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52 results about "Dendrite (metal)" patented technology

A dendrite in metallurgy is a characteristic tree-like structure of crystals growing as molten metal solidifies, the shape produced by faster growth along energetically favourable crystallographic directions. This dendritic growth has large consequences in regard to material properties.

Anti-dendrite lithium metal negative electrode, preparation method thereof and solid-state battery

The invention provides an anti-dendrite lithium metal negative electrode, a preparation method thereof and a solid-state battery. The lithium metal negative electrode is of a three-layer structure and sequentially comprises a current collector, an active substance layer and a control layer, the active substance layer is a lithium metal and / or lithium alloy layer, and the control layer is a three-dimensional network structure layer containing boron nitride nanotubes and a solid electrolyte material. The solid electrolyte material comprises a polymer matrix, an inorganic reinforcing material, a lithium salt, a thickening agent and a hydrophilic additive. In the control layer, the boron nitride nanotube is of a nanoscale fibrous structure, the lattice structure and polarity of the boron nitride nanotube significantly reduce the energy barrier of lithium surface diffusion, the reversible reaction of lithium ions is promoted, and the uniform flux of the lithium ions and the inhibition of dendritic crystal growth are facilitated; the solid electrolyte material has high ionic conductivity, the flexibility of the boron nitride nanotubes is improved through the synergistic effect of the solid electrolyte material and the boron nitride nanotubes, and the compatibility of the lithium metal negative electrode and various solid battery electrolytes is improved.
Owner:CHINA ENERGY LITHIUM

Rare earth metal electrolysis system and electrolysis furnace thereof

The invention discloses a rare earth metal electrolysis system and an electrolysis furnace thereof, and relates to the technical field of metallurgy, the rare earth metal electrolysis system is characterized by comprising a potential data acquisition and preprocessing module, a dendritic crystal feature extraction and quantification module, a dendritic crystal identification and intelligent determination module and an inverse pulse control and dynamic regulation module, in the electrolysis process, potential distribution original data of the surface of a rare earth metal cathode are detected and collected in real time, the obtained original data are preprocessed, and a preprocessed potential data set is established based on a time sequence. According to the method, intelligent, real-time and accurate inhibition of dendritic crystals in the rare earth metal electrolysis process is achieved, short circuit, splashing and electrode ablation are effectively prevented, the compactness and purity of metal deposition are improved, the current efficiency is remarkably improved, and compared with a traditional scheme, the method has the advantages of being high in real-time performance, good in inhibition effect, small in interference and high in adaptability, and the method is suitable for popularization and application. And efficient and safe preparation of the rare earth metal is ensured.
Owner:GANZHOU CHENXIN METAL MATERIALS CO LTD

Smelting and casting method of high-toughness regenerated aluminum alloy

The invention relates to the technical field of metal casting, and discloses a smelting and casting method of a high-toughness regenerated aluminum alloy, which comprises the following steps: measuring the iron content of a regenerated aluminum melt, regulating and controlling the manganese-iron ratio, heating the melt to 750-790 DEG C, and carrying out overheating treatment to eliminate a hereditary core; cooling to 630-645 DEG C, applying a mechanical shear flow field with the average shear rate not lower than 60s <-1 > in the interval, stripping a diffusion boundary layer on the surface of the iron-rich phase crystal nucleus by utilizing fluid drag force, breaking dendritic crystals, and separating out in a polyhedral or spherical manner; according to the method, through active intervention of a critical shear flow field, the problem of needle-like growth of an iron-rich phase caused by solute diffusion blocking in a traditional technology is solved, in-situ generation of the harmless iron-rich phase in the high-iron-content secondary aluminum is achieved, the obdurability of a die casting is improved, and dependence on the purity of raw materials is reduced.
Owner:HUNAN QIANYUAN ALUMINUM CO LTD

Ferroelectric Separators for Suppressing Dendrites Growth in Rechargeable Batteries

A mesoporous piezoelectric or ferroelectric (FE) Al2O3 / P(VDF-TrFE) membrane can actively suppress anode dendrites formation when used as a separator in rechargeable aqueous Zn-ion batteries. When the positive polarization side of the FE separator faces the metal anode during charging, the FE separator can reverse the local energetics for Zn2+ reduction at the protrusion area and deplete incoming Zn2+ ions to the flat region. As a result, the symmetric Zn—Zn cell with this P+ separator can achieve a substantially higher cycling stability.
Owner:WISCONSIN ALUMNI RES FOUND

A carbon carrier material with sodium dendrite growth alleviation, rich in microporous and closed pore structure, and a preparation method and application thereof

The application discloses a carbon carrier material for relieving sodium dendrite growth, rich in micropores and closed pore structure, and a preparation method and application thereof, and belongs to the technical field of low-dimensional material energy storage devices. The preparation method comprises the following steps: SO1, cross-linking reaction of a phenol source, a cross-linking catalyst and a formaldehyde solution; SO2, obtaining an impurity-containing sample through a high-temperature carbonization reaction; and SO3, adding the impurity-containing sample into a solvent for soaking, suction filtration, washing and drying to obtain the carbon carrier material. The carbon carrier material prepared by the application is uniformly distributed, the selection and pore size of the pores are adjustable, can effectively provide rich sodium-philic sites for inducing uniform deposition of sodium, and can inhibit the dendrite growth of a sodium metal battery in a cycle process; the pores serve as three-dimensional Na + Transmission channels are beneficial to forming a good ion migration path, reducing the current density of a local material, reducing the possibility of forming dendrites, and improving the safety and service life of the energy storage device.
Owner:GUANGDONG UNIV OF TECH

A grid mapping method for pool dynamics and phase-field method dendrite growth calculation

The application discloses a grid mapping method for finite element method or finite volume method and phase field method dendrite growth calculation. The application relates to the technical field of welding simulation. Specifically comprises the following steps: step 1, obtaining the field variable distribution in the numerical simulation calculation of the finite element method or the finite volume method welding process; step 2, exporting the coordinates and field variable data of the nodes with the temperature greater than the metal melting point; step 3, performing triangular partitioning on the melting area according to the node coordinates; step 4, drawing the Voronoi diagram of the melting area according to the circumcenters of the Delaunay triangles; step 5, setting the phase field method nodes; step 6, sequentially processing the units in the Voronoi diagram, taking the base point of the unit and the base point directly connected with the base point as known points, and obtaining the field variable value of the phase field method nodes by the interpolation method; and step 7, using the obtained field variable value for the calculation of the phase field method grain growth.
Owner:SHENZHEN AMBER DIGITAL TECHNOLOGY CO LTD

A method for inhibiting dendrite growth on a zinc foil surface

This invention provides a zinc foil surface treatment method for inhibiting dendrite growth, comprising: immersing a zinc foil with ultrasonically cleaned surface in an acidic mixture to obtain a zinc foil with a preferred zinc (002) crystal facet under acid etching; immersing the zinc foil with the preferred zinc (002) crystal facet in a mercaptosilane coupling agent solution, and through hydrolysis, forming a nanostructured zinc-silane composite layer on the zinc foil surface; and drying the zinc foil with the zinc-silane composite layer to obtain a zinc foil that can inhibit dendrite growth. The zinc foil surface treatment method for inhibiting dendrite growth described in this invention can generate a zinc-silane composite layer and zinc with (002) crystal facet orientation on the zinc foil surface. This composite layer has a strong zinc ion adsorption capacity, which can improve ion kinetics, promote uniform zinc plating and peeling, and the preferred (002) crystal facet can induce parallel growth of zinc metal and resist electrolyte corrosion, thereby effectively inhibiting zinc dendrites and stabilizing the electrode / electrolyte interface.
Owner:HEBEI UNIV OF TECH

A biodegradable Zn-Mg-Ca-Sr zinc alloy and its preparation method and application

The present invention discloses a biodegradable Zn-Mg-Ca-Sr zinc alloy, its preparation method and application. The elements contained are by weight percentage: Mg 1.10% - 1.20%, the total amount of Ca and Sr is less than or equal to 0.3%, and the balance is Zn. The mass percentage ratio of Ca and Sr is 0, 0.5, 1, 1.5 or 2. The matrix structure of the biodegradable Zn-Mg-Ca-Sr zinc alloy is metallic zinc dendrites, and the strengthening phases in the metallic zinc dendrites are eutectic rod-like Mg2Zn 11 phase, irregular massive CaZn 13 phase and (Ca x , Sr 1‑x )Zn 13 solid solution. The present invention adds Ca and Sr through compound ratio to refine and toughen the structure, and then obtains a biodegradable Zn-Mg-Ca-Sr zinc alloy with fine structure, good morphology and distribution of strengthening phases, and high strength, hardness and toughness, providing technical support for the application of zinc alloy in biodegradable materials.
Owner:XI AN JIAOTONG UNIV +1

Continuous high-phosphorus chemical nickel plating method capable of reducing plating solution crystallization

The invention provides a continuous high-phosphorus chemical nickel plating method capable of reducing plating solution crystallization, which comprises the following steps: preparing a plating solution containing a main salt nickel sulfate, a reducing agent sodium hypophosphite, a complexing agent sodium citrate, a buffering agent and a crystallization inhibitor according to a preset concentration ratio, the crystallization inhibitor is one or more of a compound of organic polybasic phosphonate and nano titanium dioxide, a nitrogen-containing heterocyclic ring compound or a polymer with a comb-shaped structure; and the plating temperature, the pH value of the plating solution and the flow rate of the plating solution are controlled within a preset range, and continuous plating operation is conducted. The crystallization inhibitor is added into the plating solution components, and the crystallization inhibitor and metal ions such as Ni in the plating solution can form a complex and are uniformly dispersed, so that the nickel ion release speed is regulated and controlled, and local crystallization is avoided; in addition, the crystallization inhibitors can also provide a three-dimensional barrier effect and reduce dendritic crystal formation and abnormal growth of crystal grains, so that the effect of reducing crystallization of the plating solution is achieved, and the stability and production efficiency of the plating solution are improved.
Owner:SHENGZHEN KINHU ELECTROPLATING CO LTD

Preparation method of dendrite-free gel electrolyte and application thereof

The application discloses a preparation method of dendrite-free gel electrolyte and application thereof, and comprises the following steps: synthesizing a porphyrin-based covalent organic framework (PPCOF); preparing a gel precursor solution; and preparing an in-situ polymerized PMMA-based gel electrolyte. The electrolyte has the characteristics of simple preparation method, cheap and easily available raw materials, good electrode interface contact (in-situ polymerization), and the like, and can solve the problems of poor PMMA-based GPE electrode contact, low lithium ion transference number and easy growth of lithium dendrites, thereby providing guidance for the development of dendrite-free solid-state lithium metal batteries.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Artificial interface layer / current collector collaborative strategy-based dendrite-free metal anode for rechargeable battery, preparation method and battery

The invention provides a dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector collaborative strategy, and relates to the field of batteries. The metal anode comprises an artificial interface layer, an active material layer and a current collector layer which are sequentially arranged, and the preparation method comprises the following steps: constructing the artificial interface layer on the surface of one side of the active material layer, and connecting the other side of the active material layer with a current collector to obtain the metal anode. The metal anode can intervene in the deposition / stripping process of metal ions, changes the deposition / stripping mode of the metal ions, realizes spatial separation of deposition and deposition / stripping sites of the metal ions on the back of the anode, and effectively improves the interface problem of the metal anode.
Owner:SICHUAN UNIV

A method for preparing carbide microspheres

The application provides a preparation method of metal carbide microspheres, and belongs to the technical field of micro-nano materials. The method comprises the following steps: alloy powder smelting, alloy powder preparation, alloy powder screening, a metal matrix corrosion process, a cleaning process and a screening process, so that a metal carbide micro-nano spherical material is obtained. The metal carbide microspheres can be applied in the fields including but not limited to nuclear materials, energy materials and metal matrix composites. The size of the metal carbide microspheres prepared by the application can be customized in the range of 10-300 um through screening, the average thickness of metal carbide dendrites is 1-20 nm, the average dendrite spacing of the carbide is 1-5 um, and the composition of the metal carbide microspheres can be controlled by alloy composition.
Owner:CHINA MASCH INST OF ADVANCED MATERIALS (ZHENGZHOU) CO LTD

A method of laser powder bed fusion forming of a directional columnar grain structure alloy

PendingCN122644604ATransient heat transferGrain structure
The present application belongs to the technical field of metal additive manufacturing and solidification structure regulation, and particularly relates to a laser powder bed fusion forming method of a directional columnar grain structure alloy. The present application adopts a flat-top beam or a point-ring beam as a forming laser beam, inputs a single-channel three-dimensional transient heat transfer solidification model, obtains a molten pool width, a molten pool depth, a temperature gradient, a solidification rate and a columnar grain-equiaxed grain transition determination result, screens laser power and scanning speed according to the molten pool morphology with a width-depth ratio W / D>3; sets a scanning interval according to the deviation area of the molten pool side temperature gradient vector relative to the preset columnar grain growth direction, so that the overlapping area of adjacent melt channels covers different orientation dendrites or grains on the side; sets the powder layer thickness according to the sensitive area of the columnar grain-equiaxed grain transition at different heights, so that the remelting of the subsequent layer molten pool eliminates the mixed crystals, equiaxed crystals or non-target oriented grains on the top of the previous layer molten pool, and a columnar grain structure metal alloy component is obtained through continuous directional growth across the melt channel and across the layer.
Owner:SHANGHAI UNIV

A conductive dendritic composite gel, its preparation method and application

This invention discloses a conductive dendritic composite gel, its preparation method, and its applications. The invention uses a hydrogel as a matrix, leveraging the hydrophilicity of the hydrogel framework to attract tin ions. Furthermore, by in-situ deposition of metal dendrites within the gel, a highly efficient conductive pathway is constructed. The conductive dendritic composite gel of this invention achieves simultaneous improvement in both mechanical and electrical properties. In addition, the sensor prepared based on this conductive dendritic composite gel exhibits high sensitivity and a wide detection range, effectively monitoring and identifying changes in limbs, demonstrating broad application potential in the field of wearable devices.
Owner:ZHEJIANG UNIV OF TECH

Layers for Inhibiting Metal Dendrite Growth in Electrochemical Cells, and Electrochemical Cells Made Therewith

Anode-protective layer for inhibiting growth of dendrites from an anode. In some embodiments, an anode-protective layer of this disclosure includes a coating comprising a polymer system, one or more salts dispersed within the polymer system, and ceramic oxide particles dispersed within the polymer system. In some embodiments, the polymer system includes two or more polymers, with one polymer containing fluorine and at least one other polymer containing nitrogen. In some embodiments, the coating is applied to a porous material, such as a porous separator. In some embodiments, the anode comprises at least one active metal, such as lithium, and the salt(s) comprise the active metal. Electrochemical cells and secondary batteries that include an anode-protective layer are also disclosed.
Owner:SES HLDG PTE LTD

Yb and Tb co-doped alloy brazing filler metal, preparation method and brazing process

The invention relates to the technical field of brazing, and discloses Yb and Tb co-doped alloy brazing filler metal, a preparation method and a brazing process. The Yb and Tb co-doped alloy brazing filler metal comprises, by mass, 12%-13% of chromium, 3%-4% of boron, 3%-4% of silicon, 4%-5% of iron, 0.5%-2% of terbium, 0.5%-1.5% of ytterbium and the balance nickel. Yb and Tb co-doping effectively inhibits growth of dendrites, rare earth elements are easily enriched at the grain boundary to form a fine isometric crystal structure, the prepared Yb and Tb co-doped alloy brazing filler metal brazed diamond is smaller in thermal damage degree, the brazed surface is smooth and free of accumulation, and the phenomena of wrinkles and holes are reduced to a great extent. The rare earth co-doping is beneficial to improving the wettability of the brazing filler metal, the brazing filler metal and the diamond are subjected to violent chemical metallurgy, the interface bonding strength of the brazing filler metal and the diamond is improved, and therefore the machining performance of a diamond tool is improved.
Owner:ANHUI POLYTECHNIC UNIV

Dendritic-free anodes and current collectors for lithium metal and lithium ion batteries

The disclosed concept relates to lithium-ion and lithium-metal batteries including methods of preparing a multi-component alloy (MCA) system having a body-centered cubic (bcc) crystal structure as a negative electrode and current collector, where the lithium-ion or lithium-metal battery is dendritic-free throughout the charging and discharging process of the battery. The MCA system includes an alloy composition of (i) 40 at% iron, 40 at% aluminum or gallium, and 20 at% magnesium, or (ii) 10 at% iron, 40 at% aluminum or gallium, and 50 at% magnesium, or (iii) 50 at% iron, 40 at% aluminum or gallium, and 10 at% magnesium.
Owner:UNIV OF PITTSBURGH OF THE COMMONWEALTH SYST OF HIGHER EDUCATION

Electrolyte for inhibiting growth of zinc dendrites and application thereof

The invention relates to the technical field of energy storage batteries, and particularly discloses an electrolyte for inhibiting zinc dendrite growth and application thereof. The electrolyte consists of electrolyte zinc salt, sodium lactate and water, and is beneficial to inhibiting Zn dendritic crystals and reducing the reaction rate of hydrogen precipitation. Besides, lactic acid anions (SC-) are more easily combined with water, so that a solvation shell structure of Zn < 2 + > is destroyed, deposition of Zn < 2 + > is more uniform, side reactions are reduced, and the zinc metal electrode can stably circulate for more than 500 hours under the condition of 5 mA cm <-2 >. Growth of zinc dendrites can be remarkably inhibited, the service life of the zinc metal negative electrode is prolonged, and the method has the advantages of being simple in preparation process, low in cost and good in application prospect.
Owner:HUBEI UNIV OF AUTOMOTIVE TECH

Metallographic corrosive agent for austenitic stainless steel welded joint and corrosion method of metallographic corrosive agent

The invention discloses an austenitic stainless steel welded joint metallographic corrosive agent and a corrosion method thereof, and belongs to the technical field of metal material detection. Dissolving picric acid in deionized water until the solution is saturated to obtain a saturated picric acid aqueous solution; dissolving ferric chloride and hydrochloric acid in a solvent to obtain a ferric chloride hydrochloric acid solution; and after the saturated picric acid aqueous solution and the ferric chloride hydrochloric acid solution are evenly mixed, a hand sanitizer containing a surfactant is added and evenly mixed, and the austenitic stainless steel welding metallographic corrosive agent is obtained. After the metallographic structure of the austenitic stainless steel welded joint is corroded, the metallographic structure is clear, dendrites and sizes of the austenitic stainless steel welded joint can be accurately distinguished, and then the metallographic structure, grain size and other data of the austenitic stainless steel welded joint can be accurately obtained, so that the welding process can be adjusted in time; the method is very important for improving the performance of the austenitic stainless steel welded joint.
Owner:HUNAN VALIN LIANYUAN IRON & STEEL CO LTD

Method for calculating stress on nitride dendrite in forced convection during solidification of molten steel

The application provides a method for calculating stress of nitride dendrites under forced convection in a steel liquid solidification process, and relates to the technical field of metal solidification. The composition of the steel grade and the involved thermodynamic and kinetic parameters and complex F-H boundary conditions are collected. The free boundary condition is added to the right side along the x direction velocity, and the stress growth model of Fe-C-M-N quaternary alloy steel in the flow field is established by coupling D2Q9 and cellular automaton model. Finally, the visual processing module is used to analyze the shape, size and flow field distribution of the nitride dendrites during solidification. The application optimizes the solidification technology, predicts the stress analysis of the nitride dendrites under forced convection, and provides theoretical guidance for improving the quality of the casting blank.
Owner:NORTHEASTERN UNIV CHINA

High-nitrogen superaustenitic stainless steel as-cast dendritic crystal corrosive agent and use method thereof

The invention belongs to the technical field of steel billet dendritic structure metallographic analysis, and relates to a high-nitrogen superaustenitic stainless steel as-cast dendritic crystal corrosive agent and a use method. The corrosive agent is a mixed solution of nitric acid, hydrochloric acid, oxalic acid, ferric chloride, sodium molybdate and copper chloride, wherein the concentrations of the oxalic acid and the ferric chloride are fixed at 1.1-1.3 g / L and 7.5-8.5 g / L; the concentrations of the sodium molybdate and the copper chloride are 9.0-11.0 g / L and 6.0-7.0 g / L respectively; the mass percentage concentrations of the nitric acid and the hydrochloric acid are 65-68% and 36-38% respectively, and the ratio of the nitric acid to the hydrochloric acid is determined according to the nitrogen content in the steel. According to the method, the optimal corrosive agent proportion and corrosion time can be calculated by utilizing an empirical formula according to the element content in the steel, the corrosion effect is greatly improved, the problem that corrosion is too deep or too shallow easily occurring in the corrosion process is solved, and the method has important significance on researching the dendritic crystal spacing and form of the high-nitrogen super austenitic stainless steel.
Owner:NORTHEASTERN UNIV CHINA

Spray forming method for preparing copper alloy

The invention discloses a spray forming method for preparing copper alloy. According to the spray forming method, liquid metal atomization and the deposition phase of atomized molten drops are uniformly combined, so that flowing of segregation liquid phases among dendrites is reduced, formation of macrosegregation is avoided, and the compact metal blank with the rapid solidification structure characteristic can be directly prepared. According to the spray forming method, a high-pressure nitrogen atomization process is adopted, so that alloy melt is atomized into small alloy particles, the surface area of the melt is increased, and therefore the cooling speed is increased, rapid solidification is promoted, grain refinement is facilitated, and the mechanical performance of the material is improved; by controlling the deposition rate and the spraying distance, the size and the shape of the alloy ingot blank can be accurately controlled, the consistency and repeatability of products are ensured, and meanwhile material waste is reduced.
Owner:YANTAI WANLONG VACUUM METALLURGY

Automatic control method and system for precious metal purification process

The invention relates to the technical field of precious metal purification, and discloses an automatic control method and system for a precious metal purification process. The method comprises the following steps: constructing a quadrant acoustic monitoring coordinate system to obtain a real-time acoustic energy vector, establishing an acoustic energy entropy increase coordinate system, defining an entropy increase polygon, and executing a multi-stage judgment mechanism to output an entropy increase directivity report; starting an optical information conversion mechanism to generate an optical shadow map, converting the optical shadow map into a resistance value distribution map by using a photoresistor array, and executing a gating gain modulation rule to output a local suppression field instruction; and formulating a directional intervention strategy based on the report, constructing a resonance cooperative shielding mechanism, and realizing dendritic crystal removal through a reverse current pulse and sine cleaning pulse sequence. According to the method, the problems of local dendritic crystal risk perception lag and extensive intervention in electrolytic refining are solved, self-organization growth of dendritic crystals is effectively blocked through acousto-optic fusion monitoring and grading synergistic inhibition, and the product purity and the process stability are remarkably improved.
Owner:SHENZHEN BOYUAN PRECIOUS METAL TECH CO LTD

Continuous high-phosphorus electroless nickel plating method capable of reducing crystallization of plating solution

The present application provides a continuous high-phosphorus electroless nickel plating method capable of reducing the crystallization of the plating solution, comprising the following steps: preparing a plating solution containing nickel sulfate as the main salt, sodium hypophosphite as the reducing agent, sodium citrate as the complexing agent, a buffer, and a crystallization inhibitor according to a predetermined concentration ratio, wherein the crystallization inhibitor is one or more of a composite of an organic polyphosphonate and nano-titanium dioxide, a nitrogen-containing heterocyclic compound, or a polymer having a comb-like structure; controlling the plating temperature, the pH value of the plating solution, and the flow rate of the plating solution within a preset range, and performing continuous plating operations. By adding a crystallization inhibitor to the components of the plating solution, the crystallization inhibitor can form a complex with metal ions such as Ni²⁺ in the plating solution and be uniformly dispersed, regulating the release rate of nickel ions and avoiding local crystallization; these crystallization inhibitors can also provide a three-dimensional barrier effect, reducing the formation of dendrites and abnormal grain growth, thereby achieving the effect of reducing the crystallization of the plating solution and improving the stability and production efficiency of the plating solution.
Owner:SHENGZHEN KINHU ELECTROPLATING CO LTD

A metallurgical process for reducing the point segregation of GCr15SiMn bearing steel ingot

The application discloses a metallurgical process for reducing point segregation in GCr15SiMn bearing steel ingot, and the obtained ingot has high cleanliness, and meanwhile, the ingot has a composite inclusion with MgO-Al2O3 oxide as a core and MnS as a peripheral wrapping. The ingot cleanliness requires that the oxygen content in the steel is controlled to be 6-10 ppm, and the titanium content is less than or equal to 25 ppm. The composite inclusion has a core oxide with a size of 0.1-2 microns, and a peripheral wrapping MnS inclusion, and the total size is controlled to be less than 5 microns, and the number density is greater than or equal to 10 per mm 2 . The composite inclusion is spontaneously formed in the solidification process of the molten steel and serves as a nucleation core of early austenite, thereby inhibiting the enrichment of solute elements such as C and Si between the solidification front dendrites, and achieving the purpose of reducing the point segregation of the ingot. The EAF-LF-VD-VC process route is adopted, and the methods such as strictly controlling the end composition of the electric furnace tapping, the Al content in the whole process, the composition of the refining slag and the double vacuum process are adopted to realize the purpose.
Owner:UNIV OF SCI & TECH BEIJING

A nanocrystalline toughened titanium-based amorphous composite material and its preparation process

The present invention belongs to the technical field of metallic materials, and relates to a nanocrystalline toughened titanium-based amorphous composite material and a preparation process thereof. The copper mold suction casting method + high-pressure torsion process is adopted, and the morphology and size of dendrites in the composite material are regulated by a large plastic deformation method, so as to realize the evolution of micron-scale dendrites in the composite material into nanoscale ones, thereby obtaining a nanocrystalline toughened titanium-based amorphous composite material. The size of the nanocrystals is 20-300 nm, the nanoindentation hardness is ≥4.05 GPa, and the uniform plastic deformation strain is ≥4%. The formation of nanocrystals avoids the softening caused by highly localized shear in the amorphous matrix and improves the work hardening ability of the titanium-based amorphous composite material.
Owner:ZHONGBEI UNIV

Ferritic stainless steel metallographic corrosive agent and preparation method and corrosion method thereof

The invention discloses a ferritic stainless steel metallographic corrosive as well as a preparation method and a corrosion method thereof, and belongs to the technical field of metal material detection. Dissolving picric acid in deionized water until the picric acid is saturated to obtain a saturated picric acid solution; uniformly mixing ferric chloride, hydrochloric acid and a solvent to obtain a ferric chloride hydrochloric acid solution; and uniformly mixing the saturated picric acid solution and the ferric chloride hydrochloric acid solution, adding the hand sanitizer containing the surfactant, and uniformly mixing to obtain the ferritic stainless steel metallographic corrosive. After the ferritic stainless steel is corroded, the metallographic structure of the ferritic stainless steel is clear, the dendritic crystal and the size of the ferritic stainless steel can be accurately distinguished, then the metallographic structure, the grain size and other data of the ferritic stainless steel can be accurately obtained, accordingly, the welding process can be adjusted in time, and the method is extremely important for improving the performance of the ferritic stainless steel.
Owner:HUNAN VALIN LIANYUAN IRON & STEEL CO LTD

Method for preparing single-crystal high-temperature alloy blade by directional solidification based on optimized seed crystal method

The invention relates to a method for preparing a single-crystal high-temperature alloy blade by directional solidification based on a seed crystal optimization method, which comprises the following steps of: introducing a specially designed runner into a die shell seeding section and a blade cavity transition section, taking the runner as a metal melt casting momentum constraint section, assembling prepared high-temperature alloy seed crystals into the seeding section in a close fitting manner, and then casting the high-temperature alloy seed crystals into the seeding section to obtain a single-crystal high-temperature alloy blade. The whole special mold shell structure is stably placed on the chilling plate; and the special mold shell assembled with the high-temperature alloy seed crystals is transferred to a preset station in a heater, and high-temperature alloy blade smelting and directional solidification are carried out. Compared with the prior art, a section of specially designed runner is introduced into the die shell seeding section and the blade cavity transition section and is used as a metal melt casting momentum constraint section, and the constraint section reduces the impact of a high-temperature alloy melt on dendritic crystals in a seed crystal remelting area by reducing the melt volume and the melt momentum; therefore, the purposes of eliminating mixed crystals in a remelting area, removing a crystal selector and promoting a seed crystal method to enter large-area industrial application are achieved.
Owner:SHANGHAI JIAOTONG UNIV

Tin-based interface layer protection potassium metal negative electrode and preparation method and application thereof

The invention provides a tin-based interface layer protection potassium metal negative electrode and a preparation method and application thereof, and belongs to the technical field of electrochemistry. The preparation method comprises the following steps: uniformly coating the surface of a potassium metal sheet with tin fluoride powder, so that the tin fluoride powder and potassium metal are subjected to an in-situ reaction to generate a multifunctional interface layer consisting of potassium-tin alloy and potassium fluoride; the multifunctional interface layer can homogenize K < + > flow, induce the K < + > flow to uniformly nucleate and inhibit the growth of potassium dendrites, so that the cycle life of the battery is prolonged. In addition, the preparation method is simple and convenient to operate and low in cost, and has great industrialization potential.
Owner:CHINA UNIV OF MINING & TECH

Systems and methods for forming directional crystal microstructures

A 3D printed metallic object having large scale cubic crystal structures is produced by controlling hatch distances and melt pool depth. Moving the melt pool in a first powder layer along a first layer scan pattern produces a first patterned layer. The scan pattern has parallel scan lines spaced by a hatch distance along a hatch direction perpendicular to the scan lines. As the melt pool cools, a dendrite grows in a dendrite growth direction. The hatch distance promotes a dendrite growth direction orthogonal to the scan lines and discourages a dendrite growth direction with a directional component opposite the hatch direction. Moving the melt pool in a powder layer on top the first patterned layer produces a second patterned layer. The melt pool's pool depth discourages dendrite growth directions in the first patterned layer from being less than 45 degrees relative to the melt pool's top surface.
Owner:BEEHIVE IND LLC