1051 results about "Composite ceramic" patented technology

The invention discloses a carbon composite ceramic linear resistor and a preparation method thereof, and belongs to the technical field of power electronic components. The invention provides a preparation method of a carbon composite ceramic linear resistor, which comprises the following steps: uniformly mixing bentonite, silicon carbide and nano carbon black to obtain powder, uniformly mixing the powder and ethanol, drying, adding a binder solution, and carrying out green body forming to obtain a green body; carrying out heat preservation on the green body at 1150-1300 DEG C in a nitrogen-containing gas atmosphere to obtain a sample; and polishing the sample, and spraying aluminum to obtain the carbon composite ceramic linear resistor. According to the method for preparing the carbon composite ceramic linear resistor, the resistivity of the material can be reduced, and the thermal shock resistance of the ceramic resistor can be improved.

The preparation method comprises the following steps: brushing ultrahigh-temperature ceramic oxide slurry on the surface of a graphite base material, carrying out first heat treatment to obtain a porous transition layer, then brushing ultrahigh-temperature carbide slurry on the surface of the porous transition layer, and carrying out second heat treatment to obtain the high-temperature-stable and corrosion-resistant multi-layer composite ceramic coating on the surface of the graphite base material. The preparation method comprises the following steps: performing primary heat treatment on the surface of an ultra-high-temperature carbide layer, drying to obtain the ultra-high-temperature carbide layer, performing roughening treatment on the surface of the ultra-high-temperature carbide layer by adopting ultra-high-temperature carbide slurry, performing secondary heat treatment to obtain a rough carbide layer, and performing point pressure on the surface of the rough carbide layer by adopting metal carbide ceramic mixed slurry to obtain dense bulges; according to the method disclosed by the invention, not only can the bonding firmness among the layers be remarkably improved, but also the situation that the graphite base material and the surface protection layer react at high temperature, so that the coating fails and falls off is effectively avoided, the use limit of the protection layer is further enhanced, and the method has a wide application prospect.

The invention discloses a tungsten alloy material containing a silicon carbide reinforced Al2O3-SiO2-based multiphase ceramic coating and a preparation method of the tungsten alloy material, and belongs to the field of ceramic material preparation. The method comprises the following steps: ball-milling and mixing powder raw materials containing modified silicon carbide, aluminum oxide, silicon dioxide and lead oxide with a solvent, and defoaming to obtain ceramic slurry; the ceramic slurry is brushed on the surface of a tungsten alloy matrix subjected to surface pretreatment, and after drying, vacuum sintering is performed to obtain the tungsten alloy. The compact silicon carbide reinforced Al2O3-SiO2-based multiphase ceramic coating is introduced to the surface of a tungsten alloy matrix, the hardness, the high-temperature oxidation resistance and the high-temperature carburization resistance of a tungsten alloy material are remarkably improved, the stability of the coating can be improved through the silicon carbide distributed in a dispersed point shape, the thermal expansion coefficient of the coating is evenly reduced, and the hardness, the high-temperature oxidation resistance and the high-temperature carburization resistance of the tungsten alloy material are improved. The thermal expansion coefficient difference value between the multiphase ceramic coating and a tungsten alloy matrix is reduced, and the thermal shock resistance of the coating is improved.

The invention relates to the field of ceramic materials, in particular to a high-temperature-resistant composite ceramic material and a preparation method thereof.The high-temperature-resistant composite ceramic material is prepared from, by weight, 80-100 parts of zirconium oxide, 10-20 parts of silicon carbide, 5-10 parts of aluminum nitride, 1-5 parts of a sintering aid and 5-10 parts of modified silicon powder; the modified silicon powder takes nano silicon powder as a core body, the core body is sequentially coated with a transition metal organic polymer and oxidized asphalt, and the prepared composite ceramic material is good in mechanical strength and excellent in high temperature resistance and has important application value in the field of aerospace.

The invention relates to the technical field of high-entropy ceramic preparation, and particularly discloses (TiZrNbHfTaV) C-SiC high-entropy composite ceramic as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing the (TiZrNbHfTaV) C-SiC high-entropy composite ceramic consisting of double phases of (TiZrNbHfTaV) C and SiC by adopting a rapid hot pressed sintering technology. The preparation process is simple and efficient, and large-scale industrial application is facilitated; the prepared multiphase ceramic is high in density, uniform in organization structure and reasonable in component design, the multiphase ceramic shows excellent mechanical properties, and the hardness, the fracture toughness and the wear rate are 34.00 GPa, 6.4 MPa.m < 1 / 2 > and 1.8 * 10 <-6 > mm < 3 > N <-1 > m <-1 > respectively. Compared with the traditional binary carbide ceramic, the (TiZrNbHfTaV) C-SiC high-entropy composite ceramic disclosed by the invention has excellent hardness and toughness, and the friction and wear properties are remarkably improved.

The invention relates to the technical field of surface engineering, discloses a method and a system for preparing a yttrium fluoride composite ceramic coating through atmospheric plasma spraying, and aims to solve the problems that the yttrium fluoride coating generates a brittle aluminum fluoride layer on the surface of an aluminum substrate due to fluorine ion diffusion, so that the bonding strength is low, and the yttrium fluoride coating is easy to peel off and lose efficacy. The method comprises the following steps: sequentially carrying out mechanical polishing, ultrasonic cleaning and sand blasting roughening on an aluminum base material; preparing composite powder formed by mixing yttrium fluoride, yttrium oxide and nanometer aluminum oxide according to the mass ratio of 75: 20: 5; sequentially depositing a yttrium oxide transition layer, a composite barrier layer and a yttrium fluoride functional layer by adopting atmospheric plasma spraying; and finally carrying out vacuum post-heat treatment. According to the system, through the synergistic effect of the three layers of gradient structures, the transition layer forms an yttrium aluminate metallurgical bonding interface, the barrier layer inhibits fluorine ion diffusion through the dual mechanisms of nanometer aluminum oxide physical barrier and yttrium oxide chemical adsorption, and the functional layer guarantees the plasma erosion resistance. According to the method, the bonding strength of the coating is remarkably improved to 50 MPa or above, the porosity is lower than 3%, stripping is avoided under 500-hour high-energy plasma bombardment, the process cost is reduced by 40%, and the method is suitable for cavity protection of semiconductor etching equipment.

The invention discloses an NZP-high-entropy (Ln1 / n) PO4 monazite type multiphase ceramic solidified body and a preparation method thereof, the chemical general formula of the NZP-high-entropy (Ln1 / n) PO4 monazite type multiphase ceramic solidified body is (1-x) Sr0. 5Zr2 (PO4) 3-x (Ln1 / n) PO4, x represents molar percentage, the value range is 0.1-0.9, x represents molar percentage, and the value range is 0.1-0.9. The NZP-high-entropy (Ln1 / n) PO4 monazite type multiphase ceramic solidified body is NZP-high-entropy (Ln1 / n) PO4 monazite type multiphase ceramic solidified body. N represents the number of element types of Ln lattice sites in the high-entropy (Ln1 / n) PO4 monazite type, and n is an integer and is larger than or equal to 5 and smaller than or equal to 7; the Ln element types comprise La, Nd, Sm, Eu, Gd, Ho, Er, Sr0. 5Zr2 (PO4) 3 and (Ln1 / n) PO4, and the molar ratio of the Ln element types to the Sr0. 5Zr2 (PO4) 3 to the (Ln1 / n) PO4 can be freely regulated and controlled. The NZP-high-entropy (Ln1 / n) PO4 monazite type multiphase ceramic solidified body adopts an in-situ preparation process, and integration of crystal phase synthesis and sintering densification can be realized. The preparation method comprises the following steps: uniformly mixing the raw materials, pretreating, adding a sintering aid, mixing again, granulating and aging the obtained powder, molding, removing plastic, and sintering to obtain the NZP-high-entropy (Ln1 / n) PO4 monazite type composite ceramic solidified body. The preparation process disclosed by the invention has the advantages of flexible composition design, capability of simultaneously curing various fission products and (sub) actinide series nuclides, short preparation period, low production energy consumption, high product compactness and the like.

The invention relates to a diffusion-resistant layer enhanced high-temperature oxidation-resistant composite ceramic coating for a niobium surface and a preparation process thereof. The coating system is composed of a diffusion layer, an anti-diffusion layer and a composite ceramic coating in sequence. In the preparation process, the Al2O3 diffusion-resistant layer is accurately constructed by adopting a slurry spin-coating method, and the method can realize accurate regulation and control of the thickness of the diffusion-resistant layer, so that uniform distribution of the Al2O3 layer is ensured. The introduction of the diffusion-resistant layer significantly improves the high-temperature stability and oxidation resistance of the coating, effectively delays the oxidation process of the material under an extreme high-temperature condition, and greatly prolongs the service life of the material.

The invention provides a plasma spraying high-temperature-erosion-resistant coating and a coating preparation method, and relates to the technical field of material surface treatment. Comprising the following components in parts by mass: 30-45 parts of tungsten carbide, 15-25 parts of chromium carbide-nickel-chromium alloy, 15-25 parts of yttria-stabilized zirconia, 5-10 parts of aluminum oxide-titanium dioxide composite ceramic, 10-20 parts of nickel-chromium-aluminum-yttrium alloy, 1-3 parts of nano aluminum oxide and 1-3 parts of lanthanum oxide. Multiphase collaborative design is adopted, tungsten carbide and chromium carbide-nickel-chromium alloy form double hard phases, the hardness is higher, aluminum oxide-titanium dioxide composite ceramic fills pores and improves compactness, rare earth and nanometer are adopted to cooperate, lanthanum oxide and nanometer aluminum oxide react to generate a LaAlO3 protective layer, oxidation weight gain is small, oxygen diffusion is inhibited, nanometer aluminum oxide refines grains, and the hardness is higher. In conclusion, the high-temperature oxidation resistance is high, and the erosion rate is low.

The invention relates to the technical field of metal material coatings, in particular to a PVD composite coating and a preparation method thereof. The preparation method comprises the following steps: pretreating a metal matrix to obtain a pretreated matrix; carrying out magnetron sputtering deposition on the surface of the pretreated matrix by using a composite target material, carrying out plasma spraying and laser texturing for multiple times, and repeating the process to form a composite coating crude product containing a third rare earth doped high-entropy alloy coating; the composite coating crude product is subjected to post-treatment, and the composite coating is obtained; wherein the composite target material is AlCoCrFeNi-Y, and the composite oxide comprises aluminum oxide, titanium oxide and cerium oxide. According to the preparation method, the bonding strength, hardness and strength of the composite coating can be remarkably improved through magnetron sputtering deposition of the rare earth doped high-entropy alloy coating, plasma spraying formation of the composite ceramic coating with the gradient content, laser texturing treatment, alternate construction of multiple layers of coatings and the like in combination with elaborately selected materials with low expansion coefficients.

The invention provides a diaphragm and a preparation method thereof, and a lithium ion battery, the diaphragm comprises a base membrane, a composite ceramic coating and an interface layer, the composite ceramic coating contains inorganic ceramic particles and organic microcapsule particles, the organic microcapsule particles comprise a core material with a melting point range of 55-65 DEG C and a polymer shell coating the surface of the core material, and the polymer shell is coated on the surface of the core material. The polymer shell is selected from at least one of polyurethane, polyurea, polyamide and polycarbonate, the interface layer is formed by depositing an interface modification polymer on the surface of the composite ceramic coating, and the interface modification polymer is selected from at least one of polycatechol derivatives, polyaniline, polyvinyl pyridine, polyacrylic acid and polyacrylamide. The core material in the organic microcapsule particles is melted when heated to trigger hole closing at the initial stage of thermal runaway at 60-80 DEG C, the hole closing rate can reach 92%, the hole closing response time is shortened by 30%, and the porous structure of the interface layer can enhance the liquid absorption rate.

The invention discloses a self-cleaning composite piezoelectric ceramic membrane as well as a preparation method and application thereof, and belongs to the field of composite ceramic membranes. The technical problem that an existing ceramic membrane separation technology is poor in biomembrane pollution resisting effect is solved. According to the preparation method, the barium titanate ceramic membrane is firstly prepared to serve as the base membrane, then the copper oxide one-dimensional nanostructure is loaded on the piezoelectric ceramic substrate, and the base membrane has a large membrane surface area and can be combined with more catalysts, so that more active sites are provided for catalytic reaction; according to the composite membrane, the hydrophilicity, the anti-pollution performance and the piezoelectric catalysis self-cleaning performance of the membrane are remarkably improved, and pollutants in water can be quickly and effectively separated, so that the flux and the anti-pollution performance of the membrane are improved.

The embodiment of the invention relates to the technical field of ceramics, in particular to conductive silicon carbide-based composite ceramic and a preparation method thereof. The conductive silicon carbide-based composite ceramic comprises the following components in parts by weight: 75-95 parts of silicon carbide and 5-25 parts of niobium diboride, the niobium diboride is generated by reaction of boron powder and niobium powder, and the mass ratio of the boron powder to the niobium powder is 1: 4. The conductivity and fracture toughness of the silicon carbide-based ceramic are improved.

The invention provides a silicon carbide fiber reinforced ceramic-based composite material as well as a preparation method and application thereof, and belongs to the technical field of ceramic-based composite materials. The composite material comprises a silicon carbide fiber reinforced phase, a boron nitride interface layer and a silicon-based multiphase ceramic matrix from inside to outside, the silicon-based multiphase ceramic matrix comprises an infiltration reaction generation phase, an introduced ceramic particle phase and a silicon-containing binary alloy phase, and the infiltration reaction generation phase comprises a water-oxygen corrosion resistant phase, a silicon phase, a silicon carbide phase and a boride phase. The water oxygen corrosion resistant phase comprises a compound of boron and any element of yttrium, ytterbium, hafnium, molybdenum and aluminum, the boride phase comprises B12 (C, Si, B) 3, the bending strength of the composite material is larger than or equal to 600 MPa, and the fracture toughness of the composite material is larger than or equal to 19 MPa.m < 1 / 2 >. According to the preparation method, the matching property among the components of the composite material is optimized, the mechanical property of the composite material is improved, and a new thought and a process method are provided for preparing the high-strength and water-oxygen-corrosion-resistant ceramic matrix composite material.

The invention provides high-energy-storage-density strontium barium calcium niobate / CaAl2Si2O8 dielectric composite ceramic and a preparation method thereof, belongs to the technical field of composite ceramic materials, and aims to solve the technical problem of low energy storage density of composite ceramic. According to the invention, high-entropy ceramic is combined with a second phase composite technology to enhance the energy storage characteristic of strontium barium calcium niobate dielectric ceramic, Sr < 1 / 3 > Ba1 / 3 > Ca < 1 / 3 > Nb < 1-0.2 x > Zr < 0.2 x > Mg < 0.2 x > Ti < 0.2 x > Hf < 0.2 x > Ta < 0.2 x > O < 3 > nano powder is prepared by a microwave sol-gel method, and the strontium barium calcium niobate / CaAl < 2 > Si < 2 > O < 8 > dielectric composite ceramic is prepared by a spark plasma sintering method. The composite dielectric ceramic prepared by the invention has relatively high breakdown-resistant field strength, relatively high dielectric property, energy storage density and good discharge efficiency, the breakdown-resistant field strength reaches 850kV / cm, and the maximum energy storage density reaches 8.23 J / cm < 3 >.

The invention relates to the field of coatings, and discloses a wear-resistant and corrosion-resistant high-entropy alloy composite coating and a preparation method thereof.The wear-resistant and corrosion-resistant high-entropy alloy composite coating is prepared by depositing functional high-entropy alloy composite powder on the surface of a base body in a laser cladding mode, the functional high-entropy alloy composite powder comprises high-entropy alloy powder, a modified additive and composite ceramic powder, the modified additive is prepared by using urea and titanium tetrachloride as raw materials, growing nano titanium nitride particles on the surface of a silicon carbide nanowire in situ to prepare a nano titanium nitride / silicon carbide nanowire composite material, and then coating a layer of nano titanium dioxide particles on the surface of the nano titanium nitride / silicon carbide nanowire composite material by using tetrabutyl titanate; and the composite ceramic powder is prepared by compounding zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide. The hardness, wear resistance and corrosion resistance of the high-entropy alloy coating are enhanced by adding the modified additive and the composite ceramic powder.

The invention discloses a preparation method of near-stoichiometric ZrB2 doped SiC fibers, which comprises the following steps: preparing a zirconium-containing multiphase ceramic precursor (PZMS) and polymethylsilane (PMS) into a PZMS / PMS mixed precursor, and blending the PZMS / PMS mixed precursor with spinning-grade polycarbosilane (PCS) to obtain a mixed precursor; the ZrB2-doped silicon carbide fiber with the C / Si atomic ratio close to an ideal value is obtained through the processes of melt spinning, electron beam / BCl3 crosslinking-heat treatment, hydrogen high-temperature pyrolysis, high-temperature sintering and the like in sequence, and regulation and control of fiber components are achieved.

The invention discloses a hafnium hybrid carbon-rich polysiloxane flexible ablation material as well as a preparation method and application thereof, and belongs to the field of advanced materials. According to the invention, a hafnium hybrid carbon-rich siloxane system is designed; in the ablation process, on one hand, a continuous stable carbon skeleton is constructed through a phenyl / vinyl carbon-rich structure; on the other hand, an Hf-O-Si structure is introduced into a polysiloxane main chain, so that formation of SiHfOC composite ceramic at high temperature is promoted, the ablation resistance of the flexible polysiloxane material is remarkably improved, and the flexible polysiloxane material can be used as a base material of a flexible thermal protection coating, a structural part and the like and has a very good application prospect in the field of thermal protection materials.

The invention relates to preparation of a ZTA composite ceramic material, and belongs to the field of inorganic nonmetal composite materials. The raw material composition formula comprises aluminum oxide, zirconium oxide, zirconium dioxide, yttrium oxide, magnesium oxide and titanium dioxide. The low-sodium microcrystalline alumina powder with the original grain size of 0.40 [mu] m is selected and ground to the original grain size in advance, so that zirconia can be more uniformly distributed between alumina grain boundaries, which is a precondition for obtaining more uniform ZTA. Zirconium dioxide is creatively introduced, and compared with a conventional method in which stable zirconium oxide is directly used, the cost of ZTA is greatly reduced. The pre-calcined granulation powder is adopted, so that a ZTA product which is uniformly mixed in the early stage is cured by adding a stabilizer, and then the uniform and stable ZTA ceramic can be obtained through later-stage forming and firing.

The present application belongs to the technical field of ceramic alloy flywheel, and particularly relates to a liquid-liquid composite ceramic inlaid high-wear-resistance flywheel and a preparation method thereof, which is suitable for high-strength impact environment such as mines and metallurgy. The flywheel realizes metallurgical bonding of ceramic-metal by step-by-step pouring and temperature control solidification of basalt melt and high-density W-Ni-Fe alloy melt in a specific mold structure. The ceramic core is composed of multiple inorganic oxides and low-melting-point glass powder, and has excellent interface compatibility and structural stability. During the preparation process, the initial setting state of basalt and the alloy flow path are accurately controlled to improve the interface bonding strength and overall density. The finally obtained flywheel has high hardness, high toughness and excellent wear resistance, and significantly prolongs the service life.

The invention belongs to the technical field of ceramic materials, and particularly relates to a composite ceramic material and a preparation method and application thereof. The eutectic ceramic is prepared by taking aluminum oxide and yttrium oxide stabilized tetragonal phase zirconium oxide powder as raw materials and adopting a laser suspension zone melting directional solidification method, the drawing speed of the laser suspension zone melting directional solidification is greater than or equal to 100 mu m / s, and the laser power is greater than or equal to 300W; the eutectic ceramic is sequentially subjected to crushing, smashing and wet screening, eutectic ceramic powder is obtained, and the particle size of the eutectic ceramic powder is 20-100 microns; mixing the eutectic ceramic powder, silicon carbide whiskers and a sintering aid to obtain mixed powder; the mixed powder is subjected to hot pressing sintering, the composite ceramic material is obtained, and the hot pressing sintering temperature is smaller than or equal to 1550 DEG C. The composite ceramic material obtained by the preparation method provided by the invention has both a large size and a fine structure and has a micro-nano eutectic structure, and the mechanical properties of the material are remarkably improved.

The invention relates to a method for preparing a diffusion bonding layer on a nickel-based alloy and YSZ ceramic coating interface, and belongs to the technical field of metal material surface protection and ceramic coatings. According to the preparation method, a YSZ composite ceramic coating is deposited on the surface of the nickel-based alloy by adopting an electrophoretic deposition method, and then an MCr2O5 (M is Zr, Y, Ce, Yb and Al) diffusion bonding layer is prepared on the interface of the nickel-based alloy and the YSZ composite ceramic coating by adopting a pressureless discharge sintering and thermal diffusion treatment method. The bonding layer prepared through the diffusion method is good in interface bonding, the thermal stress between the nickel-based alloy and the YSZ ceramic coating is effectively buffered, the defects that a bonding layer prepared through a traditional method is large in pore impurity amount and the like can be overcome, and the bonding force between the ceramic coating and a base body and the high-temperature anti-oxidation and anti-stripping performance are remarkably improved.

The invention discloses medium and low temperature porous wave-absorbing iron-based composite ceramic and a preparation method thereof. The medium and low temperature porous wave-absorbing iron-based composite ceramic is prepared from the following raw materials in percentage by weight: 10 to 50 weight percent of wave-absorbing functional phase, 20 to 40 weight percent of ceramic matrix, 5 to 15 weight percent of pore forming agent, 5 to 10 weight percent of dielectric loss phase, 0.5 to 1 weight percent of stearic acid, 0.2 to 0.5 weight percent of silane coupling agent and 30 to 34.5 weight percent of binding phase. According to the preparation method, a low-temperature sintering process is adopted for optimization, and the activity of the magnetic loss phase is protected. The iron-based composite ceramic with a gradient porous structure is obtained by adopting a freezing injection molding method, and broadband efficient wave absorption can be realized. The magnetic-dielectric cooperative loss is enhanced, and the limitation of a single mechanism is broken through. Starch or rice hull ash microspheres are used as a degradable pore-forming agent, so that green process and short-process design are realized. The mechanical property and the stability of the iron-based composite ceramic structure are improved, the application scene is expanded, and the cost advantage is achieved.

The invention belongs to the technical field of composite ceramics, and discloses a synergistically reinforced silicon nitride composite ceramic, and a preparation method and application thereof, the raw materials comprise the following components by mass: 40-90 parts of alpha-Si3N4; 8-15 parts of a sintering aid; 0.1 to 15 parts of nano TiN; 0.1 to 12 parts of SiCw (silicon carbide w); in the sintering aid, the mass ratio of Al2O3 to Y2O3 to CaF2 is (5-10): (1-5): (0.5-3). According to the invention, the nano TiN particles and directionally arranged SiCw are creatively added, and freeze drying and hot pressed sintering technologies are combined, so that the problem that strength and toughness of Si3N4 ceramic are difficult to synchronously improve in the prior art is solved, and the defect of poor toughening effect caused by random distribution of a whisker toughening phase in a matrix is overcome. By accurately regulating and controlling the microstructure, uniform dispersion and directional arrangement of a reinforcement phase are realized, the toughening potential of the whisker is fully exerted, and the comprehensive mechanical property of the Si3N4 ceramic is remarkably improved.

The invention relates to the technical field of ceramic material preparation, in particular to core-shell structure ceramic powder and a preparation method and application thereof.The surface of boride ceramic powder is coated with a uniform carbon layer, then the carbon layer is mixed with silicon powder, thermal treatment is conducted through Joule thermal equipment, and the boride ceramic powder coated with a silicon carbide layer is obtained; the prepared composite ceramic powder has good sinterability and oxidation resistance, a composite ceramic block or a ceramic-based composite material is prepared by sintering the composite ceramic powder as a raw material, and the long-acting oxidation / ablation resistance can be effectively improved, so that the composite ceramic powder can be used as a thermal structure component on a remote high-speed aircraft; the preparation process is simple, the reaction condition is mild, the period is short, the cost is low, and the problems that in the prior art, the boride and silicon carbide composite ceramic powder preparation process is complex, and the service requirement in an extreme environment cannot be met are solved.

The application belongs to the technical field of ceramics, and particularly relates to a preparation method of high-entropy boride-silicon carbide composite ceramics, which comprises the following steps: mixing high-entropy boride powder and carbon source powder, and then adopting a ceramic forming method to prepare a ceramic green body; embedding the ceramic green body with silicon powder, and performing liquid silicon infiltration treatment in a vacuum environment to obtain high-entropy boride-silicon carbide composite ceramics. The application mixes high-entropy boride and carbon source, and then performs liquid phase silicon infiltration, so that the process is simpler, the residual Si content is relatively less, and high-entropy boride-silicon carbide composite ceramics with a density of more than 99% can be obtained, which is suitable for large-scale production and application.

The invention provides a red mud resource reutilization method which comprises the following steps: weighing raw materials according to the proportion of the raw materials, and grinding the raw materials into powder to obtain mixed powder; the raw materials comprise 70%-95% of matrix ceramic, 0.1%-30% of auxiliary ceramic and 0.1%-30% of red mud. Putting the mixed powder into a planetary ball mill, taking out after wet milling, and drying in a vacuum drying oven; crushing the dried powder by using a crusher, and screening by using a screen; the sieved powder is loaded into a graphite mold to be pre-pressed; and sintering the graphite mold filled with the green body in a discharge plasma sintering furnace. And cooling along with the furnace to obtain the red mud doped alumina-based composite ceramic material. According to the method for recycling the red mud, efficient utilization of the red mud is achieved, the red mud is combined with aluminum oxide and auxiliary ceramic, the red mud-doped aluminum oxide-based composite ceramic material is prepared through the processes of high-energy ball milling, spark plasma sintering and the like, and the prepared material has the advantages of being high in toughness, hardness and strength and the like.

The invention relates to a method for producing a part made of ceramic matrix composite material, the method comprising at least: - a step of forming (10) a fibrous preform; - a step of consolidating (20) the fibrous preform; - an injection step (30), during which a slurry comprising a powder of silicon carbide particles is injected into the fibrous preform, so as to obtain a raw part (100); and - an infiltration step (60), during which a molten silicon-based composition is infiltrated, so as to form a part made of ceramic matrix composite material. The method further comprises: - a step of depositing (40) at least one finishing layer (200) over all or part of the raw part (100); and - a thermocompression step (50), during which the finishing layer (200) is thermocompressed according to a final geometry of the part made of ceramic matrix composite material.

The invention discloses a perovskite-type potassium-sodium niobate-based composite ceramic and a preparation method thereof, the perovskite-type potassium-sodium niobate-based composite ceramic is prepared from two kinds of lead-free piezoelectric ceramics, which are 0.965 (K < 0.48 > Na < 0.52 >) (Nb0.955 Sb < 0.045 >) O < 3 >-0.035 (Bi < 0.5 >, Na < 0.5 >) HfO3 and (K < 0.5 > Na < 0.5 >) NbO < 3 >-1% mol Cu, and the two kinds of lead-free piezoelectric ceramics are firstly pre-synthesized into powder and then mixed, dried and sintered to prepare the perovskite-type potassium-sodium niobate-based composite ceramic. The potassium-sodium niobate-based composite ceramic prepared by mixing potassium-sodium niobate-based ceramic powder of two different systems according to different molar ratios, dry-pressing and sintering has excellent piezoelectric property, good temperature stability and good mechanical quality factor, the piezoelectric constant d33 of the potassium-sodium niobate-based composite ceramic is 254 pC / N, kp reaches 0.51, Qm is 173, and Tc is 304 DEG C.

The invention discloses a preparation method of a copper-zirconium alloy wear-resistant coating based on laser cladding, relates to the technical field of wear-resistant coatings, and is used for solving the technical problem that a high-performance wear-resistant coating cannot be prepared due to poor bonding quality and low cladding efficiency of a cladding layer and a copper-zirconium alloy matrix in the existing laser cladding process. The preparation method of the copper-zirconium alloy wear-resistant coating based on laser cladding comprises the following steps: obtaining a copper-zirconium alloy matrix; preparing a CuSn film layer on the surface of the copper-zirconium alloy matrix, wherein the thickness of the CuSn film layer is 0.5-2 microns; preparing an iron-based coating on the surface of the CuSn film layer, wherein the thickness of the iron-based coating is 0.8-1.0 mm; preparing a wear-resistant layer on the surface of the iron-based coating, wherein the thickness of the wear-resistant layer is 1-1.2 mm; the material for preparing the wear-resistant layer is nickel-based alloy composite ceramic powder, and the nickel-based alloy composite ceramic powder comprises nickel-based alloy and ceramic powder.