17results about How to "Improve fatigue performance" patented technology

This application relates to a weathering steel, its preparation method, and its application, belonging to the field of steel preparation technology. The chemical composition of the steel includes C 0.030-0.050%; Si ≤0.10%; Mn 1.25-1.70%; P ≤0.020%; S ≤0.003%; Al 0.02-0.05%; Nb 0.010-0.030%; Ti 0.03-0.07%; Ni 0.02-0.05%; Cu 0.2-0.5%; Cr 0.8-1.5%; N ≤0.0040%; Ca 0.001-0.004%. It adopts a reasonable ratio of weathering-resistant elements such as copper, chromium, and nickel added on a low-carbon, low-silicon, and low-manganese basis. The combination of Cu and Cr can form a dense α-FeOOH oxide rust layer on the surface of the steel, preventing further corrosion of the steel matrix.

This invention belongs to the field of metal welding technology and relates to a heat treatment method for hypereutectoid rail steel after flash welding, comprising the following steps: post-weld cooling: the welded joint is allowed to cool naturally in air after flash welding; normalizing treatment: the welded joint is heated to a normalizing temperature above the austenitizing temperature and held at that temperature; controlled cooling: the temperature of the weld heat-affected zone of the welded joint is cooled from the normalizing temperature to the isothermal transformation temperature within the pearlite phase transformation temperature range at a first cooling rate, held at that temperature until the austenite undergoes pearlite transformation, and then the welded joint is cooled from the isothermal transformation temperature to below 200°C at a second cooling rate lower than the first cooling rate. The method of this invention can effectively eliminate the network cementite structure in the flash welding heat-affected zone, while avoiding the introduction of harmful structures such as martensite or bainite, ensuring that the microstructure of the weld heat-affected zone is pearlite with fine lamellar spacing.

The application discloses an environment-friendly rubber composite material and a preparation method and application thereof, and relates to the technical field of tire rubber materials.The environment-friendly rubber composite material comprises, in parts by mass, 100 parts of a rubber matrix, 10-60 parts of a bio-based filler, 0.5-10 parts of an interface modifier, 1-8 parts of a vulcanizing component and 0.5-5 parts of a crosslinking aid; wherein the rubber matrix comprises natural rubber and butadiene rubber; the bio-based filler comprises at least one of lignin, cellulose or a derivative thereof; the interface modifier comprises a compounded system of a silane coupling agent and a bio-based small molecule containing multiple functional groups; and the crosslinking aid comprises a borate compound and a low-molecular polymer containing a dynamic hydrogen bond structure.The application also provides a preparation method and application of the material.The application improves the proportion of the bio-based material, improves the long-term stability of the interface between the bio-based filler and the rubber matrix, reduces the interface damage accumulation and dynamic heat generation under the action of cyclic load, and improves the fatigue performance and comprehensive service performance of the rubber composite material.

The application discloses a method for electron beam fuse additive manufacturing of beta titanium alloy components, and belongs to the technical field of additive manufacturing. The application aims to solve the problems of long preparation period, low efficiency, low utilization rate, serious oxidation, significant beta spot and poor strength and toughness of the prior art. The method comprises the following steps: pretreating the printing wire and the substrate; establishing a three-dimensional entity model based on the target beta titanium alloy component, performing slice processing on the three-dimensional entity model to generate multi-layer two-dimensional slice data, and then importing the slice data into an electron beam fuse additive manufacturing equipment, and setting a scanning path, preheating parameters and printing process parameters; starting the equipment and performing vacuumization, printing the beta titanium alloy according to the set printing parameters and procedures, completing all layers, and obtaining the beta titanium alloy component. The beta titanium alloy component prepared by the application has high density, and provides a reliable technical approach for the preparation of high-performance beta titanium alloy components in the fields of aviation and aerospace.

This invention discloses a highly efficient degassing refining agent for magnesium alloy ingots and its preparation method in the field of molten metal purification. The refining agent is composed of lanthanum fluoride-supported titanium carbide nanocomposite, calcium zirconate and graphene oxide nanohybrid, and various components such as anhydrous magnesium chloride, anhydrous sodium fluoride, anhydrous potassium chloride, metallic calcium powder, barium carbonate, and alumina micro powder in a specific ratio. Its preparation mainly includes: first, dispersing titanium carbide nanoparticles and reacting them with a lanthanum fluoride-containing solution, followed by hydrothermal treatment and calcination to obtain the lanthanum fluoride-supported titanium carbide nanocomposite; second, mixing a zirconium calcium salt solution with a graphene oxide dispersion, followed by urea co-precipitation, hydrothermal reaction, and calcination under a protective atmosphere to obtain the calcium zirconate and graphene oxide nanohybrid. This invention, through the synergistic effect of two inorganic modifying compounds, can deeply remove hydrogen and inclusions from magnesium melt, thereby significantly improving the metallurgical quality and overall performance of magnesium alloy ingots.

This invention relates to the field of hot extrusion manufacturing technology, specifically to a high-strength weldable 6xxx series aluminum alloy profile, its manufacturing method, and its application. The aluminum alloy profile is composed of the following weight percentages: Si: 0.80%~1.2%, Fe≤0.20%, Cu: 0.40%~0.80%, Mn: 0.30%~0.70%, Mg: 0.70%~1.1%, Cr≤0.25%, Zn≤0.10%, Ti≤0.10%, Zr: 0.05%-0.20%, Pb<0.01%, with the balance being Al and unavoidable impurities. The profile meets the following performance requirements: tensile properties, R... m ≥420MPa, R p0.2 ≥330MPa, A 50mm ≥8.0%; Fatigue performance: at r=0.1, N=1×10 7 Under the same conditions, the fatigue strength σ of the smooth sample is ≥145MPa, realizing the lightweight manufacturing of high-speed trains.

The application discloses a metal powder type flux-cored wire suitable for 1.5GPa-grade aluminum-silicon plated layer hot forming steel and a preparation method thereof. The component design of the application is reasonable, the process compatibility is good, the welding penetration is large, the workpiece deformation is small, and the welding efficiency is high, so that the high reliable connection requirement of 1.5GPa-grade aluminum-silicon plated layer hot forming super-high-strength structural parts can be met. Meanwhile, the preparation process is mature, and the application can be produced on a large scale. The technical problems of insufficient joint strength, serious softening of heat affected zone, poor crack resistance and weak laser welding adaptability of the existing similar welding wires are solved.

The application belongs to the technical field of heterogeneous steel additive manufacturing, and particularly relates to a kind of heterogeneous steel based on laser additive manufacturing and a preparation method of shell-like nacreous layer structure, the shell-like nacreous layer structure heterogeneous steel includes multiple layers of bionic heterogeneous structure layer, each layer of bionic heterogeneous structure layer includes multiple shell-like nacreous layer structure unit bodies, each shell-like nacreous layer structure unit body includes four square modules, each square module includes two long rectangular martensite steel regions and two long rectangular austenite steel regions which are parallel to each other, long rectangular martensite steel regions and long rectangular austenite steel regions are arranged at intervals, the direction of long rectangular martensite steel regions and long rectangular austenite steel regions in any two adjacent square modules in each layer of bionic heterogeneous structure layer is perpendicular, and the direction of long rectangular martensite steel regions and long rectangular austenite steel regions in any two adjacent square modules in any two adjacent layers of bionic heterogeneous structure layer is perpendicular, and the application realizes the synergy of strength and toughness of material.

This utility model relates to the field of building structure vibration reduction technology, specifically to a viscous damper with external circulation and intelligent monitoring, comprising: a damper body, an external circulation system, an intelligent monitoring system, and a protective cover. The external circulation system is installed on the outside of the damper body, the intelligent monitoring system is installed on the damper body, and the protective cover is installed on the damper body with the external circulation system located inside the protective cover. The external circulation system includes: an external circulation pipe; the intelligent monitoring system includes: a temperature and pressure integrated sensor and a force sensor. This utility model has advantages such as high heat dissipation efficiency, long service life, and real-time monitoring capability, and is suitable for the field of building structure vibration reduction.

The invention provides a laser three-dimensional forming preparation method for preparing a gradient reinforced composite material turbine blade of a gas turbine. The method comprises the following steps: ball-milling and mixing nickel-based alloy, nano silicon carbide and boron carbide powder according to a mass ratio of (92-96): (2-4): (2-4); a laser three-dimensional forming technology is adopted, a three-section gradient structure of a non-strengthening area (pure nickel base alloy), a transition area (gradient mixing) and a strengthening area (composite material) is constructed in the root-tip direction of the blade through a two-way powder feeding system, and near-net forming of the functional gradient strengthening turbine blade with the ceramic strengthening phase strengthening at the tip end of the blade and the root part maintaining toughness is achieved. The prepared turbine blade of the gas turbine has excellent high-temperature creep resistance, fatigue resistance, corrosion resistance and wear resistance, works for a long time in severe environments such as high temperature, high pressure, wear and corrosive media, has excellent high-temperature creep damage resistance, low-cycle fatigue damage resistance, corrosion damage resistance and friction damage resistance, and can effectively prolong the service life of the gas turbine.

The application belongs to the technical field of titanium alloy materials, and relates to a heat treatment method for realizing high strength, high toughness and high fatigue of Ti55531 titanium alloy, which comprises the following steps: firstly, Ti55531 titanium alloy bars are kept at a first two-phase zone temperature for heat preservation until the core temperature and the surface layer temperature are consistent, and then the temperature is raised to a specific temperature range in a single-phase zone for heat preservation to obtain beta single-phase structure titanium alloy bars; secondly, the beta single-phase structure titanium alloy bars are subjected to first cooling, the temperature is lowered to a second two-phase zone temperature, and after heat preservation, second cooling is performed, and then aging heat treatment is performed, so that finally Ti55531 titanium alloy finished bars are obtained. The Ti55531 titanium alloy finished bars have the comprehensive performance of high strength, high toughness and high fatigue, and the heat treatment method fully expands the application potential of Ti55531 titanium alloy in the structural part field.

This invention relates to the field of alloy material preparation technology, and discloses a steel with excellent machinability and fatigue resistance, its preparation method, and automotive parts. The disclosed steel with excellent machinability and fatigue resistance includes a matrix and martensitic-austenitic islands distributed within the matrix; both the matrix and the martensitic-austenitic islands contain carbon and manganese; the concentration of carbon in the matrix is ​​'a', and the concentration of carbon in the martensitic-austenitic islands is 'b', where (1.0~2.0)a=b; the concentration of manganese in the matrix is ​​'c', and the concentration of manganese in the martensitic-austenitic islands is 'd', where (0.6~2.0)c=d. This steel exhibits a small hardness difference between the M-A islands and the matrix. A small hardness difference results in a high porosity. Even when the steel is a high-strength steel, meeting the above requirements for the carbon and manganese concentration difference between the M-A islands and the matrix ensures excellent machinability.

This invention provides a modular, actively load-bearing, prefabricated composite reinforcement device and method. The reinforcement device, used for reinforcing tunnels, includes: at least one reinforcement body connected to the surface of the tunnel to be reinforced. Each reinforcement body is a multi-curvature column conforming to the tunnel structure, comprising several substrates and compressive-resistant material. The substrates are connected by connecting components. Each substrate has a hollow structure, and the compressive-resistant material fills the cavities. An exhaust pipe is provided on the higher section of the substrate on the reinforcement body, and an injection hole is provided on the lower section of the substrate. When there are more than two reinforcement bodies, they are arranged parallel to each other along the axial direction of the tunnel at intervals. Several reinforcement bodies are arranged in a parallel, ring-shaped distribution along the circumferential direction of the tunnel structure's axis, and are spaced apart. Adjacent reinforcement bodies are connected by joints and force transmission rods, forming a grid-like overall structure that provides overall stability.

This invention relates to the field of highway engineering technology, and provides a design method and a method for asphalt mixtures that maintain long-term skid resistance. The method includes the following steps: testing the basic characteristics of multi-lithological aggregates and constructing an aggregate characteristic database; controlling the volumetric blending ratio of the mixed aggregates based on the volumetric method; initially selecting mixed aggregate combinations based on the differences in polishing effects and complementary performance principles of mixed aggregates from different lithologies, and setting a blending ratio gradient; conducting abrasion and polishing tests on the initially selected mixed aggregates, and determining the optimal combination based on the experimental results; designing and verifying the mix proportion of the asphalt mixed aggregates based on the optimal combination; and determining the final mix proportion based on the experimental results through balanced optimization. This approach helps guide the rational selection and optimized mix proportion of mixed aggregates, ensuring the long-term, stable maintenance and even improvement of skid resistance, while simultaneously achieving the goals of saving high-quality aggregates and controlling and reducing costs in the anti-skid surface layer of asphalt pavements.

The application relates to the field of bridge engineering and provides a layout method and a construction method of a shear connector of a fabricated steel-concrete composite girder bridge, which are based on machine-bridge coupling vibration response, a finite element model of a steel-concrete composite taxiway bridge is established, the influence of bolt cluster degree and unevenness parameters on the dynamic performance of the fabricated steel-concrete composite girder bridge is deeply studied, the layout mode of the shear connector is optimized, the vibration response under the machine-bridge coupling effect is effectively reduced, and the performance of the bridge structure under the action of the airplane dynamic load and the operation quality of the airplane are improved. Compared with the prior art, the application can significantly reduce the vibration response of the bridge under the airplane dynamic load, prolong the service life of the bridge, and improve the comfort of airplane operation. The technical scheme of the application provides a new theoretical basis and practical guidance for the design and construction of the steel-concrete composite girder bridge, and has important engineering application value and market promotion prospect.

This invention discloses a robotic arm based on rotary friction welding and its manufacturing method. The robotic arm includes an arm body and a first flange. The arm body has a tubular structure, and the first flange is connected to the end of the arm body. The two are welded together by rotary friction welding. This invention experimentally screened 6061-T6 aluminum alloy or 7075-T6 aluminum alloy as suitable materials for the robotic arm. Through process debugging, rotary friction welding process parameters that enable reliable welding of the arm body and the first flange were obtained. This effectively solves the technical problems of insufficient strength, low precision, large welding deformation, softening of weld joints, and poor production economy in the manufacturing and application of existing industrial robotic arms. By fully utilizing the material advantages of 6061-T6 aluminum alloy or 7075-T6 aluminum alloy, the invention significantly improves the structural strength, stiffness, and fatigue performance of the robotic arm while achieving lightweight design, ensuring dimensional and assembly accuracy, and improving the structural reliability and service life of the robotic arm.

The utility model belongs to the technical field of contact networks, and particularly relates to a hinge-type connected anti-skid fatigue-resistant positioning stand column which comprises an upper hoop, a lower hoop hinged to the upper hoop and a positioning column fixed to the lower hoop, the upper hoop comprises a first ring body, a first hinge portion and a first limiting portion, and the lower hoop comprises a second ring body, a second hinge portion and a second limiting portion. The lower hoop comprises a second ring body, second hinge parts and second limiting parts connected between every two adjacent second hinge parts, and each second limiting part is provided with a notch allowing the corresponding first limiting part to be embedded and limiting the rotation amplitude of the first limiting part; the stress state in the matching process of the positioning stand column and the positioning pipe is improved, the fatigue performance is improved, the service time of the positioning stand column and the positioning pipe is prolonged, the hinge type connecting structure enables the lower hoop to be thicker and more reliable, damage and breakage of the connecting portion caused by oblique shear stress are avoided, and an attaching contact plane is designed on the enclasping face of the lower hoop and the positioning pipe, so that the service life of the lower hoop is prolonged. The clamping force on the positioning pipe in the holding state is improved, the positioning pipe is prevented from sliding, and the overall reliability is improved.