13 results about "Non oxide ceramics" patented technology

The invention discloses a gradient composite reinforced anti-corrosion treatment method for a metal alloy guardrail, and belongs to the technical field of metal material surface treatment. The method comprises the following steps: carrying out ultrasonic cavitation micro-etching and electrochemical gradient activation pretreatment on the surface of a substrate; a metal ceramic composite layer containing a non-oxide ceramic reinforced phase is generated on the surface in situ through a micro-arc oxidation-chemical vapor deposition coupling process, and a component transition layer is formed with the assistance of vacuum gradient diffusion alloying treatment; and finally, coating an intelligent resin coating containing a corrosion inhibitor capsule and a corrosion indicator, and constructing a super-hydrophobic surface. By constructing a multi-layer composite protection system of the gradient diffusion layer / the metal ceramic layer / the intelligent coating / the super-hydrophobic layer, the anti-corrosion performance is remarkably improved, and the obtained guardrail has excellent bonding strength, wear resistance and long-acting anti-corrosion service life, has the intelligent functions of damage self-repairing and corrosion state visualization and is suitable for popularization and application. The method is especially suitable for harsh service environments.

The application discloses a kind of preparation methods of multi-component photocuring composite ceramic, by adding tetraethyl orthosilicate in multi-component ceramic powder, obtain modified ceramic powder, then it is mixed with photosensitive resin prepolymer, dispersing agent, diluent, photo initiator uniformly, subsequently sequentially through DLP photocuring 3D printing, debinding, sintering after obtaining composite ceramic.The application utilizes the hydrolysis condensation characteristics of tetraethyl orthosilicate, makes it react on the surface of different ceramic powder, uniformly coats silica layer, can improve the phenomenon of curing uneven caused by the difference of refractive index, absorbance and reaction sensitivity of powder;The layer has low refractive index, can also solve the problem of insufficient curing depth of non-oxide ceramic.In addition, during sintering, the silica layer forms Y-Ce-Si-O ternary eutectic system with CeO2 and Y2O3, reduces the initial temperature of liquid phase, further promotes sintering densification, provides a feasible scheme for composite ceramic, high-entropy ceramic 3D printing.

A method of forming a non-oxide ceramic matrix composite, such as SiC / SiC, is described. The method includes forming a prepreg composition from fibers of a non-oxide material (e.g., silicon carbide) and a non-oxide powder (e.g., silicon carbide), curing the prepreg composition, forming a pre-ceramic composition by pressure infiltrating the cured prepreg composition with a fluid polymer and crosslinking under pressure, and heat treating the pre-ceramic composition to form a non-oxide ceramic matrix composite (CMC). The steps of pressure infiltration, crosslinking, and heat treatment may be repeated (on the resulting non-oxide CMC) to increase densification of the CMC.

The invention discloses a high-temperature-resistant and anti-electromagnetic-interference ceramic fiber composite cable, and relates to the technical field of ceramic composite material preparation, and the ceramic fiber composite cable comprises a cable core and a protection layer wrapping the outer side of the cable core. The protective layer is an integrated ceramic fiber composite layer formed by sequentially stacking a plurality of ceramic fiber sub-layers along the radial direction of the cable core and bonding the ceramic fiber sub-layers in situ through non-oxide ceramics; the silicon nitride-silicon carbide composite crystalline phase non-oxide ceramic fibers are adopted to construct a multi-layer protection structure, and performance cooperative increasing and gradient distribution are achieved; a non-oxide ceramic in-situ bonding process is used for eliminating gaps and stress concentration and improving the integrity; the preparation process is optimized, and the mechanical property and the environmental adaptability are enhanced; double precursors are selected to prepare fibers, the cable cores are reasonably matched, the insulating layer and the protective layer are homogeneously bonded to form an integrated system, multiple properties are comprehensively considered, the traditional defects are overcome, and the requirements of the high-end field are met.

The invention relates to the technical field of electrochemical electrode materials, in particular to a ceramic-based composite boron-doped diamond electrode and a preparation method thereof. The boron-doped diamond electrode comprises a diamond ceramic matrix layer and a boron-doped diamond functional layer, the diamond ceramic matrix layer comprises diamond particles, non-oxide ceramic powder and a conductive additive. The ceramic-based composite boron-doped diamond electrode can effectively solve the problems that an existing BDD electrode is poor in bonding stability, short in service life and low in electrochemical efficiency, and the ceramic-based composite boron-doped diamond electrode integrates high bonding force, large thickness adaptability, low resistivity and high mechanical strength.

The application belongs to the field of non-oxide ceramic powder, and discloses a porous high-entropy carbide powder, a preparation method and application thereof. The porous high-entropy carbide powder is prepared by the following steps: adding mixed powder of ammonium metavanadate, ammonium chromate, ammonium niobate oxalate, ammonium molybdate, ammonium metatungstate and ammonium citrate into deionized water, heating in a water bath at 70-80 DEG C until the powder is completely dissolved, drying the obtained ammonium salt aqueous solution at 45-75 DEG C to obtain a high-entropy carbide ammonium salt precursor; then drying and pressing the high-entropy carbide ammonium salt precursor into a blank body, performing heat treatment in a nitrogen atmosphere, heating to 1500-1600 DEG C and keeping the temperature, and cooling after the temperature is finished. The high-entropy carbide powder has a single high-entropy carbide phase, and the surface has a porous structure; the powder particle size is 0.47-0.79 mu m; and the powder is applied in aerospace parts or chemical catalysis.

The present application belongs to the technical field of high-entropy non-oxide ceramics, and relates to a five-element high-entropy boride ceramic powder material and a preparation method and application thereof. The present application adds chlorides of five transition metal elements into a mixed solution of ethanol and acetylacetone, then adds a carbon source and a boron source after reaction, and continues to react to obtain a high-entropy boride liquid precursor; the high-entropy boride liquid precursor is subjected to two-stage drying and two-stage cracking to obtain a high-entropy boride ceramic powder. The prepared high-entropy boride ceramic powder has high configuration entropy, high element distribution uniformity, uniform hexagonal plate-like single crystal structure and good sintering activity, and the preparation method has the advantages of low cost, simple operation, low operation temperature, short reaction time, low equipment requirement and the like, is suitable for large-scale industrial production and has the characteristics of green environmental protection.

The invention discloses a combined scraper and roller type powder spreading device of three-dimensional printing equipment and a control method, and the combined scraper and roller type powder spreading device comprises a roller which is installed on a scraper support through a bearing and a gear; the scraper is connected with the driving motor through a belt; the scraper is fixedly connected with the roller through a scraper bracket to realize synchronous horizontal reciprocating motion; the gears are installed at the two ends of the roller, the rack is fixed to the side wall of a forming cavity of the powder laying device, and horizontal movement of the scraper is converted into circumferential rotation of the roller through meshing of the gears and the rack. The roller and the scraper are combined to spread ceramic powder, the three-dimensional printing requirement of the high-performance silicon carbide-based ceramic is met, and the three-dimensional printing equipment is not only suitable for the silicon carbide ceramic but also suitable for all non-oxide ceramics such as silicon carbide and silicon nitride, oxide ceramics such as aluminum oxide and zirconium oxide.

The application provides a photocured 3D printing fiber-reinforced ceramic-based composite slurry and a preparation method thereof, which comprises a ceramic precursor powder, a reinforcing fiber, a photosensitive resin mixture and a polymer dispersant. The application provides a photocured 3D printing fiber-reinforced ceramic-based composite slurry and a preparation method thereof, by introducing a ceramic precursor powder with a lower absorbance into the slurry, the problems of low curing thickness and long forming time of non-oxide ceramic powder with high absorbance in the photocured forming printing process can be solved. The application can improve the slurry curing thickness, shorten the forming time, and thus effectively improve the printing forming efficiency.

The invention relates to the technical field of non-oxide ceramic powder, in particular to low-oxygen-content and high-alpha-phase silicon nitride as well as a preparation method and application thereof. The method comprises the following steps: mixing silicon powder and absolute ethyl alcohol, performing mechanical activation pretreatment to reduce the particle size of the silicon powder, increase the specific surface area and reduce the thickness of an oxide layer on the surface of the silicon powder, and performing vacuum drying to obtain activated silicon powder; and nitriding the activated silicon powder, carrying out two-stage cooling treatment, and then carrying out crushing and sieving treatment to obtain the low-oxygen-content and high-alpha-phase silicon nitride. Through the assistant-free negative-pressure silicon thermal nitriding and mechanical activation synergistic process, the problems that in the prior art, the oxygen content is high, the alpha-phase content is low and difficult to control, powder agglomeration is serious, the morphology is uneven, presintering is not facilitated, the purity is reduced and the cost is increased due to the fact that an assistant needs to be added, and industrialization is difficult due to the fact that the reaction is violent are solved.

Embodiments of the present application provide a composite substrate and a preparation method of the composite substrate. The composite substrate comprises a carrier substrate, a transition layer, the transition layer being a non-oxide ceramic layer, the transition layer being stacked on one side of the carrier substrate in the thickness direction, and a donor substrate, the donor substrate being stacked on the side of the transition layer away from the carrier substrate. The transition layer can withstand higher temperature, avoiding the melting or decomposition of the transition layer in the annealing process, and thus avoiding the case that the structure of the first interface and the second interface is destroyed to cause the rapid increase of the resistivity. Moreover, the cleanliness of the surface of the carrier substrate or the surface of the donor substrate or the process environment can be ensured by high temperature assistance, which can assist in eliminating impurities on one hand and avoiding the entry of impurities on the other hand, and thus the internal defects of the first interface and the second interface can be reduced, so as to improve the effect of reducing the resistivity between the carrier substrate and the donor substrate.

The invention provides a pore-filling slurry and a preparation method and application thereof, and relates to the technical field of electronic packaging, the pore-filling slurry comprises the following components by mass: 13-25 parts of an organic carrier; 73 to 86 parts of inorganic powder; the inorganic powder is composed of oxide ceramic and non-oxide ceramic; the mass of the non-oxide ceramic accounts for 1%-3% of the mass of the inorganic powder; the oxide ceramics are aluminum oxide and zirconium oxide; the non-oxide ceramic is selected from one or more of silicon carbide, boron nitride and boron carbide. The pore-filling slurry provided by the invention is not sintered at annealing and sintering temperatures, for example, after the pore-filling slurry is filled into a glass substrate and a green ceramic through hole, the deformation of the substrate through hole and the shrinkage of the green ceramic through hole can be prevented in the annealing / sintering process. Moreover, the non-oxide ceramic powder can generate gas under a high-temperature condition, so that the slurry is fluffy and easy to remove after annealing / sintering.

The application relates to an ultraviolet light-near infrared light synergic additive manufacturing device and method, which comprises a displacement mechanism, a forming platform connected with the displacement mechanism, an ultraviolet material tank, a cleaning tank and a non-oxide ceramic material tank, the ultraviolet material tank, the cleaning tank and the near infrared material tank are arranged side by side along a preset direction and are all within the operation stroke range of the displacement mechanism, an ultraviolet light source is arranged correspondingly to the ultraviolet material tank, and a near infrared light source is arranged correspondingly to the near infrared material tank. The high-precision characteristics of ultraviolet light curing are used to layer by layer build a soluble resin shell as a sacrificial mold and temporary support, which not only ensures the part contour precision, but also realizes the forming of a cantilever structure, then the high penetration of near infrared light is used to realize the deep heat curing of high refractive index or high light absorption materials (non-oxide ceramics, metals, carbon-based materials and the like) layer by layer, and the mechanical, thermal, electrical and other performances of the workpiece are ensured, and the device has the dual advantages of shape control and property control.