107 results about "Graphite substrate" patented technology

The invention discloses a graphite piece silicon carbide coating and a preparation method thereof, and belongs to the technical field of inorganic non-metallic materials. The method comprises the following steps: firstly, carrying out surface polishing, cleaning and drying pretreatment on a graphite piece; then a solution containing phosphinazine functionalized silazane and a boron-silicon carlamide compound is adopted for spraying the pretreated graphite piece, drying and curing are conducted, and a surface modification layer is formed; and finally, placing the surface-modified graphite piece in chemical vapor deposition equipment, and depositing at specific temperature, pressure and atmosphere to form the silicon carbide coating. According to the method, uniform nucleation and crystallization of the silicon carbide coating are effectively promoted through unique surface modification treatment, and the compactness and uniformity of the coating and the binding force of the coating and a matrix are remarkably improved. The obtained coating graphite piece has excellent thermal corrosion resistance, oxidation resistance and mechanical property, the service life and the use frequency of the coating graphite piece in semiconductor epitaxial equipment are remarkably prolonged, the whole preparation process is environmentally friendly, and the coating graphite piece is suitable for coating treatment of a large graphite base material.

The invention belongs to the technical field of silicon carbide coatings, and particularly relates to a method for quickly depositing a silicon carbide coating through CVD (Chemical Vapor Deposition), which comprises the following steps: pretreating a graphite substrate; debugging the equipment; placing the pretreated substrate in a reaction furnace, closing a furnace door, starting a vacuum system, pumping the pressure in the reaction furnace to-Pa, and reducing the interference of air in the furnace on the reaction; introducing a small amount of hydrogen into the reaction furnace, rapidly raising the temperature in the furnace to 800-900 DEG C, maintaining the temperature, then introducing a very small amount of silicon source and carbon source gas, and carrying out preliminary deposition on the surface of the substrate; and hydrogen, silicon tetrachloride and methane are sequentially introduced. The preparation method of the CVD silicon carbide coating can solve the problems of low deposition rate, long preparation period and the like when the existing CVD process is used for preparing the silicon carbide coating, so that the production efficiency can be greatly improved, the cost can be reduced, and the preparation method has important significance in promoting the application of the silicon carbide coating in more fields.

The invention discloses a method for preparing a carbide coating with high bonding strength on a graphite surface. The method comprises the following steps: roughening the graphite surface to obtain roughened graphite, coating transition layer slurry on the roughened graphite surface, performing first sintering to obtain a transition layer, coating surface layer slurry on the transition layer surface, and performing second sintering to obtain the carbide coating. According to the preparation method, the synergistic effect of chemical bonding and mechanical embedding is achieved by optimizing the surface roughness, designing the transition layer and sintering the carbide coating, the carbide coating with the high interface bonding force is prepared on the graphite surface, and the preparation method is suitable for surface modification of graphite-based materials under the harsh working conditions of high temperature, high corrosion and the like.

The invention provides an inner hole plasma spraying high-bonding-strength bonding layer and Y2O3 coating material and a preparation technology thereof. The bonding layer comprises a middle transition layer formed after Si and C on the surface of a graphite matrix are subjected to a chemical reaction. The inner hole plasma spraying high-bonding-strength bonding layer provided by the invention is composed of a silicon carbide transition layer generated by in-situ reaction of molten silicon and carbon on the surface of a graphite matrix, and can form a Si-O-M bridged bond with a subsequent ceramic coating, so that interface bonding is converted into chemical bonding from mechanical anchoring, and the bonding strength is improved. And meanwhile, by utilizing the thermal expansion characteristic of silicon carbide between graphite and ceramic, the purposes of buffering thermal mismatch stress step by step on the atomic scale, blocking high-temperature diffusion of carbon elements and endowing the coating with lasting high bonding strength and thermal cycling stability are achieved.

A field emission (FE) cathode for a vacuum electronic device (VED) includes a graphite substrate or framework in the shape of a hollow cylinder, and at least one continuous carbon nanotube (CNT) fiber in tension or compression around at least a portion of the graphite substrate. The at least one continuous CNT fiber can include a filament, yarn, braided yarn, film, fabric, or combination thereof. The at least one continuous CNT fiber is secured to the electrically conductive substrate by vacuum brazing or any other suitable means.

The application discloses a kind of multilayer composite ceramic coating with high-temperature stability and corrosion resistance on graphite surface and a preparation method thereof, ultra-high temperature ceramic oxide slurry is brushed on the surface of graphite substrate, first heat treatment is carried out, porous transition layer is obtained, then ultra-high temperature carbide slurry is brushed on the surface of porous transition layer, ultra-high temperature carbide layer is obtained after drying, then roughening treatment is carried out on the surface of ultra-high temperature carbide layer using ultra-high temperature carbide slurry, then second heat treatment is carried out, rough carbide layer is obtained, then dense projection is obtained by point pressure on the surface of rough carbide layer using metal carbide ceramic mixed slurry, and protective layer material is sprayed, and the method of the application can significantly improve the firmness of each layer, effectively avoid the reaction between graphite substrate and surface protective layer at high temperature, leading to coating failure and falling off, further enhance the use limit of protective layer, and have wide application prospect.

This invention discloses a graphite part, its preparation method, its application, and its evaluation method. The graphite part includes a graphite substrate and an amorphous carbon coating disposed on the surface of the graphite substrate. The graphite part satisfies Q=Y×Δρ×(Ra^0.5) / d≥4.0: By coupling the coating's energy dissipation capacity (Y), the substrate's gradient densification degree (Δρ), the substrate's surface morphology characteristics (Ra^0.5), and the coating's geometric constraints (d) to a single parameter Q, quantitative characterization and engineering controllability of the crack resistance performance of the amorphous carbon coating during high-temperature carbonization are achieved. In the graphite part prepared when Q≥4.0, the amorphous carbon coating does not crack or shed powder, which is beneficial for its application in ion implanters.

The invention discloses a preparation method and application of doped graphite, and belongs to the technical field of doped graphite. The method comprises the following steps: performing vacuum annealing on a single crystal metal substrate adsorbed with a doped element compound to obtain a doped element embedded single crystal metal substrate; the single crystal metal substrate embedded with the doping elements is attached to a graphite base material, heat preservation is conducted for 1-3 h at the temperature of 1000-1500 DEG C in a non-oxidizing atmosphere, then heat preservation is conducted for 4-12 h at the temperature of 700-900 DEG C, and the doped graphite is obtained after cooling. According to the invention, the doping elements are embedded into the single crystal metal substrate, and the graphite is doped through variable temperature growth, so that the super-lubricity is maintained while the doping uniformity and controllability are ensured, and the method is more suitable for being applied to electronic devices needing to maintain the super-lubricity.

The invention provides a method for repairing a wafer carrying disc, and the method comprises the following steps: providing a wafer carrying disc to be repaired, the wafer carrying disc to be repaired comprises a graphite substrate and a silicon carbide coating, the graphite substrate comprises a first surface and a second surface which are oppositely arranged, and the silicon carbide coating is located on the first surface; the to-be-repaired wafer loading disc is provided with a concave hole, and the concave hole penetrates through the silicon carbide coating and a part of the thickness of the graphite substrate; filling the concave hole with a repair material comprising a resin material, and graphitizing the resin material to obtain a graphitized repair structure; the maximum distance between the surface, away from the second surface, of the graphitization repair structure and the second surface is smaller than the distance between the surface, away from the graphite substrate, of the silicon carbide coating and the second surface; and forming a silicon carbide repairing structure in the concave hole, wherein the surface, away from the graphite substrate, of the silicon carbide repairing structure is flush with the surface, away from the graphite substrate, of the silicon carbide coating. Recycling and reusing of the wafer carrying disc can be achieved.

The invention provides a large-area (100) oriented metal organic framework ZIF-8 film as well as a preparation method and application thereof. Specifically, the method comprises the following steps: enabling at least part of the surface of a graphite substrate to be in contact with a ZIF-8 film synthesis solution containing Zn < 2 + > and 2-methylimidazole, enabling the Zn < 2 + > to react with the 2-methylimidazole, and forming the ZIF-8 alignment film on the graphite substrate. The ZIF-8 oriented film prepared by the method disclosed by the invention is uniform and compact, is highly oriented and has high H2 selective separation performance.

This invention discloses a method for preparing a SiC-coated graphite substrate transition layer for semiconductors. The method is implemented using a preparation device for this transition layer. The device includes a support base, with a vapor deposition reaction chamber located at the upper center of the support base. An air inlet is located at the upper center of the vapor deposition reaction chamber. A set of first suction pumps is installed on both the lower left and lower right sides of the vapor deposition reaction chamber. By incorporating a storage and exchange mechanism, the heat from the previous step is exchanged for the gas required for preheating in the next step, reducing heat loss and saving energy. Furthermore, by incorporating a first recovery mechanism and a second recovery mechanism, the efficiency of gas separation is improved, making the entire separation process more precise.

The application relates to a graphite base material grinding processing equipment for fuel cell bipolar plates, which comprises a graphite crusher, a polishing box arranged below the graphite crusher, a material guiding assembly arranged at the top of the polishing box, a first polishing assembly arranged in the polishing box, the first polishing assembly comprising a first polishing block, a first rotating assembly arranged on the first polishing assembly, a second polishing assembly arranged in the polishing box, the second polishing assembly comprising a second polishing block, a second rotating assembly arranged on the second polishing assembly, a driving assembly arranged at the bottom of the polishing box, and a conveying assembly arranged in the polishing box, wherein the first polishing block and the second polishing block are used for polishing graphite blocks into spherical graphite in the rotating process, and the conveying assembly is used for conveying the graphite blocks at the bottom of the polishing box from bottom to top, so that the polishing efficiency is improved, the graphite blocks at the bottom of the polishing box can also be polished, and the polishing quality is improved.

The invention relates to a method for improving a graphite pore silicon carbide coating, which comprises the following steps: placing a graphite base material in a reaction cavity, and introducing hydrogen to activate the graphite base material; introducing silicon-based precursor gas and hydrogen, and performing permeable reaction treatment on the graphite base material subjected to activation treatment so as to form a SiC permeable layer in the graphite base material and form a SiC plugging layer on the surface of the graphite base material; and continuously introducing the silicon-based precursor gas and hydrogen, and depositing on the SiC plugging layer to form a SiC main coating. According to the preparation method, the integrated preparation of the comprehensive plugging of the air holes and the functional coating is realized through the steps of plugging the air holes through siliconizing and growing the main coating through the conventional CVD process.

An electrolysis reactor for electrolytically generating one or more metal cathode product(s) includes a dimensionally stable anode (DSA) and a cathode positioned in a molten salt electrolyte containing fused salts, wherein the DSA includes a graphite substrate and a non-ceramic, transition metal oxide coating on the substrate and wherein during electrolysis the one or more metal cathode product(s) are produced at the cathode.

The invention discloses a preparation method of a graphite substrate tantalum carbide coating based on a gradient buffer layer, and belongs to the technical field of third-generation semiconductor production. A Ta2C / TaC gradient buffer layer is generated on a graphite substrate in situ, the TaC molar fraction is gradually transited to 90% or above of a surface layer from about 10% close to the graphite substrate, and then the gradient buffer layer is converted into a single-phase TaC coating through medium and low temperature pretreatment and high temperature annealing treatment. The lattice constant and the thermal expansion coefficient of Ta2C are between those of graphite and TaC, and thermal stress can be effectively and gradually released, so that cracking and stripping of the coating are remarkably inhibited. According to the continuous component gradient design, the thermal expansion coefficient can realize stable transition from the graphite substrate to the pure TaC coating, the interface stress concentration caused by sudden change of the thermal expansion coefficient is remarkably reduced, and the interface residual stress is reduced, so that microcrack initiation and interface stripping of the coating in the high-temperature circulating process are effectively inhibited.

The invention relates to the technical field of graphite film production, and discloses a microstructure ultrathin graphite film production process and equipment based on laser processing, and the microstructure ultrathin graphite film production process based on laser processing comprises the following steps: providing an ultrathin graphite film base material; etching the surface of the ultrathin graphite film substrate by adopting a laser beam to form a micropore or microcrack structure; compounding a plurality of layers of ultrathin graphite film base materials; pET black and white adhesive layers are adhered to the two sides of the composite ultrathin graphite film. In the preparation process of the ultrathin graphite film, the micro-pore or micro-crack structure is processed on the ultrathin graphite base material through the laser etching process, the size of the micro-pore or micro-crack structure is controllable, micro relative slippage and bending deformation between sheet layers of the ultrathin graphite film base material are allowed, and strain energy is absorbed, so that the flexibility is improved; and therefore, the cable can bear a certain degree of repeated bending without being broken.

The invention provides a photo-thermal regulation and control multilayer film and a preparation method thereof, and belongs to the technical field of optical films, the film comprises a fourth film layer, a third film layer, a second film layer and a first film layer which are sequentially sputtered and deposited on the surface of a graphite substrate from bottom to top; wherein the first thin film layer and the second thin film layer are used for realizing visible light structural color regulation and mechanical protection, the third thin film layer is used for realizing directional radiation of a target angle in a medium and long infrared band, and the fourth thin film layer, the third thin film layer, the second thin film layer and the first thin film layer form a Fabry-Perot resonant cavity. Therefore, the wave absorbing performance of the whole film in a medium-long infrared band can be regulated and controlled. The photo-thermal regulation and control multi-layer thin film successfully realizes organic coupling of mechanical protection, visible light structural color regulation and control, and medium and long infrared directional radiation and radiation heat dissipation.

The invention provides an in-situ preparation method of a trace gold self-supporting catalyst loaded on a graphite substrate, which comprises the following steps: adding a neutral polar solvent into a gold source, carrying out ultrasonic dissolution to obtain a precursor solution, dispensing the precursor solution on the graphite substrate, standing at room temperature for reaction, cleaning with distilled water, and drying at room temperature to obtain the trace gold self-supporting catalyst loaded on the graphite substrate. The trace gold self-supporting catalyst loaded on the graphite substrate is obtained. The invention also provides an application. The trace gold self-supporting catalyst loaded on the graphite substrate prepared by the invention is used for an electro-catalysis hydrogen evolution reaction. The trace gold self-supporting catalyst loaded on the graphite substrate is prepared in situ through a simple room temperature method, the gold loading capacity of the catalyst is extremely low, and the cost is low; no binder or conductive agent is used, the conductivity is good, and shedding or agglomeration of the catalyst is avoided; the preparation method is simple and does not need extra energy. The obtained catalyst is high in catalytic activity and strong in stability, and has a wide application prospect in the field of electro-catalytic hydrogen evolution.

A crystalline graphite substrate having a carbon purity of 95% or more, in which a surface roughness Ra is from 1 μm to 8 μm inclusive, and a FWHM for a peak in X-ray diffraction corresponding to a layer interval at which hexagonal mesh structures in which six-membered rings of carbon atoms are continuous are stacked is from 3.5 degrees to 9 degrees inclusive.

The invention provides a gradient composite coating graphite crucible which comprises a graphite substrate and a gradient composite coating arranged on the surface of the graphite substrate, and the gradient composite coating comprises an interface whisker reinforcing layer, a grain boundary sealing layer and a double-phase composite oxygen barrier layer which are sequentially distributed from one side to the outer side of the graphite substrate. The invention further provides a preparation method and application of the gradient composite coating graphite crucible. The gradient composite coating comprises the interface whisker reinforcing layer, the grain boundary sealing layer and the double-phase composite oxygen barrier layer which are sequentially distributed from one side to the outer side of the graphite matrix, thermal stress is effectively relieved through toughening of beta-SiC whiskers, a three-dimensional network structure formed by a Si3N4 phase and a SiC phase and an overall gradient structure, and thermal shock resistance is greatly improved. The solution spraying is matched with the conventional sintering process, compared with CVD coating preparation, the preparation method has the advantages of being simple in process, lower in energy consumption and higher in productivity, and meanwhile the product percent of pass is up to 92% or above.

The application provides a method for sealing pores of a graphite surface based on phase separation resin coating derived carbon, comprising the following steps: S1. mixing epoxy resin and epoxy soybean oil in proportion, defoaming, adding a curing agent, and uniformly mixing to obtain a pore sealing agent; S2. adding a diluent to the pore sealing agent prepared in step S1, and diluting to obtain a pore sealing solution; S3. coating or spraying the pore sealing solution prepared in step S2 on the surface of a graphite substrate after cleaning and drying for one or more times; S4. curing the graphite substrate obtained in the above step at a gradient temperature to obtain a graphite substrate loaded with resin; and S5. carbonizing the graphite substrate loaded with resin in an inert atmosphere at a high temperature to obtain a pore-sealed graphite material. The carbon formed by coating the resin coating on the surface of the graphite after high-temperature graphitization is used to seal the pores of the graphite surface, has good coating adhesion, and further improves the durability of the graphite sealing and the service life of the graphite product.

The invention provides a preparation method of a high-density tantalum carbide coating, and belongs to the technical field of semiconductor processing. The preparation method comprises the following steps: adding ammonium citrate, Arabic gum and water into TaC powder and low-melting-point tantalum-containing powder, uniformly mixing, and granulating by using a spray granulator to obtain low-melting-point tantalum-containing primary mixed powder adsorbed on the surface of the TaC powder; secondary mixed powder formed by wrapping the surface of TaC powder obtained after sintering with low-melting-point tantalum-containing powder is crushed, screened, mixed with an organic binder and water and then coated on the surface of a graphite base material, and a tantalum carbide precoating is obtained after sintering, so that liquid-phase-assisted TaC powder sintering is achieved, and the tantalum carbide precoating is formed; the periphery of the TaC powder is wrapped with a layer of tantalum-containing powder with a low melting point by means of spray granulation and sintering, crack pores generated between crystal boundaries in the sintering process are relieved, combination between the coating and a base material is facilitated, the crack pores at the TaC crystal boundaries are filled with liquid, the compactness of the tantalum carbide precoating is higher, and the service life of the tantalum carbide precoating is prolonged. The growth requirements of high-quality SiC single crystals are met.

Disclosed are a positive electrode, a preparation method thereof, and a rechargeable lithium battery including the positive electrode. The positive electrode includes a positive electrode current collector, a positive electrode active material layer on the positive electrode current collector, and a positive electrode coating layer between the positive electrode current collector and the positive electrode active material layer. The positive electrode coating layer includes a graphite-based material, a phosphorus-based extinguishing agent, and a binder, and the positive electrode coating layer includes about 1 part by weight to about 45 part by weight of the phosphorus-based extinguishing agent based on 100 parts by weight of a total of the graphite-based material and the phosphorus-based extinguishing agent.

The innovative method is for removing a silicon carbide layer from a bulk piece; the bulk piece comprises a graphite substrate underlying the silicon carbide layer; the method comprises in succession the steps of: a) submerging the bulk piece in a first solution containing nitric acid, b) submerging the bulk piece in a second solution containing hydrofluoric acid and an oxidizing agent, and typically c) submerging the bulk piece in a third solution containing preferably only or essentially deionized water until the layer detaches from the piece; this method can advantageously be used to clean components of an epitaxial reactor e.g. after their use in the reactor in silicon carbide deposition processes.

The invention relates to a method for producing a solar cell for converting incident electromagnetic radiation into electrical power, wherein a layer structure is formed, comprising at least one charge-selective front contact structure, at least one charge-selective rear contact structure, and an absorber structure comprising at least perovskite, wherein the rear contact structure is designed to comprise at least one rear graphite layer. According to the invention: a sub-cell comprising at least the front contact structure and the absorber structure is formed; the rear contact structure, which comprises at least the rear graphite layer and a charge-selective rear contact layer, is initially formed separately from the sub-cell; and, after the rear contact structure has been formed, the rear contact structure is arranged on the sub-cell such that the charge-selective rear contact layer is positioned between the rear graphite layer and the sub-cell.

The invention relates to a graphite coated tantalum carbide material and a preparation method thereof, and the material comprises a graphite base material, a first tantalum carbide inner coating arranged on the inner side of the graphite base material, a second tantalum carbide inner coating arranged on the first tantalum carbide inner coating, and a third tantalum carbide inner coating arranged on the second tantalum carbide inner coating, the tantalum carbide outer coating is arranged on the third tantalum carbide inner coating; wherein the molar ratio of C to Ta in the first tantalum carbide inner coating is 1: (0.2-0.3), the molar ratio of C to Ta in the second tantalum carbide inner coating is 1: (0.4-0.6), the molar ratio of C to Ta in the third tantalum carbide inner coating is 1: (0.7-0.8), and the molar ratio of C to Ta in the tantalum carbide outer coating is 1: (0.9-1). The tantalum carbide coating is provided with a transition layer with C / Ta continuously changing, the thermal expansion coefficient difference of graphite and tantalum carbide can be effectively relieved, the cracking and falling risks of the coating are reduced, and the service life of the tantalum carbide coating is prolonged.

The application discloses a method for preparing a titanium carbon oxide electrode by coating, and the method comprises the following steps: A. crushing and screening titanium carbon oxide, mixing the titanium carbon oxide with a pore-forming agent and a binder to obtain a mixture, and adding water into the mixture to prepare a slurry; B. coating the slurry on a graphite substrate by using a doctor blade; and C. drying and sintering the coated graphite substrate to obtain the titanium carbon oxide electrode. The application provides a method for preparing a titanium carbon oxide electrode by coating, the titanium carbon oxide electrode is prepared by coating and sintering the mixed slurry on a graphite substrate, the peeling problem of the electrode caused by gas scouring in an electrolysis process is avoided, the loose and porous structure formed by sintering makes the electrode have relatively high dissolving performance, the anode dissolving rate is increased from 50% to more than 80%, and the problem of low dissolving rate of the titanium carbon oxide anode in the electrode process is solved.

The invention discloses a graphite anti-ablation composite coating and a preparation method thereof, and belongs to the technical field of coatings. The invention discloses a graphite anti-ablation composite coating. A SiC compact transition and sealing layer, a ZrC porous heat insulation and strain tolerance layer and an HfC-TaC compact ultrahigh-temperature ablation coating are sequentially arranged on the surface of a graphite matrix from inside to outside; the linear expansion coefficients of the SiC compact transition and sealing layer, the ZrC porous heat insulation and strain tolerance layer and the HfC-TaC compact ultrahigh-temperature ablation coating are gradually reduced from outside to inside. The coating provided by the invention is in gradient distribution in the aspects of components, mechanical properties and thermal expansion coefficients, and the continuous change can effectively relieve the performance mismatching between the matrix and the coating, so that the outermost layer is subjected to smaller tensile stress in the ablation process. The obtained coating is stable in adhesive force under the action of thermal stress, free of layering and cracking and good in ablation resistance.

The invention provides a high-temperature-resistant coating for a graphite crucible as well as a preparation method and application of the high-temperature-resistant coating, and belongs to the field of high-temperature-resistant coatings. The high-temperature-resistant coating is an isolating layer covering the inner wall of the graphite crucible and is prepared from the following raw materials: 90-98% of aluminum oxide powder and 2-10% of a high-temperature-resistant adhesive. The high-temperature-resistant adhesive comprises one or more of a phosphate adhesive, dextrin and silica sol. According to the application, an effective isolation barrier is introduced between the inner wall of the graphite base and the high-temperature slag, so that the adhesion between the slag and the graphite substrate is remarkably reduced or eliminated, and the slag can be quickly and effectively stripped from the inner wall of the graphite substrate, so that the repeated utilization of the graphite base is realized, and the service life of the graphite base is prolonged. Finally, the purposes of reducing the detection cost and reducing the resource consumption are achieved.

The invention belongs to the field of vapor deposition processes, and discloses a graphite release agent as well as a preparation method and a use method thereof. The graphite release agent comprises graphite powder, bismaleimide resin, polyvinylpyrrolidone and an organic solvent, according to the mass fraction, the content of the graphite powder is 1wt%-10wt%, the content of the bismaleimide resin is 1wt%-15wt%, the content of the polyvinylpyrrolidone is 1wt%-15wt%, and the balance is the organic solvent. The graphite powder can fill defects on the surface of the substrate and block metal vapor permeation and reaction; the bismaleimide resin is resistant to high temperature and has proper binding power, and coating cracking caused by expansion coefficient difference can be relieved; the polyvinylpyrrolidone can improve the dispersion stability and the film forming uniformity of the system. Through the synergistic effect of the three components, a deposited film layer can be prevented from being bonded with the graphite substrate, the deposited film layer is easy to separate, high flatness and no pollution of the substrate are maintained, and the repeated utilization rate and the process stability of the substrate are remarkably improved.