2402 results about "Thermal shock" 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 invention relates to the technical field of preparation of a ceramic silica gel composite belt for a power battery of a new energy automobile, in particular to a super-high-temperature-resistant and impact-resistant ceramic silica gel composite belt for an automobile and a preparation method of the super-high-temperature-resistant and impact-resistant ceramic silica gel composite belt. The phase change toughening effect of the core-shell structure filler is generally utilized to generate pressure stress, inhibit crack propagation and improve fracture toughness through volume change during phase change, meanwhile, the core-shell structure filler is subjected to thermal expansion coefficient gradient structure design, interface stress in the core-shell structure filler at high temperature is relieved, thermal stress concentration is avoided, thermal shock resistance is improved, and the service life of the core-shell structure filler is prolonged. And the ceramic layer is prevented from cracking, so that the ceramic layer has good high-temperature resistance and flame retardance, flame spreading can be effectively prevented, and thermal runaway of the power battery is prevented.

The invention belongs to the technical field of semiconductors, and particularly relates to a gradient transition composite tantalum carbide coating and a preparation method thereof.The gradient transition composite tantalum carbide coating is located on the surface of a graphite substrate material and sequentially comprises a pyrolytic carbon coating, a tantalum carbide-pyrolytic carbon composite coating and a tantalum carbide coating from inside to outside; wherein the thermal expansion coefficient of the pyrolytic carbon coating is 2.5-4.5 * 10 <-6 > / K, the thermal expansion coefficient of the composite coating is 4.5-6.0 * 10 <-6 > / K, and the thermal expansion coefficient of the tantalum carbide coating is 6.1-8.0 * 10 <-6 > / K. According to the gradient transition structure of the coating, the problem that thermal expansion coefficients between the coating and a base body are not matched is solved, the thermal shock resistance of the coating is effectively improved, meanwhile, the pinning effect can be achieved, the adhesive force between the coatings is enhanced, and the service life of a product is prolonged; compared with a single tantalum carbide coating, crack accumulation and through holes cannot be generated.

The invention relates to the technical field of temperature control of high-precision industrial heating equipment, in particular to an anti-interference precise temperature control method and system for heating an upper die, and the method comprises the steps: starting a multi-region heating array, heating the upper die to a target temperature according to a preset temperature rise curve, and building a uniform thermal field; before the high-pressure medium is introduced, heat load change caused by the high-pressure medium is predicted based on medium process parameters; in the medium introduction process, dynamic anti-interference compensation control is executed, a feedforward power compensation instruction based on a thermal load and a feedback power fine tuning instruction based on temperature deviation are generated respectively, and the feedforward power compensation instruction and the feedback power fine tuning instruction are weighted and fused into a composite power driving signal for adjusting a heating array; when the temperature fluctuation converges to a stable threshold value, the feedforward compensation weight is gradually reduced, smooth switching to steady-state control is achieved, transient thermal shock caused by a high-pressure medium is effectively restrained through feedforward and feedback cooperative compensation and dynamic weight adjustment, the temperature fluctuation is reduced, and the temperature control precision and stability are improved.

The invention provides a spacecraft quartz powder heat insulation tile which is prepared by adopting high-purity quartz powder (SiO2) as a main raw material and combining a high-temperature-resistant ceramic fiber reinforcement and a nano aerogel heat insulation layer through a high-temperature sintering process. The heat insulation tile has the following advantages: 1, the heat insulation tile has excellent high temperature resistance, and can tolerate 1600 DEG C high temperature for a long time and tolerate 1800 DEG C instantaneous thermal shock for a short time; 2, repeated use: the structure is stable, and high strength is still kept after multiple thermal cycles; light weight: the density is low (less than or equal to 0.5 g / cm < 3 >), and the load of a spacecraft is reduced; and 4, the thermal conductivity is low (less than or equal to 0.05 W / m.K), and heat transfer is effectively isolated. The method is suitable for thermal protection systems (TPS) of spacecrafts, such as thermal insulation of reentry capsules and rocket engine nozzles.

The invention provides a polysilazane green special refractory ceramic coating and a preparation method thereof, and belongs to the field of ceramic coatings. The ternary core material composed of titanium carbide, zirconium boride and silicon nitride provides high hardness, oxidation resistance, thermal shock resistance and excellent thermal stability; the silicon dioxide-aluminum oxide composite shell layer remarkably improves the oxidation resistance and reliability of the coating through the synergistic oxidation resistance and crack self-repairing function; the multi-metal oxygen cluster network endows the coating with excellent electrical conductivity, thermal conductivity and corrosion resistance; the intercalated montmorillonite enhances the crack resistance and oxidation resistance through a layered structure and embedded active ions; and the boron nitride coated vanadium carbide particles provide lubricity, oxidation resistance and wear resistance. Through collaborative optimization of multiple components, the comprehensive performance of the coating is comprehensively improved in the aspects of oxidation resistance, thermal conductivity, interface stability, high-temperature performance, mechanical performance and the like, so that the coating shows excellent long-term stability and functionality in an extreme environment.

The invention relates to a magnesia-carbon refractory material with high thermal shock resistance and erosion resistance and a preparation method thereof. The magnesia-carbon refractory material with high thermal shock resistance and erosion resistance is prepared from fused magnesia aggregate, fused magnesia fine powder, silicon powder, crystalline flake graphite, Al2O3-MgO-CaO core-shell structure raw materials and phenolic resin. The Al2O3-MgO-CaO core-shell structure raw materials are prepared by the following steps: uniformly mixing calcium carbonate, magnesium hydroxide and alumina micro powder by adopting a planetary ball mill, and then carrying out granulation treatment by adopting a disc granulator by taking polyvinyl alcohol as a binding agent, so as to obtain core particles; and mixing the inner core particles and the alumina micro powder by taking alumina sol as a binding agent, and further sintering to obtain the core-shell structure raw material. The Al2O3-MgO-CaO core-shell structure raw material is utilized to improve the comprehensive performance of the magnesia-carbon refractory material, and the prepared magnesia-carbon refractory material has excellent thermal shock resistance and slag corrosion resistance and can meet the requirements of the current steel industry for the magnesia-carbon refractory material.

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 a modified chrome corundum ramming material and a preparation and construction process thereof, and belongs to the technical field of chrome corundum ramming materials. The ramming material comprises a material A, a material B and a material C, wherein the material A comprises chrome corundum aggregate, titanium dioxide coated aluminum oxide microspheres, calcium sulfide dehydrate and silicon carbide porous microspheres; the material B comprises chromium oxide-zirconium oxide composite nano powder, sodium thiosulfate pentahydrate, tricalcium phosphate and hexagonal boron nitride flaky crystals; and the material C comprises an aluminum dihydrogen phosphate-magnesium hydroxide compound, a calcium fluoride-aluminum oxide co-melt and a silane coupling agent. The preparation process comprises the steps of pretreatment of all the components, preparation of composite powder and layered preparation. The construction process comprises the steps of pretreatment, wet-process mixing, layered ramming, negative-pressure permeation, medium-temperature reaction, spraying curing, integral firing and the like. Generation of hexavalent chromium can be effectively inhibited, the thermal shock resistance, the mechanical strength and the heat-conducting property of the material are remarkably improved, and the material has the advantages of being good in environment friendliness, long in service life, excellent in construction performance and the like.

The invention belongs to the technical field of solid oxide batteries, and discloses a nickel-iron support body of a metal-supported solid oxide battery, a total battery and a preparation method. The nickel-iron supporting body of the metal-supported solid oxide battery is made of a nickel-iron alloy material in a reducing atmosphere, a gradient pore structure with gradient pore distribution is prepared and formed through a double-layer casting phase inversion process, and the gradient pore structure is a composite structure comprising a finger-shaped pore channel layer and a skin layer. Compared with a ceramic material, the composite material has higher mechanical strength and thermal conductivity, can better bear thermal shock and mechanical stress, is particularly suitable for high-temperature and rapid thermal cycle working environments, and can keep good structural stability under the rapid heating condition of 50 DEG C / min.

The invention provides a high-temperature-resistant magnesia-carbon composite refractory brick and a preparation method thereof, and belongs to the technical field of magnesium oxide refractory wall bricks, the refractory brick comprises the following raw materials: double-layer modified magnesium oxide, modified crystalline flake graphite, zircon powder, modified liquid phenolic resin and a benzoxazine cross-linking agent; the double-layer modified magnesium oxide is obtained by firstly coating magnesium oxide with powder phenolic resin, aluminum oxide and zirconium oxide and then coating magnesium oxide with asphalt, micron magnesium oxide, zirconium oxide and calcium oxide; the modified crystalline flake graphite is obtained by coating crystalline flake graphite with strontium hydroxide, asphalt and boron carbide; the modified liquid phenolic resin is formed by mixing liquid phenolic resin with a silane coupling agent and a polyacrylate cross-linked polymer. Double-layer modified magnesium oxide, modified crystalline flake graphite and modified liquid phenolic resin are prepared by adopting special components and a method and are matched with zircon powder and a benzoxazine cross-linking agent for use, and a reasonable forming and sintering process is designed, so that the refractory brick has good high-temperature stability, oxidation resistance, thermal shock resistance and the like.

The invention relates to the technical field of rare earth metal electrolysis cathode protection coatings, in particular to a high-temperature-corrosion-resistant yttrium-stabilized zirconia gradient coating on the surface of a tungsten cathode. A metallurgically bonded strong bonding bottom layer is constructed on a tungsten substrate through surface pretreatment and reactive sintering, then an atmosphere plasma technology is adopted to spray a creep-resistant gradient layer with continuous components to buffer thermal stress, and finally a sol-gel technology is utilized to construct an extremely compact corrosion-resistant surface layer in a superposition mode. The high-temperature-corrosion-resistant yttrium-stabilized zirconia gradient coating is constructed through a multi-scale and multi-mechanism synergistic effect, the problems that a tungsten cathode coating is insufficient in binding force and poor in thermal shock resistance are fundamentally solved, molten salt permeation can be blocked, and the service life of a tungsten cathode in a severe environment is remarkably prolonged.

The invention discloses a thermal shock failure prediction and laser repair device for a thermal barrier coating and an application method. The device comprises a multi-physics field coupling simulation analysis module, a thermal shock experiment loading module, an online damage monitoring and failure diagnosis module, a robot laser repair execution module and a central control and data processing core unit. A thermal-mechanical-chemical coupling model is established to predict a coating failure behavior, a high-frequency induction heating and gas quenching system is adopted to simulate an extreme thermal shock environment, a multi-band thermal infrared imager, an ultrasonic probe and a digital image related system are integrated to monitor damage evolution in real time, and in-situ repair of a damaged area is realized based on a six-degree-of-freedom industrial robot. According to the method, the whole-process closed-loop control from failure prediction to repair regeneration is realized, the problems of single function and lack of multi-field coupling analysis and real-time repair capability in the prior art are solved, and the service reliability evaluation precision and the remanufacturing efficiency of the thermal barrier coating are remarkably improved.

The invention relates to the field of welding devices, and discloses a laser swing welding device and a welding method.The laser swing welding device comprises a supporting table, an adjusting mechanism, a swing mechanism, a laser welding head, a gradient temperature changing mechanism, a housing, an air supply mechanism, an air injection preheating mechanism and a clamping mechanism; the adjusting mechanism is arranged on the supporting table and connected with the gradient temperature changing mechanism so as to change the welding position of the laser welding head. A first plate body and a second plate body are placed on the supporting table so as to be limited by the clamping mechanism. The laser welding head is rotationally arranged on the housing and driven by the swing mechanism so as to conduct swing welding on the welding position between the first plate body and the second plate body. Through cooperation of the gradient temperature changing mechanism, the ultrasonic transducer and the gas supply and jet preheating mechanism and cooperation of the eccentric driving disc and the swing frame, preheating of protective gas, gradient cooling after welding and heating are achieved, thermal stress and thermal shock are reduced, the welding seam performance is improved, laser energy is evenly distributed, and the welding quality of dissimilar metal plates is improved.

The invention relates to a high-temperature-resistant light stealth coating material and a preparation method thereof, and belongs to the technical field of functional materials, the high-temperature-resistant light stealth coating material comprises the following raw materials: boride, silicide, a titanate fluxing agent, metal coated carbide, a zinc oxide coated nano carbon material and a sintering aid; according to the prepared high-temperature-resistant light stealth coating material, the infrared emissivity at the wavelength of 3-5 [mu] m is 0.231-0.245, the infrared emissivity at the wavelength of 8-14 [mu] m is 0.424-0.441, the tensile bonding strength is 40.8-46.4 MPa, and the thermal shock resistance frequency is 153-167.

The invention discloses high-toughness ultrathin flexible glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The ultrathin flexible glass is prepared from the following raw materials: silicon dioxide, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, a modified nano reinforced phase, a high-temperature melting regulator and cerium dioxide. The modified nano reinforced phase is prepared by the following steps: pre-treating silicon carbide and silicon nitride with hydrochloric acid, and mixing with nano zirconium oxide to obtain a mixture; and modifying the mixture with a silane coupling agent to obtain the modified nano reinforced phase. The high-temperature melting regulator is a mixture of lithium borate, sodium sulfate and lithium fluoride. The preparation method of the ultra-thin flexible glass comprises the following steps: preparing the modified nano reinforced phase, melting and homogenizing the glass, forming the glass substrate, and preparing the ultra-thin flexible glass. The ultra-thin flexible glass prepared by the invention has relatively high fracture toughness and structural rigidity, excellent flexibility and bending fatigue durability, and excellent thermal shock resistance.

The invention discloses a high-oxygen-storage zirconium solid solution material and a preparation method, and belongs to the technical field of rare earth catalytic materials, and the method comprises the following steps: precursor preparation, ultrasonic dispersion, double-gradient precipitation, ultrasonic aging, solid-liquid separation, three-section roasting and furnace cooling. Through the synergistic effect of double-gradient precipitation and ultrasonic aging, coarse grains and non-uniform particle size distribution are avoided, and the material is not prone to abnormal growth of the grains and structural collapse in long-term high-temperature service. Meanwhile, according to the gradient roasting process, through step-by-step regulation and control of crystal densification and crystal lattice reconstruction, separation of a fluorite phase and a pyrochlore phase easily occurring in traditional low-temperature single-section roasting is reduced, a stable crystal phase structure is maintained, it is ensured that the material can still keep sufficient active surface and pore channel structures under the working conditions of high temperature and thermal shock alternation, and the performance of the material is improved. The oxygen storage capacity and the long-term durability of the catalyst carrier are obviously improved.

The invention relates to the technical field of machine tool control, in particular to a milling cutter positioning self-adaptive control method and system. Comprising the following steps: synchronously collecting structure state data and external environment parameters of a machine tool in a preset sampling period; based on the structure state data, the external environment parameters and thermal-structure and dynamic physical characteristic parameters of the machine tool, a positioning deviation prediction model is established in a preset look-ahead time window, and the future three-dimensional total positioning deviation of the milling cutter relative to the theoretical track is obtained; and a prospective compensation instruction opposite to the future three-dimensional total positioning deviation is generated according to the future three-dimensional total positioning deviation, and compensation motion of the milling cutter is achieved. The problem that in the prior art, in the long-time operation process of a machine tool, the actual position of a milling cutter deviates from a preset path due to an internal heat source, and an existing thermal error compensation model cannot accurately predict and deal with severe and local thermal shock caused by sudden change of an external environment, so that the machining precision is affected is solved.

The invention provides a low-oxygen high-strength TZM alloy material and a preparation method thereof. According to the low-oxygen high-strength TZM alloy material, the crystal grains are of an isometric crystal structure, random orientation is achieved, all-directional performance is consistent, and the average crystal grain size ranges from 25 micrometers to 35 micrometers. The TZM alloy material has the advantages of being high in density, low in oxygen content, high in strength, high in heat dissipation capacity, good in thermal shock resistance and the like.

The invention relates to the technical field of electric equipment cooling, and particularly discloses a micro-channel liquid cooling circulation system heat dissipation device with impact resistance. A transition bin; the plurality of groups of micro-channel units are distributed in the bracket at equal intervals; the heat conduction units are embedded between the adjacent micro-channel units; and the circulating adjusting unit is arranged in the transition bin. The circulation adjusting unit can be switched among three states according to heat dissipation requirements, so that the functions of mixed temperature equalization, partitioned heat dissipation and intermittent slow flow of cooling liquid are achieved; in the first state, thermal stress impact and fluid pulsation caused by local temperature difference are effectively reduced, and the thermal stability and thermal impact resistance of the system during continuous high-load operation are enhanced; in the second state, the peripheral flow path can be suspended, and the cooling liquid is concentrated in the central core area to enhance heat dissipation; and in the third state, the cooling liquid is temporarily detained in the micro-channel unit, the heat exchange time is prolonged, and the mutability of fluid flowing is slowed down.

The invention relates to the technical field of ceramic phase coatings, in particular to a high ceramic phase gradient coating preparation process which comprises the following steps: (1) metal matrix pretreatment; (2) constructing a coating material; (3) plasma spraying; (4) thermal shock strengthening treatment; according to the preparation technology of the high-ceramic-phase gradient coating, through reasonable matching of all the components and optimization of the technology, the performance in multiple aspects is obviously improved. In the metal matrix pretreatment stage, a micro-nano rough surface is constructed by adopting a laser texturing technology, so that the roughness of the surface of the matrix is increased, more mechanical occlusion points are provided for the coating, pollutants and an oxide layer on the surface are removed, the activity of the surface of the matrix is improved, and the bonding strength of the coating and the matrix is remarkably enhanced. Mainly, mechanical interlocking is formed between the rough surface structure and the coating, and chemical bonding between the coating and a base body is promoted through the clean and high-activity surface, so that the bonding strength is greatly improved.

The invention relates to the technical field of adhesives and pouring sealants, and particularly discloses a high-thermal-conductivity and high-temperature-resistant epoxy resin pouring sealant with cold and hot impact resistance, which comprises 100 parts of organic silicon modified epoxy resin with the epoxy value of 0.450-0.550 eq / 100g and the viscosity of 3000-25000mPa. S at 25 DEG C; the capsule wall material is a polyurea-silicon dioxide compound, and the wall thickness of the capsule wall material is 0.5-2 microns; 600 to 1000 parts of surface modified composite heat conduction powder; the core layer is made of nitrile rubber, the shell layer is made of polysiloxane, and the shell layer accounts for 10-30 wt%; through the synergistic effect of the surface modified composite heat-conducting powder and the core-shell structure elastomer, the mechanical strength of the material is remarkably improved while high heat conductivity is guaranteed, and compared with a traditional system, the heat-conducting property and the tensile strength are improved.

The invention discloses a special composite enamel coating for a chromium-nickel alloy base material and a preparation method of the special composite enamel coating, when the special composite enamel coating structurally comprises one layer, the special composite enamel coating comprises the following components in parts by mass: 40-65 parts of a basic glass phase, 30-55 parts of a high-melting-point ceramic reinforced phase, 2-10 parts of a thermal expansion coefficient regulator and 0.5-5 parts of an interface bonding accelerant. Compared with the prior art, the enamel coating can achieve nearly perfect thermal expansion coefficient matching with a chromium-nickel alloy matrix, a tough chemical bonding interface is formed, the enamel coating can stably work for a long time in the extreme high-temperature environment of 1,100 DEG C or above, and meanwhile the enamel coating has the excellent abrasion resistance, repeated rapid cooling and rapid heating cycle resistance and thermal shock resistance.

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 invention belongs to the technical field of glass materials, and discloses thermal shock resistant transparent high borosilicate glass which comprises the following components in percentage by weight: 60-70% of silicon dioxide, 18-22% of diboron trioxide, 4-7% of aluminum oxide, 3-5% of magnesium oxide, 2-4% of alkali metal oxide, 0.5-1.5% of nano silicon nitride and 0.5-1% of nano aluminum titanate. The thermal shock temperature difference of the glass within the temperature change range of 20-200 DEG C is larger than or equal to 180 DEG C, the light transmittance within the visible light range of 400-760 nm is larger than or equal to 85%, the alkali metal oxide is composed of sodium oxide and potassium oxide, the weight ratio of the sodium oxide to the potassium oxide is 1: 1-3: 1, the average particle size of the nanometer silicon nitride is smaller than or equal to 100 nm, and the nanometer silicon nitride is evenly dispersed in the glass matrix; according to the thermal-shock-resistant transparent high borosilicate glass and the preparation method thereof, the thermal shock resistance and light transmittance of the glass are improved by optimizing the chemical components of the glass and adding the special nanoparticles in cooperation with a specific preparation process, and the thermal shock resistance of the glass is improved. The problems that existing high borosilicate glass is insufficient in thermal shock resistance and low in light transmittance in a high-temperature environment are solved.

The invention provides a preparation method of an ultrahigh-temperature oxidation ablation resistant tantalum-based ceramic and silicon carbide composite thermal protection coating, which comprises the following steps: (1) mixing a polymer binder and a solvent to form a solution, and carrying out ball-milling mixing on the solution, a tantalum-containing compound, silicon carbide, silicon and other components to prepare precursor slurry; (2) uniformly coating the surface of a carbon substrate with the slurry obtained in the step (1) by a dip-coating method, and drying; (3) realizing curing and pyrolysis of the coating through segmented heat treatment; and (4) the coating is subjected to vacuum siliconizing treatment, and the composite thermal protection coating is obtained. According to the tantalum-based ceramic and silicon carbide composite thermal protection coating prepared through the method, the ultrahigh-temperature oxidation resistance, ablation resistance, thermal shock resistance and heat insulation performance of the coating are remarkably improved. After the coating is ablated for 2400s under oxyacetylene flame at the temperature of 1650 DEG C, the integrity and excellent thermal protection effect of the coating can still be kept.

The invention discloses a preparation method of thermal shock resistant magnesium aluminate spinel transparent ceramic, and belongs to the technical field of ceramic materials. The preparation method comprises the following steps: (1) synthesizing crystalline MgAl2O4 nano powder by adopting an additive-free hydrothermal method; (2) depolymerizing the powder, performing water-based gel casting to prepare a green body, and performing staged debonding treatment on the green body; (3) carrying out two-step vacuum presintering on the green body; (4) carrying out hot isostatic pressing densification treatment in a subgrain growth temperature region of 1380-1420 DEG C; and (5) carrying out annealing treatment on the densified ceramic. High-purity crystalline powder is synthesized through an additive-free hydrothermal method, grain boundary impurities are eliminated, and the intermediate infrared transmittance is remarkably improved; by combining the synergistic effect of optimized two-step pre-sintering and hot isostatic pressing in a sub-grain region, precise refinement of the grain size is realized; and finally, the bending strength, the fracture toughness and the critical thermal shock temperature difference of the material are greatly improved under the strengthening mechanism of ultrafine grains and defect-free grain boundaries.

The invention discloses a preparation process of a sintering kiln silicon carbide guide roller with thermal shock resistance and high-temperature corrosion resistance. The process comprises the following steps: sequentially carrying out surface pretreatment such as reticulate pattern laser engraving, sand blasting and cleaning and drying on a silicon carbide guide roller substrate; performing plasma spraying on a pure aluminum oxide coating after preheating; carrying out segmented laser remelting on the coating to improve the compactness; and finally, coating the nano silicon carbide slurry, calcining and curing. The thermal shock resistance and the high-temperature corrosion resistance of the guide roller are remarkably improved by enhancing the binding force of the coating through laser engraving, optimizing the density of the coating through laser remelting and combining post-treatment of nano silicon carbide slurry, and the service life of the guide roller in a lithium battery positive electrode material sintering kiln is prolonged.

The invention relates to the technical field of refractory materials, in particular to a magnesium-calcium-zirconium-carbon brick production method which comprises the following components in parts by weight: 60-80 parts of sintered magnesium-calcium-zirconium sand particles, 10-30 parts of fused magnesia particles, 2-4 parts of zirconium oxide, 0.5-3 parts of silicon carbide fine powder, 2-6 parts of nano yttrium oxide high-dispersion particles, 1-2 parts of C9 petroleum resin powder, 2-7 parts of graphite, 4-6 parts of binding agent and 0.3-0.5 part of urotropin. The rare earth material nano yttrium oxide high-dispersion particles are introduced, the magnesium-calcium-zirconium-carbon brick has the advantages of high temperature resistance, good hydration resistance, good thermal shock resistance, good oxidation resistance and good erosion resistance, the magnesium-calcium-zirconium-carbon brick is dried by an electric drying kiln as an unburned brick, a tunnel kiln firing process is omitted, the labor cost and energy consumption are reduced, and the production cost is reduced. And the emission of greenhouse gas and toxic and harmful gas generated by fuel combustion is avoided, and the biomass fuel is an environment-friendly product.

The invention relates to a high-purity corundum brick with high thermal shock resistance and a preparation method thereof, and belongs to the technical field of refractory materials. The high-purity corundum brick with high thermal shock resistance is prepared from the following raw materials in parts by mass: 55 to 65 parts of tabular corundum particles, 20 to 25 parts of tabular corundum fine powder, 8 to 12 parts of modified fused zirconia corundum particles, 5 to 8 parts of nano aluminum oxide powder, 2 to 3 parts of rho-aluminum oxide powder, 0.3 to 1 part of toughening agent and 0.3 to 1.5 parts of binding agent. The toughening agent increases the fracture toughness of the high-thermal-shock-resistance high-purity corundum brick through a plurality of strengthening mechanisms such as crack deflection, crack branching and microcracks, so that the high-thermal-shock-resistance high-purity corundum brick has high thermal shock resistance and mechanical properties. Meanwhile, the fused zirconia corundum has a short fiber structure through modification, and fibers can hinder linear propagation of main cracks, force the cracks to deflect and form crack branches, so that the thermal shock resistance and mechanical properties of the high-purity corundum brick with high thermal shock resistance are further enhanced.