6876 results about "Thermal dilatation" patented technology

The invention relates to the technical field of electronic manufacturing equipment, in particular to an adaptive thermal compensation system and method for a high-precision mounting head of a chip mounter, and the system comprises a temperature-deformation sensing unit, a thermal-mechanical coupling analysis unit, a dynamic compensation control unit, and a closed-loop execution unit. The temperature-deformation sensing unit collects temperature and deformation data of multiple parts of the mounting head in real time, the thermal-mechanical coupling analysis unit reconstructs a three-dimensional temperature field based on a finite element algorithm, the thermal expansion distribution quantity is dynamically calculated, the problem of rough model of traditional single-point temperature measurement is solved, and the measurement precision is improved. The dynamic compensation control unit predicts the thermal drift amount in the future 5 ms through online parameter identification and a long-short-term memory network model, a compensation strategy is adaptively adjusted in combination with the motion working condition, the closed-loop execution unit decomposes the compensation amount into displacement and torsion correction instructions, accurate offset of thermal deformation is achieved, and a whole-process thermal compensation closed loop is constructed. The precision stability of the mounting head in a complex thermal environment is improved, and the production efficiency is improved.

The invention provides an aluminum alloy auxiliary frame welding accurate positioning and quality control method and system. The method comprises the steps that S4, welding gun track control parameters are updated through a dynamic adjustment instruction, laser tracking data are fused to optimize the welding path angle in real time, and the accurate movement track of each section of welding seam is determined; s5, acquiring real-time thermal expansion data during welding execution, monitoring temperature field distribution of a welding seam area by adopting an optical measurement technology, and judging whether thermal deformation adjustment exceeds a preset threshold value or not; s7, micron-sized welding spot positioning operation is executed according to the stable positioning state, the dynamic path optimization result is fused to generate a final welding instruction, and consistent welding seam quality data is output; and S8, after weld joint quality data are obtained, weld joint deviation and geometric consistency are detected through a laser tracking technology, whether welding quality meets design requirements or not is judged, and a quality verification report is generated. According to the method, the precision and consistency of intelligent welding of the aluminum alloy auxiliary frame are remarkably improved.

The invention belongs to the field of equipment coupling monitoring, and particularly relates to a dynamic coupling compensation method for thermal expansion and axial displacement, which comprises the following steps of: calculating a first characteristic value for representing reference dynamic offset of a sensor based on a three-dimensional thermal-structure coupling model by acquiring a thermal expansion parameter and axial displacement parameter sequence of a casing; calculating a second characteristic value representing the real position change of the rotor in combination with a rotor-casing axial thermodynamic model, establishing a piecewise coupling function considering a nonlinear effect, working condition self-adaption and cross interference, and eliminating the mechanical thermal inertia and measurement system lag influence through a dynamic delay compensation mechanism; an accurate axial displacement measurement total error compensation index is generated, and grading compensation actions are intelligently triggered according to error grades; the problem of measurement distortion caused by dynamic coupling of thermal expansion and axial displacement is effectively solved, and the accuracy and reliability of state monitoring of the rotating machine are remarkably improved.

An airfoil having: a composition gradient defining a first coefficient of thermal expansion and a second coefficient of thermal expansion that differs from the first coefficient of thermal expansion; and a thermoelectric junction operationally coupled to the composition gradient, wherein the composition gradient is formed of either of a plurality of dissimilar metals or of plastic with fillings or fibers.

The invention relates to the field of numerical control machining, discloses a numerical control machining method and system integrating thermal expansion dynamic compensation, and aims to solve the problem that precision is out of control due to thermal deformation in high-speed cutting of motorcycle light alloy castings. The method comprises the steps that distributed temperature and displacement sensors are arranged in a key area of a workpiece, and a temperature field and thermal expansion amount are collected in real time; constructing a local thermal deformation prediction model based on a material expansion coefficient and a geometric structure, and correcting a tool path in real time through a coordinate system dynamic offset algorithm; and an on-line measurement feedback mechanism is introduced, and model parameters are adaptively optimized, so that closed-loop compensation is realized. The system comprises a sensing module, a thermal deformation modeling and compensation calculation module, a coordinate dynamic correction module, an online measurement feedback module and a parameter adaptive updating module. Through millisecond-level dynamic compensation and closed-loop self-optimization, the size precision and form and position stability of the complex thin-wall part under the high-temperature working condition are remarkably improved, the rejection rate and cooling energy consumption are reduced, and the method is suitable for a high-precision batch machining scene.

The invention relates to the technical field of material testing, and discloses a coating performance simulation method based on high and low temperature circulation and prestress loading. The method comprises the following steps: constructing a coating matrix composite geometric model containing a microporous structure by acquiring actually measured working condition data of a pipeline or a part, and quantifying surface roughness and interface curvature characteristics in combination with reverse engineering; a dynamic temperature-pressure coupling equation is generated based on the thermal expansion effect of a high-pressure medium, a micropore optical load is converted into equivalent heat flux density through a ray tracing algorithm, transient boundary conditions of a temperature field and a stress field are associated, a crack initiation path is simulated through an extended finite element method, and a life attenuation curve is predicted in combination with a Paris formula. And material parameters are dynamically corrected based on experimental data, and a multi-parameter collaborative optimization model is generated. According to the method, the problems of interface stress evaluation distortion and life prediction deviation under the combined load are solved, and multi-physics field co-simulation support is provided for coating compression resistance optimization.

The invention provides a bridge structure monitoring method and device based on a microwave deformation radar, and relates to the technical field of bridge structure monitoring, and the method comprises the steps: obtaining the multi-point three-dimensional displacement data of a bridge structure through the microwave deformation radar, carrying out the thermal expansion pseudo displacement compensation and multi-point space smoothing through combining with temperature information, and obtaining a displacement field after environment correction; secondly, extracting a vertical component and separating the vertical component into a static deformation component and a dynamic vibration component by adopting variational mode decomposition; further analyzing and identifying a decoupling region through a time window coherence coefficient, performing recursive quantitative analysis, bispectrum analysis and energy distribution entropy calculation on a dynamic signal of the region, and constructing a high-order damage sensitive feature set; and finally, the dynamic characteristics and the static curvature change are fused to form a comprehensive degradation degree index, the deviation degree is judged according to working condition classification and the mahalanobis distance, and multi-dimensional and cross-working-condition degradation identification and risk early warning of the bridge structure are achieved.

The invention relates to the technical field of production line control, and discloses an intelligent control method and system for production line mold machining. According to the method, a pressure distribution state is determined by obtaining initial cutting parameters of a cutter and surface pressure data of a mold, mold node stress distribution is calculated by utilizing a three-dimensional finite element model, and a stress concentration position is identified. And predicting a mold deformation trend through a linear regression model according to the thermal expansion coefficient and the environment temperature data. Meanwhile, the initial cutting parameters are optimized by combining a cutting parameter optimization objective function, and the objective function comprehensively considers factors of tool wear, surface quality and residual stress. And on the basis of a die deformation prediction result, a dynamic compensation algorithm is adopted to adjust supporting structure parameters and optimize cutting parameters, and finally optimal cutting parameters and a target tool path are generated. According to the method, precise coordination control over pressure distribution and mold deformation under the complex working condition is achieved, the residual deformation risk is reduced, and the mold machining precision is improved.

The invention discloses an intelligent cleaning and feature extraction system and method for multi-modal industrial data, and relates to the technical field of equipment state monitoring. The method is used for solving the problems that multi-source heterogeneous signal time alignment is not accurate, fault features are easily covered by background noise, a causal chain is not clear under working condition changes, and feature stability is poor. Firstly, a matching window is dynamically adjusted based on the main vibration frequency of rotating equipment, temperature signal delay is calculated in combination with a material thermal expansion coefficient, and modal alignment is achieved; then, a fault sensitive frequency band is solved through a bearing pedestal kinetic equation, a frequency band protection window is constructed, frequency domain filtering and gradient truncation operation are executed, and microcrack high-frequency features are extracted; secondly, recognizing a fault propagation path by combining image definition and envelope spectrum kurtosis, and dynamically shrinking a frequency domain window bandwidth according to a real-time load; finally, the feature vector is reconstructed to a phase space, when the curvature change rate or the temperature drift exceeds the limit, parameter updating and frequency band readjustment feedback are triggered, and the stability and adaptability of the system are improved.

The invention relates to the field of industrial pipeline systems, in particular to a displacement analysis evaluation and compensation method for optimizing pipeline thermal expansion. The method comprises the following steps: collecting multi-temperature thermal state snapshots to form a thermal state change sequence; determining a thermal expansion constraint boundary according to the thermal state change sequence, and forming boundary condition data; fixed points and free points of the pipeline system are identified according to the boundary condition data, and a degree-of-freedom distribution diagram is constructed; based on the degree-of-freedom distribution diagram, analyzing a displacement transfer relation of each pipe section, and generating displacement transfer chain data; identifying a thermal expansion concentrated release area through displacement transfer chain data, and performing node resonance detection to form vibration risk assessment data; and designing a thermal stress digestion path based on vibration risk assessment data, and setting flexible constraints to form a balanced stress network. The thermal expansion displacement transmission path is tracked in real time through displacement transmission chain analysis, the resonance frequency is synchronously recognized in combination with vibration mode detection, and dynamic association of the thermal expansion process and the vibration mode is achieved.

The invention relates to the technical field of material simulation models, and particularly discloses a finite element analysis and thermal expansion mismatch effect-based comprehensive simulation model construction method, which comprises the following steps of performing geometric model construction on a target material; constructing a geometric model: adopting modeling software to create the geometric model of the target material, and obtaining a thermal mismatch target area interface; parameter data of a target material are obtained for assignment, and then a target material grid is preprocessed; performing boundary condition constraint on the geometric model of the target material, and applying a temperature load; establishing a thermal stress corresponding mechanism for the geometric model of the target material, calculating to obtain thermal stress values of the unit grids, and converting the thermal stress value on each unit grid into a cloud picture in a color manner based on the thermal stress values of the unit grids to obtain a thermal expansion mismatch effect comprehensive simulation model; the quantitative analysis capability of the thermal stress difference of multiple materials is realized; potential stress concentration areas caused by thermal expansion mismatch can be identified.

The invention relates to a stacking packaging method and system for AI-DSP mixed audio processing chips, and the method comprises the following steps: employing a first bonding machine to carry out the flip-chip bonding of an AI chip and a DSP chip, and obtaining a flip-chip bonding chip; the flip-chip bonding chips are interconnected, and an interconnected chip structure is obtained; vertically stacking the interconnected chip structures to obtain a stacked chip structure; packaging the stacked chip structure by adopting a second bonding machine to obtain a packaging body; according to the AI-DSP mixed audio processing chip and the packaging method thereof, the packaging body is subjected to heat dissipation treatment through the preset heat dissipation substrate, the packaged AI-DSP mixed audio processing chip is obtained, and the technical problems that in a traditional packaging scheme, an AI chip and a DSP chip generally adopt different process nodes and manufacturing processes, and thermal expansion coefficients are not matched and stress distribution is uneven during direct integration are solved.

The invention relates to the technical field of intelligent regulation and control of fusion data, in particular to a rolled finished product-based size precision intelligent regulation and control system and method, which comprises a data acquisition unit, a data fusion unit, a deep learning prediction unit and a compensation execution unit, multi-source data such as temperature gradient, roll gap fluctuation and tension spectrum are collected in real time through a sensor array, thermal expansion compensation correction is carried out through a data fusion unit based on a rolling elasticoplastic deformation equation, an anti-interference coupling feature vector is generated by using adaptive Kalman filtering, and a deep learning prediction unit is used for predicting the rolling elasticoplastic deformation through a dual-channel space-time convolutional network. The thickness error and the width error are predicted by combining the constraint of a rolling force balance equation, the compensation execution unit dynamically generates the roll gap adjusting amount and the rolling force compensation amount according to a three-level response mechanism, phase lag compensation current is injected to suppress resonance, the high-end steel yield and the rolling precision are improved, and the rolling quality is improved. And an intelligent closed-loop control scheme is provided for high-precision rolling under complex working conditions.

The invention discloses a method for simulating a mold temperature field and curing deformation through finite elements and a mold optimization design method based on the method. The finite element analogue simulation method comprises the following steps: firstly, modeling and simulating a mold grid; secondly, calculating equivalent thermal and mechanical parameters of the composite material by adopting a multi-scale homogenization method; then, a heat conduction model of the mold and the composite material blade is constructed and coupled with the curing dynamic model through temperature, and mold temperature distribution is simulated; and finally, establishing a mold thermal expansion and curing stress coupling model, and predicting thermal deformation and stress change of the mold. By identifying the weak area of the mold in the simulation process, the mold is optimally designed. By improving a mold temperature field distribution simulation method, optimizing a grid modeling process and introducing an accurate calculation method of equivalent material parameters, the precision of mold design and the controllability of a curing process are effectively improved, so that the problem of inaccurate mold temperature field distribution and curing deformation prediction is solved.

The invention discloses a preparation method of a nickel-based tungsten carbide laser cladding wear-resistant gradient coating, which comprises the following steps: step 1, preparing mixed powder of a transition layer, a functional layer and a repair layer; step 2, pretreating a matrix: removing oxide skin on the surface of the matrix, polishing to be smooth, and preheating the matrix to 350-500 DEG C; step 3, sequentially preparing a first functional layer, a transition layer, a second functional layer and a repair layer by adopting a laser cladding process; and 4, coating post-treatment is conducted, specifically, the surface of the repairing layer is polished to the specified thickness, and the defect-free wear-resistant gradient coating is formed. Through gradient component layered design, the functional layer adopts high tungsten carbide content to maximize wear resistance, and the transition layer relieves thermal expansion difference between the coating and a matrix, reduces interface stress and reduces crack initiation; according to the repairing layer, micro-cracks and air holes generated in the cladding process are filled through low-hardness nickel-based components, and the compactness and surface integrity of the coating are remarkably improved.

The embodiment of the invention discloses an epoxy molding compound, an epoxy molding film and an electronic component, the epoxy molding compound comprises epoxy resin and a zeolite imidazole framework material, and the zeolite imidazole framework material comprises imidazole ligands and metal ions. The zeolite imidazole framework material is used as a curing agent and a nano reinforced phase, imidazole groups on the surface of the zeolite imidazole framework material can be subjected to a ring-opening reaction with epoxy resin to form covalent bonds, the zeolite imidazole framework material can induce the epoxy resin to generate a microcrack deflection mechanism, and the zeolite imidazole framework material can promote curing of the epoxy resin, so that the epoxy resin is cured, and the curing effect is improved. Therefore, the thermal expansion coefficient of the epoxy molding compound is reduced, the fracture toughness of the epoxy resin is improved, and the thermal stability of the epoxy molding compound is improved.

The invention relates to the technical field of high-voltage PCB design, and particularly provides a large-model-based high-voltage PCB current path optimization design method and system, and the method comprises the steps: S2, obtaining current distribution according to electrical parameters and layout information through employing an electrical simulation model; s3, acquiring temperature field distribution according to the current distribution, the resistivity of the via hole array and the heat conductivity coefficient of the PCB substrate; s4, acquiring first thermal mechanical stress distribution according to the temperature field distribution, the thermal expansion coefficients of the via hole array and the PCB substrate and the elastic modulus of the via hole array and the PCB substrate; s5, analyzing whether the first thermal mechanical stress distribution meets a preset requirement or not, if yes, taking new layout information as final layout information, and if not, adjusting layout parameters of the via hole array according to the first thermal mechanical stress distribution, and returning to the step S2; according to the method, the problems of local hot spots and thermal mechanical stress caused by uneven current distribution in the high-voltage PCB via hole array can be solved.

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 the field of high-temperature anti-oxidation coatings, in particular to a tantalum-tungsten alloy surface high-temperature anti-oxidation composite coating and a preparation method thereof.The coating is composed of two layers of coatings with different components, the thermal expansion coefficients of the coatings and a base body are matched, the thermal expansion coefficients of the coatings are matched, and residual stress and thermal stress are reduced. The coating is prepared by adopting an embedding boriding and slurry melting method, and the used material components comprise ZrB2, MoSi2, 8YSZ, B, La2O3, Al2O3, NaF, TaSi2 and the like. The preparation method specifically comprises the following steps: putting a substrate into embedding powder for boronizing treatment, then mixing a coating material with ethanol and a binder, putting the mixture into a ball mill for wet mixing to prepare coating slurry, spraying the coating slurry on the surface of the substrate, and putting the substrate into a vacuum tube furnace for sintering to prepare a coating, thereby obtaining the high-temperature anti-oxidation composite coating. The binding force between the developed coating and the tantalum-tungsten alloy matrix is strong, and the tantalum-tungsten alloy matrix can be protected from oxidation corrosion or the oxidation rate can be slowed down within 500-2500s at the high temperature (2000 DEG C or above).

The invention discloses a special cooling device for a computer GPU (Graphic Processing Unit) cluster server, which comprises a box body, a support frame, a circulating pipe, a cooling box, a first piston cylinder, a liquid outlet pipe, an injection pipe, a liquid inlet pipe, a heat dissipation mechanism, a cooling mechanism, a detection mechanism and an auxiliary mechanism, meanwhile, a filter plate can prevent dust in air from entering, a detection mechanism monitors the temperature in the box body in real time by utilizing the thermal expansion characteristic of alcohol, and a signal is transmitted to an external controller through a pressure sensor so that a worker can master the operation temperature state of the server in real time; the cooling mechanism automatically adjusts the flow speed and flow of cooling liquid according to temperature changes so as to meet the heat dissipation requirements of the server under different loads, the auxiliary mechanism conducts rolling sweeping on a filter plate through a cleaning roller, smooth air circulation is ensured, the efficient and intelligent cooling effect is achieved, and the service life of the server is prolonged. And the operation stability and the service life of the GPU cluster server are improved.

The invention relates to the field of semiconductor optoelectronic device manufacturing, in particular to an LED epitaxial wafer growing method capable of reducing warping. Comprising the following steps of: growing a nucleating layer on a substrate at low temperature by adopting an MOCVD (Metal Organic Chemical Vapor Deposition) process, and annealing to form a three-dimensional island-shaped structure to release stress; growing an AlGaN / GaN superlattice or gradient layer as a gradient buffer layer, and adjusting lattice constants layer by layer; a heavily doped or co-doped layer is inserted before growth of n-GaN, and thermal stress is pre-compensated by using local pressure stress; and finally, continuously growing a device layer and carrying out in-situ heat treatment to obtain the LED epitaxial wafer. The method effectively counteracts the macroscopic tensile stress caused by the difference of thermal expansion coefficients in the cooling process, and greatly improves the integrity of the epitaxial wafer.

The invention provides a preparation method of an inertial sensor and the sensor. The preparation method comprises the following steps: sequentially forming a first cavity and a first oxide layer on a first silicon wafer; bonding the first silicon wafer and a second silicon wafer, wherein the second silicon wafer is a low-resistance silicon wafer; forming an inertia sensitive structure in the second silicon wafer; correspondingly forming a second cavity on a third silicon wafer, wherein the third silicon wafer is a low-resistance silicon wafer; bonding the third silicon wafer and the second silicon wafer; an isolation groove penetrating through the third silicon wafer is formed through etching, a conductive silicon column and an electric signal isolation ring are formed, and the conductive silicon column is connected with the inertia sensitive structure; and forming a sealing insulating layer on the surface of the third silicon wafer, and forming a signal lead-out pin in the sealing insulating layer. According to the scheme, thermal stress caused by thermal expansion coefficient mismatch among the three layers of wafers is reduced through an all-silicon wafer level packaging process, and the full-temperature characteristic of the device is greatly enhanced; and the preparation process flow is optimized, the process control difficulty is reduced, and the preparation cost is reduced.

The invention relates to a semiconductor packaging structure and a packaging method thereof, and belongs to the technical field of semiconductor devices.The semiconductor packaging structure comprises a substrate, a chip, a radiator and a packaging shell, and further comprises an alloy needle matrix arranged below the radiator and a heated self-deformation fin arranged between the upper surface of the chip and the packaging shell; needle bodies of the alloy needle matrixes penetrate through the through holes in the substrate, needle tips of the alloy needle matrixes directly make contact with the back faces of the chips through the heat conduction springs, the heated self-deformation fins are unfolded through heating and abut against the top of the radiator, a double-channel vertical heat dissipation system is constructed, heat conduction paths from the chips to the radiator are directly broken through, and the double paths work in parallel. It is ensured that heat is vertically transmitted to the radiator through the shortest path, loss of traditional transverse heat diffusion is avoided, and the problems of thermal resistance accumulation caused by series connection of multiple layers of media, interface shear stress and micro cracks caused by mismatch of material thermal expansion coefficients of an existing semiconductor packaging structure are solved. And the problems of heat dissipation path failure and local high temperature of the chip caused thereby are solved.

The invention discloses a pre-welding deviation rectifying device for a submerged-arc welding straight seam steel pipe, and relates to the technical field of steel pipe submerged-arc welding. The submerged-arc welding device comprises a machining table, a first linear sliding rail module and a second linear sliding rail module are installed at the top of the machining table, a submerged-arc welding assembly is installed on the second linear sliding rail module, a fixed plate is fixedly installed at the left end of the top of the machining table, a movable plate is installed on the first linear sliding rail module, and three-jaw chucks are installed on the movable plate and the fixed plate correspondingly. A three-jaw chuck drives an inner correction rod to expand outwards to conduct center positioning on a steel pipe, an inner circle can be corrected, then a guide disc is rotated to enable a connecting rod to enter an arc groove part of an inner correction guide groove to lock the position of the inner correction rod, and a swing rod drives an outer correction rod to swing through a telescopic rod. The outer correcting rods correct the outer circle of the steel pipe, the two sets of outer correcting rods are pressed on the two sides of a welding seam to clamp the welding seam, and therefore welding deformation caused by thermal expansion and contraction in the welding process is reduced.

The invention relates to the technical field of automatic control, in particular to an automatic control method and system for intelligent cooking equipment, and the method comprises the following steps: obtaining the liquid mass change and diffusion area based on a to-be-cooked food material, calculating the diffusion rate ratio, recognizing the structure type, calculating the fire power initial gradient, and generating the initial power; and constructing a composite expression quantity by combining a thermal expansion monitoring value, judging regional softening response information, identifying a heat flux gradient anomaly and marking an overheating trend, implementing offset stirring adjustment output, and generating dynamic regulation and control information. In the invention, based on food material structure feature information identification, classification number identification aiming at different structure types is realized, accurate matching of an initial control strategy is realized, fine control of heat energy supply at the initial stage of cooking is ensured, and the cooking efficiency is improved. Based on the thermal expansion coefficient, combined with the tissue compactness grade coefficient and the water activity change rate, composite calculation is carried out, and local over-cooking or under-cooking of food materials caused by insufficient expansion monitoring is avoided.

The embodiment of the invention provides a UV (ultraviolet) thermal dual-curing adhesive and a preparation method thereof. The UV thermal dual-curing adhesive comprises the following components in percentage by mass: 30-55% of a photocuring prepolymer; 5%-25% of an active diluent monomer; 1%-10% of a photoinitiator; 1%-20% of a thermal initiator; 10%-40% of a filler; 0.5%-5% of a coupling agent; 1%-10% of a thixotropic agent; 1%-10% of pigment; 2%-8% of an auxiliary agent; wherein the photocuring prepolymer comprises epoxy resin. According to the UV thermal dual-curing adhesive and the preparation method thereof provided by the embodiment of the invention, the dual-curing adhesive with low shrinkage and low thermal expansion coefficient is obtained by optimizing the structure of the photocuring prepolymer and matching the components, and the prepared adhesive can be rapidly cured under the irradiation of LED 365nm ultraviolet light, or can be thermally cured under the low-temperature condition of 80 DEG C, so that the UV thermal dual-curing adhesive can be widely applied to the field of ultraviolet curing. The product can resist high and low temperature cycle impact of-50 DEG C to 140 DEG C, and has a good application prospect.

The invention discloses a ceramic-metal composite structure with a low thermal expansion coefficient and a middle layer for assisting two-step temperature control brazing and a preparation method of the ceramic-metal composite structure. The composite structure is formed by metallurgical bonding of a ceramic matrix, a titanium-containing active brazing filler metal layer, a low-thermal-expansion-coefficient (2 * 10 <-6 > / K-9 * 10 <-6 > / K) middle layer, a low-temperature brazing filler metal layer and metal base metal in sequence. During preparation, a step-by-step temperature control brazing process is adopted, wherein in the first step, ceramic / intermediate layer connection is achieved through titaniferous active brazing filler metal with the solidus larger than or equal to 780 DEG C under the vacuum condition smaller than or equal to 5 * 10 <-3 > Pa; and secondly, under the vacuum or inert atmosphere, brazing filler metal with the solidus being smaller than or equal to 650 DEG C is adopted for completing connection of the middle layer and the metal base metal. The low-stress and high-strength ceramic-metal composite structure is successfully constructed on the basis of the thermal matching design of the low-thermal-expansion-coefficient middle layer and the ceramic and the stress gradient release mechanism of the two-step temperature control brazing process in a cooperative coupling mode, and the low-stress and high-strength ceramic-metal composite structure is particularly suitable for the high-temperature and high-reliability fields of aerospace thermal protection systems, high-power electronic device packaging and the like.

A vacuum insulating panel includes first and second substrates (e.g., glass substrates), a hermetic edge seal, a pump-out port, and spacers sandwiched between at least the two substrates. The gap between the substrates may be at a pressure less than atmospheric pressure to provide insulating properties. The vacuum insulating panel may include a multi-layer edge seal structure with coefficients of thermal expansion (CTEs) of layers of the seal structure optimized for CTE grading.

The invention belongs to the technical field of film materials, and particularly relates to a lower supporting film for a flexible folding display screen and a preparation method of the lower supporting film. The supporting film sequentially comprises a protective film layer, a stainless steel base material layer, an adhesive layer and a release film layer from top to bottom; wherein the adhesive layer is prepared by coating a release film with modified organic silica gel liquid, drying and curing. The ultra-thin stainless steel is used as the base material layer, can resist external force impact and scraping, is low and stable in thermal expansion coefficient, can reduce the influence of environment temperature and humidity on the size of the supporting film, and guarantees the structural consistency of the screen module in long-term use; and through multi-component composite modification of polyurethane-thiazole-organic silicon, the peeling strength of the adhesive layer and stainless steel and the bending frequency of the supporting film are improved, and the service life of the supporting film is prolonged.

The invention provides a compressible high-thermal-conductivity graphene thermal interface material and a preparation method thereof. The preparation method comprises the following steps: preparing a graphene oxide film with low structural unit thickness by adopting a centrifugal spin-coating film casting method, performing limited thermal expansion delamination, compounding with polysiloxane, and performing directional lamination to obtain a highly-oriented graphene / organic silicon composite material. And applying shear stress after pressurizing and densifying along the normal direction of the graphene sheet layer, so that the graphene structure unit forms a continuous buckling structure which is high in density and easy to compress. The densification process promotes the interaction among delamination structure units, broadens a phonon transmission channel, inhibits phonon-boundary scattering, enhances the comprehensive heat-conducting property, plays a role in promoting stress transmission among graphene, and ensures the formation of a continuous buckling structure under shear stress. A continuous buckling structure and a relatively low structure unit thickness (llt in the graphene structure unit; and the compression modulus of the densified vertical graphene array is jointly reduced by means of high density, high thermal conductivity and high compressibility of an existing thermal interface material, and the method can be applied to the fields of new energy automobiles, high-power chips, aerospace electronic equipment and the like, and the problem that high density, high thermal conductivity and high compressibility of the existing thermal interface material are difficult to consider at the same time is solved.