353 results about "Graphite crucible" patented technology

The invention discloses a graphite crucible silicon infiltration resistant coating based on a gradient boron nitride-silicon carbide composite structure and a preparation method thereof. The coating is composed of hexagonal boron nitride nanosheets, beta-type silicon carbide nanowires, yttrium aluminum garnet precursor sol and the like, and effective blocking of 1500-1600 DEG C silicon melt is achieved through gradient structural design and an in-situ self-repairing mechanism. The preparation process comprises the steps of h-BN activation, S C carbon layer deposition, slurry mixing and spraying and segmented heat treatment. The molten silicon contact angle of the coating reaches 158 + / -2 degrees at the temperature of 1550 DEG C, through cracks do not exist after 50 times of thermal shock circulation, the coating is effective after being continuously used for 48 batches under the industrial working condition, the problems of silicon infiltration interface adhesion and thermal shock failure of a traditional graphite crucible are solved, and the coating has remarkable industrial application value.

The utility model relates to the technical field of single crystal preparation by a liquid phase epitaxy method, in particular to a leading forced convection introducing device for single crystal growth by a resistance heating LPE method, which comprises a graphite crucible and a graphite heating component arranged on the outer side of the graphite crucible, one end of the graphite seed crystal rod extends into the graphite crucible and is connected with the graphite seed crystal support; the seed crystal is adhered to the bottom surface of the graphite seed crystal support; the graphite annular turbofan is arranged in the graphite crucible; the graphite annular turbofan is connected with the graphite seed rod through a jackscrew clamp; the other end of the graphite seed crystal rod is externally connected with a seed crystal lifting and rotating mechanism; and the graphite seed crystal rod drives the seed crystal and the graphite annular turbofan to do lifting and rotating motion. According to the device, the influence of adverse convection on the whole flow field is weakened, and the controllability of the whole flow field can be improved; and meanwhile, an ideal temperature field for growing high-quality silicon carbide crystals in the growth cavity is ensured.

The invention discloses an inner wall defect detection device for graphite crucible production based on vision, and relates to the technical field of vision detection. Through cooperation of the clamping assembly and the adjusting assembly, the device can automatically adjust and position according to the actual material volume and height; the surface conditions of the inner wall of the crucible at different angles can be simultaneously detected by the device through the detection assembly, so that the capability of accurately detecting fine defects by the device is realized; the analysis module is used for firstly eliminating the regional images with the abnormal count exceeding the preset threshold value, then calculating the mean value of the numbered gray blocks corresponding to the remaining regional images as gray value data, and comparing the gray value data with the gray image of the standard component, so that the interference of the abnormal region on the overall data analysis is effectively avoided, and the reliability of the detection result is ensured; meanwhile, the total abnormal area is obtained by calculating the product of the number of the abnormal gray blocks and the area of the pixel blocks, a quantitative basis is provided for defect judgment, and the detection result is more persuasive.

The invention discloses equipment and a method for preparing an aluminum silicon carbide (Al-SiC) composite material through a pressure infiltration process, and belongs to the technical field of metal matrix composite material preparation. The efficient pressure preparation equipment for the aluminum-silicon carbide composite material comprises a furnace body, a lower graphite crucible, an upper graphite crucible, a liftable graphite rod, an inflation connector and an exhaust connector, during specific use, an aluminum ingot and a silicon carbide preform are heated respectively and prevented from making contact with each other, so that the interface reaction strength is relieved, and combination of aluminum and silicon carbide is facilitated; after the target temperature is reached, the graphite rod is lifted to open the leak hole, so that the molten aluminum falls into the lower graphite crucible, and under the action of high-pressure gas, the molten aluminum is infiltrated into the silicon carbide prefabricated body, so that the aluminum-silicon carbide composite material is prepared; the problems of low density, poor process stability, violent interface reaction and low bonding strength in the prior art can be solved.

The invention relates to the field of silicon carbide wafer preparation, in particular to a semi-insulating silicon carbide wafer annealing device and method, the annealing device comprises a crucible cover and a graphite crucible which are detachably connected, an annealing chamber is arranged in the graphite crucible, the annealing chamber comprises a wafer supporting area and a powder area, and the powder area is arranged in the crucible cover. The gas pressure control assembly is used for controlling gas components and pressure intensity in the annealing chamber; the heating device is used for heating the annealing chamber in a partitioned manner; and the heat preservation system is arranged outside the crucible cover and the graphite crucible in a sleeving manner. By means of the annealing device, the problems of silicon carbide wafer intrinsic point defect screening and concentration control can be effectively solved, the Fermi energy level is controlled at the EH6 / 7 energy level position, and the silicon carbide wafer obtained through annealing finally achieves control over the electrical resistivity larger than 1E12 ohm cm.

The invention discloses a ceramic component gradient modified C / C-SiC-ZrC composite material and a preparation method thereof, and belongs to the technical field of carbon / carbon composite material matrix modification preparation, a carbon fiber preform and a heating element are placed in chemical liquid phase vaporization deposition equipment, a precursor solution is added until the carbon fiber preform is fully soaked, and a ceramic component gradient modified C / C-SiC-ZrC composite material is obtained; and carrying out chemical liquid phase vaporization deposition reaction to obtain the low-density C / C composite material with porosity in unidirectional gradient distribution. And putting the mixture into a graphite crucible with a carbon-rich area facing downwards and a carbon-less area facing upwards, completely putting the graphite crucible into the ceramic powder for modification, reacting and infiltrating, and cooling to room temperature to obtain the C / C-SiC-ZrC composite material with the gradient modified ceramic components. The end with high ceramic content endows the material with a high-temperature thermal protection function, the end with high pyrolytic carbon content can effectively conduct heat generated in a ceramic-rich area, and the end with low ceramic content can effectively conduct heat generated in a ceramic-rich area. Due to the gradient design from the ceramic-rich area to the carbon-rich area, the material has high-temperature oxidation resistance and ablation resistance and is light, and lightweight design of an aerospace thermal protection structure is facilitated.

The invention discloses a molybdenum-vanadium-aluminum intermediate alloy and a low-cost preparation method thereof. The molybdenum-vanadium-aluminum intermediate alloy comprises the following chemical components in percentage by mass: 39-41% of Mo, 39-41% of V and the balance of Al. The method comprises the following steps: uniformly mixing vanadium oxide (tablets replace powder), molybdenum trioxide, metal aluminum, calcium fluoride, calcium oxide and a cold material according to a mass ratio of (28-32): (24-26): (32-35): (10-13): (1.5-4): (5-10); then putting the mixture into a graphite crucible for tamping treatment; and finally, the metal powder is directly ignited for a reduction reaction, and the molybdenum-vanadium-aluminum intermediate alloy can be obtained. According to the method, the recovery rates of the molybdenum and the vanadium are increased by adjusting the components and the ratio of the raw materials and the auxiliary materials and adopting a one-step aluminothermic reduction method, and the recovery rates of the molybdenum and the vanadium can reach 95 wt% or above and 96 wt% or above respectively.

The invention relates to a silicon nitride crystal based on high static nitrogen pressure and active nitrogen regulation and a growth method thereof. The silicon nitride crystal is prepared by the growth method, and the method adopts a physical gas phase transmission process and specifically comprises the following steps: introducing high static pressure nitrogen (1-3 bar) and trace NH3 / N2 mixed gas into source powder formed by mixing high-purity beta-Si3N4 and polycrystalline silicon, and dynamically maintaining the gas phase N / Si molar ratio to be (1.33 + / -0.1): 1, thereby inhibiting the decomposition of the source powder and stabilizing the crystal growth; carrying out spray granulation on the source powder, carrying out compression molding, placing the obtained product in a graphite crucible with the inner wall coated with TaC, and carrying out ordered epitaxial growth by controlling the temperature difference of a temperature zone at 1800-2000 DEG C and the axial temperature gradient; according to the method, the dislocation density and the carbon impurity content of the silicon nitride crystal can be remarkably reduced, then the high-purity silicon nitride crystal with a complete structure and a smooth surface is obtained, and the method is suitable for the fields of high-temperature electronic devices and deep ultraviolet light electronics.

The invention provides a method for synchronously recovering iron and rare earth from iron separation tailings, which comprises the following steps of: roasting the pretreated iron separation tailings in a graphite crucible to obtain a roasted product; the roasted product is crushed and screened, oversize products and undersize products are obtained, and the oversize products are reduced iron products; the screen underflow and an acid solution are mixed for leaching, and leaching liquid containing rare earth elements and acid leaching residues are obtained; and adding a precipitant into the leachate to obtain a precipitate containing rare earth elements, and recovering fluorite concentrate from the acid leaching residues. According to the method, the traditional disjunction mode of pre-enrichment and then smelting is broken through, a roasting-acid leaching integrated process with deep beneficiation and smelting coupling is provided, the complex pre-enrichment link is abandoned, efficient and synchronous recovery of iron and rare earth is achieved, and the method has the advantages of being short in process, low in energy consumption, few in flotation reagent, high in rare earth recovery rate, high in resource comprehensive utilization rate and the like.

The invention discloses a method for preparing oxide eutectic ceramics in an ultrafast high-temperature furnace. Proportioning the raw material powder according to the eutectic components, and sequentially carrying out ball milling, drying, sieving and compression molding; putting the green body into a thin-wall graphite crucible, and putting the thin-wall graphite crucible into an interlayer hole of a heating carbon felt element; and heating to a set temperature in an ultrafast manner, keeping the temperature for an extremely short time, and cooling to obtain the oxide eutectic ceramic. According to the method, the eutectic structure of the oxide ceramic is rapidly formed by adopting ultrafast heating and Joule heat radiation heating at the furnace temperature far lower than the eutectic temperature, and the structure morphology of the eutectic ceramic can be regulated and controlled by adjusting temperature parameters. The obtained eutectic structure is fine in size and excellent in mechanical property; the problems that an existing oxide eutectic ceramic preparation method is long in consumed time, high in cost, complex in bulk material preparation process and the like are solved.

The invention provides a production method of a vanadium-aluminum alloy. The production method comprises the following steps: treating raw materials; the high-purity calcium fluoride is dried; lime and water are mixed according to the proportion of 1: 1, and the mixture is put into a drying box to be dried; the preparation method comprises the following steps: proportioning the following raw materials: vanadium pentoxide, aluminum powder and calcium fluoride according to the ratio of 1: (0.58-0.68): (0.02-0.13), proportioning the calcium fluoride according to the unit reaction heat of 3100-3150 KJ / kg, and uniformly mixing; filling the mixture into a reaction furnace body, compacting, and spreading an ignition agent on the material; ignition reaction; after the reaction is finished, standing the furnace body for 24 hours, moving out the furnace body, naturally cooling for 48 hours, and discharging from the furnace; the method mainly solves the problems of high alloy carbon content caused by graphite falling of the alloy graphite crucible and oxidation film and nitride film phenomena caused by metal solidification cracks.

The invention belongs to the technical field of preparation of high-temperature heat-insulating and electromagnetic wave-absorbing materials, and relates to a bamboo-like silicon carbide nanowire based on freeze-dried vegetables / fruits and a preparation method and application of the bamboo-like silicon carbide nanowire based on the freeze-dried vegetables / fruits, and the preparation method comprises the following steps: putting the vegetables / fruits in a freeze dryer to obtain the freeze-dried vegetables / fruits; putting the freeze-dried vegetables / fruits into a high-temperature tubular furnace for carbonization to obtain a carbon template; putting the carbon template and a silicon source into a graphite crucible, putting the graphite crucible into a high-temperature tubular furnace, and calcining to obtain the bamboo-like silicon carbide nanowire based on the freeze-dried vegetables / fruits. The bamboo-like silicon carbide nanowire prepared by the method has excellent high-temperature heat insulation property and remarkable broadband electromagnetic wave absorption property, so that the enhancement of double functions of heat insulation and wave absorption is synergistically realized on the basis of a single material. The preparation process is simple and stable in flow, good in repeatability, green in raw material and extremely low in cost, and the problems of collapse and atrophy of the material structure caused by high temperature are solved.

To provide a method for manufacturing a graphite crucible hard to be exhausted even when put at high temperature.SOLUTION: A method for manufacturing a single crystal growth graphite crucible, capable of growing the single crystal on the main surface of a seed crystal substrate by a sublimation recrystallization method comprises: the molding step of molding a raw material including coke mainly constituted of needle coke and binder pitch; the calcination step of calcining the molded molding to obtain a calcined product; the first impregnation calcination step of performing the impregnation and calcination of additional binder pitch once or more to the calcined product to obtain an impregnation calcination product; the graphitization step of heating and graphitizing the impregnation calcination product at 2000°C or more to obtain a graphitization product; and the second impregnation calcination step of performing the impregnation and calcination of additional binder pitch once or more to the graphitization product.SELECTED DRAWING: Figure 1

The invention relates to the technical field of physical detection, in particular to a graphite crucible detection device which comprises a shell, a supporting table, a storage table, a positioning and sealing unit and a detection unit, the positioning and sealing unit comprises a limiting assembly, a transmission control assembly and a clamping and sealing assembly, the limiting assembly is used for automatically centering and positioning a graphite crucible arranged on the storage table, and the transmission control assembly is used for transmitting the transmission control assembly to the clamping and sealing assembly; the transmission control assembly drives the clamping sealing assembly to press downwards in a linkage mode, so that the sealing seat is tightly attached to the crucible and the object placing table to form a sealed space, the detection unit comprises a detector capable of lifting and rotating and a water injection detection system, and the detector is used for scanning the inner wall of the crucible to detect mass distribution uniformity; according to the invention, rapid positioning, sealing and multi-index integrated detection of the graphite crucible are realized, the detection efficiency and accuracy are significantly improved, and the graphite crucible crack detection device is suitable for comprehensive evaluation of the quality of the graphite crucible in an industrial field.

The application provides a preparation method of a Si-based multi-component alloy bonding layer in an environmental barrier coating, and steps are as follows: S1, substrate preparation: taking SiC fiber reinforced SiC composite material as a substrate; S2, preparation of the Si-based multi-component alloy bonding layer: S21, the preparation process is carried out in a directional solidification crystal growth furnace, the furnace comprises a quartz glass tube, a graphite crucible and a heating device; S22, adding silicon material and X metal material into the graphite crucible; S23, fixing the substrate above the graphite crucible; S24, vacuumizing the quartz glass tube; S25, introducing cooling water, turning on the power supply, heating the graphite crucible through the heating device, until the silicon material and the X metal material in the graphite crucible are completely melted into Si-based alloy melt with fluidity; S26, immersing the pre-grown coating composite material substrate into the melt, and then gradually separating the substrate from the Si-based alloy melt through slow downward pulling of the graphite crucible, growing the Si-based alloy on the surface of the composite material uniformly, and preparing the Si-based multi-component alloy bonding layer.

The utility model belongs to the technical field of swing mechanism, especially a graphite crucible calcination tunnel kiln swing mechanism, including the ditch, swing car track, swing car, tunnel track, kiln car, the ditch sets up below ground, and the kiln car includes swing platform, and the bottom of swing platform is equipped with wheel shaft support, and the inner side of wheel shaft support is rotatably installed with driving axle, driven axle, and the both ends of driving axle, driven axle are fixedly connected with driving wheel, driven wheel respectively, and the top of swing platform is installed with transfer track, and the top of swing platform is also equipped with mounting groove, and the inner side of mounting groove is installed with kiln car push -and -pull mechanism, and the top of swing platform is equipped with first sliding slot, second sliding slot, the device can prevent the guide wheel of kiln car bottom from extruding transfer track due to inertia in the swing car operation process, causes its wear and tear and deformation damage to be unable to use the problem of, promotes the service life of transfer track, ensures swing operation process safety and stability.

The utility model discloses a graphite crucible clamping tool which comprises a base, a machine frame and a clamping device, the base is provided with the machine frame capable of extending and descending, the machine frame is provided with a traction mechanism, the traction end of the traction mechanism is connected with the clamping device capable of clamping a crucible, and the clamping device is connected with the base. The clamping device further comprises a triangular claw handle and clamping claws with adjustable angles and lengths, the top end of the claw handle is connected with the traction end of the traction mechanism, and the left end and the right end of the bottom of the triangular claw handle are rotationally connected with two sets of clamping claws respectively. The crucible carrying device has the functions that the crucible can be carried out conveniently, workers are prevented from being scalded by high temperature on the surface of the crucible, and meanwhile the situation that a double-layer crucible cannot be carried out manually due to the fact that the weight of the double-layer crucible is too large is avoided.

The application belongs to the technical field of metallurgy, and particularly relates to a device and method for preparing high-purity silicon film based on vacuum degree control electrolytic silicon purification. The device creates a closed environment through a vacuum cabin, and utilizes a connected vacuumizing mechanism and a vacuum degree adjusting device to accurately control the vacuum degree in the cabin. A material storage mechanism is used for storing silicon materials, and is composed of a corundum crucible and a graphite crucible sleeved outside the corundum crucible. A heating mechanism heats the materials through electromagnetic induction. The method first heats impurity-containing electrolytic silicon in a vacuum environment in a deimpurification mode, so that impurities with higher saturated vapor pressure are preferentially volatilized and deposited on the inner wall of the cabin, thereby realizing preliminary purification. Then, in an evaporation mode, the purified silicon material is heated to a volatilization temperature again, so that it is vapor-deposited on the upper base material to directly form a high-purity silicon film. The scheme integrates the purification and film forming processes, and simplifies the process.

The present disclosure provides a method for reducing and separating lithium battery black powder. A method for reducing and separating lithium battery black powder, the separation method comprising the following steps: S1, a molten salt including NaF-AlF3 base or KF-AlF3 base or NaF-KF-AlF3 base is contained in a graphite crucible, and the black powder and the metal reducing agent are contained in the graphite crucible; S2, the graphite crucible is placed in a stainless steel crucible as a whole; S3, the stainless steel crucible is placed in a high-temperature resistance furnace as a whole, the substance in the graphite crucible is melted by heating, and the stainless steel crucible is rotated at the same time; S4, the stainless steel crucible and the graphite crucible are disassembled, white molten salt and Ni, Mn, Co metal alloy are obtained, by reacting the black powder with the molten salt and the metal reducing agent, the Ni, Co, Mn compound is converted into the corresponding metal alloy in the molten salt and the metal reducing agent, and then deposited at the bottom of the molten salt, finally through the operation such as slagging, the precipitate can be taken out.

The utility model relates to a graphite crucible belongs to high temperature smelting equipment technical field. Among them, graphite crucible includes: the crucible body has the first wall body and second wall body with the wall thickness is formed, and the first wall body is located the outside of second wall body, the top of second wall body is lower than the top of first wall body, to make second wall body and first wall body form the step between, the cover body, cover is established on the step, among them, the recess is provided on the first wall body, and the recess is along the circumference of the crucible body and sets up, and the depth of recess is greater than 0 and is less than or equal to 10. Through the recess along the circumference of the crucible body and sets up, to make the gripper of mobile equipment when the graphite crucible is clamped, the gripper can be held at the recess, to realize the quick positioning of the crucible body, simultaneously, still can make at least partial gripper can be housed in the recess, with the recess forms the card and holds, avoids the sliding between the gripper and the crucible body, to avoid the occurrence of the fall of the crucible body, improves the service life of the crucible.

The application discloses a high-crystalline semiconductor silicon carbide powder and a preparation method thereof. High-purity silicon carbide single crystal is cracked or broken, and silicon carbide powder with a particle size of 10-200 microns is screened out and mixed with high-purity carbon powder. The mixed carbon powder and silicon powder are placed at the bottom of a graphite crucible, and the mixed silicon carbide powder and high-purity carbon powder are placed at the upper part. A graphite cover is installed to seal the graphite crucible, and the graphite crucible is placed in a high-temperature sintering furnace. The furnace chamber is closed and vacuumized. The temperature is raised to 1050-1350 DEG C, and the temperature is kept for 1-15 hours. High-purity argon is introduced into the chamber until the pressure in the chamber reaches 10000-80000 Pa. The temperature is continuously raised to 1750-2000 DEG C, and the temperature is kept for 8-15 hours to synthesize the bottom silicon carbide powder. The temperature is continuously raised to 2000-2500 DEG C, and the pressure in the chamber is reduced to 1000-10000 Pa. High-purity argon is continuously introduced at a flow rate of 5-800 sccm, and the temperature is kept for 30-80 hours. The argon introduction is stopped, and the graphite crucible is cooled to room temperature to obtain the high-crystalline semiconductor silicon carbide powder. The high-crystalline semiconductor silicon carbide powder can be applied to the preparation of the third-generation semiconductor material silicon carbide single crystal material with high performance, low defects and low inclusion density.

The invention relates to the technical field of mixing and kneading pot mixing, in particular to automatic numerical control graphite crucible machining equipment which comprises a base, a pot body is arranged on the base, a sealing cover is arranged at the upper end of the pot body, two Z-shaped stirring cutters are rotationally arranged in the pot body, and a conical lining plate is arranged at the bottom end in the pot body. The liner plate in the pot body is conical, and the rotating track of the Z-shaped stirring knife is also a matched conical body, so that when the gap exceeds a preset range due to abrasion of the liner plate and the Z-shaped stirring knife, the Z-shaped stirring knife can axially move along the small end of the conical liner plate, the gap is recovered to a reasonable range, and the stirring knife does not need to be frequently disassembled for surfacing and polishing; the influence of maintenance time on the mixing efficiency is reduced.

The hydrogen storage alloy is prepared from magnesium-zinc alloy powder, lanthanum-nickel alloy powder and PE plastic particles. The magnesium-zinc alloy comprises the following components in percentage by weight: 28 to 32 percent of Zn (zinc), 0.004 to 0.008 percent of Al (aluminum), 0.0010 to 0.0015 percent of Fe (iron), 0.0008 to 0.0014 percent of Si (silicon), 0.0008 to 0.0015 percent of Mn (manganese), 0.00010 to 0.0002 percent of Cu (copper), 0.00020 to 0.0003 percent of Ni (nickel) and the balance of Mg (magnesium); the lanthanum-nickel alloy comprises 46-52 wt% of La, 48-54 wt% of Ni, less than 0.2 wt% of Fe and less than 0.03 wt% of C; the magnesium-zinc alloy powder and the lanthanum-nickel alloy powder are mixed according to the mass ratio of 98: 2 and then mixed with the PE plastic particles according to the mass percent of 2: 1; and putting the mixed raw materials into a graphite crucible, and smelting the mixed raw materials by adopting an argon arc welding machine to obtain the hydrogen storage alloy of a blocky sample. The scheme is low in cost, and plastic recycling is achieved.

The utility model provides a graphite crucible shelf which comprises a base, a stand column and a supporting plate assembly, a groove is formed in the middle of the base, a sleeve is installed in the groove, the bottom end of the stand column is inserted into the sleeve, the supporting plate assembly comprises two supporting plate mechanisms symmetrically installed on the two sides of the stand column, and each supporting plate mechanism comprises an upper supporting plate, a middle supporting plate and a lower supporting plate. The graphite crucible placing rack is novel in structural design, graphite crucibles of different sizes can be placed on the graphite crucible placing rack, the overall structural strength is high, the graphite crucibles can be conveniently taken and placed, and the working efficiency is improved.

The utility model provides a gas pre-decomposer for a high-temperature purification furnace, and belongs to the technical field of high-temperature industrial electric furnaces. The problem that an existing gas pre-decomposition device for the high-temperature purification furnace is low in decomposition efficiency is solved. Comprising a shell, a graphite crucible is arranged in the shell, the outer side of the graphite crucible is coated with a heat preservation layer, an induction coil is wound on the outer side of the shell, a filter element is arranged in the graphite crucible, an air inlet is formed in one end of the shell, an air outlet is formed in the other end of the shell, and thermocouples are arranged on the two sides of the air inlet respectively. The thermocouple penetrates through the heat preservation layer and then is inserted into the filter element, a blocking screen assembly is arranged at the front end of an air channel of the air outlet, and cooling systems are further arranged at the two ends of the shell respectively. According to the utility model, the halogen gas required by the high-temperature purification furnace can be obtained by decomposing the five-poison cheap raw material gas.

The application is suitable for the technical field of crucible furnace, and provides a graphite crucible for carbonizing lithium battery negative electrode material, which comprises two furnace bodies with furnace covers, a crucible and a heating mechanism arranged in the inner cavities of the furnace bodies, and the inner cavities of the two furnace bodies are communicated through two flow guide pipes, and an air extractor is installed on each flow guide pipe, a guide frame is arranged between the inner walls of the furnace bodies and the outer surface of the heating mechanism, two air ducts penetrating through the furnace bodies and communicated with the inner cavities of the furnace bodies are arranged on the furnace bodies, and the air duct at the bottom of one side of one furnace body is communicated with the air duct at the top of one side of the other furnace body through the flow guide pipe.The application realizes the circulation of hot air between the heated furnace body and the unheated furnace body by the flow guide pipe and the air extractor, effectively transfers the waste heat in the cavity of the heated furnace body to the unheated furnace body, preheats the negative electrode material in the unheated furnace body, significantly reduces the power consumption, improves the overall energy utilization rate, and realizes the recycling of the hot air between the two furnace bodies, reduces the heat loss, and greatly improves the utilization efficiency of unit energy.

The invention discloses a device for automatically spraying a graphite crucible mold cavity release agent and automatically shaping raw materials in a mold cavity. According to the device, a chain plate type conveyor is used for conveying a graphite crucible mold, a transverse hydraulic cylinder pushes a Z-shaped support to enable a vertical hydraulic cylinder and the mold to be coaxial, and the vertical hydraulic cylinder drives a motor box to ascend and descend. The water pump extracts the release agent from the release agent container, and the release agent is distributed to the multiple nozzles through the annular pipe and the manifold and evenly sprayed into the mold. And then the raw materials are fed, the vertical hydraulic cylinder is pressed downwards again, the servo gear motor in the motor box drives the blades to rotate, the raw materials are flattened and shaped in the pressing-down process, and it is guaranteed that the raw materials are evenly distributed. A bearing is arranged in a through hole in the bottom of the motor box to guarantee stable rotation of a motor output shaft, and gaps are reserved between the blades and the fixing disc to avoid interference. In addition, the device is further provided with a liquid level sensor, the liquid level of the release agent can be monitored in real time, timely liquid supplementing is facilitated, and it is guaranteed that the production process is conducted stably and efficiently.

The utility model discloses a graphite crucible negative oxygen combustion gas tunnel kiln which comprises a tunnel kiln outer frame, installation columns are installed on the periphery of the lower end of the tunnel kiln outer frame, the tunnel kiln outer frame comprises a material base layer, an inner heat preservation layer is arranged on the inner surface of the material base layer, and a fireproof layer is arranged on the inner surface of the inner heat preservation layer. According to the tunnel kiln outer frame, due to the arrangement of the inner heat preservation layer, the heat conductivity coefficient is low, the high temperature resistance is good, heat loss can be effectively reduced, the good heat preservation effect on the tunnel kiln outer frame is achieved, the sealing performance of the tunnel kiln outer frame is guaranteed, and heat loss is prevented; the tunnel kiln outer frame has the primary function of reducing chemical erosion and mechanical abrasion of high-temperature gas and materials to the tunnel kiln outer frame, so that the tunnel kiln outer frame is protected, a part of heat is absorbed from the gas, the heat is transmitted to the materials in different conduction and radiation modes, the heat serves as a heat transfer medium, and a good heat preservation effect on the tunnel kiln can be achieved.

The application discloses a method for preparing oxide eutectic ceramics by using an ultrafast high-temperature furnace. Raw material powders are proportioned according to eutectic composition, and then are sequentially subjected to ball milling, drying, sieving and compression molding; the green body is placed in a thin-wall graphite crucible and is put into a heating carbon felt element sandwich hole; the temperature is rapidly increased to a set temperature by using ultrafast heating, and the temperature is kept for a very short time, and then the oxide eutectic ceramics are obtained after cooling. The oxide eutectic ceramics are rapidly formed by using ultrafast heating and Joule heat radiation heating at a furnace temperature far below the eutectic temperature, and the microstructure of the eutectic ceramics can be controlled by adjusting the temperature parameters. The eutectic structure obtained is fine in size and excellent in mechanical properties; and the problems of long time consumption, high cost and complex block material preparation process in the existing oxide eutectic ceramic preparation method are solved.

The invention discloses a novel combined graphite crucible for growth of 12-inch silicon carbide single crystals, which comprises an upper heating electrode, a middle heat preservation structure and an upper heater, and is characterized in that the middle heat preservation structure comprises a first middle heat preservation structure, a through hole is formed in the middle of the heat preservation top, a graphite rod is inserted into the heat preservation top, and a crucible cover is in threaded connection with the lower part of the graphite rod; a crucible barrel is in threaded connection with the lower portion of the crucible cover, a crystallization ring is arranged in the crucible barrel, a support is arranged above the crystallization ring, a graphite support is arranged above the support, a pressing ring is arranged below the crystallization ring, a backing ring is arranged below the pressing ring, and the backing ring is located on the crucible bottom. The crucible structure with high density and low porosity is manufactured by adopting an isostatic pressing process, so that the service life of the crucible can be prolonged, and the stability of the crucible can be improved; and a combined crucible structure is adopted, so that the use cost of the crucible can be reduced, the service life is prolonged, and the crystal quality can be improved by regularly replacing part of components.