640 results about "Silicon alloy" patented technology

The invention provides a pre-buried brazing flux aluminum alloy brazing filler metal plate blank and a preparation method thereof, a pre-buried brazing flux composite aluminum alloy brazing plate strip and a preparation process and application thereof. After the mixed powder of the aluminum-silicon alloy and the brazing flux is pressed into the cylinder, the cylinder is extruded into the aluminum alloy brazing filler metal plate blank with the pre-embedded brazing flux through the semi-continuous extruding machine, the production efficiency is high, the yield is high, and the prepared aluminum alloy brazing filler metal plate blank with the pre-embedded brazing flux is uniform in component and good in extensibility. The prepared pre-buried brazing flux aluminum alloy brazing filler metal plate blank and an aluminum alloy core material are easy to roll and compound, the obtained pre-buried brazing flux composite aluminum alloy brazing plate strip has a good compound interface, does not have obvious defects such as slag inclusion, bubbles, layering and peeling, has the mechanical property meeting the requirements, has excellent ductility and good brazing performance, and is suitable for large-scale production. And the brazing effect with other aluminum components is good, the surface of a workpiece is bright, and soldering flux traces are not left. The technology can greatly simplify the manufacturing process of the aluminum heat exchanger, and can be used for large-scale industrial production.

The invention discloses a method for manufacturing 7072 alloy high-performance air conditioner foil in a low-carbon, efficient and short-process mode, and relates to the technical field of aluminum foil machining. S2, continuous casting and rolling; s3, cold foil rolling; s4, finished product annealing; and S5, checking and packaging. Through component adjustment, iron and silicon alloy elements are controlled at the lower limit of the national standard, generation of coarse aluminum-iron-silicon phases is reduced, and low ductility caused by coarse grains after finished product annealing is avoided; in the cold foil rolling process, indexes of a working roll and rolling oil are adjusted, process parameters are optimized, the blank is directly rolled into a finished product, the direct rolling process is beneficial to improving the mechanical property of the finished product, and punching production of downstream customers is facilitated; and after triple continuous rolling is finished, subsequent cold foil rolling continuous rolling is rapidly arranged, deformation heat generated by triple continuous rolling and rolling of each pass is fully utilized, and large-machining-rate rolling of each pass is achieved.

The invention provides a manganese-silicon alloy and a production method thereof, and the production method comprises the following steps: respectively crushing a manganese-containing material, silica and coke in proportion, mixing with a dephosphorizing agent, adding a binder and a proper amount of water to prepare a premix, pressing the premix into smelted pellets, and drying; the dried smelting pellets are put into a closed electric furnace to be smelted, and alloy melt is obtained; transferring the alloy melt into a steel ladle, and blowing magnesium powder for desulfurization; the desulfurized alloy melt is subjected to slagging-off, and manganese-silicon alloy molten iron is obtained; and the manganese-silicon alloy molten iron is poured into a mold for ingot casting, and a manganese-silicon alloy finished product is obtained after cooling. According to the method, the raw materials such as the manganese material, the silica, the coke and the dephosphorizing agent are crushed respectively and then mixed, briquetted and smelted, so that the dephosphorizing and desulfurizing effects can be improved, and sulfur in the alloy can be further removed by spraying magnesium powder outside the furnace for desulfurization, so that the quality of the manganese-silicon alloy is improved.

The invention provides a negative plate and a battery. The negative plate comprises a negative current collector and a coating, and the coating is divided into an inner layer and an outer layer; the inner layer is close to the surface of the negative current collector and the outer layer is away from the surface of the negative current collector; the first negative electrode active substance of the inner layer comprises a silicon-based negative electrode material, and the silicon-based negative electrode material comprises at least one of silicon oxide, silicon carbide, nano silicon and silicon alloy. The second negative electrode active material of the outer layer comprises a carbon negative electrode material, and the carbon negative electrode material comprises at least one of natural graphite, artificial graphite, hard carbon, soft carbon, mesocarbon microbeads and graphene. By adopting the specific double-layer active material layer structure, the performance of the negative electrode is effectively improved, and the energy density and the fast charging performance of the battery are improved. Meanwhile, due to the special multi-layer structural design, the volume expansion effect of the silicon-based negative electrode material can be effectively relieved, the structural stability of the negative electrode is optimized, the structural stability of the negative electrode can be kept for a long time in the charge-discharge cycle, and then the battery performance is optimized.

The invention relates to an aluminum-based composite material, in particular to a preparation method of an in-situ micro-nano Al2O3 particle reinforced aluminum-based composite material. The preparation method comprises the following steps: carrying out ball-milling pre-dispersion on silica powder, calcined kaolin and aluminum powder according to a specified ratio, stirring an Al-Si alloy melt at a semi-solid temperature, adding ball-milling mixed powder, heating to a temperature above an Al-Si alloy liquidus, dispersing reactant powder by using a blade-tray integrated stirring device, heating, carrying out heat preservation, carrying out heat preservation, and carrying out vacuum drying to obtain the aluminum-silicon alloy. And reacting to generate in-situ micro-nano Al2O3 particles, cooling, supplementing alloy elements, refining, and pouring to obtain the in-situ micro-nano Al2O3 particle reinforced composite material. According to the blade-tray integrated stirring device, mechanical stirring and the rolling and impacting effects of the ceramic balls are combined, the problem of one-time dispersion of micro-nano reactant powder is effectively solved, meanwhile, passivation of edges and corners of micron particles is achieved, and the comprehensive performance of in-situ particle reinforced aluminum matrix composites is improved.

The invention discloses a component global homogenized C / C-UHTCs composite material and a preparation method thereof.The preparation method comprises the steps that non-woven cloth is laid, then needling is conducted in the Z direction to obtain a carbon fiber preform, chemical vapor deposition is conducted on the carbon fiber preform to obtain a C / C composite material, molten salt infiltration treatment is conducted on the C / C composite material, a C / C-UHTCs porous body containing a UHTCs interface layer is obtained, and the C / C-UHTCs porous body containing the UHTCs interface layer is obtained; carrying out reactive infiltration treatment on the C / C-UHTCs porous body by adopting silicon-containing alloy powder to obtain a C / C-UHTCs composite material; the C / C-UHTCs composite material prepared by the preparation method provided by the invention has the advantages of extremely high density, extremely low porosity, no fiber damage, intact interface and uniformization of components, the mass ablation rate is a negative value after the C / C-UHTCs composite material is ablated by oxyacetylene flame at 2600 DEG C for 180s, and the C / C-UHTCs composite material has extremely excellent ablation resistance.

The invention provides an amorphous copper nanolayer coated spherical porous silicon composite material and a preparation method and application thereof.The preparation method includes the step that the surface of spherical porous silicon is coated with an amorphous copper conductive nanolayer through a simple solution method.On the basis of the principle of replacement reaction, aluminum in aluminum-silicon alloy is replaced with copper to be coated on the surface of silicon, and the amorphous copper nanolayer coated spherical porous silicon composite material is obtained. And meanwhile, the rate of the replacement reaction is slowed down by utilizing different reaction activities of copper chloride in an organic solvent, so that the spherical morphology is kept, and meanwhile, the surface of silicon can be coated with a layer of amorphous copper nano layer with high conductivity. The invention also provides a preparation method of the material. Tests find that the conductivity of the material can be effectively improved due to the excellent conductivity of the copper nano layer, and the volume expansion effect of the material in the electrochemical cycle process can be effectively relieved due to the porous structure. Therefore, the combination of the two effectively improves the problems of poor conductivity and unstable structure of the silicon negative electrode material, and effectively improves the application performance of the silicon negative electrode material in the lithium ion battery negative electrode.

A package includes a bridging element (an OMIB), and first and second photonic paths, forming a bidirectional photonic path. The OMIB has first and second interconnect regions to connect with one or more dies. Third and fourth unidirectional photonic paths may couple between the first interconnect region and an optical interface (OI). A photonic transceiver has a first portion in the OMIB and a second portion in one of the dies. The first and the second portions may be coupled via an electrical interconnect less than 2 mm in length. The die includes compute elements around a central region, proximate to the second portion. The OMIB may include an electro-absorption modulator fabricated with germanium, silicon, an alloy of germanium, an alloy of silicon, a III-V material based on indium phosphide (InP), or a III-V material based on gallium arsenide (GaAs). The OMIB may include a temperature compensation for the modulator.

The invention discloses a modified silicon negative electrode material and a preparation method and application thereof, belongs to the technical field of all-solid-state batteries, and can compensate the active lithium loss of the whole battery, improve the cycle performance of the battery and relieve the volume change through negative electrode pre-lithiation. The method comprises the following steps: pressing silicon powder into blocks under a certain pressure; coating the blocky silicon and the cut lithium foil according to a certain proportion, grinding and mixing to obtain a precursor I; under the protection of inert gas, the precursor I is heated for the first time, and a powder precursor II is obtained; and grinding the precursor II, pressing the precursor II into blocks, heating the blocks in a vacuum or inert atmosphere to a preset temperature, and grinding the blocks to obtain the lithium-silicon alloy. The preparation process is simple, the silicon negative electrodes with different pre-lithiation degrees can be prepared by controlling the lithium addition amount, the cycling stability of the battery is improved, and the volume expansion of the electrode is relieved.

A seamless flux-cored wire for 10CrNiCu steel for ships, applied to welding of continuous casting 907A steel for a main hull and composed of a low-carbon steel sheath and a flux core. The diameter of the wire is 1.0-1.4 mm; the filling rate of flux-cored powder is 14%-16%; measured as the mass percentage of the flux-cored wire, the flux core contains rutile, aluminum oxide, ferroboron, zircon sand, quartz, bismuth oxide, potassium titanate, sodium fluoride, electrolytic manganese, ferrotitanium, magnesium powder, manganese-silicon alloy, nickel powder, metal chromium, copper powder, and iron powder. The seamless flux-cored wire for 10CrNiCu steel for ships has the advantages of good welding performance, stable mechanical properties, good crack resistance, low diffusion hydrogen content, high moisture absorption resistance, excellent rust resistance, and the like. Also provided is a method for manufacturing the seamless flux-cored wire for 10CrNiCu steel for ships

The invention discloses a method for preparing a lithium-copper composite negative electrode by utilizing lithium slag and application, and the preparation method of the negative electrode comprises the following steps: adding the lithium slag with certain concentration after removing impurities such as Ca < 2 + >, Mg < 2 + > and Fe < 3 + > through acid treatment into metal lithium in a molten state, and fully stirring until the reaction is complete; and coating the molten metal lithium obtained after the reaction on a current collector to obtain the modified lithium metal negative electrode plate. The prepared lithium-copper composite negative electrode has a lithium-loving 3D frame structure, volume expansion in the circulation process can be inhibited, lithium oxide, lithium aluminum alloy and lithium silicon alloy existing on the 3D frame structure can serve as lithium-loving sites for uniform lithium ion deposition, lithium dendrite growth is inhibited, and long-term stable circulation of the lithium metal negative electrode is promoted.

The invention provides a method for improving the manganese recovery rate of a silicon-manganese alloy, which comprises the following steps: sequentially filling smelting raw materials into a closed electric furnace for smelting to obtain an alloy melt; transferring the alloy melt into a steel ladle, and blowing magnesium powder for desulfurization; the desulfurized alloy melt is subjected to slagging-off, and manganese-silicon alloy molten iron is obtained; the manganese-silicon alloy molten iron is poured into a mold for ingot casting, and a manganese-silicon alloy finished product is obtained after cooling; the smelting raw materials are sequentially filled with a backing material, a mixture and a surface material from bottom to top in the closed electric furnace; the surface material comprises aluminum powder and calcium carbide which are mixed according to a certain proportion, in the method, the surface material comprises the aluminum powder and the calcium carbide which are mixed according to a certain proportion, the effect of a reducing agent can be achieved while the ignition effect is achieved, manganese can be directly reduced in the reaction through addition of the aluminum powder, and therefore the effect of improving the manganese recovery rate is achieved.

The invention relates to the technical field of cast aluminum-silicon alloys, in particular to a low-cost ultrahigh-toughness cast aluminum-silicon alloy material and a preparation method thereof. The aluminum-silicon alloy material comprises the following components in percentage by weight: 7.0%-9.0% of silicon, 0.30%-0.50% of magnesium, 1.60%-2.00% of copper, less than or equal to 0.2% of zinc, less than or equal to 0.2% of iron, 0.20%-0.40% of manganese, less than or equal to 0.2% of chromium, 0.05%-0.3% of zirconium, 0.03%-0.2% of titanium, less than or equal to 0.04% of strontium and the balance of aluminum and other impurities. Wherein the total content of other impurities is less than or equal to 0.15%, and the content of a single impurity is less than or equal to 0.05%. The aluminum-silicon alloy material provided by the invention has relatively excellent comprehensive properties such as tensile strength and elongation and relatively low cost, and can replace traditional cast aluminum, deformed aluminum, medium-low grade ductile iron, gray iron, carbon steel, plates and other materials, so that the weight-reducing and light-weight design of parts is realized.

The invention relates to the field of material science and mechanical engineering, in particular to a high-strength aluminum-magnesium-silicon material bolt for a new energy automobile and a preparation method of the high-strength aluminum-magnesium-silicon material bolt. The bolt is made of an aluminum-magnesium-silicon alloy, and the alloy contains magnesium, silicon, manganese, iron, chromium, titanium, scandium, rare earth elements and the balance of aluminum. By optimizing the proportion of rare earth elements (yttrium, lanthanum and cerium) and scandium, grains are effectively refined, the tensile strength, the yield strength and the ductility are improved, and meanwhile the corrosion resistance and the fatigue resistance are enhanced. The preparation method comprises the steps that vacuum melting is combined with the ultrasonic-assisted technology, alloy elements are evenly distributed, and then the material structure is optimized through solution treatment at the temperature of 540 DEG C for 1.5 h and aging treatment at the temperature of 160 DEG C for 8 h. And the surface of the bolt is subjected to anodic oxidation and coated with a composite coating containing silicon dioxide nanoparticles, so that the wear resistance and the corrosion resistance are improved. Through verification, the bolt has the excellent performance that the tensile strength is larger than or equal to 490 MPa, the yield strength is larger than or equal to 440 MPa, the ductility is larger than or equal to 8.5%, and the salt spray test time is larger than or equal to 1500 hours, and the fastening requirement of the new energy automobile under the complex working condition is met.

The invention provides natural color anodized aluminum alloy powder and a preparation method and application thereof, and belongs to the field of additive manufacturing. The method comprises the following steps: remelting an aluminum-silicon alloy and magnesium silicate to obtain an aluminum-magnesium-silicon alloy; a mixed raw material is prepared from an aluminum-magnesium-silicon alloy, pure magnesium, pure aluminum and an aluminum-zirconium alloy, and is formed based on ultrasonic suspension smelting and rapid cooling; the aluminum alloy powder comprises the following components in percentage by weight: 1.0-5.0% of Zr, 1.0-5.0% of Al, 1.0-5.0% of Zr, and the balance of aluminum. 0.4 to 1.0 wt% of Mg; 0.4 to 1.0 wt% of Si; the balance is Al and inevitable impurities; wherein the weight ratio of Si to Mg is 1: 1. The material can be used for additive manufacturing molded consumer electronics. According to the method disclosed by the invention, on the premise of reducing the types and the dosage of strengthening elements, the aluminum alloy which is uniform in structure, free of obvious segregation, isotropic in mechanical property, free of the problems of pits and layer lines after anodizing and free of color difference is prepared by adopting an ultrasonic suspension smelting and hypersonic inert gas atomization method.

The invention relates to the technical field of coatings, in particular to a coating suitable for niobium-silicon alloy surface high-temperature protection and a preparation method of the coating. The coating comprises the following raw materials in parts by weight: 100-120 parts of deionized water, 60-80 parts of nickel-chromium-aluminum-yttrium alloy powder, 60-80 parts of enamel glaze, 50-60 parts of filler, 20-40 parts of a binder, 10-20 parts of nano titanium dioxide and 6-10 parts of an additive. According to the invention, during preparation of the coating, through addition of the filler, the negative thermal expansion performance of zirconium tungstate in the filler and volume shrinkage of zirconium tungstate in a high-temperature state, a buffer space is provided for thermal expansion of other materials in the coating, cracks of the coating due to thermal stress are avoided, and the high-temperature resistance of the coating is improved; kH560 enhances the interfacial compatibility of zirconium tungstate, avoids agglomeration of zirconium tungstate, and enables the zirconium tungstate to be more uniformly distributed in a coating system.

The invention discloses a heat-resistant aluminum-based composite material and a selective laser melting forming preparation method and application thereof, and belongs to the technical field of metal material additive manufacturing. According to the method, aluminum-silicon alloy matrix powder and nano CuO powder are mixed to serve as cladding powder, Al2O3 and Al2Cu nano particles and precipitated phases which are evenly distributed are directly generated in matrix alloy through in-situ reaction of Al-CuO in a selective laser melting process under the action of high-energy laser, and an aluminum-silicon eutectic structure can be refined to 200-300 nm. Cooperative strengthening of multiple precipitated phases and multiple interfaces is achieved, and the problems of coarse precipitated phases, unmelted particles and the like generated by traditional alloying methods and the like are solved. According to the method, the high-temperature mechanical property of the selective laser melting forming aluminum-based composite material can be remarkably improved. The prepared composite material is suitable for high-temperature light-weight components such as aerospace and nuclear energy equipment, and has a wide application prospect.

The present invention discloses a preparation method and use of an Al2O3-Al composite packaging material, and the preparation method comprises the following steps: step A: uniformly mixing aluminum powder, aluminum oxide powder, CuO-TiO2 powder and ceramic particle additive powder to obtain a mixed raw material A; step B: adding a polyvinyl alcohol aqueous solution to the mixed raw material A and grinding it fully to obtain a mixed raw material B; step C: placing the mixed raw material B in a ball mill for ball milling, and obtaining a mixed raw material C after the ball milling is completed; step D: cold-pressing the mixed raw material C to obtain a prefabricated block; step E: placing the prefabricated block in a resistance furnace for sintering, and cooling it to room temperature with the furnace after the sintering is completed, to obtain an Al2O3-Al composite packaging material. The composite packaging material is used to encapsulate an aluminum-silicon alloy phase change heat storage material. The composite packaging material prepared by the present invention can be used to encapsulate an aluminum-silicon alloy phase change heat storage material, and has the advantages of good corrosion resistance and not easy to leak.

A Si alloy powder for a negative electrode, the Si alloy powder including: a Si phase; a SiX compound phase; and at least one selected from the group consisting of a SnY compound phase and a AlY compound phase, in which the element Y in the SnY compound phase and the AlY compound phase includes at least one element selected from the group consisting of Cu, Fe, Ni, Cr, Co, Mn, Zr, and Ti, the Si alloy powder has an average particle diameter of 30 μm or less, and an amount of the Si phase in an entire Si alloy is 30 mass % to 95 mass %.

The invention provides a secondary battery and an electrochemical device, and relates to the field of electrochemical energy storage. The secondary battery comprises an electrolyte and a negative pole piece, the electrolyte comprises a first substance, and the first substance comprises at least one of compounds with a structure as shown in a formula I; the negative pole piece comprises a negative pole material layer; the negative pole material layer comprises carbon black, single-walled carbon nanotubes, carbon fibers and a silicon-based material; the silicon-based material comprises at least one of a silicon-carbon material, a silicon-oxygen material, a silicon alloy material and a pure silicon material. According to the secondary battery, the electrolyte is designed to contain a compound with a specific structure as shown in the formula I, the mass content of the compound is controlled to be 0.5%-30%, and meanwhile, the negative electrode material layer comprises carbon black, single-walled carbon nanotubes and carbon fibers, so that the high-temperature storage performance, the cycle performance and the high-low-temperature fast charging performance of an electrochemical device containing a silicon negative electrode are remarkably improved.

The invention relates to the technical field of secondary aluminum-silicon alloys, in particular to a preparation method of a heat-treatment-free secondary aluminum-silicon alloy. An Mn element and a Cr element are adopted for conducting iron-rich phase modification on the iron-containing secondary aluminum-silicon alloy, and the secondary aluminum-silicon alloy comprises, by mass, 10.0%-12.0% of Si, 1.0%-3.0% of Cu, 0.8%-1.1% of Fe, 0.5%-3.0% of Cr, 0.1%-2.0% of Mn, smaller than 0.30% of Mg, smaller than 2.0% of Zn, smaller than or equal to 0.18% of inevitable impurities and the balance aluminum. The composite modifier is composed of an intermediate alloy containing Mn and Cr elements, the mass ratio of the Mn element to the Cr element in an alloy melt is 0.1-1.5, and the ratio of the mass sum of the Mn element and the Cr element in the alloy melt to the mass of the Fe element is 2.8. By adding the composite modifier, the morphology of the iron-rich phase in the secondary aluminum-silicon alloy is effectively modified, and meanwhile, the eutectic Si phase is regulated and controlled, so that the purposes of refining the alloy structure and improving the mechanical property of the material are achieved.

The invention provides a preparation method of a fully-active lithium-silicon alloy negative electrode material, which comprises the following steps: (S1) adding lithium foil and silicon powder treated by hydrofluoric acid into a ball milling tank, and performing ball milling in an inert atmosphere to obtain mixed powder; (S2) pressing the mixed powder into a compact precast block; heating the precast block to 450-550 DEG C by using a smelting furnace, and keeping the temperature for 10-20 minutes, so that the lithium part is molten to wet the silicon; (S3) the temperature is increased to the reaction temperature of 680-850 DEG C, heat preservation reaction is carried out for 10-30 min, metal lithium and silicon are fully reacted, and molten alloy is obtained; and (S4) the molten alloy is sprayed to a water-cooled rotating copper roller through a quartz nozzle, the rotating speed of the rotating copper roller is 3000-5000 rpm, and the fully-active lithium-silicon alloy is obtained after cooling. The obtained lithium-silicon alloy has the characteristic of high amorphization, has extremely high ion-electron conductivity and relatively low hardness, and can relieve expansion and shrinkage of a negative electrode in a charging and discharging process, so that the rate capability and the cycling stability of a sulfide solid-state battery are improved.

The invention discloses an anti-fatigue aluminum alloy bar. The anti-fatigue aluminum alloy bar is formed by compounding 90-95 wt% of modified aluminum alloy and 5-10 wt% of a porous composite ceramic framework. A modified aluminum alloy is a hypereutectic aluminum-silicon alloy, a used modifier is a P + La + Gd composite modifier, the size and morphology of primary silicon and eutectic silicon can be effectively improved, the effects of melt purification, refining and degassing are achieved, and the organization structure and performance of the aluminum alloy are optimized. The porous composite ceramic skeleton is composed of cubic boron nitride and aluminum nitride, the porosity is 65-75%, the aperture is 200-300 microns, and the porous composite ceramic skeleton has high strength, high hardness and a three-dimensional network structure, is well combined with an aluminum alloy matrix, and has isotropy as an alloy reinforcement. The aluminum alloy bar integrates high plasticity and high toughness of an aluminum alloy and high strength and high hardness of a ceramic material, is excellent in comprehensive mechanical property and has excellent anti-fatigue performance.

The invention provides a manganese-silicon alloy smelting feeding regulation and control method and system, manganese iron ore and silica are pretreated to obtain fine manganese iron ore materials and silica powder, and the fine manganese iron ore materials and the silica powder are mixed with quick lime to obtain a spherical mixture; the spherical mixture meeting the preset morphological structure is screened for preheating treatment, and the feeding state of at least part of the preheated spherical mixture to the smelting furnace is adjusted based on the real-time preheating state characteristics of the spherical mixture; based on the feeding amount of the spherical mixture of the smelting furnace, the feeding state of coke to the smelting furnace is adjusted; the smelting reaction state in the smelting furnace is recognized on the basis of tail gas emission characteristics of the smelting furnace, so that the feeding state of the coke into the smelting furnace is adjusted again, all the spherical mixtures have material components with proper proportions, different materials make full contact, it is guaranteed that all the spherical mixtures can be independently subjected to smelting reaction, and the smelting efficiency is improved. And the feeding amount of the spherical mixture and the coke is adaptively adjusted, and the smelting reaction efficiency and the manganese-silicon alloy smelting yield are improved.

The invention provides a battery negative electrode plate and a battery, the battery negative electrode plate comprises a silicon-based negative electrode active material and a binder, the binder is a product obtained by crosslinking a phenylboronic acid compound modified polyacrylic acid compound and a hydroxylated carbon nanotube, the silicon-based negative electrode active material comprises at least one of a silicon material, a silicon oxide material, a silicon carbon material and a silicon alloy material. The invention provides a battery negative plate. A three-dimensional conductive network binder based on crosslinking of a phenylboronic acid compound modified polyacrylic acid compound and a hydroxylated carbon nanotube and a silicon-based negative electrode material are adopted. The network structure provides excellent mechanical strength and flexibility for the negative electrode, and due to the excellent mechanical strength and flexibility, the silicon negative electrode shows excellent cycling stability, high reversible capacity and stable electrochemical impedance in a battery test.

A back-contact cell and a preparation method therefor, and a cell module, which belong to the technical field of back-contact cells. The back-contact cell comprises: a silicon wafer, which has a front surface and a back surface; and first semiconductor layers and second semiconductor layers, which are disposed on the back surface and are alternately arranged in the Y-axis direction of the silicon wafer. The back-contact cell further comprises a silicon alloy layer and a metal conductive layer, which are sequentially disposed outwards in the Z-axis direction of the silicon wafer, wherein the silicon alloy layer is disposed on the outer surfaces of the second semiconductor layers and extends to the outer surfaces of adjacent first doped silicon crystal layers; and the sheet resistance of the silicon alloy layer is 60-100 Ω / □, and the sheet resistance of the metal conductive layer is 3-50 Ω / □. In the back-contact cell, it is unnecessary to additionally provide a transparent conductive film layer, fingers and busbars, and the manufacture procedure is simpler; in addition, the use of expensive low-temperature silver paste and transparent conductive film layers is not required, thereby significantly reducing the production costs of the cell, and also ensuring excellent cell conversion efficiency.

The invention discloses a Sr, La and Ti composite modified refined hypoeutectic aluminum-silicon alloy and a preparation method thereof, and relates to the technical field of metal materials. The preparation method comprises the following steps: S1, heating an aluminum-silicon alloy ingot until the aluminum-silicon alloy ingot is completely molten, and introducing argon for refining treatment to obtain alloy liquid; s2, a modifier containing Sr is added and stirred, then a modifier containing La is added and stirred, and finally a refiner containing Ti is added and stirred; and S3, the alloy liquid is cast, and an aluminum-silicon alloy casting is obtained. By means of Sr, La and Ti composite modification and refinement, eutectic silicon in the hypoeutectic aluminum-silicon alloy can be changed into a fine fiber shape from a thick sheet shape, the long modification effect is maintained, meanwhile, Sr air suction is avoided, and the pinhole defect of a casting is reduced. A compound formed by the added Ti element can serve as a nucleation mass point of alpha-Al to play a role in refining, a rare earth La compound separated out firstly in the solidification process can pin a grain boundary, and the mechanical property of the hypoeutectic aluminum-silicon alloy is further improved.

The invention belongs to the technical field of lithium ion battery negative electrode material preparation, and relates to a method for preparing a silicon alloy negative electrode based on three-dimensional spin control magnetron co-sputtering, which comprises the following steps: 1, substrate preparation: selecting carbon particles as a negative electrode material substrate; 2, particle three-dimensional spinning suspension: placing the carbon particles in a three-dimensional spinning suspension device, and continuously rolling and rotating in a plurality of space directions in a high vacuum environment; 3, sputtering target material configuration, wherein a silicon target and at least one alloy metal target are arranged in a magnetron co-sputtering cavity; 4, co-sputtering deposition: performing magnetron co-sputtering on the rotating carbon particles in a high-purity argon working atmosphere, and dynamically adjusting the input power of each target to enable a deposition coating to form a gradient composite alloy structure from a rich metal buffer layer to a high-silicon content region to obtain a composite powder material; the high silicon content is guaranteed, meanwhile, a buffer alloy phase and an interface bonding layer are introduced, and the problems of volume expansion and interface stripping in the circulation process are effectively solved.

The invention relates to the technical field of metal heat treatment, in particular to a silicon alloy steel bearing ring high-temperature salt bath quenching process for a high-temperature load environment, which comprises the following steps: S1, carrying out surface sand blasting treatment on a silicon alloy steel bearing ring; s2, stepped heating-heat preservation-cooling treatment is carried out, and the uniformly austenitized ferrule is obtained; s3, the uniformly austenitized ferrule is immersed in a composite salt bath; s4, staged cooling treatment of an air cooling stage and an oil cooling stage is conducted in sequence; s5, the martensite matrix ferrule is subjected to subzero treatment and staged heating; and S6, multi-stage tempering treatment with different temperature gradients is conducted, and the final high-temperature bearing ring is obtained. Through the combined process of stepped austenitizing, composite salt bath ultrasonic quenching, graded cooling, deep cooling and multi-stage tempering, homogenization and stabilization of the structure of the bearing ring are achieved, and the dimensional stability and the tempering resistance of the bearing ring in the high-temperature load environment are improved.

The invention provides a flux-cored wire for marine crack arrest steel and a preparation method and application of the flux-cored wire, and particularly relates to the technical field of welding materials. The flux-cored wire comprises a steel strip and a flux core filled in the steel strip, and the flux core comprises the following components in parts by weight: 10-15 parts of rutile, 5-6 parts of quartz, 2-4 parts of ferrotitanium, 20-40 parts of sodium fluoride, 20-40 parts of potassium feldspar, 6-18 parts of manganese-silicon alloy, 4-8 parts of low-carbon ferromanganese, 1.5-2.5 parts of magnesium powder, 1.5-2 parts of rare earth ferrosilicon, 0.2-0.4 part of ferroboron, 1-2 parts of metallic nickel and 1.5-6 parts of iron powder. The ship crack arrest steel flux-cored wire has the advantages of being high in strength, good in low-temperature toughness, good in crack resistance, high in deposition rate, stable in electric arc, little in splashing, easy in slag removal and attractive in weld joint forming, and is suitable for welding of crack arrest steel at a core structure part of an ultra-large container ship.