher than 7 wt%. The vanadium-titanium magnet tailings are used as main raw materials, endowed characteristic elements such as Fe and Ti in the vanadium-titanium magnet tailings are used as nucleating agents in the microcrystal cast stone production process, the low adding amount of the nucleating agents can be achieved, and even when the content of TiO2 and / or Fe2O3 in the vanadium-titanium magnet tailings is high enough, zero-adding nucleating agents can be achieved. Furthermore, the vanadium-titanium magnet tailings are taken as a main material and supplemented with other solid waste raw materials, solid waste matching is reasonably carried out, the solid waste mixing amount is increased, and the microcrystalline cast stone can be prepared from nearly all solid wastes. Further, the building material prepared from the material has a wide application prospect.

The invention discloses a method for preparing oriented alumina fiber toughened ceramic by using supergravity, and relates to the technical field of high-performance ceramic. The alumina fiber provided by the invention can be used as a reinforcing phase and is directionally arranged in at least one spatial dimension in a zirconia ceramic matrix, and the invention also provides a preparation method of the alumina fiber reinforced zirconia ceramic, which comprises the following steps: firstly, preparing zirconia slurry added with the alumina fiber; then realizing directional arrangement of the alumina fibers in the zirconium oxide green body in a supergravity environment, and finally drying and sintering the zirconium oxide green body to obtain the alumina fiber reinforced zirconium oxide ceramic with directional arrangement. The alumina fiber reinforced zirconia ceramic prepared by the invention has excellent bending strength and fracture toughness, and the preparation method is simple, high in efficiency and suitable for large-scale production.

The invention discloses a preparation method of a prefabricated autoclaved aerated concrete slab made of a solid-waste-based sulfur-aluminum-iron binding material. The preparation method comprises the following steps: preparing dry substances of the material; carrying out solid waste pretreatment by a mechanical ball milling method; adding ardealite, aluminum ash, coal gangue, fly ash, steel slag and carbide slag at the moment; calcining and directionally mineralizing after pretreatment; secondarily grinding the intermediate material; adding the secondarily ground intermediate material, cement, aluminum powder and water, and foaming; after the slurry is thickened, multi-frequency vibration is carried out in the pouring process; after pouring is completed, multi-temperature curing is conducted; after curing is completed, the highly-doped solid waste-based functional prefabricated autoclaved aerated concrete slab product is obtained. According to the autoclaved aerated concrete slab, dependence on natural resources is effectively reduced, meanwhile, carbon dioxide emission in the production process is reduced, and meanwhile, the compressive strength and the breaking strength of the autoclaved aerated concrete slab are improved; the service life of the material is prolonged; the preparation process is simplified, and the production difficulty and cost are reduced.

The invention provides foamed light soil. The foamed light soil is prepared from the following raw materials in percentage by mass: 0.01%-30.00% of aeolian sand, 0.01%-30.00% of oily sludge pyrolysis residues, 25.00%-76.00% of cement, 3.00%-5.00% of a foam group and 20.00%-25.00% of water, wherein the foam group is prepared by mixing a foaming agent with water and then foaming. The invention provides a preparation method of foamed light soil. The foamed light soil prepared by compounding the aeolian sand and the oily sludge pyrolysis residues with the cement has good fluidity and mechanical properties, such as high compressive strength, high breaking strength, no heavy metal leaching, no influence on the environment and the like, meets the requirements of different layers and different grades of highway subgrades, and has good application prospects. And the regulation of foam light soil on the roadbed strength is met.

The utility model provides a bridge abutment back roadbed structure which comprises a first graded broken stone hardcore, a first earthwork standard room, a first bidirectional geogrid, a foam light soil layer group, a second bidirectional geogrid, a second graded broken stone hardcore, a second earthwork standard room and a concrete layer group, the first graded broken stone hardcore, the first two-way geogrid, the foam light soil layer group, the second two-way geogrid, the second graded broken stone hardcore and the concrete layer group are sequentially arranged from bottom to top, the first geocell is arranged in the first graded broken stone hardcore, and the second geocell is arranged in the second graded broken stone hardcore. And the second geocell is arranged in the second graded broken stone hardcore. According to the abutment back roadbed structure, the settlement characteristic of the roadbed is improved, the overall stability and the bearing capacity of the roadbed are improved, and the dead weight of the roadbed can be effectively reduced, so that post-construction settlement at the bridge joint is reduced, the stability and the bearing capacity of the roadbed are improved, and the safety and the comfort of driving are ensured.

The utility model provides a temporary stand column system of a foundation pit supporting structure, which comprises a foundation pit wrapped by an enclosure wall, a stand column foundation pile is arranged in the middle of the foundation pit, a stand column is arranged at the top of the stand column foundation pile, the stand column is connected with the enclosure wall through a beam body, and the beam body comprises a plurality of temporary stand column supporting pieces. The two ends of the temporary stand column supporting pieces are connected, the temporary stand column supporting pieces arranged at the two ends of the beam body are fixed to the stand column and the enclosure wall respectively, an operation inner cavity is formed in the stand column, and limiting holes are formed in the side wall of the operation inner cavity. According to the utility model, the temporary supporting column supporting pieces are established, the temporary supporting column supporting pieces can be flexibly disassembled and can be conveniently assembled and connected for the second time, so that a temporary supporting column system of the foundation pit supporting structure realizes a recycling function, and the assembled temporary supporting column supporting pieces are supported by the vertical columns and are fixed by using butt-joint bolts; and the temporary supporting column supporting piece can be separated only by disassembling the bolt.

The invention provides a contaminated site emergency barrier 3D printing material and a preparation method thereof, and the 3D printing material comprises the following components by mass: 45-65% of a first component; 25%-40% of granular steel slag; 2%-10% of a basalt fiber group; 2%-12% of water-soluble anionic polyurethane; wherein the first component is a mixture of steel slag powder, carbide slag powder and red mud powder. According to the contaminated site emergency barrier 3D printing material and the preparation method thereof, a barrier formed by printing the contaminated site emergency barrier 3D printing material is low in permeability coefficient and diffusion coefficient and high in breaking strength.

The invention discloses green and environment-friendly sea sand mortar as well as a preparation method and application thereof, and belongs to the technical field of building materials. The sea sand mortar comprises sea sand, a composite alkali activator, a cementing material and water, the composite alkali activator comprises potassium carbonate and sodium silicate; the cementing material comprises slag powder and fly ash. The preparation method of the sea sand mortar comprises the following steps: S1, pretreating sea sand; s2, mixing and stirring the slag powder, the fly ash and the sea sand in proportion; s3, adding the composite alkali activator, and stirring twice to obtain the sea sand mortar. The sea sand mortar provided by the invention has good compressive strength and breaking strength and short setting time, so that the mortar is suitable for construction application of rapid repair, and also has the characteristics of low carbon and environmental protection.

The invention discloses special cement for a wind power generation concrete tower and a preparation method and belongs to the technical field of cement. The brick comprises the following components in parts by mass: 80-85 parts of clinker, 3-5 parts of gypsum, 3-4 parts of stones, 8-12 parts of mineral powder and a grinding aid, the content of tetra calcium aluminoferrite in the clinker is greater than or equal to 14%, and the alkali content is 0.45-0.55%; comprising the following steps: (1) adding clinker, gypsum and stones into a roller press, and extruding to obtain a component A; (2) selecting the component A by a powder concentrator, and mixing the selected component A with a grinding aid to obtain a component B; and (3) uniformly mixing the mineral powder and the ground component B to obtain the special cement for the wind power generation concrete tower. The prepared special cement for the wind power generation concrete tower has relatively high compressive strength; the low-alkali clinker is adopted, so that the low-alkali clinker has high adaptability, and the content of tetra calcium aluminoferrite in the clinker is greater than or equal to 14%, so that the low-alkali clinker has relatively high breaking strength; the proportion of the clinker in the special cement for the wind power generation concrete tower is high, and the proportion of other auxiliary materials is low, so that the standard consistency water consumption of the cement can be effectively reduced.

The invention discloses a maintenance and reinforcement method for improving the bearing capacity of a beam bridge, and belongs to the technical field of bridge reinforcement. The maintenance and reinforcement method for improving the bearing capacity of the beam type bridge comprises the steps that a prestressed carbon fiber plate is tensioned on a bottom plate of a beam body so as to improve the flexural capacity of the beam body; a plurality of inclined steel plates are fixed to the web shearing and bending section of the beam body in the longitudinal direction of the beam body so as to improve the shear bearing capacity of the beam body; the prestressed carbon fiber plate is arranged in the longitudinal direction of the beam body, and the tensioned prestressed carbon fiber plate is bonded with a bottom plate of the beam body; a certain included angle is formed between each inclined steel plate and the longitudinal direction of the beam body; first steel pressing strips are distributed on the multiple inclined steel plates, the first steel pressing strips are arranged in the longitudinal direction of the beam body and anchored to a web plate of the beam body, and the first steel pressing strips are used for pressing the multiple inclined steel plates to the web plate of the beam body. According to the reinforcing method for improving the bearing capacity of the beam bridge, the bending resistance and the shearing resistance of the existing beam bridge can be effectively improved, the reinforcing method is simple, and construction is convenient.

The invention provides a preparation method of pressureless sintered boron nitride composite ceramic, and relates to the technical field of ceramic composite material preparation. The method comprises the following steps: carrying out surface modification on boron nitride whiskers by using ethanolamine, and activating hexagonal boron nitride powder in a ball milling tank by using an alkaline solution; the preparation method comprises the following steps: uniformly mixing the boron nitride powder and the boron nitride powder in a mixing tank, carrying out cold isostatic pressing to obtain a cold-pressed green body, and carrying out high-temperature calcination on the cold-pressed green body in an inert atmosphere to finally obtain the boron nitride composite ceramic. According to the invention, the physical property characteristics of the boron nitride whisker are fully utilized, and the boron nitride whisker can be fully combined with the hexagonal boron nitride powder subjected to surface activation during calcination through further chemical surface modification, so that relatively high mechanical strength can be realized only by using one phase of boron nitride on the premise of not introducing other sintering aids; the method has the characteristics of high product purity, low production cost and high mechanical strength.

The utility model discloses a thermoplastic cellular board, which belongs to the technical field of high polymer materials and comprises a cellular core and a surface layer completely wrapping the outer surface of the cellular core, and the surface layer comprises an upper surface layer, a lower surface layer and a side surface layer. Each of the upper surface layer, the lower surface layer and the side surface layer independently comprises a continuous fiber reinforced thermoplastic composite material sheet and a resin film; the surface layer is arranged on the outer surface of the honeycomb core, the edge of the honeycomb core can be effectively wrapped, the wrapped edge is attractive, the sealing performance is good, edge breakage is not prone to occurring, meanwhile, the upper surface layer, the lower surface layer and the side surface layer are made of the same materials, the honeycomb core can be effectively protected, the sealing effect of the honeycomb core can be effectively improved, the honeycomb plate has the flame-retardant, anti-aging and waterproof functions, and meanwhile the service life of the honeycomb plate is prolonged. And the compressive strength and the bending strength of the cellular board are greatly improved.

The invention discloses a high-bending-strength flexible graphite bipolar plate micropore plugging agent which comprises the following components in parts by weight: 20-30 parts of glycidyl ether oxypropyl cyclotetrasiloxane, 70-80 parts of oxetane or alicyclic epoxy resin, 0.1-2.0 parts of a cationic thermal initiator and 0.5-2 parts of a flatting agent, and the sum of the parts by weight of the two is 100. The flexible graphite bipolar plate plugging agent has excellent ethylene glycol resistance due to an organosiloxane structure, and each molecule of glycidyl ether oxypropyl cyclotetrasiloxane contains four epoxy groups capable of being subjected to cationic curing, so that after curing, the flexible graphite bipolar plate plugging agent is high in crosslinking density, good in heat resistance, low in curing shrinkage rate and small in residual stress; compared with a (methyl) acrylate plugging agent, the plugging agent has higher bending strength.

The invention belongs to the technical field of cutter materials, and particularly relates to a nano-composite coating hard alloy cutter for intermetallic compound / high-temperature alloy machining and a preparation method of the nano-composite coating hard alloy cutter. An intermetallic compound / high-temperature alloy is a novel key material for aero-engines, is a difficult-to-process material, has high red hardness and good wear resistance, is easy to generate brittle fracture at high temperature, and is easy to generate thermal expansion and deformation in the processing process. Lanthanum-doped tungsten carbide and modified nickel powder are matched with other raw materials to prepare a novel hard alloy matrix, a boron nitride composite material and magnetic chitosan in the coating are matched, the hard alloy cutter is prepared, through the combined action of multiple components, the bending strength and hardness of the cutter material are effectively improved, and the service life of the cutter material is prolonged. Therefore, the good binding force between the coating and the matrix is enhanced.

The invention relates to a water surface and underwater equipment laying and recycling device suitable for complex sea conditions. The water surface and underwater equipment laying and recycling device comprises a frame A and a swing stopping mechanism. The oscillation stopping mechanism comprises an oscillation stopping device and an anti-collision net mechanism; the oscillation stopping device comprises a swinging connecting rod, an oscillation stopping oil cylinder and a connecting circular ring; the upper end of the swinging connecting rod is hinged to the A frame body; the upper end of the anti-swing oil cylinder is connected with the swing connecting rod and the lower end is connected with the connecting ring; a group of steel cable launchers are arranged around the connecting ring, the steel cable launchers can release the steel cable through ejection, and the steel cable can be continuously released or recycled through a steel cable winch in the steel cable launchers; the lower end of a steel cable in the steel cable emitter is connected with a steel cable clamp, and the steel cable clamp is provided with an opening and closing mechanism and can grab and release a lifting lug on target equipment; the anti-collision net mechanism comprises two sets of supporting arms and an anti-collision net clamped by the far ends of the two sets of supporting arms, and the near ends of the two sets of supporting arms are hinged and fixed to the A frame base. The precision and success rate of equipment recovery can be improved.

The invention discloses a method for improving the bending strength of a neodymium-iron-boron magnet, which comprises the following steps: (1) according to the proportion of Al < x > Cu < y > Ga < z > Re < (1-x-y-z) >, smelting metal raw materials into a repair alloy, and Re refers to a rare earth element; x ranges from 0.005 to 0.3, y ranges from 0.01 to 0.5, and z ranges from 0 to 0.1; the repair alloy is smashed to be made into alloy powder with the particle size being 3-50 micrometers; mixing the alloy powder with an organic solvent and glue to prepare alloy slurry; and (2) coating the surface of the magnet substrate or an easy-to-crack area with alloy slurry, drying a solvent, then carrying out vacuum high-temperature repair treatment at 500-700 DEG C, carrying out heat preservation for 0.5-10 hours, cooling, and then carrying out tempering treatment, so as to obtain the magnet with improved bending strength. The Al-Cu-Ga-Re alloy adopted by the invention has the characteristics of low melting point and good magnet wettability, cracks in the magnet can be repaired, the magnetic performance of the magnet is not influenced, the bending strength of the magnet is improved and reaches 400 MPa or above, the risk of fragmentation of the magnet in the use process is effectively reduced, and the service life of the magnet is prolonged.

The invention relates to the field of composite materials, and particularly discloses a bamboo fiber composite material plate as well as a formula and a production process thereof. The bamboo fiber composite material plate comprises a surface layer, a core layer and a bottom layer which are compounded from top to bottom, the surface layer and the bottom layer are respectively formed by pressing mixed slurry of magnesium oxide, magnesium sulfate and bamboo powder, the core layer is formed by pressing mixed slurry of magnesium oxide, magnesium sulfate, bamboo fiber and bamboo powder, glass fiber cloth is laid in the core layer, and the surface layer, the core layer and the bottom layer are integrally formed by pressing. The three-layer structure is arranged, the bamboo powder is added into the surface layer and the bottom layer to be mixed and pressed, gaps are filled, the surface layer and the bottom layer of the plate have high density, and after the bamboo powder is added, the wear resistance is excellent; the bamboo fibers and the bamboo powder are added into the middle core layer, the fracture resistance of the board is greatly improved through the added bamboo fibers, the overall structure becomes more compact through the bamboo fibers mixed in the slurry, the bamboo fibers have the effect of embedded reinforcing ribs, and the load bearing strength and the fracture resistance of the board are greatly improved.

The invention belongs to the field of ceramics, and particularly relates to a high-purity silicon carbide ceramic and a preparation method thereof. Comprising the following steps: adding powder into a ball mill, adding deionized water, stirring, and carrying out ball milling to form water-based slurry; the powder is prepared from micron-scale alpha-silicon carbide powder, nano-scale alpha-silicon carbide powder, polyethylene glycol and polyvinyl alcohol which are different in particle size; carrying out spray granulation on the obtained water-based slurry; and adding the obtained granulated powder into a graphite mold in an oscillating hot-pressing sintering furnace, pre-pressing, heating and boosting to a set sintering temperature and a set sintering pressure, and performing oscillating hot-pressing sintering to obtain the high-purity silicon carbide ceramic. By adopting the method, the mechanical property of the high-purity silicon carbide ceramic can be remarkably improved.

According to the preparation method of the zirconium oxide-doped aluminum nitride ceramic substrate provided by the invention, the zirconium oxide powder is added into the aluminum nitride ceramic powder, and the high-toughness aluminum nitride ceramic is prepared through a series of working procedures of premixing, ball milling, defoaming and the like, so that the bending strength of the aluminum nitride ceramic substrate can be obviously improved; the generation of cracks of the aluminum nitride substrate in actual use is reduced, and the use reliability of the product is improved.

The invention belongs to the technical field of concrete slabs, and particularly discloses a preparation method and application of a fiber-reinforced autoclaved aerated concrete plank.The preparation method comprises the steps that pretreated raw materials are prepared according to a formula; uniformly distributing and mixing the raw materials to obtain slurry I, slurry II and slurry III in sequence; pouring the slurry III into a mold, and standing; demolding and cutting the green body; the cut blank is subjected to steam curing and cooling, and then a concrete slab finished product is prepared; structural steel bars are replaced with fibers, the steel bar consumption is reduced, steel bar corrosion caused by cutting is avoided, and therefore the plate yield and the production efficiency are improved, waste of waste is avoided, and the actual preparation efficiency is improved; and secondly, by adopting the fibers and the active exciting agent, the concrete slurry is more uniformly aerated, and the fibers are uniformly distributed in a multi-stage dispersion manner, so that the bending resistance, the compression resistance, the crack resistance, the nail-holding power, the mildew resistance and the saltpetering resistance of the concrete slab are effectively improved, and the product quality is remarkably improved.

The invention discloses a tundish cover castable, and relates to the technical field of tundish refractory materials. The tundish cover castable is prepared from the following raw material components in percentage by mass: 7.8 to 9.6 percent of alumina of 8 to 5mm, 2.6 to 4.3 percent of alumina of 5 to 3mm, 2.6 to 4.3 percent of alumina of 1 to 0mm, 17.4 to 20.8 percent of alumina of 200 meshes, 9.6 to 13 percent of mullite of 5 to 3mm, 22.6 to 26 percent of mullite of 3 to 1mm, 9.6 to 13 percent of mullite of 1 to 0mm, 7 to 8.7 percent of mullite of 200 meshes, 2.6 to 3.5 percent of composite binding agent, 0.8 to 1.7 percent of aluminum silicate, 0.05 to 0.07 percent of SiC nanowire, 0.2 to 0.3 percent of aluminum titanate and the balance of water. The invention discloses a tundish cover castable which comprises the following components in percentage by weight: 0.4-0.7% of alumina micro powder, 0.08-0.11% of sodium tripolyphosphate, 2.6-3.5% of silica fume, 0.87% of steel fiber and 1.3-1.7% of high-alumina cement. Compared with a traditional process, the tundish cover castable has the advantages that the overall performance of the tundish cover castable is remarkably improved, the breaking strength and compression strength of the castable are effectively enhanced, the service life is remarkably prolonged, and the production cost is reduced. And the production cost is greatly saved, and the economical efficiency and the operation rate of continuous casting operation are improved.