56results about How to "Inhibition of microcracks" patented technology

The invention provides a laser processing method and laser processing equipment. The laser processing method comprises the steps as follows: radiating the laser through an incident surface of a material to be processed, and colleting the light on the initial cutting surface of or close to the material to be processed so as to gasify and/or melt the material to be processed at a light collecting point and/or in an area close to the light collecting point; forming an initial thermal removing area on the initial cutting surface; continuously distributing the initial thermal removing areas on the initial cutting face along a preset path so as to form an initial thermal removing line; irradiating the laser to collect the light on the surface of or close to the material to be processed formed in the thermal removing step so as to gasify and/or melt the material to be processed at the light collecting point and/or the area close to the light collecting point, thereby forming a follow-up thermal removing area; and continuously distributing the follow-up thermal removing areas along the preset path so as to form a follow-up thermal removing line.

The invention discloses zero-VOC (volatile organic compound) cement-based water-proof material copolymer emulsion and a preparation method thereof. The preparation method adopts a zero-VOC copolymer emulsion component A and an inorganic powder component B, the zero-VOC copolymer emulsion component A is prepared from deionized water, alkyl acrylate, styrene, acrylic acid functional monomers, emulsifying agents, initiators, a buffer agents, polymerization inhibitors, oxidizing agents, reducing agents, sterilizing agents and defoaming agents through polymerization of pre-emulsification semi-continuous seed emulsion, and the inorganic powder component B comprises ordinary portland cement, quartz sand and water reducers. The prepared emulsion is high in solid content, low in viscosity, uniformin particle size and good in stability and has excellent rheological property and coating water absorption, the content of a residual monomer in an emulsion product is lower than 300ppm and meets national zero-VOC emulsion standards, the emulsion is environmentally friendly and free from toxicity and pollution, the compatibility of the emulsion and cement is good, and a prepared polymer cement waterproof coating is excellent in water resistance, good in low-temperature flexibility and low in water absorption.

The invention discloses a preparation method of a high-nickel ternary NCM622-nanowire material. The method comprises the following steps: weighing certain amounts of a lithium source, a nickel source, a cobalt source and a manganese source according to a certain element mole ratio, adding the weighed sources into ethanol in order to a uniform and transparent solution; weighing a certain amount of polyvinylpyrrolidone, adding the polyvinylpyrrolidone into the above solution, and magnetically stirring the polyvinylpyrrolidone and the solution to completely dissolve the polyvinylpyrrolidone; weighing a certain amount of organic sugar used as a water absorption inhibitor into the above solution, and continuously stirring the organic sugar and the solution to completely dissolve the organic sugar; transferring the obtained solution into a syringe, carrying out electrostatic spinning, and receiving nano-fibers by aluminum foil; sintering the above obtained product in air; and carrying out high temperature calcination on the sintered product in an argon atmosphere to obtain the high-nickel ternary NCM622-nanowire material. The finally obtained product is made of nanowires formed by interconnecting LiNi0.6Co0.2Mn0.2O2 particles, has a high specific capacity and a good structure stability as alithium ion battery positive electrode active material, and improves the cycle stability and the rate performances of the lithium ion battery positive electrode active material.

The invention discloses a laser additive manufacturing shear type phase change crack resistance method. The method comprises the steps of adopting a laser additive manufacturing technology and takinghigh-entropy alloy powder with FCC-HCP martensite phase change as additive manufacturing special powder; drying the metal powder in a vacuum drying oven for 12 hours at a drying temperature of 120 DEGC; and carrying out additive manufacturing and printing on the dried high-entropy alloy powder, wherein the printing parameters are as follows: the laser power is 400 W, the scanning speed is 800-1600 mm/s, the scanning distance is 0.09 mm, the powder laying thickness is 0.03 mm, and the substrate preheating temperature is 100 DEG C. The problem of metallurgical defects such as thermal crack deformation and the like are caused by high temperature and high stress gradient in a molten pool in the traditional laser additive manufacturing process is solved. On the basis of the study, the idea ofsuppressing hot cracks in additive manufacturing alloys by stress-induced martensitic transformation is extended to other additive manufacturing alloy systems, and a new method is provided for additive manufacturing of crack-free alloys.

The invention provides a magnetic toughening method for inhibiting machinery damage of hard and brittle materials and belongs to the technical field of quality control of machinery process. Accordingto the method, a hard and brittle material is immersed in a clamping mold filled with a magnetorheological fluid, and then the magnetorheological fluid infiltrates into pores, cracks and other defectson the surface layer of the hard and brittle material and liquid-state encapsulation is formed around workpieces; and during machining, a controllable magnetic field is applied such that the magnetorheological fluid is affected by the magnetic force to generate a magnetorheological effect and a high-viscosity elastic film having high yield strength is formed. Thereby, the magnetorheological fluidin the defects on the surface layer of the hard and brittle material is solidified to form a hole-sealed toughening mechanism. The magnetorheological fluid around the material is solidified to form three-dimensional circumferential compressive pre-stress encapsulation, and impact vibration and energy applied by cutters such as a grinding wheel, etc. on the workpieces can be absorbed, and it is helpful for inhibiting the cracks from extending in the deep radial direction or towards side edges. Thereby, defects such as cracks, surface fracture, breaking of edges, etc. are reduced, and machiningquality is improved.

The invention provides a method of controllable growth of a graphene covering film on the surface of a copper plated steel fiber.The method mainly comprises the following technical steps: 1) cleaning the copper plated steel fiber, 2) performing high-temperature annealing treatment on the copper plated steel fiber, 3) adjusting a chemical vapor deposition technical parameter and a position of the copper plated steel fiber, and 4) growing graphene on the surface of the copper plated steel fiber to form uniform covering and controllable thickness graphene film.The technical flow is simple and easy to operate; the graphene on the surface of the copper plated steel fiber is stable in chemical property; the strength and corrosion resistance of the copper plated steel fiber in a cement-based composite can be effectively improved; the copper plated steel fiber can serve as a nucleation point of cement hydration reaction so as to profitably promote the cement hydration reaction; cement forms a dense structure; finally, crack formation is effectively avoided; and the strength of the cement-based composite is improved.The method has a wide application prospect in the field of the cement-based composite.

The invention discloses a nanometer inorganic zinc-rich composite anticorrosive coating and a preparation method thereof. The anticorrosive coating is prepared through mainly mixing a component A with a component B, wherein the component A comprises a silicate adhesive, an acrylic emulsion, a wetting dispersant and an antifoaming agent; and the component B comprises flake zinc powder and nano-modified polyaniline, and the nano-modified polyaniline is a fibrous core-shell structured attapulgite-polyaniline composite material. The preparation method of the coating comprises the following steps: uniformly mixing the silicate adhesive, the acrylic emulsion, the wetting dispersant and the antifoaming agent to obtain the component A; and adding the component A to the component B, and uniformly mixing to obtain the anticorrosive coating. The nanometer inorganic zinc-rich composite anticorrosive coating has the advantages of strong combination force with a metal base material, salt spray resistance, scrape corrosion resistance and impact resistance, and can be used in various different situations; and the preparation method has the advantages of simplicity, good controllability, easy operation, low production cost and easy industrial production.

The invention discloses a low-cost asphalt-based spherical activated carbon with hierarchical porouse structure. According to the invention, asphaltic coal with softening point of 130-230 DEG C is used as a raw material, a low-temperature decomposable organic matter is used as a pore forming agent, after mixing, crushing, spheroidizing, air oxidation, liquid phase oxidation, charring, steam activation, and pickling, the asphalt-based spherical activated carbon is prepared.Regarding the asphalt-based spherical activated carbon, sphere diameter is 0.4-1.5 mm, density is 0.5-0.85 g/cm<3>, ratiospecific surface area is 800-1,500 m<2>/g, vibration strength is greater than 95%, microporous content is 60-83%, mesoporous content is 30-5%, macroporous content is 10-12%, and sphericity is greater than 99%.The invention has significant important significance for promoting the engineering of asphaltpitch-based spherical activated carbon and promoting the application of spherical activated carbon in civil, industrial, aerospace and other fields.

The invention relates to a method for controlling surface micro cracks of pitch-based spherical activated carbon. The method comprises the following steps: carrying out modification with high softening point coal tar pitch, improving pelletizing conditions of naphthalene-containing pitch granules, and changing a removal method for naphthalene in the naphthalene-containing pitch granules, thereby obtaining the pitch-based spherical activated carbon which is smooth in surface, free of surface micro crack and high in sphericity degree, wherein the pitch-based spherical activated carbon has a density of 0.5-0.85g/cm<3>, a specific surface area of 800-1300m<2>/g, vibration strength greater than 95% and a micro pore content greater than 83%. By adopting the method, while the pitch-based spherical activated carbon is prepared, the problem of micro cracks on the surface of the pitch-based spherical activated carbon can be effectively solved, the mechanical properties of the material are improved, and the method has great significances for promoting engineering progress of the material and widening the application range of the material.

The present invention relates to one kind of cement concrete admixture for repairing cement concrete road. The cement concrete admixture consists of industrial slag 70-80 wt%, bentonite 10-15 wt% and silica powder 8-15 wt%, and is produced through mixing the materials and grinding to specific surface area greater than 500 sq m/kg. It is added into cement concrete, with the weight ratio between cement and the admixture being 1 to 0.025-0.035. It has the features of high early strength, slight early expansion, no after shrinkage, anticracking and antiseepage, no corrosion to reinforcing bar, etc. It is especially suitable for use in the repair engineering of cement concrete road, bridge, culvert, tunnel, etc.

The invention belongs to the technical field of lithium ion battery materials, and discloses a nickel-cobalt-boron precursor material, a nickel-cobalt-boron positive electrode material and a preparation method. The chemical formula of the nickel-cobalt-boron precursor material is NixCoyBz (OH) 2, and the surface energy of the (003) crystal face of the precursor material is calculated to be 1.1-2.5 J/m < 2 > by using CASTEP software. In the process of preparing the nickel-cobalt-boron precursor material through coprecipitation, the temperature of a reaction system is controlled to be 30-90 DEG C, the pH value is 11-12.8, the concentration of a complexing agent is 5-8 g/L, the stirring speed is 300-450 rmp, and the solid content is 150-400 g/L. The nickel-cobalt-boron precursor material is mixed with lithium and calcined to obtain the positive electrode material, and the positive electrode material can be further coated with an indium coating with conductive ions. The positive electrode material prepared by the method is excellent in electrochemical performance.

Provided are an aluminum-zinc alloy plated steel sheet having excellent hot workability and corrosion resistance, and a method for manufacturing same. The plated steel sheet has an Al—Zn hot-dip aluminized coating layer on a base steel sheet, wherein: the coating layer is composed of a lower layer part and an upper layer part; the lower layer part comprises 40-50% of Fe, 50-60% of Al, 1% or less of Si, and other unavoidable impurities, on the basis of wt % of the lower layer part itself; the upper layer part comprises 10-30% of Zn, the balance of Al, and 0.05% or less of at least one of Cr, Mo, and Ni as an impurity, on the basis of wt % of the upper layer part itself; and the thickness of the upper layer part accounts for 30% or less of the total thickness of the coating layer.

The invention discloses a method for overcoming defects of a silicon chip with STI (Shallow Trench Isolation). A method for constructing STI on the silicon chip comprises the following steps of: depositing a pad oxides layer (103) and a silicon nitride layer (104) on a silicon substrate (101) of the silicon chip sequentially, covering the surface of the silicon chip by using photoresist, performing pattern transferring, and etching silicon nitride, pad oxide and the silicon chip by using the photoresist as a mask to construct an STI structure of which the bottom part is positioned in the silicon substrate. The method is characterized in that: After the silicon nitride layer (104) is deposited on the silicon chip and before the surface of the silicon chip is covered by the photoresist and pattern transferring is performed, the method comprises following step of: performing first annealing on the silicon chip to remove the internal stress of the silicon. The invention also discloses other methods for overcoming the defects of silicon chip with STI and methods for constructing the STI on the silicon chip. The technical scheme can effectively remove the internal stress of the silicon chip, thereby avoiding micro cracks in corners of the STI caused by internal stress and overcoming the defects of the surface of the silicon substrate.

The invention discloses a femtosecond laser processing method and device for a micro-nano structure of a cladding on the surface of an optical fiber. According to the method, femtosecond laser passing through a focusing microscope objective passes through a spherical aberration introducer to generate spherical aberration, so that paraxial focuses and non-paraxial focuses of the femtosecond laser form a plurality of focuses separated along an optical axis, the focuses form a light filament structure, the light filament structure processes a micro structure on the surface of the optical fiber, and the size of the micro structure is between several microns and hundreds of microns. According to the method, the positive correlation between a laser focal spot and the focal depth and the nonlinear effect caused by energy distribution along the optical axis are greatly improved, so that a micro structure with a large depth-diameter ratio can be generated on the surface of the optical fiber.

The invention belongs to the technical field of sodium ion batteries, and discloses a nitrogen-doped-polymerized porous nano-deposited positive electrode material and a preparation method and application thereof, the general formula of the nitrogen-doped-polymerized porous nano-deposited positive electrode material is NatLifNisZ1-sO2 (at) aNMC-Y, 0.8 < = tlt; 1, 0 < = flt; 0.3, 0.5 < = slt; 1, 0lt; a < lt >; z is at least one of Mn, Mo, Co, Mg and Al, and Y is at least one of Cu, Ga, Zn, Cr and Zr. According to the nitrogen-doped-polymerized porous nano deposited positive electrode material prepared by the invention, a plurality of layers of compact films are obtained on the surface of the NMC-Y deposited NatLifNisZ1-sO2 material, and after the nitrogen-doped-polymerized porous nano material is deposited, on one hand, the nitrogen-doped-polymerized porous nano material can contribute a considerable specific surface area; on the other hand, the migration path of ions in the material can be shortened, and the electrochemical performance is improved.

The invention discloses a creep aging forming method for a large-curvature wallboard. The method is mainly used for increasing the creep aging forming curvature of the wallboard, improving the corrosion resistance and fatigue resistance of the large-curvature wallboard, and improving the creep aging forming efficiency. The method comprises the following steps of performing solid solution on an aluminum alloy wallboard blank at 420-520 DEG C for 1-3 hours, and performing quenching; then performing shot peening strengthening treatment on a selected area of the wallboard; then performing creep aging on the wallboard in a hot pressing tank; and finally, performing polishing treatment on the selected area of the wallboard. According to the method, the generation of microcracks during creep aging forming of the large-curvature wallboard can be effectively avoided, the precipitation efficiency of reinforced phases is promoted, the corrosion resistance and fatigue resistance of the wallboard are enhanced, the creep aging forming curvature of the wallboard is increased, and the application range of the creep aging forming process is improved.

The invention provides an ultrasonic-assisted laser micro-cladding device for a gradient functional composite material. The ultrasonic-assisted laser micro-cladding device comprises a rack, a preset piece sample preparation assembly and an ultrasonic-assisted laser micro-cladding assembly, wherein the preset piece sample preparation assembly and the ultrasonic-assisted laser micro-cladding assembly are installed on the rack. The ultrasonic-assisted laser micro-cladding assembly comprises a laser micro-cladding head assembly and an ultrasonic-assisted workbench assembly. The invention also provides an ultrasonic-assisted laser micro-cladding method for the functional gradient composite material, which comprises the following steps: in the early stage of implementation, according to the gradient material theory, preparing a preset sheet sample through the procedures of controlling the component proportion of the copper-based composite material, performing a wet ball milling process, performing ultrasonic-assisted processing on the preset sheet, performing vacuum drying and demolding and the like; and then preparing the preset sheet sample into the graphene/copper-based gradient functional composite coating through a multi-channel and multi-layer processing mode under the action of a composite energy field based on an ultrasonic-assisted laser micro-cladding process. According to the method, the high-quality gradient functional composite coating can be formed in a metallurgical bonding mode through the laser micro-cladding technology.