11results 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.

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 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.

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 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 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.