3336 results about "Crazing" patented technology

The invention relates to the technical field of detection, and discloses a polyurethane material performance detection method, which comprises the following steps: clamping a material to be detected on a loading platform, cooperatively controlling and simulating the stress effect of a target application scene, and capturing a time sequence image of the microstructure of the surface of the material by adopting a visual unit; synchronously acquiring internal strain distribution data through a distributed strain sensing array, acquiring a dynamic stress response spectrum in combination with a piezoelectric mechanical sensor, and generating a multi-modal deformation characteristic data set; performing crack density and texture orientation analysis on the time sequence image, extracting a crack growth rate and a direction consistency coefficient, and marking a strain concentration area; calculating an apparent elastic modulus attenuation rate based on the dynamic stress response spectrum, establishing a material performance degradation model, generating a dynamic flexible performance index through a weighted fusion algorithm, and performing graded evaluation on the material; material detection is upgraded from a single mechanical test to a multi-physics coupling intelligent evaluation system, and accurate and reliable detection support is provided for multiple application scenes.

The invention provides a thermal protection coating as well as a preparation method and application thereof. The thermal protection coating comprises a NiCoCrAlY first bonding layer, a NiCoCrAlY second bonding layer, a CeYSZ first ceramic layer and a GdYbYSZ second ceramic layer which are sequentially arranged on the surface of a base material, and the second NiCoCrAlY bonding layer is made of CeO2 (CeO2) and Al2O3 (Al2O3). According to the invention, a thermal protection coating structure with double bonding layers and double ceramic layers is constructed on the surface of the base material, and CeO2 and Al2O3 nano-particle reinforced phases are introduced, so that the use temperature of the thermal protection coating is increased, and the thermal strain tolerance, the crack resistance and the oxidation resistance are greatly improved.

The invention discloses a brittle material laser cutting thermal stress control method and system, and the method comprises the steps: obtaining real-time temperature distribution through infrared thermal imaging, combining finite element analysis and material characteristic dynamic data, constructing a thermal stress and fracture relation model, carrying out the iterative calculation of a thermal stress out-of-control threshold through a lambda algorithm, and determining a regulation boundary condition. According to the boundary condition, laser parameters are optimized, synchronous cooling airflow is introduced, the temperature gradient is dynamically controlled through an airflow pressure adjusting algorithm, historical data are processed through a convolutional neural network, the optimal laser parameter combination is predicted, in the cutting process, the microcrack diffusion state is monitored in real time, and auxiliary technological parameters are finely adjusted when necessary. The problem of fracture caused by out-of-control thermal stress in laser cutting of the brittle material is effectively solved, the cutting quality and efficiency are improved, and a new technical scheme is provided for precision machining of the brittle material.

The invention relates to the technical field of power transmission, and discloses a composite single-core power cable, comprising: a composite core composed of carbon fibers, glass fibers and a resin matrix containing a self-repairing microcapsule, the self-repairing microcapsule being capable of releasing a repairing monomer and repairing a microcrack when the composite core generates the microcrack; the conductor layer is arranged around the composite core and is composed of an aluminum conductor containing nano graphene; the insulating layer wraps the conductor layer and is made of a temperature-sensitive polymer material; and the outer sheath wraps the insulating layer and is made of a waterproof corrosion-resistant material. The composite core of the cable can recover more than 90% of original strength (the loss of tensile strength after repair is only 3%, which is recovered from 580Ksi to 570Ksi) within 24 hours after microcracks (such as the depth of 10mu m) generated by mechanical stress or fatigue in the operation process, and the self-repairing mechanism does not need manual intervention or external equipment, so that the self-repairing performance is greatly improved. And the sudden failure of the traditional cable caused by micro-damage accumulation is avoided.

An ultrafine grain cemented carbide additive manufacturing method. WC-Co is used as a raw material, a crystal grain growth inhibitor is added, and a rare earth oxide is added as a reinforcing phase; paraffin and a trace amount of low-valence rare earth oxide powder are added, ball milling is carried out for coating cemented carbide powder, and oxygen control is carried out; the cemented carbide powder obtained by ball milling and an organic adhesive are loaded in a vacuum banbury mixer-granulator to prepare a printing feed, then a green body is printed using fused deposition modeling (FDM), and finally, degreasing and two-step sintering are carried out on the green body to prepare ultrafine cemented carbide. By means of the combined effect of the components and process optimization design, the powder properties are regulated, the process range of vacuum banburying and granulation and additive manufacturing is widened, and the problems of pores, interlayer cracks, and oxygen absorption in a printed green body, and abnormal grain growth, oxidation decarburization, and the formation of brittle η-phase in a sintered sample are solved. The prepared ultrafine grain cemented carbide exhibits high relative density, is free of metallurgical defects, possesses excellent mechanical properties, and is suitable for large-scale and mass production.

The invention provides an analysis method and system for dynamic fracture of a quasi-brittle material. The method is used for solving the technical problem that an existing method is insufficient in dynamic fracture capturing capacity in quasi-brittle materials. The method comprises the following steps: constructing a representative volume element RVE of a quasi-brittle material with two embedded fracture planes; a dual-scale model of the RVE is constructed, the dual-scale model comprises a macroscale sub-model and a mesoscale sub-model, and the crack traction force and the displacement jump increment in the mesoscale sub-model meet the rate-dependent cohesive friction law; identifying the parameters of the dual-scale model; and embedding the dual-scale model into finite element software to simulate the dynamic fracture of the quasi-brittle material. The contained mesoscale crack plane has the key characteristics of the dynamic fracture behavior of the quasi-brittle material, and has remarkable advantages compared with a classical empirical model.

The invention discloses a high-corrosion-resistance heating stainless steel composite pipe and a preparation technology thereof, and belongs to the technical field of composite pipe preparation. The stainless steel pipe serves as the innermost layer and the outermost layer, the carbon steel pipe serves as the middle part, the space between the stainless steel pipe and the carbon steel pipe is filled with the low-melting-point glass powder, the low-melting-point glass powder is melted under the high-temperature and high-pressure conditions in the machining process, and therefore welding defects such as weld cracks, air holes or gaps possibly generated in the machining process of the steel pipe are fully repaired; and the interface bonding strength and the corrosion resistance of chemical substances such as acid and alkali of the composite pipe are greatly improved, and longitudinal heat preservation and transverse heat transfer of the heating pipeline are facilitated.

The invention discloses shrinkage-free aluminoferrite cement-based ultra-high performance concrete and a preparation method thereof, and belongs to the technical field of novel wall materials, and the shrinkage-free aluminoferrite cement-based ultra-high performance concrete comprises the following components: an activated cementing material, mineralized aggregate, an additive, reinforced fibers and mixing water. Due to the slow release effect of the methyl cellulose coating on the composite expanding agent, precise compensation of self-constriction is achieved, and contraction deformation in the curing and using process is effectively inhibited. Due to the unique mineral composition of the aluminoferrite cement, the early strength of the concrete is sharply improved, and the production cycle of prefabricated parts is greatly shortened. The steel fibers subjected to sand blasting and pre-wrapping modification can effectively bridge microcracks in the concrete and limit crack propagation; the polycarboxylate superplasticizer disperses the modified carbon nanofibers, crack initiation is inhibited from the microscopic level, and mechanical properties such as fracture resistance and impact resistance of the joint part and the prefabricated part are remarkably improved through cooperation of the polycarboxylate superplasticizer and the modified carbon nanofibers.

The invention relates to a crack repairing method for an additive manufacturing nickel-based high-temperature alloy part, and relates to the technical field of high-temperature alloys. According to the main technical scheme, filler powder and solder powder are adopted for conducting crack repairing on the additive manufacturing nickel-based high-temperature alloy part; wherein the solder powder comprises the following chemical components in percentage by weight: 11.0 to 17.0 weight percent of Cr, 5.0 to 9.0 weight percent of W, 1 to 4 weight percent of B, less than or equal to 0.06 weight percent of C, less than or equal to 0.1 weight percent of Co and the balance of Ni; wherein the filler comprises the following chemical components in percentage by weight: 6 to 10 weight percent of Cr, 6 to 10 weight percent of Co, 6 to 10 weight percent of W, 0.5 to 3 weight percent of Mo, 3 to 6 weight percent of Al, 0.5 to 2 weight percent of Ti, 3 to 6 weight percent of Ta, less than or equal to 0.2 weight percent of C, less than or equal to 0.1 weight percent of B, less than or equal to 2 weight percent of Hf and the balance of Ni; the additive manufacturing nickel-based superalloy comprises the following chemical components in percentage by weight: 6 to 10 percent of Cr, 6 to 10 percent of Co, 6 to 10 percent of W, 0.5 to 3 percent of Mo, 3 to 6 percent of Al, 0.5 to 2 percent of Ti, 3 to 6 percent of Ta, less than or equal to 0.2 percent of C, less than or equal to 0.1 percent of B, less than or equal to 2 percent of Hf and the balance of Ni. The method is mainly used for solving the problem of repairing and remanufacturing the cracks of the additive manufacturing nickel-based superalloy part, and has important application value.

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 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 present application belongs to the technical field of superalloys. Disclosed is a preparation method for a nickel-based superalloy. The present application solves the problem of a nickel-based superalloy in the prior art making it difficult to satisfy the comprehensive requirements of a component for both a long alloy endurance life and a low crack propagation rate. The preparation method comprises: step 1: performing smelting, so as to obtain a cast ingot; step 2: subjecting the cast ingot to a homogenizing heat treatment, wherein the homogenizing heat treatment comprises two sections of heat preservation; and after the second-section heat preservation, performing furnace cooling to 1000+ / -10°C or below, and then performing discharging and air cooling; step 3: preparing a bar blank and a forging piece by means of forging; step 4: performing a solution treatment; and step 5: performing a stabilization and aging treatment, so as to obtain a nickel-based superalloy. The nickel-based superalloy prepared by means of the method of the present application has a high strength, good low-cycle fatigue performance, a low crack propagation rate and excellent comprehensive performance.

The invention belongs to the technical field of aerogel, and particularly relates to high-conductivity aerogel powder as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly preparing a graphene / polypyrrole nanosheet composite material with a three-dimensional structure, and then preparing the polyimide / graphene / polypyrrole ternary hybrid conductive aerogel by taking a polyamide acid solution as a precursor through a solution dipping and freeze drying process. Polyimide is used as a framework of high-conductivity aerogel powder, excellent mechanical strength and structural integrity are provided, the common brittleness problem of a pure graphene carbon material or polypyrrole conductive polymer aerogel is solved, and the three-dimensional graphene / polypyrrole nanosheet composite material has excellent elasticity and toughness and can be used for preparing a composite material with high conductivity. The polyimide aerogel prepared by the method can be dispersed in a polyimide matrix as a nano reinforcement, can effectively transfer stress and prevent crack propagation, and endows the aerogel with higher mechanical properties.

The invention provides a thermal interface material based on vinyl imidazole ionic liquid as well as a preparation method and application of the thermal interface material. The thermal interface material is prepared from the following raw materials: the vinyl imidazole ionic liquid, a heat-conducting filler subjected to surface treatment by a silane coupling agent, an initiator and a cross-linking agent. The thermal interface material is based on the vinyl imidazole ionic liquid and the heat-conducting filler, the limitation of a traditional thermal interface material base body is broken through, dispensing can be achieved, no solvent is needed in the preparation process, the adverse effect of solvent residues on the performance of a chip when the thermal interface material is applied to the chip subsequently can be avoided, and the thermal interface material has ideal interface bonding strength; the heat conduction effect is remarkable and stable, the heat stability is good, the material can be well attached to an interface, the problems of stress concentration, cracks and the like are not prone to occurring, and the material can be widely applied to the heat conduction and heat dissipation fields of aerospace, advanced energy, electronic information, military industry and the like.

The invention provides a refrigerating and heating device which comprises a driver, a solid elastic clamping unit and a pipeline, the solid elastic clamping unit comprises a sleeve and a plurality of solid elastic clamping material plates stacked in the sleeve, each solid elastic clamping material plate comprises a through hole, and the through holes are stacked to form a flow cavity; the driver loads or unloads the multiple solid elastic clamping material plates to generate phase change or reverse phase change so as to generate heat or cold, the pipeline is communicated with the flow cavity, and media in the pipeline are subjected to heat exchange through the flow cavity so that the heat or the cold can be conveyed to the heating end or the refrigerating end. The solid elastic clamping material is arranged to be in a plate shape, in the loading and unloading process, even if a certain solid elastic clamping material plate cracks, the cracks cannot spread to other solid elastic clamping material plates, after the plate-shaped solid elastic clamping material is stacked, buckling deformation of the material can be avoided in the loading process, and the service life of the solid elastic clamping material is greatly prolonged.

The invention belongs to the field of material testing, and discloses a method and a system for testing a hydrogen-induced cracking threshold value based on a notched round rod tensile sample, the testing method comprises the following steps: in a hydrogen environment and an inert gas environment, respectively carrying out a slow strain rate tensile test on the notched round rod tensile sample to obtain test data and two elongation rates; the hydrogen embrittlement sensitivity index of the material is obtained through the two elongation rates; acquiring elastic-plastic parameters by using the hydrogen embrittlement sensitivity index of the material and test data; when the elastic-plastic parameter is greater than 3.5, acquiring a hydrogen induced cracking threshold value by adopting an elastic-plastic crack propagation mechanism; and when the elastic-plastic parameter is not greater than 3.5, a hydrogen induced cracking threshold value is obtained by adopting a linear elastic crack propagation mechanism. The test method is short in period, high in efficiency and high in universality.

The invention relates to the technical field of HB450-grade thick-specification wear-resistant steel plates, in particular to a flame cutting delayed crack-free HB450-grade thick-specification wear-resistant steel plate and a production method thereof. The steel is composed of the following chemical components in percentage by weight: 0.18%-0.22% of C, 1.00%-1.10% of Si, 0.8%-1.0% of Mn, 0.015%-0.03% of Nb, 0.6%-0.70% of Cr, 0.06%-0.09% of Al, 0.0005%-0.0020% of B, more than or equal to 1.4% and less than or equal to 1.6% of Mn and Cr, and the balance of Fe and inevitable impurities. The production process flow comprises the steps of smelting, refining, slab continuous casting, casting blank heating and slow cooling, slab heating, controlled rolling, stacking and slow cooling, quenching and tempering heat treatment, flame cutting with temperature and slow cooling with hot water. The surface hardness is larger than or equal to HB450, the thickness ranges from 40 mm to 80 mm, the tensile strength is larger than or equal to 1250 MPa, the retained austenite content is 5%-7%, delayed cracks do not exist after fire cutting, the trimming hardness is larger than or equal to HB410, AKV at the temperature of-40 DEG C is larger than or equal to 40 J, and A is larger than or equal to 12%.

The invention relates to a method for simulating fatigue small crack propagation of a polycrystalline metal material. The method comprises the following steps: determining a crystal plastic constitutive model and accurate values of all undetermined parameters of the crystal plastic constitutive model; establishing a crack propagation finite element model of the polycrystalline metal material, and embedding the crystal plasticity constitutive model of which each undetermined parameter has a respective accurate value and a pre-obtained crack propagation criterion into the crack propagation finite element model; applying load and boundary conditions to the crack propagation finite element model, and performing crack propagation finite element analysis to obtain a finite element analysis result, including stress-strain data calculated based on the crystal plasticity constitutive model and crack propagation data calculated based on a crack propagation criterion and the stress-strain data. According to the method for simulating the fatigue small crack growth of the polycrystalline metal material, the Hall epicy size effect is introduced into the crystal plasticity constitutive model to consider the influence of the grain size on the sliding resistance, so that the simulation accuracy is improved.

The invention provides a preparation method of a self-repairing waterborne polyurethane coating based on a synergistic effect of a dynamic disulfide bond and a pH response microcapsule. The preparation method comprises the following steps: step 1, preparing a dynamic disulfide bond-containing waterborne polyurethane (D-WPU) emulsion; step 2, preparing a pH response microcapsule; step 3, preparing a self-repairing waterborne polyurethane coating; a dynamic disulfide bond of the self-repairing waterborne polyurethane coating rapidly repairs macrocracks at 50-60 DEG C through mercaptan catalysis, and pH < lt > is caused by local corrosion of a pH response microcapsule; when the pH value is 4.0, cysteine is released, sulfydryl accelerates recombination of dynamic bonds, and amino enhances cohesive force of the coating and neutralizes H < + >. And in combination with a hydrogen bond network of the nanocellulose, the coating has low-temperature repair (the mechanical strength recovery rate is greater than or equal to 90%), high toughness (the water absorption rate is less than or equal to 2.1%) and long-acting corrosion resistance (the salt spray resistance life is greater than or equal to 600 hours), and is suitable for severe environments such as ocean engineering and new energy equipment.

The invention discloses an ion beam polishing method for coupled silicon carbide in-situ growth based on quantum dots, and belongs to the technical field of SiC surface polishing. The preparation method of the SiC material with the quantum dot sacrificial layer grown in situ comprises the following steps: mixing a lead source, a cesium source and a solvent to obtain a CsPbBr3 precursor solution; and dropwise adding the CsPbBr3 precursor solution to the surface of the SiC material, flattening, heating for crystallization, and annealing to obtain the SiC material with the quantum dot sacrificial layer grown in situ. According to the ion beam polishing method based on quantum dot coupling silicon carbide in-situ growth, the quantum dot layer serves as the sacrificial layer of the SiC wafer, the thickness of the sacrificial layer can be effectively reduced, the flatness of the SiC surface can be remarkably improved, and the good fluorescence labeling effect can be achieved. The CsPbBr3 quantum dot prepared by the method has extremely small nano size, can deeply fill micro cracks and micro-nano scratches on the surface of a SiC wafer, is completely coupled with the micro cracks on the surface of the SiC wafer, and realizes accurate filling of defects.

The invention discloses a rolled extra-thick stainless steel composite plate and a production method thereof. Base layer steel comprises the following chemical components in percentage by weight: 0.12-0.16% of C, 0.18-0.30% of Si, 1.30-1.50% of Mn, less than or equal to 0.012% of P, less than or equal to 0.003% of S, 0.02-0.04% of Alt, 0.15-0.25% of Cr, 0.50-0.60% of Mo, 0.55-0.65% of Ni, less than or equal to 0.10% of Cu, less than or equal to 0.02% of Nb, less than or equal to 0.0010% of B and the balance of Fe and inevitable impurity elements. The cladding stainless steel comprises the following chemical components in percentage by weight: less than or equal to 0.03% of C, less than or equal to 0.75% of Si, less than or equal to 2.00% of Mn, less than or equal to 0.035% of P, less than or equal to 0.015% of S, 8.0-12.0% of Ni, 18.0-20.0% of Cr, less than or equal to 0.10% of N and the balance of Fe and inevitable impurity elements; the process route comprises the steps of blank welding compounding, vacuumizing, controlled rolling and quenched-tempered heat treatment. The SA533B CL1 + SA240304L stainless steel composite plate with the thickness of 62-69 mm is produced, the inspection yield strength is larger than 345 MPa, the tensile strength is larger than 550 MPa, the impact energy at the temperature of 10 DEG C is larger than or equal to 200 J, the shear strength is larger than 310 MPa, and the intergranular corrosion crack rate is 0.

The invention discloses a nano-microporous composite aerogel material and a preparation process thereof, and belongs to the technical field of aerogel materials, the composite aerogel material comprises modified PTFE dispersion liquid, SiO2 sol, a magnetic hydrophobic modifier, self-repairing microcapsules, reinforced fibers and a surface modifier. The double-shell structure of the self-repairing microcapsule provides excellent mechanical strength and chemical stability, and the self-repairing microcapsule can crack and release the siloxane prepolymer core material during microcrack propagation. The PTFE dispersion liquid is pretreated through plasma-initiated graft polymerization, so that the interface bonding force between the reinforced fiber and the composite aerogel is remarkably improved. According to the treatment method, a chemical bonding layer is formed on the surface of the fiber, and the mechanical interlocking and chemical bonding force of an interface are enhanced, so that the layering phenomenon is avoided, and the stability of the material in a repeated impact environment is further improved.

The invention discloses multi-scale toughened concrete and a preparation method thereof, and belongs to the technical field of high leakage, and the multi-scale toughened concrete comprises aluminoferrite cement, a low-shrinkage auxiliary cementing material, a water reducing agent, multi-scale composite fibers, a shrinkage compensation agent, fine aggregate, coarse aggregate and water. A traditional toughening mode is broken through, a physical-chemical composite connection interface is established through a magnetron sputtering metal gradient coating of crude fibers and a laser-induced dendritic crystal structure, a strain hysteresis effect is triggered under an impact load, impact energy is converted into interface phase change energy, and a high-efficiency energy dissipation channel is formed; an amino functional group and free radical cross-linked network is introduced into the fine fibers, and the fibers are endowed with microcosmic dynamic enhancement capability in combination with directional arrangement of the carbon nanotubes, so that the concrete forms cooperative interaction between macroscopic crack bridging and microcosmic crack inhibition, the crack resistance under complex stress is remarkably improved, and microcrack propagation is effectively inhibited.

The invention discloses a high-strength modified high-density polyethylene double-wall corrugated pipe and a preparation method thereof, and relates to the technical field of high-density polyethylene double-wall corrugated pipes. The high-strength modified high-density polyethylene double-wall corrugated pipe is prepared from the following components: high-density polyethylene, ultra-high molecular weight polyethylene, reinforcing filler, a compatilizer, an antioxidant and a lubricant. The preparation method comprises the following steps: reinforcing filler surface modification; all the components are subjected to melt blending to prepare the modified composite material; the modified composite material is subjected to extrusion molding to form the double-wall corrugated pipe; and cooling, shaping and cutting. The UHMWPE and the reinforcing filler are introduced, and the compatilizer is combined to improve interface bonding, so that macromolecular chains of the UHMWPE are entangled to form a tough network, the reinforcing filler provides rigid support, and the high-temperature modulus and creep resistance are synergistically improved; high-temperature oxidative degradation is effectively inhibited through the antioxidant, the slow crack growth resistance time is prolonged, and the service life is prolonged.

The invention discloses a thermal insulation material with enhanced thermal insulation performance and a processing method, and relates to the technical field of thermal insulation material processing. Comprising the following components in parts by weight: 100 to 200 parts of a nanopore matrix material, 20 to 120 parts of expanded perlite, 10 to 350 parts of polystyrene, 30 to 300 parts of polyurethane, 100 to 500 parts of nano titanium dioxide, 10 to 60 parts of graphene, 10 to 40 parts of silica sol and 1 to 55 parts of ferric oxide. A multi-stage pore structure is constructed through a nanopore matrix and expanded perlite, closed-cell foam of polystyrene and polyurethane is combined, and nano titanium dioxide and graphene functional filler are matched, so that the heat conductivity coefficient is reduced to 0.018 W / (mK) or below, the heat insulation efficiency is remarkably improved, nanoscale homogenization is ensured through high-shear dispersion in the process, the porosity is reserved through freeze drying, and the heat insulation performance is greatly improved. The microcapsule self-repairing layer can repair more than 85% of cracks, the service life is greatly prolonged, and in the aspect of function integration, the material has A-level fireproof, waterproof and weather-proof characteristics and heat preservation and heat insulation performance.

The invention belongs to the field of material mechanical property testing and strain measurement, and particularly relates to a local strain measurement method and system based on a four-point bending and digital image correlation (DIC) technology, and the method specifically comprises the following steps: cutting to prepare a sample, carrying out surface electrolytic polishing, preparing speckles on the surface of the sample to be tested, and carrying out a four-point bending experiment; speckle images of the lower surface of the sample are collected, displacement correction is conducted in combination with bending deflection calculation, the bending load and the strain of the upper surface of the sample are obtained in real time, the stress-strain relation and local strain distribution of the lower surface of the sample are obtained through calculation, and finally deformation and failure mechanism analysis is conducted in combination with surface deformation and crack morphology. The method provided by the invention combines four-point bending and DIC plane strain measurement technologies, can realize stretching, compression and dynamic fatigue loading on the surface of the sample, is suitable for performance test and failure analysis of tension, compression and fatigue deformation of brittle metal materials such as intermetallic compounds and amorphous materials, and has the characteristics of convenience, rapidness and low cost.

The invention discloses a corrosion-resistant polysilsesquioxane modified polyurethane emulsion and a preparation method thereof, and belongs to the technical field of emulsions.The preparation method comprises the steps that gamma-aminopropyltriethoxysilane, namely APTES, is subjected to hydrolytic condensation under the catalysis of tetraethylammonium hydroxide, and POSS is prepared; the preparation method comprises the following steps: carrying out hydrolytic condensation reaction on APTES, synchronously adding phenyltrimethoxysilane in the hydrolytic condensation reaction, forming phenyl-amino difunctional POSS (Polyhedral Oligomeric Silsesquioxane) according to a molar ratio of phenyltrimethoxysilane to APTES of 1: 4, and grafting POSS and graphene oxide GO in dimethyl sulfoxide through amidation reaction to prepare a POSS / GO composite material; dispersing POSS / GO / Zn in the polyurethane prepolymer, adding a curing agent and a solvent, and stirring to form a homogeneous emulsion; through phenyl trapezoid polysilsesquioxane modification and dynamic reversible self-repairing network design, the wear resistance of the coating is improved, microcracks can be closed at the temperature of 60 DEG C, and the maintenance requirement is reduced; laser micro-nano structured base material treatment is combined, the adhesive force is increased to be larger than or equal to 20 MPa, and meanwhile a gamma-butyrolactone low-VOC solvent is adopted.

The invention relates to the technical field of metal powder processing, and discloses a high-performance dissimilar metal powder precision forming process which comprises the following steps: filling powder into a mold cavity, applying vibration disturbance, monitoring the change rate of a phase lag angle, judging that the powder is dense when the change rate is lower than an offset threshold value, outputting a pressing mode switching signal, an induction heating device is used for applying transient thermal load to induce cracks of an oxide film on the surfaces of particles, the pressure load is applied, the side wall is adjusted to generate shear displacement to peel off the oxide film, and metallurgical bonding is achieved through fresh metal surface contact. An interface is activated through thermal expansion mismatch and mechanical friction synergistically, a high-density uniform green body is obtained at low temperature, generation of brittle intermetallic compounds is inhibited, and the fatigue resistance of a formed part is enhanced.

The invention belongs to the technical field of tunnel construction, and discloses an upper-soft lower-hard composite stratum shield hob impact load determination method and system.The method comprises the steps that rock is divided into a plurality of concentric circle areas through a cavity expansion model, the radius of each area is determined, and the relation between the damage states of different positions of rock mass and the distance position of the center of a blade is obtained; the influence of section penetration is introduced, and based on the influence of the damage difference between a vertical crack area and a dense nuclear area in the hob rock breaking process, the damage state of the hob section away from the center of a blade within the range of a hob lower contact area and the damage distribution state of the hob lower hard rock side in the interface vertical crack expansion process are determined; and determining an expression of stress change of the transition section based on a CSM model, and realizing impact load prediction when the shield hob passes through the upper-soft and lower-hard composite stratum in combination with the influence of damage of the lateral shearing region. The damage effect and cavity expansion model theory is introduced for the first time, the compatibility of the prediction model and the actual situation is improved, and the abnormal damage rate of the hob is reduced.