18results about How to "Retain mechanical properties" patented technology

The invention relates to the technical field of ceramic welding, in particular to a novel reaction sintering boron carbide ceramic self-infiltration connection method. According to the method, the to-be-connected surfaces of the reactive sintering boron carbide ceramics are polished to be consistent in roughness at the normal temperature and then pressed, the two reactive sintering boron carbide ceramics can be successfully connected at the high temperature through diffusion and interface reaction of residual silicon of the reactive sintering boron carbide ceramics, and the formed connecting layer mainly comprises three phases of Si, SiC and B12 (C, Si, B) 3; compared with the prior art, the method has the advantages that the adaptability between the connecting layer and the base material boron carbide is good, almost most of the mechanical properties of the base material boron carbide are reserved, in addition, many fine silicon carbide phases are formed at the interface, and the interface bonding is good, so that the connection of the reactive sintering boron carbide ceramic is simply realized under the condition of not adding any middle layer, and the service life of the reactive sintering boron carbide ceramic is prolonged. And a connection interface is complete, defects such as air holes are few, and most of the bending strength is reserved.

The application discloses a metal mask plate and a manufacturing method of the metal mask plate, and the metal mask plate is used for evaporating and depositing an organic light-emitting layer of an OLED device. The metal mask plate comprises a mask plate body, a plurality of mask holes are formed on the mask plate body, the mask plate body comprises a first surface and a second surface which are opposite to each other, the mask holes penetrate through the first surface and the second surface, the mask holes form first openings on the first surface, the mask holes form second openings on the second surface, and the ratio of the aperture of the first opening to the aperture of the second opening is between 1 and 1.5. The metal mask plate has the characteristics of high tensile strength and high resolution.

The invention discloses a medical-grade modified PEEK composite material and a preparation method thereof. The preparation method comprises the following steps: S1, dispersing a bioactive material into dissolved diphenyl sulfone, and heating until a solvent is volatilized to obtain a bioactive material / diphenyl sulfone composite material; s2, adding the bioactive material / diphenyl sulfone composite material into a reaction kettle, heating in an inert atmosphere until diphenyl sulfone is molten, adding sodium carbonate, difluorobenzophenone and hydroquinone, and continuously heating for reaction; s3, heating a polymerization product in S2, and then cooling to 250-260 DEG C; and when the temperature is reduced to 250 DEG C, naturally cooling, and pulverizing the obtained sample by a pulverizer. The preparation method comprises the following steps: firstly preparing a bioactive material / diphenyl sulfone composite material, and in a PEEK polymerization reaction process, adding nano particles as effective nucleation sites, and growing a PEEK polymer by taking the nano particles as crystal nucleuses, so that steric resistance potential energy exists among the particles, thereby enlarging potential barriers among the particles and effectively reducing the agglomeration phenomenon of the nano particles.

The invention discloses a performance regulation and control method for additive manufacturing of an aluminum-silicon alloy, and belongs to the technical field of aluminum alloy additive manufacturing. The performance regulation and control method comprises the following steps that S1, Al-Si alloy powder is prepared; s2, the Al-Si alloy powder is subjected to a selective laser melting process to form a component; s3, direct aging heat treatment is conducted on the component; the microstructure of the additive manufacturing Al-Si alloy is improved through direct aging heat treatment, and the heat conductivity coefficient of the alloy is improved while the alloy is endowed with superior mechanical strength. The method can be used for solving the problem of heat dissipation of high-power devices existing at present, and has great significance in development of efficient and light radiators and application of the radiators in the related fields of aerospace, automobiles and the like.

This invention discloses a high-performance meta-aramid / mica composite insulating paper and its preparation method. The paper is formed by wet papermaking and hot pressing of a mixed slurry composed of meta-aramid chopped fibers, meta-aramid precipitated fibers, and mica flakes. The composite insulating paper has a thermal decomposition temperature ≥425℃, tensile strength ≥52N / mm, tear strength ≥2.2N / mm, and voltage breakdown strength ≥13.8kV / mm. The mass ratio of chopped fibers to precipitated fibers is (50~80):(50~20). The amount of mica flakes added is 5wt%~10wt% of the total mass of the two aramid fibers. The hot pressing adopts a segmented hot pressing process of "low-temperature pre-pressing - medium-temperature strengthening - high-temperature setting". By controlling the key parameters of the precipitated fibers and optimizing the ratio of chopped fibers to precipitated fibers and the proportion of mica flakes added, the paper is prepared through processes such as raw material pretreatment, graded mixing and dissociation, wet papermaking, and segmented hot pressing. Advantages: Through multi-parameter coordinated control and process optimization, the technical bottlenecks such as the mechanical and insulation properties of existing aramid composite insulating paper and insufficient thermal stability have been solved.

The invention relates to an experimental device and an experimental method for wet granulation of solvent type supramolecular polyurethane urea, and belongs to the technical field of new materials. The device comprises a solvent polymerization reaction device, a feed liquid conveying device, a spraying and curing device, a separation device, a drying device and a screening and collecting device, the solvent polymerization reaction device, the feed liquid conveying device, the spraying and curing device and the separation device are sequentially connected, and the drying device and the screening and collecting device are sequentially arranged on the upper side of the separation device. The spraying and curing device comprises a spraying device and a curing device, the curing device is arranged below the spraying device, the curing device is connected with a separating device, the separating device comprises a filtering system and a curing agent recovery system, and the filtering system is connected with the curing agent recovery system. The particle size and shape can be accurately controlled by adjusting parameters, high-temperature operation is avoided, environmental pollution is reduced, the consistency and mechanical performance of products are remarkably improved, and the production efficiency is improved.

The application belongs to the technical field of modified copolymer nylon and specifically relates to a modified PA6 material and a preparation method thereof. The application aims to solve the problem of high moisture absorption and lack of high insulation of the existing copolymer modified PA6 material. The application mixes caprolactam and lauryl lactam to obtain a PA6 / 12 random copolymer; pre-blends modified graphene oxide, boron nitride nanosheet and polyamide oligomer to obtain a composite suspension; coats the PA6 / 12 random copolymer on the surface, feeds the coated PA6 / 12 random copolymer into an extruder, adds the composite suspension after complete melting, uniformly mixes the composite suspension and the PA6 / 12 random copolymer, adds a flame retardant aid, and finally extrudes to obtain the modified PA6 material. The modified PA6 material prepared by the application has low water absorption and good insulation, and is not prone to electric leakage and tracking in a high-temperature working environment.

The invention provides a PLGA (poly (lactic-co-glycolic acid))-hydroxyapatite composite porous microsphere as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) adding 1-100 mL of a span80 solution and 0.25-25 g of PLGA (poly (lactic-co-glycolic acid)) into 10-1000 mL of ethyl acetate, stirring and dissolving to obtain a mixed solution; (2) continuously stirring the mixed solution, adding an ammonium bicarbonate solution containing hydroxyapatite, and emulsifying to obtain w / o emulsion; (3) uniformly mixing 100 mL to 10000 mL of a PVA solution and 10 mL to 1000 mL of a Tween 80 solution, continuously stirring, adding the w / o emulsion, and emulsifying to obtain a w / o / w emulsion; and (4) stirring until the organic solvent is volatilized, sieving, washing with water, centrifuging, and freeze-drying the obtained precipitate to obtain the composite porous microspheres. The preparation method is simple and easy to implement and simple to operate.

The invention relates to a high-strength, high-modulus and wear-resistant thermotropic liquid crystal polyarylester fiber and a preparation method thereof, particularly, ultra-high molecular weight polyethylene is adopted as a coating material, a thermotropic liquid crystal polyarylester fiber is adopted as a core material, the overall wear resistance of the composite fiber is effectively improved by utilizing a modification technology, and meanwhile, the original high mechanical property is retained. The tensile strength of the prepared thermotropic liquid crystal polyarylester composite fiber is higher than 24 cN / dtex, the tensile modulus is higher than 800 cN / dtex, the strength retention rate after 10000 times of friction is higher than 90%, and meanwhile, the thermotropic liquid crystal polyarylester composite fiber has low dielectric constant (smaller than or equal to 2.5) and dielectric loss (smaller than or equal to 0.005).

This invention discloses a furfuryl alcohol copolymer-coated ammonium polyphosphate and its application in the preparation of flame-retardant composite materials, belonging to the field of flame-retardant materials technology. The invention involves mixing furfuryl alcohol, electron-accepting monomers, crosslinking agents, and initiators with ammonium polyphosphate in a solution, causing furfuryl alcohol, electron-accepting monomers, and crosslinking monomers to precipitate and polymerize on the surface of the ammonium polyphosphate, forming a furfuryl alcohol copolymer-coated ammonium polyphosphate. This furfuryl alcohol copolymer-coated ammonium polyphosphate, as a flame retardant, can be compounded with polyurethane foam, thermoplastic polymers, and thermosetting polymers to prepare polyurethane foam flame-retardant composite materials, thermoplastic flame-retardant polymer composite materials, and thermosetting flame-retardant polymer composite materials, respectively. The furfuryl alcohol copolymer-coated ammonium polyphosphate exhibits good dispersibility in the polymer matrix, good interfacial compatibility, and is easily modified, significantly improving the flame-retardant properties of the composite material while maintaining its excellent mechanical properties.

The invention discloses a springback type composite sheet and a preparation method thereof, and belongs to the technical field of composite sheets. The sheet comprises an inner layer, a springback layer, a blocking layer and an outer layer which are sequentially arranged in a stacked mode. The base material of the rebound layer is polyester or polyamide, the tensile strength of the rebound layer is limited to be larger than or equal to 150 MPa, the elongation at break of the rebound layer is larger than or equal to 50%, the thickness of the rebound layer is 10-30 microns, meanwhile, the melt flow rate of the polyester under the condition of 275 DEG C / 2.16 kg is controlled to be 5-20 g / 10 min, and / or the melt flow rate of the polyamide under the condition of 235 DEG C / 2.16 kg is controlled to be 5-18 g / 10 min. The springback layer further comprises functional auxiliaries such as maleic anhydride grafted polyethylene and oxazoline grafted polyolefin, and polyester or polyamide is preferably subjected to two-way stretching treatment. The preparation method comprises the following steps: performing corona treatment on each layer of substrate film, sequentially compounding each layer at different temperatures and pressures by adopting a step-by-step dry-method compounding process, and finally performing curing treatment. The method is used for improving the rebound resilience of the composite sheet packaging.

The application discloses a kind of tapered roller bearing and its preparation process, including bearing inner ring, bearing outer ring, roller and cage, bearing inner ring is made of carburizing steel material, bearing outer ring is made of carburizing steel or high-carbon chromium bearing steel material, bearing inner ring outer wall and bearing outer ring inner wall are all provided with raceway, bearing inner ring and bearing outer ring are all processed by heat treatment process to make raceway surface form carbon potential layer, further including a preparation process, including following flow: S1, after cutting seamless steel tube, it is prepared into bearing outer ring and bearing inner ring by cold extrusion molding;S2, bearing outer ring is processed by heat treatment;S3, bearing inner ring is processed using carburizing heat treatment process and cold treatment process.The application solves the problems that traditional tapered roller bearing inner and outer ring material adaptability is poor, raceway wear resistance and strength performance are uneven, bearing is easy to appear wear deformation and fatigue failure when serving, and the overall heat treatment process lacks pertinence.

The invention discloses a method for modifying the surface of a PEEK base material and improving the binding force of the PEEK base material and a conductive metal layer, and relates to the technical field of electronic additive manufacturing. Comprising the following steps: printing a PEEK base material sample by using an FDM technology, carrying out surface polishing treatment on the PEEK base material sample, carrying out laser treatment and concentrated sulfuric acid treatment on the PEEK base material sample, printing a nano-silver conductive layer on the surface of the surface-modified PEEK base material sample, sintering and curing the nano-silver conductive layer and the like. According to the method, surface modification of the PEEK base material sample is achieved, the surface roughness of the PEEK base material sample is increased, the surface contact angle is reduced, active functional groups are increased, the binding force of the surface of the PEEK base material sample and the nano-silver layer is effectively improved, and a practical method is provided for the field of electronic additive manufacturing.

The invention provides a preparation method of an antioxidant heat-conducting PPS composite material and fiber and a PPS fiber, and belongs to the technical field of polyphenylene sulfide fibers. The preparation method comprises the following steps: preparing a small-flake-diameter graphene / zinc oxide / boron carbide nano composite material through an intercalation-sanding method; mixing the graphene / zinc oxide / boron carbide composite nano material with PPS powder to prepare a PPS nano composite material, and granulating and spinning the PPS nano composite material to prepare the PPS fiber. Graphene is used as a dispersion carrier to assist dispersion of nano zinc oxide and boron carbide, a small-molecule coupling agent or a dispersing agent in the prior art is replaced, and agglomeration of zinc oxide and boron carbide in PPS is reduced, so that the uniform dispersion effect is achieved, an antioxidant component and the PPS material are well combined together, and the anti-oxidation performance of the PPS material is improved. The durability of the oxidation resistance of the PPS fiber in the long-term use process can be guaranteed, and the mechanical property of the PPS fiber can be reserved to the maximum extent.

The invention relates to the technical field of metamaterials or superstructures, in particular to an assembly type negative Poisson's ratio structure based on mortise and tenon connection and an assembly method thereof, the assembly type negative Poisson's ratio structure is composed of a plurality of annular parts and plate-shaped parts, and tenons of the plate-shaped parts and mortises of the annular parts are mutually embedded. According to the structure disclosed by the invention, under the condition that an additional connecting means is not needed, stable connection is formed by mutual embedding of the mortise and the tenon, and the limitation that a traditional integrated negative Poisson's ratio structure depends on a 3D printing process is overcome. Due to the high assembling freedom degree, expansion in any direction in a plane can be achieved, and assembling can be conducted according to actual requirements in engineering. The modularized part design can adapt to a traditional manufacturing process, the production cost and the maintenance cost of the structure are reduced, and large-batch production is achieved. The structure is suitable for engineering structures for protection, shock resistance and noise reduction.

The invention belongs to the technical field of titanium alloy material processing, and discloses a titanium alloy foil straightening method based on cooperative control. According to the method, constant-tension unwinding, pulse current auxiliary heating, whole-process synchronous transverse stress application, pulling-bending composite cycle straightening, flatness closed-loop control and constant-tension winding are adopted for conducting composite collaborative straightening on the titanium alloy foil. The method has the core advantages that the three core processes of focused pulse current heating, transverse stress applying and circulating straightening are synchronized and coordinated, and cracking and springback are inhibited from the source; and by matching with double closed-loop control of real-time temperature control of the temperature sensor and flatness closed-loop control, the technical problems that the titanium alloy foil is easy to crack during straightening, serious in rebound, uneven in breadth stress and substandard in flatness are solved in a targeted manner, and the temperature and flatness precision is remarkably improved.

The invention provides a preparation method of a polyurethane polymer, which comprises the following steps: S1, taking polyethylene glycol as an initiator, and carrying out ring-opening reaction on a cyclic ester monomer under the action of a catalyst to synthesize a polyester prepolymer; s2, reacting the dihydroxyl compound with diisocyanate, and purifying and drying to obtain a hydroxyl-terminated triblock compound; s3, carrying out condensation reaction on diisocyanate and polyethylene glycol under the action of a catalyst to prepare an isocyanate group-terminated polyurethane prepolymer; s4, the polyester prepolymer prepared in the step S1 is dropwise added into the polyurethane prepolymer prepared in the step S3, then the dimethylformamide solution of the hydroxyl-terminated triblock compound prepared in the step S2 is dropwise added continuously, purification and drying are performed after continuous reaction, and the polyurethane polymer is obtained and is good in mechanical property, high in clinical safety and low in cost.