35 results about "Linear shrinkage" patented technology

The invention discloses an iron alloy electrode paste and a preparation process, and belongs to the technical field of electrode paste preparation, the iron alloy electrode paste comprises a composite aggregate system and a composite binder system, the composite aggregate system comprises the following components by mass: 40-60% of anthracite aggregate, 15-25% of artificial graphite flake, and 3-8% of silicon carbide whisker; the composite binder system comprises the following components in percentage by mass: 70-80% of medium-temperature modified coal pitch, 10-15% of furan resin and 5-10% of dispersion liquid containing nano boron carbide, and the composite binder system is combined with the composite aggregate system through a gradient permeation process to form a three-dimensional conductive network and an enhanced interface; the composite aggregate system and the composite binder system are optimally proportioned, and gradient permeation and gradient kneading processes are combined, so that the comprehensive performance of the electrode paste is remarkably improved, the thermal shock resistance is greatly improved and the linear shrinkage rate is reduced while low resistivity is maintained, the electrode paste is suitable for smelting ferroalloys such as silicomanganese and ferrochromium, and the service life is remarkably prolonged.

The invention provides a production size control method for a hard alloy roll collar blank and an intelligent production system, and belongs to the technical field of powder metallurgy. The method aims to solve the problems of low finished product qualification rate and high cost caused by uncontrollable sintering shrinkage of the hard alloy roll collar in the prior art. According to the technical scheme, the method comprises the steps that a set of linear shrinkage coefficients of a hard alloy roll collar pressed blank are designed in advance based on the target finished product size, and the target size of the pressed blank is calculated according to the set of linear shrinkage coefficients and the target finished product size; then, according to the calculated target size, wax-doped powder serving as a raw material is subjected to compression molding, and a compressed blank is obtained; and finally, the pressed blank is transferred into a low-pressure sintering furnace for dewaxing and sintering treatment. According to the method, the quantifiable linear shrinkage coefficient is introduced, empirical estimation is converted into accurate calculation, operation is simplified, the accuracy and consistency of the size of a finished product are remarkably improved, and the rejection rate and the production cost are reduced.

The application discloses a kind of fireproof material and tunnel fireproof plate, belong to tunnel engineering fire protection technical field, the fireproof material includes: oxychloride magnesium cement gel body 100 parts, inorganic water absorbent 3-8 parts, composite inorganic phase change material 8-15 parts, inorganic flame retardant 5-12 parts, graded inorganic aggregate 40-60 parts, inorganic thermal insulation fiber 6-12 parts;The inorganic water absorbent is the mixture of anhydrous calcium chloride and anhydrous magnesium sulfate with mass ratio 3-5:1, the fireproof plate prepared from the material has thickness 8-20mm, compressive strength retention rate ≥85% at 600℃ constant temperature 2h, linear shrinkage rate ≤2%, fire resistance limit ≥2.5h, suitable for initial support and permanent fireproof lining of highway, railway, municipal tunnel, can long-term guarantee the safety of tunnel structure in fire.

A curable composition can comprise a polymerizable material and an initiator, wherein the polymerizable material can comprise at least one multi-functional vinylbenzene monomer in an amount of at least 70 wt % based on the total weight of the polymerizable material; the at least one initiator includes an azo-compound; and wherein a cured layer of the curable composition has a linear shrinkage after a baking treatment at 350° C. of not greater than 3.0%.

This invention discloses a silicone foam sheet and a battery module and battery pack containing the same, belonging to the technical field of silicone foam materials. The linear expansion coefficient α of the foam sheet's pore diameter satisfies 1≤α≤8, and the linear contraction coefficient β of the foam sheet's pore wall thickness satisfies 4≤β≤9. This invention enables the silicone foam sheet to have more spatial gaps and a lower thermal conductivity under room temperature conditions; it also enables the silicone foam sheet to maintain an intact pore structure and high strength after sintering at high temperatures, thus preventing breakage. Therefore, the silicone foam sheet of this invention has good thermal insulation performance; simultaneously, the silicone foam sheet of this invention also exhibits good cushioning performance.

The utility model provides a mine filling quality detection device, which comprises a mold, a water collection tank, a linear shrinkage detector and a curing box, and is characterized in that the curing box is used for simulating an underground filling environment, and the mold is used for filling mine filling slurry; the mold is placed on the water collecting tank and is used for collecting water separated out from the mine filling slurry in the mold; the linear shrinkage detector is arranged at the top of the mold, a detection hole is further formed in the top of the mold, the linear shrinkage detector detects the linear shrinkage of mine filling slurry in the mold through the detection hole, a mine filling test mold is prepared through the mold, and the underground filling environment is simulated through the curing box in the process of preparing the test mold. And the bleeding rate and the linear shrinkage of the mine filling slurry are simultaneously detected by using the water collecting tank and the linear shrinkage detector.

The invention relates to the technical field of sheet metal welding, and provides a sheet metal welding process weld joint quality monitoring method and system.The method comprises the steps that according to a thermal expansion coefficient, a welding temperature field and the actual weld joint length, the weld joint deformation amount used for quantifying weld joint linear shrinkage caused by the thermal expansion effect is obtained; acquiring an environment correction factor according to the real-time environment temperature and the real-time environment humidity; according to the welding arc energy, the environment correction factor and the metal plate heat dissipating capacity, metal plate welding net energy used for quantifying effective deposition energy in the welding process is obtained; acquiring a gas flow interference index according to the gas flow rate; and the weld defect probability is obtained according to the welding temperature field, the weld deformation, the metal plate welding net energy and the airflow interference index, and the weld forming quality is monitored according to the weld defect probability. The welding seam defect probability is obtained by fusing metal plate characteristics, environmental attenuation and material nonlinear heat dissipation factors, and the welding seam forming quality monitoring accuracy can be improved.

The invention discloses a stack-up structure for a large-size packaging substrate and a manufacturing method, and the stack-up structure comprises a first core plate, and the upper surface and the lower surface of the first core plate are provided with vertical isolation pads at intervals; the additional core board is stacked on the first core board, and the number of the additional core board is at least one; a first through hole is formed in the middle core in the vertical direction, and the first through hole is filled with an insulating material; the second through hole penetrates through the first through hole, the additional core plate, the vertical isolation pad and the first core plate; wherein the thickness of the vertical isolation pad is larger than or equal to 50 microns; the additional core plate comprises a second core plate and / or a third core plate, and the second core plate and / or the third core plate are / is stacked on the upper face and the lower face of the first core plate. Through heterogeneous stacking of the high-rigidity glass core plate and the BT core plate, linear shrinkage of a PP material in the cooling process is restrained, meanwhile, a stress buffering interface is provided through the design that the thickness of the vertical isolation pad is larger than or equal to 50 microns, and then the effect of reducing interlayer shearing force is achieved.

The invention discloses a high-strength low-shrinkage castable and a preparation method thereof, and relates to the technical field of refractory materials, the high-strength low-shrinkage castable is prepared by adopting special-grade high bauxite aggregate with special particle size distribution, matching with spinel fine powder, nano silicon dioxide, calcium aluminate cement, and additives such as a water reducing agent, a retarder, organic fibers and an expanding agent. The concrete is prepared through specific dry mixing, wet mixing and curing processes. Experiments show that after the castable is maintained for 28 days, the compressive strength reaches 95 MPa to the maximum, the breaking strength reaches 14 MPa, compared with a traditional product, the compressive strength is remarkably improved, and high-temperature medium scouring and high-load pressure can be effectively borne. Meanwhile, the linear shrinkage rate is only 0.4%, the shrinkage crack risk is greatly reduced, and the structural stability and the heat insulation performance are guaranteed. The lining is suitable for high-temperature equipment linings in industries of metallurgy, building materials and the like, and can prolong the service life of equipment and reduce maintenance cost and potential safety hazards.

The invention provides a carbonized flexible fabric for textile electronics and a preparation method of the carbonized flexible fabric, and belongs to the technical field of carbonized fabric preparation. The surface of the flexible textile fabric is coated with a polymer solution, the thermal decomposition temperature of a polymer is controlled to be higher than the thermal decomposition temperature of the flexible textile fabric, a thermal stable polymer coating is formed and then carbonized, and the coating serves as a structural stabilizer and a protective framework during high-temperature carbonization, so that the thermal stability of the flexible textile fabric is improved. According to the present invention, with the polymer coating, the drastic size change of the fabric during the non-carbon element removal and densification process is physically constrained, the linear shrinkage rate of the carbonized flexible fabric is reduced, the shrinkage stress is effectively relieved during the carbonization process by the polymer coating, and the interface bonding force between the single carbonized fibers is improved by the polymer carbonization residue so as to provide the good anti-adhesion effect; the three-dimensional carbon network with higher cohesiveness is formed, so that the overall mechanical property is enhanced, in addition, the carbonized product of the polymer forms a conductive network, and the conductivity of the carbonized flexible fabric is improved.

The invention discloses a device for testing permeability and linear shrinkage of a well cementation cement sheath under a heavy oil thermal recovery working condition, and belongs to the field of heavy oil recovery of oil and gas fields. The device comprises a gas injection unit, a cement sheath high-temperature performance test unit and a data acquisition and processing unit. The gas injection unit comprises a gas cylinder, a check valve, a gas heating device and a gas cooling device; the cement sheath high-temperature performance testing unit comprises a center rod, an upper end cover, a baffle, a U-shaped transmission part, a lower end cover and a displacement sensor, an annular space between the center rod and the baffle is a cement curing chamber, the edges of the upper end cover and the lower end cover are provided with protrusions, the bottom of the U-shaped transmission part is attached to the inner wall of the baffle, and the two ends of the U-shaped transmission part penetrate through radial round holes of the baffle; a displacement sensor is arranged between the edge bulges of the upper end cover and the lower end cover; the data collecting and processing unit comprises a thermocouple, a pressure sensor, a flow sensor, a displacement sensor, a data collecting module and a computer. The design of a cement paste system can be optimized, and the well cementation quality is effectively improved.

The invention discloses a fireproof material and a tunnel fireproof plate, and belongs to the technical field of tunnel engineering fireproof protection, the fireproof material comprises 100 parts of magnesium oxychloride cement gel, 3-8 parts of an inorganic water absorbent, 8-15 parts of a composite inorganic phase change material, 5-12 parts of an inorganic flame retardant, 40-60 parts of graded inorganic aggregate, and 6-12 parts of inorganic heat insulation fiber; the inorganic water absorbent is a mixture of anhydrous calcium chloride and anhydrous magnesium sulfate in a mass ratio of (3-5): 1, the thickness of a fireproof plate prepared from the material is 8-20 mm, the compressive strength retention rate at the constant temperature of 600 DEG C for 2 h is larger than or equal to 85%, the linear shrinkage rate is smaller than or equal to 2%, the fire endurance is larger than or equal to 2.5 h, and the fireproof plate is suitable for initial support and permanent fireproof lining of highways, railways and municipal tunnels. And the safety of the tunnel structure in the fire can be guaranteed for a long time.

The invention relates to the technical field of epoxy resin, in particular to low-shrinkage epoxy resin and a preparation method and application thereof.The low-shrinkage epoxy resin is at least prepared from, by weight, 40-80 parts of bisphenol A epoxy resin, 5-25 parts of hydrogenated bisphenol A epoxy resin, 5-25 parts of spiro monomers, 5-30 parts of aliphatic epoxy resin, 0.1-5 parts of gaseous silicon, 0.1-5 parts of structural auxiliaries and 0.01-1 part of photoinitiator; by optimizing the selection and matching of the raw materials in the formula system of the product, the provided product has excellent adhesive property, water-resistant effect and extremely low linear shrinkage, can be widely applied to the fields of consumer electronics cameras, vehicle-mounted ADAS sensors, high-end optical instruments and the like, and promotes the upgrading of the precision manufacturing technology.

To accurately divide a volumetric shrinkage ratio into three axial directions to enhance analysis accuracy even when a resin material that includes a crystalline resin is targeted, in a method of analyzing a resin molding, an analyzer, an analyzing program, and a storage medium.SOLUTION: In a method of analyzing a resin molding by a computer simulation, a volumetric shrinkage ratio in a solidification region of a resin material including a crystalline resin is divided into linear shrinkage ratios in three axial directions of the plate thickness, fluid flow, and perpendicular direction on the basis of the following formula, where εND: a linear shrinkage ratio in a plate thickness direction, εMD: a linear shrinkage ratio in a fluid flow direction in a plane, εTD: a linear shrinkage ratio in a perpendicular direction in a plane, εV : a volumetric shrinkage ratio, ΔT: a temperature difference, αND: a linear expansion coefficient in a plate thickness direction, αMD: a linear expansion coefficient in a fluid flow direction in a plane, and αTD: a linear expansion coefficient in a perpendicular direction in a plane. εND=αND×ΔT (1), εMD=(εV-εND)×αMD / (αMD+αTD) (2), εTD=(εV-εND)×αTD / (αMD+αTD) (3).SELECTED DRAWING: Figure 1

The utility model relates to the field of ship construction, and provides a B-type cabin supporting structure of an ultra-large ethane transport ship. Comprising a plurality of vertical supporting structures, a plurality of transverse anti-swing supporting structures and a plurality of longitudinal anti-swing supporting structures, connection and supporting of the B-type cabin and a ship body structure are achieved by arranging the vertical supporting structures distributed in an array shape, a row of longitudinal anti-swing structures are arranged along the transverse center line of the B-type cabin, and a row of transverse anti-swing structures are arranged along the longitudinal center line of the B-type cabin. Buffering between the B-type cabin and the ship body structure in a bumping state is achieved, and damage to the connecting position is avoided. A combined supporting structure is adopted at the linear contraction position of the bow and the stern of the ship body, vertical supporting structures are connected and reinforced mutually or a plurality of vertical supporting structures are designed into an integrated structure, supporting space is saved, the vertical supporting structures are reinforced between the anti-swing structures through reinforcing plates, and on the basis that the space is saved, the supporting space is saved. The structural strength is ensured, and the service life is prolonged.

The invention discloses an expansive soil expansion and shrinkage measuring method based on optical fiber distribution and further discloses an expansive soil expansion and shrinkage measuring device based on optical fiber distribution. A soil unit body for testing is treated, optical fibers are arranged in the x direction, the y direction and the z direction, and according to the environment state, temperature and humidity setting is conducted on an environment box; according to the stress state of the soil unit body, normal stress is applied to the soil unit body, then a moisture absorption or dehumidification test of the soil unit body is carried out according to experimental requirements, and the linear expansion rate, the linear shrinkage rate, the volume expansion rate and the volume shrinkage rate of the soil unit body in a three-dimensional space are obtained through an optical fiber sensor; the method and the device for measuring the expansion and shrinkage of the soil unit body provided by the invention can more comprehensively and truly reflect the three-dimensional expansion and shrinkage deformation of the expansive soil unit body in a complex working condition and pressure state.

The utility model provides an epoxy high-temperature mold, relates to the technical field of molds, and aims to solve the problems that a common glass fiber reinforced plastic mold is relatively large in thermal expansion coefficient, is easy to thermally deform and is greatly damaged by high-temperature curing when the conventional mold is used for producing. The epoxy high-temperature mold comprises a mold body and a mounting component, the mold body is an epoxy high-temperature mold body, and the mold body comprises a main body made of an epoxy composite material; the mounting assembly is connected with the mold body, the gap part of the framework is welded in a # shape, and the framework is in contact with the mold body. The main body can bear higher temperature, can meet the requirements of various high-temperature processes, can keep the stability and the dimensional precision of a mold in the manufacturing of a high-temperature cured and molded composite material, is small in linear shrinkage rate, is favorable for ensuring the precision and the quality of a product, has better tolerance to various resins, and is suitable for large-scale production. And the epoxy mold can be repaired in a repairing manner, so that the production cost is reduced.

The invention discloses a preparation method of an integrated polyimide aerogel special-shaped part. The method comprises the following steps: S1, compounding a polyamide acid solution with SiO2 nanoparticles subjected to surface modification by a silane coupling agent KH550, and carrying out ultrasonic dispersion to obtain a precursor solution; s2, injecting the solution into a special-shaped mold; s3, after pregelation, staged heating curing including at least one low-temperature dehydration stage and one high-temperature imidization stage is carried out under inert gas protection; and S4, carrying out CO2 supercritical drying (controlling the pressure relief rate) and gas-phase hydrophobic treatment on the gel. Through the synergistic effect of interface chemical bonding enhancement, gradient curing stress management and controllable pressure relief drying, the technical bottlenecks of high shrinkage and difficult forming in the polyimide aerogel preparation process are solved, near-net forming of special-shaped parts is achieved, the linear shrinkage rate is smaller than or equal to 10%, and the product has excellent mechanical strength, heat insulation performance and super-hydrophobicity and is suitable for industrial production. The method is suitable for aerospace, precision electronics and other fields.

The application provides a wave-shaped crucible and a gallium oxide crystal growth method, and belongs to the technical field of gallium oxide preparation. The application provides a wave-shaped crucible, and the edge of the cross section of the wave-shaped crucible is a concave-convex shape. The technical problem of the shrinkage amount of platinum rhodium (iridium) exceeding the shrinkage amount of the crystal in the cooling stage is solved by increasing the initial crucible circumference according to the structure design of the wave-shaped crucible. In the growth process of the gallium oxide crystal, the crucible wall of the wave-shaped crucible and the gallium oxide crystal are in close contact. After the gallium oxide is melted and the crystal growth is completed, the wave-shaped crucible and the gallium oxide crystal start to cool. The linear shrinkage amount of the wave-shaped crucible is greater than the shrinkage amount of the circumference of the gallium oxide crystal. In the concave part of the wave-shaped structure of the crucible, a gap is naturally formed between the wave-shaped crucible and the gallium oxide crystal, so that the wave-shaped crucible and the gallium oxide crystal are locally separated, the mechanical stress defect is reduced, and a high-quality gallium oxide single crystal is grown.

Disclosed herein are embodiments of a method in which a continuous green tape is fired in a furnace to form a ceramic ribbon of sintered lithium garnet. The continuous green tape includes particles of lithium garnet that are coated with a passivation layer or that have been tape-cast in a dry atmosphere. The continuous green tape has a length, a width, and a thickness. The width is greater than the thickness, and the length is greater than the width. The continuous green tape has a linear shrinkage of less than or equal to 25% after firing to form the ceramic ribbon.

The application discloses a kind of for large size package substrate's superstructure and manufacturing method, comprising: first core plate, first core plate upper and lower surface is provided with vertical spacer;Additional core plate is stacked on the first core plate, and the additional core plate is at least provided with one;First via hole is opened in the vertical direction of the intermediate core, and the first via hole is filled with insulating material;Second via hole is penetrated in the first via hole, additional core plate, vertical spacer and first core plate;Wherein, the vertical spacer thickness is greater than or equal to 50 μm;Additional core plate includes second core plate and / or third core plate, and second core plate and / or third core plate are stacked on the upper and lower surfaces of first core plate.The application is heterogeneous stacking by high-rigidity glass core plate and BT core plate, linear shrinkage of PP material is constrained during cooling process, and the design of vertical spacer thickness greater than or equal to 50 μm provides stress buffer interface, to reduce interlaminar shear force.

The reinforcing filler in the dental resin cement composition provided by the present invention has a particle size distribution that simultaneously satisfies D75-D25≤0.95μm, D25-D15≤0.7μm, and D50 of 0.5~1.0μm. Specifically, the present invention improves the chemical curing time, edge sealing, and linear shrinkage rate of dental resin cement by controlling the D15 / D25 / D75 and D50 of the reinforcing filler in the matrix and catalytic portions to have the above-mentioned specific numerical relationships.

A geopolymer early linear shrinkage strain time-varying rule prediction method based on fractal dimension relates to the technical field of building materials, and comprises the following steps: acquiring mercury intrusion method test data of a geopolymer sample; on the basis of the test data, determining a fractal dimension representing the pore surface complexity of the geopolymer; establishing a mathematical model for predicting the early linear shrinkage strain of the geopolymer under a specific environmental condition; and inputting the fractal dimension as a key parameter into the mathematical model so as to calculate the early linear shrinkage strain of the geopolymer. According to the method, the model is established to predict the geopolymer early-stage linear air shrinkage strain time-varying rule, and compared with a traditional method that only the empirical relation between air shrinkage and time or the water loss rate is established, the scientificity and the nature of prediction are remarkably improved.

This invention presents the utilization of amorphous porous silicate particles (APSP) derived from rice husk agricultural waste sourced from Mindanao, Philippines, as an additive and replacement to sand in cement mortars. The solid-liquid ratio, percent water absorption, total porosity, specific gravity, linear shrinkage, surface morphology, modulus of rupture (MOR), and thermal conductivity of the cement blocks were analyzed. Additionally, the researchers valuated different formulations, such as the control and the three different APSP formulations, namely APSP-33, APSP-50, and APSP-100. Moreover, analysis shows that the formulation of APSP100 cement mortars reveals a higher MOR value, lightweight at 0.77 in density, and a lower thermal conductivity. Furthermore, experiment results showed that the APSP could be used as an additive or to replace sand and can be a potential material for thermal management applications with a thermal conductivity of 0.1497 w / mK. The possible use of this material can be found suitable for commercial use, such as lightweight blocks, boards, and other household applications for thermal management.

The invention provides a simulation method and a simulation process of ceramic shrinkage. The thermal strain of ceramic in the sintering and temperature rising process is shown in the specification; the temperature represents normal temperature, the highest temperature in the sintering heating process and the linear shrinkage rate of the ceramic. According to the ceramic shrinkage simulation method and simulation process provided by the invention, the modeling and simulation prediction of the ceramic sintering shrinkage behavior can be realized through an equivalent method for mapping the linear shrinkage rate of the ceramic into the negative thermal expansion coefficient related to the temperature, namely by adopting the negative thermal expansion coefficient model and combining the existing simulation software. The method does not depend on porosity evolution or explicit coupling of a chemical reaction equation, only existing simulation software is utilized, simulation software with complex additional components is not needed, and the method has the advantages of being concise in modeling, controllable in parameter and good in convergence and can be used for ceramic structure pre-design and composite structure redundancy optimization.

The invention relates to an ultrahigh temperature-resistant light nano-microporous heat insulation plate and a preparation method thereof.The heat insulation plate is composed of 60-90% of nanoscale fumed silica with the particle size of 5-100 nm, 0-25% of fumed alumina, 10-35% of a micron opacifying agent with the particle size of 1.5-6.0 microns and 2-10% of reinforced fibers with the diameter of 4-15 microns, and the heat insulation plate is achieved through the synergistic effect that 1, convective heat transfer of gas at the temperature of 1000 DEG C is inhibited; 2) reflecting infrared radiation heat; and 3) maintaining the integrity of the fiber structure. The preparation method comprises the following steps: sequentially feeding and stirring aluminum oxide, silicon dioxide and the opacifying agent step by step; adding fibers for dispersion; three layers of functional paddles (a radial dispersion layer / a hinge mixed fiber layer / an anchor type anti-deposition layer) are adopted for low-speed stirring; and slowly pressing and forming. The invention has the following beneficial effects: under the density of 240-290 kg / m, the heat conductivity coefficient at 1000 DEG C is less than or equal to 0.038 W / m.K, the linear shrinkage rate is less than or equal to 2.0%, the fiber fracture rate is less than 0.5%, and the technical contradiction between light weight and ultrahigh temperature resistance is solved.

This invention belongs to the field of high-temperature resistant fiber application technology, specifically disclosing a high-temperature resistant multi-element doped modified high-silica fiber. It is prepared using sodium borosilicate ternary glass as a precursor through Cr-Al-B multi-element synergistic doping and deep impurity removal. The fiber's mass percentage composition is: SiO2 ≥ 97-99%, Cr2O3 0.2%–0.9%, Al2O3 1.5%–2.8%, B2O3 0.4%–1.8%, ZrO2 0.10%–0.25%, with the remainder being unavoidable impurities. The fiber contains Na... + With K + The total content is less than 40-55 ppm; the linear shrinkage rate after constant temperature heat treatment at 1100℃-1200℃ for 5-10 hours is less than 0.5-1.3%; and the high-temperature strength retention rate after constant temperature heat treatment at 1100℃-1200℃ for 80-100 hours is greater than 82-90%. The beneficial effects of this invention are: the use of a stepped dynamic acid leaching method combining cyclic countercurrent and dynamic fiber bundle rotation eliminates radial component segregation in the fibers, ensuring uniform doping; and the use of ultrasonic assistance to enhance mass transfer through cavitation effect improves acid leaching efficiency by more than 40%, resulting in Na... + / K + The removal rate is ≥99%; the multi-stage gradual heating sintering process is used to form a stable amorphous structure in the fiber, which effectively inhibits the crystallization of quartz above 1000℃.

The invention provides an inorganic thermal insulation pipe shell with gradient distribution of composite hollow glass beads and a preparation method. The preparation method comprises the following steps: preparing the composite hollow glass beads, averagely dividing a base material into three parts, mixing 35-50% of the composite hollow glass beads with one part of the base material, and preparing an inner layer material; 20%-45% of composite hollow glass beads are mixed with one part of the base material, and a middle layer material is prepared; 20%-30% of composite hollow glass beads are taken to be mixed with one part of the base material, and an outer layer material is prepared; sequentially injecting the inner-layer material into the mold and then applying pressure, injecting the middle-layer material and injecting the outer-layer material and then applying pressure to obtain an inorganic thermal insulation pipe shell blank; and finally, the inorganic thermal insulation pipe shell blank is subjected to staged curing and curing. According to the method, the continuity of the hierarchical pore structure in the inorganic thermal insulation pipe shell can be improved, the compressive strength is remarkably improved, the heat conductivity coefficient is reduced, and the purposes of high hydrophobicity and low linear shrinkage are synchronously achieved.

The invention discloses a rolling mill stand resin sand gravity casting liquid weight calculation method, and relates to the technical field of equipment manufacturing, and the method comprises the following steps: selecting the linear shrinkage rate epsilon L of a casting in different directions according to the wall thickness and length of the casting; obtaining a resin sand box expansion rate fv based on measured data; adjusting the process blank model based on the linear shrinkage rate epsilon L and the resin sand box expansion rate fv; a pouring pipeline model and a riser model are designed based on the process blank model, and the volume of the process blank model, the volume of a pouring pipeline and the volume of a riser are obtained based on three-dimensional design software; and calculating the mass of molten iron required for pouring based on the adjusted volume of the process blank model, the volume of the pouring pipeline and the volume of the riser. According to the method, epsilon L and fv are obtained through a standardization method, cost reduction, energy conservation and zero mold testing are achieved, and the problems that in an existing rolling mill stand resin sand gravity casting technology, the precision of an empirical coefficient method is low, the difference of linear shrinkage in different directions is not considered, the box expansion rate is not quantized, and the accuracy is poor are solved.

The application discloses a kind of high solid content low viscosity SiC ceramic double solidification slurry and low shrinkage green body preparation method, it is related to SiC ceramic additive manufacturing technical field.For solving the problem of existing slurry solid content low, viscosity high, green body shrinkage big, green body strength low, the modified SiC powder of surface in-situ growth SiO2 / phenolic resin composite core-shell is used in the present application, with photosensitive resin and thermal gel matrix, build double solidification slurry system;After photo-curing layering, thermal gel secondary reinforcement, ladder debinding and pressureless sintering, obtain low shrinkage, high strength SiC green body and dense ceramic.The application realizes slurry solid content 65~72vol%, viscosity≤1200mPa·s, green body linear shrinkage rate≤8%, green body strength≥8MPa, and is suitable for semiconductor precision ceramic component additive manufacturing.