64results about How to "Promote densification" patented technology

The invention provides a method for preparing a carbon sequestration underground cemented filling material by carbonizing and activating all solid wastes. Firstly, alkaline solid waste and water are compounded to obtain solid waste slurry, and an inducer and the solid waste slurry are stirred at a low speed to obtain first slurry; secondly, under the condition of continuously introducing carbon dioxide, carrying out wet grinding treatment on the first slurry to obtain second slurry, and then adding a stabilizer to continuously carry out wet grinding treatment to obtain third slurry; and finally, uniformly mixing the third slurry, semi-hydrated phosphogypsum, iron tailings and water, and vibrating for multiple times to obtain the carbon sequestration underground cemented filling material. The carbon sequestration rate of the prepared carbon sequestration underground cemented filling material can reach 12.2%-20.4%, the softening coefficient can reach 0.86, and the carbon sequestration underground cemented filling material meets the requirements of tailing concrete of C3 strength grade, F3 expansion degree and S1 shrinkage rate in JC / T 2478-2018 Mine Goaf Filling Tailing Concrete, and has a wide application prospect as a mine and underground filling material.

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 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.

The invention relates to the technical field of preparation of hexagonal boron nitride ceramic materials, in particular to a preparation method of a hexagonal boron nitride-based ceramic crucible. The hexagonal boron nitride combined crucible with adjustable porosity and low volatile matter content is prepared by a method of ball milling, hot pressed sintering, machining and heat treatment, so that the purposes of adjusting the porosity rate and improving the mechanical property of the hexagonal boron nitride ceramic material are achieved. After the blank material is prepared, the hexagonal boron nitride crucible with the required specification can be directly prepared by adopting a linear cutting and machining method according to the specification or requirement of the actually used crucible. The porosity-adjustable hexagonal boron nitride combined crucible solves the problem that the service life of an existing crucible prepared from pure hexagonal boron nitride ceramic is short due to low material strength.

The invention provides a multiphase reinforced high-toughness and high-conductivity TiB2-based composite material and an in-situ preparation method thereof, and belongs to the field of TiB2 composite materials. The preparation method comprises the following steps: selecting a Ti source, B4C powder and TiB2 powder with different particle sizes as raw materials, firstly mixing a sintering aid, then adding the aid into a TiB2 matrix, carrying out ball-milling mixing and screening granulation, and carrying out oscillation hot pressing or spark plasma sintering under a vacuum condition to obtain the multiphase reinforced TiB2-based composite material. According to the preparation method, an in-situ reaction sintering process is adopted, and a competitive reaction in a system is regulated and controlled, so that the metallurgical-grade combined high-toughness and high-conductivity TiB2-based composite material which takes a TiB2 matrix as a framework and multiple reinforced phases (TiCx, TiB, C and the like) as fillers is constructed. Meanwhile, the cost of the raw materials is low, the preparation process is simple, and the optimization of the components, the structure and the performance of the TiB2-based composite material can be realized only by regulating and controlling the component proportion of the raw materials, so that the application requirements in the extreme environment fields such as aluminum electrolysis cathode materials, high-temperature engine materials and aerospace materials can be better met.

The invention relates to the technical field of dielectric energy storage device materials, in particular to high-entropy designed bismuth ferrite-based energy storage ceramic as well as a preparation method and application thereof, the chemical composition formula of the material is (0.7-x) Bi < 0.9 > (Sm < 0.5 > Gd < 0.5 >) < 0.1 > FeO < 3-0.3 > (Sr < 0.5 > Ba < 0.5 >) TiO < 3-x > NaNbO < 3-y > MnO < 2 >, the value range of x is 0-0.15, and the value range of y is 0-0.005. The relaxation ferroelectric material is designed by adopting a high-entropy strategy, and various elements occupy the same site of the material to generate lattice distortion, so that the relaxation characteristic of bismuth ferrite-based ceramic is promoted, and a ferroelectric hysteresis loop is optimized. The NaNbO3 anti-ferroelectric material is introduced, the long-range ferroelectric order is destroyed, the local random field is enhanced, and a low Pr value can be obtained. And in addition, the concentration of oxygen vacancies can be reduced by properly adding 0.5% mol of MnO2, so that the leakage current of the material is reduced, the energy storage efficiency is improved, and the material design not only enriches the application field of the high-entropy ceramic, but also provides a new thought for improving the performance of the energy storage ceramic.

The invention discloses a rolling deformation method for improving the mechanical property of a CoCrFeNiMo0.35 high-entropy alloy, through high-temperature severe plastic deformation, the structure of the CoCrFeNiMo0.35 high-entropy alloy is refined, meanwhile, as-cast sample structure defects such as air holes can be eliminated, the alloy structure is densified, and along with the increase of rolling reduction, the mechanical property of the CoCrFeNiMo0.35 high-entropy alloy is improved, so that the mechanical property of the CoCrFeNiMo0.35 high-entropy alloy is improved. And further refining of crystal grains is effectively promoted. This is the first main factor causing improvement of the mechanical property of the alloy. Besides, in the hot rolling deformation process, alloy grains are stretched into a flat shape in the rolling direction, the volume fraction of a sigma phase is increased along with increase of rolling reduction, the sigma phase is a common hard phase in the high-entropy alloy, and therefore improvement of the alloy strength can be promoted, and the strength of the alloy is improved. The room-temperature tensile engineering stress-strain curve of the CoCrFeNiMo0.35 high-entropy alloy corresponding to different rolling reduction amounts is shown in the figure 7. It can be seen that when the rolling reduction is increased from 10% to 50%, the yield strength and the tensile strength of the alloy are both obviously improved.

The invention relates to the field of extrusion forming of piston skirts, in particular to an extrusion forming process of a large-size piston skirt of a marine diesel engine, which comprises the following steps of: placing a piston skirt raw material in a pre-forging annular die and a pre-forging lower die, pressing and moving downwards through a pre-forging convex die, forming a piston skirt pre-forging piece, taking out the pre-forging convex die, and replacing the pre-forging convex die with a finish-forging convex die; according to the method, the extrusion deformation process of the piston skirt is optimized, the internal metal deformation is smoother, the structure is more uniform, the metal flowing state of an area A with the most concentrated stress in the using process of the piston skirt is particularly improved, and the piston skirt forging is formed through downward pressing and movement of the finish-forging male die. And the overall quality is improved.

The invention discloses raw material powder for preparing high-thermal-conductivity silicon nitride ceramic as well as a preparation method and application of the raw material powder. The raw material powder comprises silicon nitride powder; a sintering aid; and zirconium oxide chips falling off from the zirconium oxide grinding ball when the zirconium oxide grinding ball and the silicon nitride grinding ball are used for grinding. The trace doping of zirconium oxide promotes the densification of the silicon nitride ceramic and improves the relative density and the overall density on one hand, and on the other hand, zirconium oxide is mainly distributed in a triangular grain boundary position in a dispersed phase manner and is not dissolved in a silicon nitride grain lattice, so that the thickness of an intergranular phase is not increased, and the thickness of the silicon nitride is increased. The thermal conductivity of the finally obtained silicon nitride ceramic material is more than 100W / (m.K).

The invention discloses a method for preparing a fine-grain high-plasticity Ta-W alloy plate, which comprises the following steps of: adding Sc2O3 powder into Ta-W alloy preparation raw materials, uniformly mixing, then carrying out electron beam melting, and carrying out multidirectional reciprocating die forging, free forging and package rolling to prepare the Ta-W alloy plate. The Sc2O3 powder is added into the raw materials to obtain a fine-grain Ta-W alloy ingot structure, high-temperature multi-direction reciprocating die forging is combined to eliminate columnar crystals after casting to enable the structure to be more uniform, then steel plate coating hot rolling is adopted, oxidation of the Ta-W alloy plate is effectively prevented, and therefore the Ta-W alloy plate is uniform in structure, fine in grain and high in yield. The plasticity of the Ta-W alloy plate is greatly improved, and the TaW10 alloy, the TaW12 alloy and the TaW13 alloy prepared through the method serve as high-temperature structures and functional materials and are suitable for the fields of weapons, aerospace and the like.

The invention relates to the technical field of composite materials, and discloses a high-strength metal-ceramic composite material and a preparation method thereof, and the preparation method comprises the following steps: (a) mixing selected metal powder and ceramic powder according to a specific proportion to form a uniform mixture; (b) carrying out ultrasonic vibration assisted ball milling treatment on the mixture, wherein the ball milling time is 2-4 hours; (c) applying pressure to the mixture in an inert atmosphere, heating, and carrying out hot press molding for 2 hours; (d) adding a carbon nanotube subjected to surface treatment into the mixture as a nanoparticle reinforcement phase; through surface modification of the metal powder and addition of the carbon nanotubes, the interface bonding force between metal and ceramic is remarkably enhanced, the overall performance of the composite material is improved, ultrasonic vibration is adopted to assist ball milling treatment, the dispersity of the powder is improved, and the mixing uniformity is improved, so that the temperature required by sintering is reduced, and the service life of the composite material is prolonged. And deformation or decomposition of the ceramic phase at high temperature is avoided.

The invention belongs to the field of chip inductors, and provides a preparation method of a hot isostatic pressing sintered chip inductor and the sintered chip inductor. The preparation method of the hot isostatic pressing sintering chip inductor comprises the steps that alloy powder granulation powder is pressed into an inductor blank through low pressure; the inductor blank is put into a hot isostatic pressing cavity to be subjected to hot isostatic pressing sintering; wherein a hot isostatic pressing gas medium is inert gas, and the hot isostatic pressing temperature ranges from 690 DEG C to 730 DEG C; at the hot isostatic pressing temperature, normal-pressure annealing is carried out on the inductor blank subjected to hot isostatic pressing sintering; and performing pin folding on the inductor blank after normal-pressure annealing to prepare the hot isostatic pressing sintered chip inductor. A hot isostatic pressing sintering technology is adopted, high pressure in all directions can reduce single orientation of magnetic powder grains, internal stress of the magnet caused by isostatic pressing can be eliminated after annealing, and effective magnetic conductivity of the magnet and loss of inductance products are improved.

The application provides a preparation process of high-strength concrete, and belongs to the technical field of concrete, and comprises the following steps: step S1, Mg-Al-LDH-NO2 powder is prepared; step S2, microcapsules are prepared; step S3, machine-made sand, granite crushed stone, Portland cement, slag powder, limestone powder, metakaolin, microcapsules, water, a water reducing agent and Mg-Al-LDH-NO2 powder are mixed and stirred to obtain high-strength concrete. The application can achieve the purpose of improving the strength and durability of concrete.

This invention discloses a method for preparing silicon carbide fibers with an in-situ boron nitride coating. The method involves melt spinning a metal-doped polycarbosilane precursor to obtain doped polycarbosilane precursor fibers. These precursor fibers are then subjected to a non-melting treatment in an oxidizing atmosphere to obtain non-melting fibers. The non-melting fibers are then subjected to inorganic pyrolysis to obtain inorganic fibers. These inorganic fibers are then densified and sintered to obtain boron-containing SiC fibers. Finally, the boron-containing SiC fibers are subjected to high-temperature treatment in a nitrogen atmosphere to obtain silicon carbide fibers with an in-situ boron nitride coating. This invention provides a simple preparation method, resulting in an in-situ self-grown BN coating with high crystallinity, good stability, and excellent uniformity. The coating is tightly bonded to the SiC fibers, is low-cost, and can be mass-produced. Furthermore, it significantly improves the fiber's temperature resistance and high-temperature creep resistance, allowing the fiber to serve for extended periods at higher temperatures.

The application discloses a preparation method of a high-strength aluminum nitride substrate and relates to the technical field of aluminum nitride substrate preparation. The method comprises the following steps: preparing modified aluminum nitride powder; adding a non-oxygen composite sintering aid composed of fluorides and borides to the modified aluminum nitride powder to obtain a mixture; the adding amount of the composite sintering aid is 0.5wt%-5wt% of the total mass of the modified aluminum nitride powder; the mixture, a binder and a dispersant are mixed in a planetary ball mill to obtain a uniform slurry; the slurry is subjected to flow casting to form a green porcelain embryo, and then, glue removal treatment is performed under the protection of flowing inert gas to remove the binder; the green porcelain embryo after glue removal is placed in an atmosphere sintering furnace to perform a multi-stage temperature rising sintering procedure to form a ceramic body; and the sintered ceramic body is subjected to heat treatment and then cooled to obtain the aluminum nitride substrate. The application reduces the lattice thermal resistance of the aluminum nitride substrate and improves the mechanical strength of the aluminum nitride substrate.

The application relates to the technical field of special functional coating materials for lost foam casting, and particularly discloses a cast iron lost foam and universal coating for full mold casting and application thereof. The cast iron lost foam and universal coating for full mold casting comprises quartz powder, calcined bauxite, modified fly ash microbeads, microcrystalline graphite and an additive; the modified fly ash microbeads comprise fly ash and a composite coating layer coated on the surface of the fly ash, and the composite coating layer comprises aluminum oxide nanosheets and magnesium ion doped amorphous substances. Through functional design of key components, the coating can dynamically adjust its performance according to the temperature and chemical environment of the contact interface, can meet the high air permeability requirement of the lost foam process, can take into account the differentiated requirements of different cast iron materials on high-temperature strength, permeability resistance and interface purity, and can be compatible with both conventional negative pressure and non-negative pressure conditions, so that the universal coating is realized, and production management and supply chain processes are greatly simplified.

The invention relates to the technical field of silicon carbide ceramics, in particular to an in-situ induced low-temperature eutectic silicon carbide porous ceramic and a preparation method thereof. The material is prepared by mixing and sintering the following materials: silicon carbide, a synergistic sintering system, a dispersing agent, a plasticizer and water, wherein the synergistic sintering system comprises the following components: pregelatinized starch, a silicate mineral material, aluminum oxide, calcium carbonate, glass powder and rare earth oxide; the pregelatinized starch is adopted as an adhesive, the thermal decomposition behavior of the pregelatinized starch and the chemical reaction activity of the glass powder and the calcium carbonate form synergy in the process, seamless connection of the whole process from the room temperature to the sintering temperature is achieved, the sintering temperature is greatly reduced, meanwhile, the glue discharging step is omitted, and the silicon carbide porous ceramic product with good performance and few defects is obtained.

The invention discloses a viscosity modified material for keeping the homogeneity of self-compacting concrete, a preparation method and application. The material comprises the following components in parts by mass: fly ash, slag powder, metakaolin, cellulose ether, limestone powder, zeolite powder, an air entraining agent, a functional component A and a functional component B, wherein the functional component A is prepared by compounding and drying nano silica fume, modified carbon nanotubes subjected to ultrasonic dispersion by sodium dodecyl benzene sulfonate / absolute ethyl alcohol and tungsten disulfide subjected to activation-silanization-polycarboxylic acid modification treatment, and the functional component B is prepared by shearing and uniformly mixing magnesium oxide and a calcium expanding agent at a high speed. The material can improve the viscosity, delay segregation and bleeding and reduce the water use sensitivity under the condition that the yield stress is not obviously improved, meanwhile, the early strength development is promoted, the volume stability is improved, and the durability such as chloride ion permeation resistance is improved, so that the homogeneity and quality consistency of a component in the pouring process and after hardening are guaranteed.

A control valve (1) comprising a valve body (10) and a valve core (20); the valve body comprises a side wall part (11); the control valve has a valve cavity (101), the control valve comprises at least five channels (30), one end of each channel is in communication with the valve cavity, and the other end forms a valve port of the control valve; the valve core comprises an internal guide passage cavity (21), a plurality of external guide passage cavities (22), a first separation plate (23), and a second separation plate (24); the first separation plate is located between the internal guide passage cavity and an external guide passage cavity, and the second separation plate is located between two adjacent external guide passage cavities; the first separation plate has a communication hole (231), and the internal guide passage cavity is in communication with a portion of the external guide passage cavities by means of the communication hole; each channel comprises a first flow passage (31) and a second flow passage (32), the first flow passage can establish communication with an external guide passage cavity by means of the internal guide passage cavity and the communication hole, and the second flow passage can establish communication with an external guide passage cavity. Consequently, the present invention can implement fluid control for a plurality of flow paths, and is more convenient and compact when being used.

The application discloses a preparation method of a titanium nitride coating and application of the titanium nitride coating. The preparation method of the titanium nitride coating comprises the following steps: adopting a coaxial magnetron plasma acceleration method, taking industrial pure titanium as an acceleration electrode material, performing pulse discharge, and generating titanium plasma of the acceleration electrode material; under the action of electromagnetic force, the titanium plasma forms a titanium plasma jet at an outlet of the acceleration electrode; the titanium plasma jet reacts with nitrogen-containing gas to deposit and form the titanium nitride coating on a substrate surface. The coaxial magnetron plasma acceleration method is adopted, industrial pure titanium is used as an acceleration electrode, and nitrogen-containing gas is used as a specific material input source to form the titanium plasma jet. The high-speed and high-reactivity titanium plasma jet is beneficial to enhancing the impact, spreading, diffusion and reaction process of the deposition particles on the substrate surface, promoting the densification of the coating and the stable combination between the coating and the substrate, and the titanium nitride coating with high bonding strength and good wear resistance can be obtained.

The invention relates to the technical field of waste liquid treatment, in particular to a self-adaptive pH amphoteric polymer-calcium salt compounded bentonite slurry rapid sedimentation treatment method. According to the method, a calcium salt working solution, a buffer working solution, an amphoteric polymer working solution and a functionalized calcium carbonate micro-powder dispersion solution are added in stages, and the stirring speed and time are accurately controlled, so that rapid sedimentation of the slurry is realized. The amphoteric polymer is formed by copolymerizing a plurality of monomers and has wide pH adaptability; the functionalized calcium carbonate micro powder is used as a weighting carrier to enhance the floc density. The method solves the problems of slow sedimentation, high supernatant turbidity and poor adaptability to water quality fluctuation in the traditional method, has the advantages of high sedimentation speed and high supernatant clarity, can be directly reused, and is suitable for bentonite slurry treatment in the fields of electric power engineering and the like.

The invention discloses a zirconia ceramic matrix with high thermal shock resistance as well as a preparation method and application thereof. The zirconia ceramic matrix comprises a matrix and a coating layer a; the matrix comprises the following components: 90-98 wt% of zirconium oxide; 1.5 to 8 wt.% of a stabilizing agent; % of a grain boundary regulating agent; the stabilizing agent is prepared from the following components in percentage by weight: 2.0 to 4.0 percent of Sc2O3, 0.5 to 1.5 percent of Yb2O3 and 0.3 to 1.0 percent of Er2O3; the grain boundary regulating agent is a composition of a boron source and an aluminum source; in the coating layer a, the molar ratio of zirconium to aluminum is (2-3): 1; and the component 1 is polyvinyl alcohol or polyvinylpyrrolidone. The fracture toughness, bending strength and thermal shock resistance of the ceramic matrix are effectively improved, and the overall mechanical property is remarkably improved. When the material bears thermal shock, the thermal shock resistance of the material is improved, and the application scene of the zirconia ceramic material is expanded.

The invention discloses a modified aramid nanofiber / rubber composite material and a preparation method thereof.Aramid nanofibers with good water dispersibility are prepared through epoxy modification, the in-situ polycondensation effect of a silicate ester compound on the surfaces of the nanofibers is improved through a nucleophilic substitution reaction of epoxy groups and amino groups, ANFs (at) SiO2 is formed, and the modified aramid nanofiber / rubber composite material is prepared. The composite material with excellent physical and mechanical properties and ablation resistance can be obtained by using the ANFs (at) SiO2 reinforced rubber with lower parts by weight. In the ablation process, the nano silicon dioxide is firstly melted to form a protective film to coat the surface of the aramid nano fiber, so that the aramid nano fiber is prevented from being corroded and decomposed by heat flow, ceramic structures such as SiC and Si3N4 are generated in situ to promote densification of a carbon layer, and the ablation resistance of the rubber is remarkably enhanced.

The invention discloses a method for sintering open-pore structure glass ceramics from granite sludge loose powder, which belongs to the field of energy-saving building materials and comprises the following process steps: (1) mixing green silicon carbide serving as a foaming agent with granite sludge powder to obtain uniform mixed powder; (2) granulating the mixed powder, and uniformly spreading the granulated mixed powder in a refractory mold; (3) putting the refractory mold into a muffle furnace, and carrying out instantaneous sintering at high temperature, so that contact points of adjacent particles form welding points; and performing diffusion sintering at a low temperature, and forming rigid connection pore channels among particles through mass transfer diffusion of fusion points to prepare the porous microcrystalline glass with an open pore structure. The granite sludge powder has the characteristics of high utilization rate, simple and convenient production process, low production cost, adjustable porosity and the like, is suitable for producing large-size and complex-shape porous microcrystalline glass, has the characteristics of heat insulation, sound insulation, humidity adjustment and the like, is expected to be applied to high-performance lightweight wall materials and sewage purification treatment, and has wide application prospects. The high-value utilization of the granite sludge is realized.

The invention discloses a high-strength low-thermal-conductivity refractory castable and a preparation method thereof, and belongs to the technical field of refractory materials. The high-strength low-thermal-conductivity refractory castable comprises the following raw materials in parts by weight: 50-75 parts of refractory aggregate, 10-30 parts of matrix fine powder, 5-10 parts of a binding agent, 0.5-1 part of a dispersing agent, 0.3-0.5 part of a water reducing agent and 5-10 parts of deionized water. The high-strength low-heat-conductivity refractory castable prepared by the invention has a low heat conductivity coefficient and good compressive strength.

Embodiments of the present application provide a low-loss optical fiber preform, a preparation method thereof and a low-loss optical fiber. The method comprises: performing dehydroxylation treatment on a silica loose body to obtain a first intermediate; performing fluorine doping treatment and first sintering on the first intermediate in a fluorine-containing gas to obtain a second intermediate; performing second sintering on the second intermediate in a mixed atmosphere of an inert gas and the fluorine-containing gas to obtain the low-loss optical fiber preform; and the temperature of the first sintering is lower than the temperature of the second sintering. The method is used to improve the uniformity of the doping of fluorine elements in the optical fiber preform to reduce the transmission loss of the optical fiber preform at 1550 nm.

The application relates to the field of heat-sensitive ceramic materials, in particular to a high-stability rare earth-containing six-component low-resistance high-B-value NTC heat-sensitive ceramic material and a preparation method thereof. The raw material scheme of the NTC heat-sensitive ceramic material comprises trimanganese tetraoxide, nickel protoxide, reinforcing material, lanthanum trioxide, combined functional material and trimolybdenum tetraoxide. The final heat-sensitive ceramic material prepared by the application successfully breaks the technical bottleneck that the resistivity and the B value are restricted to each other in traditional NTC heat-sensitive ceramic materials, realizes good unification of low resistance and high sensitivity, significantly improves the accuracy and response speed of temperature detection; meanwhile, the long-term stability of the material under harsh service conditions such as high-temperature storage, humid heat environment and cold and hot impact is greatly improved, the resistance value drift is effectively inhibited, and the strict requirements of high-reliability scenes such as automobile electronics, industrial control and new energy battery management systems on long-term precise monitoring of temperature sensors can be met.

The invention relates to the field of electrical equipment, and discloses a roller dismounting and mounting structure and cleaning equipment, the roller dismounting and mounting structure can conveniently realize dismounting and mounting of a roller, the operation is simple and convenient, the user experience is good, the structure is compact, the occupied space is small, the side edge structure of the roller can be thinner, the distance between the roller and the wall edge is reduced, and the cleaning effect is improved. The roller dismounting and mounting structure is applied to the cleaning equipment, the cleaning equipment comprises a roller assembly, the roller assembly comprises a second support and a roller, the roller is detachably arranged in the second support, the roller dismounting and mounting structure comprises a cover body, a locking assembly and a pop-up assembly, the cover body is arranged at one end of the roller, the locking assembly is arranged in the second support, and the pop-up assembly is arranged in the second support. The locking assembly is used for locking / unlocking the cover body to disassemble and assemble the roller, the popping assembly is arranged at the other end of the roller, and the popping assembly pops the roller out of the second support when the locking assembly unlocks the cover body.

The invention relates to the technical field of metal-based composite materials, and discloses an aluminum-based diamond composite material and a preparation method thereof, which specifically comprises: optimizing and improving the formula of the aluminum-diamond composite material to adjust the thermal expansion coefficient of the aluminum-based diamond, and adopting different diamond particle gradations to ensure the density of the product; adopting a magnetron sputtering method to perform W / Re / Ir metal coating on the surface of diamond powder to improve the electrical conductivity and thermal conductivity of the diamond powder and enhance the adhesion with the aluminum-based material; in addition, combining a unique rapid hot pressing sintering technology to design a preparation process of the aluminum-diamond composite material, introducing a direct current electric field to assist sintering during the sintering process, so that the strength, rigidity and corrosion resistance life of the material are significantly improved; the aluminum-diamond composite material prepared by the invention has excellent performance and long service life, and can meet the requirements of contemporary packaging materials for high heat dissipation and high strength.

The application discloses high-strength low-thermal-conductivity refractory castable and a preparation method thereof, and belongs to the technical field of refractory materials. The high-strength low-thermal-conductivity refractory castable comprises the following raw materials in parts by weight: refractory aggregate 50-75 parts, matrix fine powder 10-30 parts, binding agent 5-10 parts, dispersing agent 0.5-1 part, water reducing agent 0.3-0.5 part, and deionized water 5-10 parts. The high-strength low-thermal-conductivity refractory castable prepared by the application has low thermal conductivity and good compressive strength.