157results about How to "Promote nucleation" patented technology

The invention relates to the technical field of titanium alloy machining, and particularly discloses a forging method for improving the macrostructure uniformity of a TC2 titanium alloy large-specification bar, which is realized through cogging forging, twice alpha + beta phase region remelting dynamic beta recrystallization forging, two-phase region upsetting and drawing forging and two-phase region drawing forging. The TC2 titanium alloy bar with the specification of phi 300-phi 400 mm prepared through the method is fine and uniform in macrostructure and meets the 1-5 grade of a macroscopic rating chart in the product standard, and the structure of a ring forge piece subjected to die forging through the bar is greatly improved and meets the standard requirement.

The invention relates to the technical field of honeycomb ceramic materials, in particular to a cordierite honeycomb ceramic material with low heat capacity and high specific surface area and a preparation method thereof. The pug comprises an inorganic solid component, an organic component and water, the inorganic solid component comprises narrow-particle-size-distribution spherical magnesium hydroxide, spherical aluminum hydroxide and spherical fused silicon dioxide; the particle size D50 of the narrow-particle-size-distribution spherical magnesium hydroxide powder is 0.1-2 microns, and the particle size D97 is smaller than or equal to 20 microns; the particle size D50 of the spherical aluminum hydroxide powder is 1-6 [mu] m, and the particle size D97 is less than or equal to 20 [mu] m; the particle size D50 of the spherical fused silica powder is 6-12 [mu] m, the particle size D97 is less than or equal to 20 [mu] m, and the sphericity is greater than or equal to 98%. The method is low in extrusion pressure, the obtained material is high in pore density, meanwhile, high porosity can be achieved without adding a pore-forming agent, and the ultra-thin wall is achieved; the composite material can be applied to various requirements of low heat capacity and high specific surface area.

The invention relates to a plasma surfacing flux-cored wire resistant to abrasive wear and a preparation method of the plasma surfacing flux-cored wire. The plasma surfacing flux-cored wire comprises an outer skin and a flux core. The flux core comprises the following components in percentage by weight: 1.6 percent to 3.8 percent of C, 0.4 percent to 1.0 percent of Si, 0.4 percent to 1.2 percent of Mn, 2.10 percent to 4.1 percent of B, 15.0 percent to 24.0 percent of Cr, 4.1 percent to 7.2 percent of Nb, 4.3 percent to 7.7 percent of W, 0.1 percent to 0.5 percent of La and the balance of Fe; and the outer skin is a cold-rolled carbon steel strip. The flux-cored wire has the advantages that welding layer metal obtained through plasma surfacing by adopting the flux-cored wire has high comprehensive mechanical properties, the hardness can reach HRC65 or above after surfacing is conducted for 2-3 mm, the flux-cored wire is used for protection of easily-abraded positions of agricultural equipment, and the service life of the agricultural equipment is greatly prolonged.

The invention relates to the technical field of aluminum alloy materials, in particular to a rare earth microalloyed aluminum alloy cast rod and a production process thereof, and the aluminum alloy cast rod comprises the following chemical components in percentage by mass: 8.0%-9.0% of Zn, 2.2%-2.8% of Cu, 1.8%-2.5% of Mg, 0.005%-0.01% of Ti, 0.005%-0.01% of Si, 0.005%-0.01% of Mn, 0.005%-0.01% of Fe, 0.01%-0.05% of Cr, 0.01%-0.05% of Cl, 0.05%-0.4% of rare earth elements and the balance of Al and inevitable impurities. The rare earth elements are La, Ce and Nd. Rare earth elements in a certain proportion are added into the chemical components, so that the proportion of the alloy components is optimized, and the mechanical property of the aluminum alloy cast rod is improved.

The invention provides a method for eliminating delta ferrite in austenitic stainless steel and the austenitic stainless steel, and belongs to the technical field of metal materials. The method comprises the following steps that an austenitic stainless steel ingot containing the delta ferrite is subjected to heat preservation for first set time at the first set temperature for first heat treatment; heating the austenitic stainless steel ingot subjected to the first heat treatment to a second set temperature, and carrying out heat preservation for a second set time at the second set temperature for second heat treatment; and cooling the austenitic stainless steel ingot subjected to the second heat treatment, or sequentially and repeatedly carrying out the first heat treatment and the second heat treatment on the austenitic stainless steel ingot subjected to the second heat treatment for at least one time, and then cooling to obtain the austenitic stainless steel subjected to delta ferrite elimination. The first heat treatment and the second heat treatment are performed, and the second set time is limited, so that the austenitic stainless steel is prevented from being in a high-temperature environment for a long time, and austenite grains are prevented from obviously growing.

The invention provides a preparation method of a flexible hydrogen delivery pipe, and relates to the field of flexible hydrogen delivery pipe manufacturing, and the flexible hydrogen delivery pipe comprises the following raw material components: polytrifluorochloroethylene, nylon 11, polyvinylidene fluoride, a micro-nano carbon material, polyethyleneimine, a compatilizer, a cross-linking agent, an antioxidant, a dispersing agent and a light stabilizer, the cross-linking agent is a thermoplastic polyurethane copolymer, the micro-nano carbon material comprises graphene oxide and graphene nanoplatelets, the dispersing agent is one of EBS, EB-G and PE wax, the antioxidant is antioxidant 1076, and the light stabilizer is one of benzophenone and 2-hydroxybenzoate; the gas barrier material has the advantages of being good in gas barrier property and high in mechanical property on the whole.

The invention discloses a method for preparing high aspect ratio calcium carbonate whiskers by carbon fixation in steel smelting slag leachate, belonging to the technical field of solid waste resource utilization. The method comprises the following steps: leaching steel smelting slag to obtain calcium-magnesium leachate and leach slag; removing impurities from the calcium-magnesium leachate by a pH swing method to obtain a calcium-magnesium purified solution; capturing the gas containing carbon dioxide by an alkaline solution to obtain a carbonated solution; adjusting the pH of the calcium-magnesium purified solution to convert magnesium ions into magnesium hydroxide, placing the solution in an ultrasonic field, adding the carbonated solution to carry out a carbon fixation reaction, and washing and drying the precipitate obtained by the reaction to obtain calcium carbonate whiskers. The method not only successfully realizes the efficient resource utilization of two wastes, steel smelting slag and carbon dioxide flue gas, but also produces high value-added calcium carbonate whisker products while stably fixing carbon dioxide, and has broad application prospects and environmental value.

The invention relates to the technical field of aqueous zinc ion battery negative electrode materials, in particular to an efficient aqueous zinc ion negative electrode plate and a preparation method thereof. A zinc metal negative electrode of an aqueous zinc ion battery has many interface side reactions and is easy to grow dendrites, so that the cycle life of the battery is relatively short. In order to solve the problems, the invention provides the efficient aqueous zinc ion negative plate which is formed by sequentially coating the surface of a Zn plate with a carbon nitride coating and a zinc titanate coating, carbon nitride in the carbon nitride coating is graphite-phase carbon nitride, and the graphite-phase carbon nitride is stable in property, large in specific surface area and rich in sp2 hybridized nitrogen atoms, so that the specific surface area of the graphite-phase carbon nitride is increased, and the specific surface area of the graphite-phase carbon nitride is increased. The nitrogen source has relatively high electronegativity and zinc affinity, generates an adsorption effect on zinc ions, forms a Zn-N bond, can promote nucleation of the zinc ions and reduce a nucleation barrier of Zn < 2 + > ions, and the carbon nitride coating is loose and porous in structure, is not stable enough in structure and is easy to fall off from the surface of an electrode in the charge-discharge cycle process of the battery, so that the performance of the battery is improved. According to the invention, the zinc titanate coating is arranged on the surface of the carbon nitride coating, and the zinc titanate coating with a compact structure can effectively prevent the carbon nitride coating from being in direct contact with an electrolyte, so that the cycling stability of the battery is effectively improved.

The invention discloses a method for preparing Ru-RuO2 core-shell nanosheets through a gas-solid phase reaction. Carbon black with amino functionalized surface is used as a carrier,-NH2 functional groups grafted on the surface of the carbon black are used for inducing deposition, dispersion and nucleation growth of Ru metal, and the growth speed of a crystal face is changed by optimizing reduction conditions and kinetic parameters and utilizing selective adsorption of reducing gas to the Ru crystal face, so that the morphology of particles is regulated and controlled, and the Ru metal particles are obtained. And synthesizing the hexagonal Ru nanosheet without the surfactant. Ru nanosheets are partially oxidized, Ru-RuO2 core-shell nanosheet structures with different atomic layer thicknesses are further obtained, and RuO2 shells with different thicknesses can accurately regulate and control the surface strain of the catalyst. The Ru-RuO2 core-shell nanosheet has the advantages that the use of a surfactant is avoided in the synthesis process, the Ru-RuO2 core-shell nanosheet can be obtained through simple loading and calcination, the large-scale mass production can be realized, and the core-shell nanosheet can be used for efficiently catalyzing the acidic OER reaction.

The invention discloses a magnetic field-ultrasonic-assisted laser polishing composite manufacturing method. The method comprises the following steps that S1, a workpiece to be machined is placed on a machining table top; s2, adjusting the direction of a magnetic field through movement of an electromagnet on a guide rail; s3, controlling a moving assembly to align the to-be-machined position of the workpiece to a laser; s4, the lifting assembly is controlled to drive the machining table top to ascend and descend, and the focus of the laser is aligned with the surface of the to-be-polished position of the workpiece; s5, the magnetic field intensity is set, the frequency and amplitude of an ultrasonic generation assembly are set, a machining path is set, and the refrigeration temperature of a refrigeration assembly is set; and S6, the electromagnet, the ultrasonic generation assembly, the moving assembly and the laser are started, the moving assembly drives the machining platform to move according to the machining path, and polishing machining is conducted. The invention provides a magnetic field-ultrasonic-assisted laser polishing composite manufacturing device. The surface quality and precision of the workpiece can be rapidly improved.

The invention relates to an electron transport layer based on fluoride treatment, a preparation method thereof and application of the electron transport layer in a perovskite solar cell, and belongs to the technical field of perovskite solar cells. The technical problem that a large number of ion defects exist on the surface and in the interior of the polycrystalline perovskite thin film in the prior art is solved. The electron transport layer based on fluoride treatment comprises an electron transport layer, the surface of the electron transport layer is treated by fluoride, and the fluoride contains coordination sites. The fluoride is introduced to the electron transport layer, so that the wettability of the perovskite precursor solution on the surface of the electron transport layer is improved, the occurrence of a perovskite nucleation process is promoted, the generation of defects is reduced, and the quality of the perovskite thin film is further improved. In addition, the introduction of the fluoride regulates and controls the defect state density in the electron transport layer and the perovskite thin film, and improves the efficiency and stability of the perovskite solar cell.

The invention discloses ultrahigh-plasticity hot-rolled austenitic stainless steel and a preparation method thereof, and belongs to the technical field of austenitic stainless steel production and manufacturing. The preparation method comprises the following steps: smelting and pouring according to a certain mass percent of chemical components to obtain a steel billet, homogenizing the steel billet, and forging the steel billet into a square billet; performing multi-pass hot rolling on the square billet to obtain a hot-rolled plate, performing interrupted solution treatment on the hot-rolled plate, and performing water cooling to room temperature; by controlling element selection of C, Cr, Mn, Ni and N and cooperating with a multi-pass hot rolling-solid solution interruption preparation method, an austenite structure after complete recrystallization is regulated and controlled firstly, then part of austenite is recrystallized again through low-temperature solid solution, and high mechanical stability and excellent strong plasticity are obtained based on two recrystallization behaviors.

The invention discloses a low-dielectric low-loss high-strength borosilicate glass ceramic composite material and a preparation method thereof, and belongs to the technical field of borosilicate glass ceramic composites.The low-dielectric low-loss high-strength borosilicate glass ceramic composite material is prepared from, by weight, 70% of low-alkali borosilicate glass ceramics with the low borosilicate ratio, 29% of Al2O3 and 1% of Bi2O3. The preparation method comprises the following steps: preparing low-alkali borosilicate glass ceramics with a high borosilicate ratio, melting the low-alkali borosilicate glass ceramics with the high borosilicate ratio and amorphous SiO2 at a set temperature to obtain the required low-alkali borosilicate glass ceramics with the low borosilicate ratio, and finally mixing and ball-milling the crushed and ground low-alkali borosilicate glass ceramics with Al2O3 and Bi2O3 to obtain the low-alkali borosilicate glass ceramics with the low borosilicate ratio. And finally, the borosilicate glass ceramic composite material is sintered at the temperature of 880-900 DEG C. The borosilicate microcrystalline glass ceramic composite material is low in dielectric, low in loss and high in strength.

The invention relates to the technical field of metal materials, and discloses a preparation process for a high-strength seamless steel pipe perforation plug. A large number of mechanically inhomogeneous bodies of hard particles are distributed on a ceramic reinforcing agent matrix, which generates contact and friction with a crack surface, so that the crack produces a closing effect and passivates the crack tip, thereby reducing the tendency of the plug to crack. The rare earth elements in the fine-grained reinforcing agent are dispersed in the crystal and at the grain boundary, which can effectively hinder the movement of dislocations, adsorb impurity elements such as oxygen and sulfur between crystals, purify the grain boundary and improve the strength of the alloy, and play a "pinning" role on dislocations during deformation. Ion soft nitriding can increase the dislocation density of the material and improve the hardness. The silicon zirconium coating has excellent wear resistance, and magnetron sputtering sputters the silicon zirconium coating material on the surface of the plug substrate to form a silicon zirconium nitride coating with a diffusion barrier effect with the nitrogen element on the substrate surface, thereby improving the strength and wear resistance of the perforation plug material.

The invention discloses a micro-texture porous multilayer structure composite current collector and a preparation method thereof. The composite current collector comprises a porous polymer film located in the middle, chemical plating metal layers located on the two sides of the porous polymer film, micro-texture metal copper layers located on the outer sides of the two chemical plating metal layers, and corrosion-resistant lithium-loving layers located on the outer sides of the two micro-texture metal copper layers. The surface area of the current collector is increased by arranging the porous polymer film and the micro-texture metal copper layer, so that the charging and discharging current is increased, and the effect of inhibiting the abnormal growth of lithium dendrites is achieved; metallization of the outer surface of the porous polymer film is realized by arranging the chemical plating metal layer, so that low-cost and high-yield metallization is realized; by arranging the corrosion-resistant lithium-loving layer, the corrosion resistance and the lithium-loving property of the current collector are improved, the corrosion-resistant requirement of a sulfide solid-state battery as a representative lithium ion battery is met, and the effects of promoting nucleation of lithium dendrites and inhibiting abnormal growth of the lithium dendrites are achieved.

A magneto-optic thin film, an optical isolator, and a method for manufacturing a magneto-optic thin film are disclosed. The magneto-optic thin film includes: a substrate; a diffusion barrier layer disposed on the substrate, where the diffusion barrier layer includes a metal oxide; a buffer layer disposed on the diffusion barrier layer; and an optical isolation layer disposed on the buffer layer. In this embodiment, the metal oxide in the diffusion barrier layer growing on the substrate is polycrystalline. This better facilitates nucleation of the buffer layer on the diffusion barrier layer, and achieves good crystallinity. In addition, the metal oxide has high density and thermal stability, and therefore can provide stable and reliable diffusion barrier effect. This further reduces optical loss of the magneto-optic thin film.

The invention provides a preparation method of a high-performance aging-free high-carbon SWRH82B hot-rolled wire rod, and relates to the technical field of hot rolling, and the preparation method comprises the following steps: feeding a high-carbon SWRH82B steel billet into a heating furnace for heating; carrying out rough rolling on the heated high-carbon SWRH82B steel billet by adopting a large square billet large compression ratio rolling technology under heavy pressure; the high-carbon SWRH82B steel billet subjected to rough rolling is fed into a finishing mill to be subjected to finish rolling; the wire rod obtained after finish rolling is fed into an ultra-long air cooling line to be cooled through ultra-large air volume; the cooled wire rod is fed into a coiling device to be coiled; and the coiled wire rod is inspected and packaged, the high-performance aging-free high-carbon SWRH82B hot-rolled wire rod is obtained, a 134m ultra-long air cooling line and a 280000m / h ultra-large air volume fan are adopted for an ultra-long air cooling line, the cooling speed is increased, and therefore the supercooling degree of austenite is increased, nucleation of ferrite is promoted, ferrite grains are refined, pearlite is refined, and the high-performance aging-free high-carbon SWRH82B hot-rolled wire rod is obtained. And the lamellar spacing of pearlite and the thickness of cementite are reduced, so that the structure is easily converted into sorbite, and the product strength and the performance stability of the same circle are improved.

The present invention relates to the technical field of honeycomb ceramic materials, and in particular to a cordierite honeycomb ceramic material with low heat capacity and high specific surface area and a preparation method thereof. The slurry comprises an inorganic solid component, an organic component and water; the inorganic solid component comprises spherical magnesium hydroxide with narrow particle size distribution, spherical aluminum hydroxide and spherical fused silica; the particle size D of the spherical magnesium hydroxide powder with narrow particle size distribution is 50 0.1‑2 μm, particle size D 97 Less than or equal to 20μm; particle size D of spherical aluminum hydroxide powder 50 1‑6 μm, particle size D 97 Less than or equal to 20μm; Spherical fused silica powder particle size D 50 6‑12 μm, particle size D 97 Less than or equal to 20μm, sphericity greater than or equal to 98%. This method has low extrusion pressure, the obtained material has high pore density, and can achieve high porosity without adding pore-forming agents, with ultra-thin walls; it can be applied to various low heat capacity and high specific surface area requirements.

The invention discloses a preparation method of a lightweight high-strength plastic Mg-Li-Zn-Gd alloy bar, which comprises the following steps: (1) in an argon atmosphere, selecting alloy raw materials according to the mass percentage, heating and melting to prepare an alloy melt; (2) carrying out casting molding on the alloy melt to obtain an alloy ingot; (3) preheating the alloy ingot, and performing extrusion forming to obtain an extruded bar of the magnesium-lithium alloy; and (5) carrying out rotary forging deformation treatment on the extruded bar at room temperature. Gadolinium (Gd) with a grain refinement effect and zinc (Zn) with a solid solution strengthening effect are added into a magnesium-lithium alloy system to serve as main alloying elements, meanwhile, nano precipitated phases such as Mg3Zn3Gd2 and MgZn2 in the alloy and segregation of the Zn element near the precipitated phases are regulated and controlled through the extrusion-rotary forging process, and therefore the strength and plasticity of the alloy are improved; the yield strength of the light high-strength plastic magnesium-lithium alloy bar reaches 276 MPa, and the tensile strength of the light high-strength plastic magnesium-lithium alloy bar is 303 MPa; the ductility is 24%; and the density is 1.565 g / cm < 3 >.

The invention belongs to the technical field of aqueous zinc ion batteries, and particularly discloses a compound additive-containing composite electrolyte for an aqueous zinc ion battery, the composite electrolyte is composed of a water-soluble zinc salt, deionized water and a compound additive, and the compound additive is formed by compounding tetrahydrofuran and phosphoric acid. The tetrahydrofuran and phosphoric acid compounded additive can effectively adjust the pH value of the electrolyte and keep the electrolyte stable in the electrochemical cycle process, the tetrahydrofuran additive changes a zinc ion solvated structure and meanwhile can partially open a ring under the induction of phosphoric acid, more stable linear polyether is formed and anchored on the surface of a zinc negative electrode, and the electrolyte is more stable in performance. Therefore, hydrogen evolution reaction and corrosion of the zinc negative electrode are inhibited, zinc ions are guided to be uniformly deposited, the problems of zinc dendrite growth and the like are solved, and finally the cycling stability of the zinc negative electrode is improved to a great extent.

The present invention discloses a method for improving the anti-swelling performance and mechanical properties of seaweed-based degradable straws, and belongs to the technical field of in-situ bionic mineralization. The present invention adopts the following method to improve the physical properties of seaweed-based straws: the seaweed-based straws are first soaked in a calcium chloride solution, and then soaked in a sodium carbonate solution, so that a layer of calcium carbonate armor is generated on the surface of the seaweed-based straws to improve the physical properties of the seaweed-based straws. The present invention successfully adds CaCO3 armor to the surface of the straw by in-situ mineralization, further enhancing the mechanical properties and water resistance of the seaweed-based straws. In addition, the present invention also expands the potential use of such straw waste as heavy metal adsorbents, indicating that seaweed-based straws are not only the most promising alternative to plastic straws, but also have extremely high economic feasibility.

The invention discloses a solvent-free solid-phase synthesis method of an LTA type molecular sieve, the solvent-free synthesis of the molecular sieve refers to that no solvent is used or the use of the solvent is greatly reduced in the synthesis process of the molecular sieve, and the molecular sieve synthesis system is mainly a solid phase. In the solvent-free synthesis process of the LTA type molecular sieve, a grinding material exerts a mechanical force effect on raw materials such as a silicon source, an aluminum source and an alkali source for synthesizing the molecular sieve. Different from a traditional rotary or stirring hydrothermal reaction kettle, the molecular sieve nucleation and crystallization growth process can be promoted by introducing mechanical force in the process. Meanwhile, the solvent-free solid-phase synthesis system can effectively reduce the use of a template agent and a solvent, reduces the generation of wastes and reduces the energy consumption of chemical synthesis, and is lower in equipment cost and easy to operate.

The invention discloses a preparation method of a degradable medical brushite (CaHPO4. 2H2O) coating on the surface of a magnesium alloy. A chemical deposition method is adopted, and the method comprises the steps of fluorination pretreatment and brushite deposition. Wherein in the brushite deposition step, a magnesium alloy sample is used as a cathode and is connected or directly contacted with an anode metal plate through a conductor, and the magnesium alloy sample and the anode metal plate are put into a brushite deposition solution to be soaked at a constant temperature, so that the brushite coating is obtained. According to the method, primary battery reaction is formed between the metal plate and the magnesium alloy sample, and hydrogen generated by the reaction is separated out from the anode metal plate, so that influence on coating deposition and coating density caused by separation of hydrogen from the surface of the magnesium alloy is avoided. Meanwhile, the cathode reaction speed of the surface of the magnesium alloy sample is accelerated through the primary battery reaction, nucleation of calcium phosphate is promoted, the roughness of the coating is reduced, and the density is improved. The coating obtained through the method is high in density and strong in binding force, the roughness is remarkably reduced, and the thickness is uniform and controllable.

This invention discloses a method for controlling the in-situ precipitation of multi-scale strengthening phases in alloys and an alloy casting, belonging to the field of metal preparation technology. The method involves placing molten alloy in a crucible of a casting equipment, with a liquid cooling medium filling the area around and below a substrate. The molten alloy is ejected from the crucible outlet and impacts the substrate. Under the spreading and flowing action of the melt, and the cooling effect of the substrate and the liquid cooling medium, submicron-level precipitates are controlled, and a solidified alloy layer is formed. The substrate is then moved downwards towards the liquid cooling medium by a certain distance. This process is repeated, allowing the molten alloy to continuously accumulate and form on the solidified alloy layer. This ensures that the solidified alloy layer undergoes a certain temperature and number of thermal cycles before entering the liquid cooling medium, achieving the control of nanoscale strengthening phases and the formation of the alloy casting. This invention controls the solidification and solid-state phase transformation process of the alloy through a layering method. The process is short, the strengthening phase control effect is good, and high-quality, high-performance alloy castings can be obtained.

The invention discloses a self-expansion prestressed grouting material and a preparation method thereof. The grouting material comprises the following components in parts by mass: 12-15 parts of a self-stress active material, 1-2 parts of an antioxidant, 1-2 parts of an interface stabilizer, 1-2 parts of a crystallization accelerant, 1-3 parts of a coagulant, 3-5 parts of a reinforcing agent and 100-120 parts of a cementing material. By introducing the self-stress active material into the grouting material, the compressive strength, tensile strength, durability, shock resistance and toughness resistance of the grouting material can be effectively improved, the grouting effect is improved, and the grouting material is simple in preparation process, low in cost and easy to popularize and use.

The invention discloses a graphite-powder-added high-thermal-conductivity devitrification-inhibiting ice crystal material and a preparation method thereof, and belongs to the technical field of ice crystal preparation, the graphite-powder-added high-thermal-conductivity devitrification-inhibiting ice crystal material comprises water and an additive, the additive comprises graphite powder with the particle size of 5-15 microns, a stabilizer, a nucleating agent, an anticorrosive agent, a surfactant and a preservative, wherein the graphite powder is added, so that the heat exchange process in the ice crystal can be accelerated. When the freezing system runs, heat in ice crystals can be transmitted to other parts of the freezing system more quickly through the graphite powder network, so that the freezing process of the ice crystals is accelerated, and the refrigerating efficiency is improved; the stabilizer can ensure that the graphite powder is uniformly distributed in the ice crystal and prevent the graphite powder from precipitating or agglomerating, so that more stable heat exchange and more uniform ice crystal growth can be realized; the nucleating agent can promote nucleation of ice crystals under specific temperature and conditions, so that the growth speed and form of the ice crystals are controlled, and the freezing effect and the product quality can be optimized.

The application discloses a method for improving notch sensitivity of a GH2909 alloy forge piece and the GH2909 alloy forge piece, and comprises the following steps: S1, selecting a rod-shaped blank to be heated for the first time and kept warm; S2, heating the rod-shaped blank in S1 for the second time and keeping warm; S3, placing the rod-shaped blank in S2, which reaches the keeping-warm time, into a forging equipment to be forged into a shape; S4, rapidly cooling the forge piece obtained in S3; S5, performing surface defect treatment on the cooled forge piece; and S6, performing aging heat treatment on the forge piece after the surface defect treatment. The GH2909 forge piece produced by the method has no persistent notch sensitivity problem, and a forge piece with qualified structure and mechanical properties can be obtained.

The present invention discloses a local high-pressurization and refinement device for wheel anti-gravity casting, the local high-pressurization and refinement device comprises a local pressurization mechanism and a refinement mechanism; the local pressurization mechanism is arranged below the position corresponding to the wheel center on the anti-gravity casting wheel mold, comprising a pressure driving unit, a pressure transmission unit and a pressure applying unit, the pressure applying mechanism contacts the metal melt, and applies pressure to the metal melt after the filling is completed; the refinement mechanism is arranged on the anti-gravity casting wheel mold, above the position corresponding to the wheel center, and refines the metal melt during its solidification process. The present invention can be applied to the anti-gravity casting molding device of aluminum alloy castings with multi-liter liquid tube filling, and locally pressurizes the metal melt at the center of the casting, eliminates shrinkage cavities and shrinkage, and realizes the refinement of grains, which significantly improves the mechanical properties of the casting.

The invention discloses a PS flame retardant masterbatch and a preparation method thereof, belonging to the technical field of flame retardant masterbatch. The preparation method comprises the following steps: preparing a first flame retardant, preparing a second flame retardant, mixing and granulating; the preparation of the first flame retardant comprises the following steps: preparing a mixed solution, preparing a cross-linked microsphere, preparing a magnesium hydroxide sol, compounding and silane modification; the preparation of the second flame retardant comprises the following steps: expansion, inclusion, intercalation and coating; the preparation method of the invention can improve the flame retardant property of a PS material prepared from the PS flame retardant masterbatch, and can also improve the transparency, anti-melting droplet property, mechanical strength and impact resistance of the PS material prepared from the PS flame retardant masterbatch, and reduce the smoke emission and thermal conductivity of the PS material prepared from the PS flame retardant masterbatch.

The invention discloses a chemical plating method for improving the surface hardness of an aluminum alloy. The chemical plating method comprises the following preparation steps: (1) preparing a nano powder solid phase; (2) preparing plating solution doped particles; (3) pickling to obtain a pickled aluminum alloy plate; (4) modifying to obtain an aluminum alloy plate surface; (5) a plating solution is prepared, the plating solution comprises doped particles, thiourea, nickel sulfate, copper sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate and lauryl sodium sulfate, and a solvent is water; and plating to obtain the aluminum alloy with high surface hardness. According to the process, the surface of the aluminum alloy is plated with a layer of doped particle-Ni-Cu-P composite coating, the corrosion resistance and the wear resistance of the aluminum alloy are remarkably improved through the coating, the durability is improved, and the maintenance cost is reduced.