78 results about "Grain boundary migration" patented technology

The invention discloses a method for homogenizing a microstructure of a low-temperature high manganese steel welding heat affected zone by using pulse current, and belongs to the technical field of welding and postweld heat treatment of high manganese steel for liquefied natural gas (LNG) storage and transportation. The treatment method comprises the following steps: (1) sampling a heat affected zone of the low-temperature high-manganese steel welded joint with microstructure gradient distribution; (2) the low-temperature high manganese steel welding heat affected zone sample is subjected to pulse current treatment at the room temperature, the pulse frequency ranges from 0.6 kHz to 6 kHz, the pulse width ranges from 0.2 ms to 6 ms, the current density ranges from 20 A / mm < 2 > to 200 A / mm < 2 >, and the treatment time ranges from 5 min to 120 min; and (3) grinding and polishing the sample, observing and analyzing the element distribution state in the heat affected zone, and quantitatively representing the grain boundary structure characteristics. According to the method, atomic diffusion, dislocation slippage and grain boundary migration of the low-temperature high-manganese steel welding heat affected zone can be promoted by applying the pulse current, redistribution of segregated atoms and dislocations in grains and at grain boundaries is rapidly achieved, and then the purposes of improving the microstructure uniformity of the low-temperature high-manganese steel welding heat affected zone and improving the impact toughness of the low-temperature high-manganese steel welding heat affected zone are achieved. The method is easy to operate, short in treatment time, environmentally friendly and particularly suitable for postweld treatment of low-temperature high manganese steel parts.

The invention relates to the technical field of temperature control, in particular to a nanocrystalline glass annealing treatment temperature dynamic monitoring control method and system, and the method specifically comprises the steps: capturing an unsteady thermal radiation signal in a glass internal microcrystalline phase change process in real time, and synchronously obtaining three-dimensional residual stress distribution data; dividing the annealing process into gradient crystallization control units according to the time-temperature transition characteristic of the glass; constructing a crystal phase evolution model, and dynamically analyzing the coupling relationship between the microcrystal nucleation rate and the residual stress of each gradient crystallization control unit; and a multi-target particle swarm optimization algorithm is adopted, and temperature field gradient distribution is corrected in real time in combination with grain boundary migration kinetic parameters. According to the invention, the problem of residual stress accumulation and grain size mismatch in a nanocrystalline glass annealing process in the prior art is solved.

The invention relates to the technical field of high-corrosion-resistance stainless steel pipe processing, and discloses a high-corrosion-resistance high-molybdenum stainless steel pipe processing technology based on gradient carbide design, which comprises the following steps: applying an axial gradient magnetic field in a stainless steel pipe rolling process, and combining with dynamic strain rate matching rolling to promote molybdenum atom grain boundary migration and inhibit carbide coarsening, so as to obtain a high-molybdenum-resistance stainless steel pipe. Nano carbide smaller than or equal to 50 nm is formed on the surface layer, and submicron carbide of 200-500 nm is formed on the core part; after rolling, micro-arc oxidation and phosphonic acid group silane dipping are immediately carried out to form a self-repairing passivation film; and finally, an alternating magnetic field and pulse current are adopted for cooperative annealing, and a grain boundary molybdenum-poor region and residual stress are eliminated. Through magnetic field-chemical-thermal multi-field coupling, the material has erosion corrosion resistance of a gradient carbide structure, dynamic passive film self-repairing and low-temperature high toughness, and is suitable for long-acting protection of deep sea oil and gas pipelines.

The invention discloses a neodymium-iron-boron magnet and a method for regulating and controlling the grain size and the grain size distribution of a coarse grain layer of the neodymium-iron-boron magnet, and particularly relates to the technical field of neodymium-iron-boron magnet material preparation. Collecting a local temperature change rate and a stress change rate in real time in a sintering temperature rise and heat preservation stage; triggering coarse grain layer structure evolution evaluation according to the monitoring data, and extracting a feature data set; a diffusion coupling non-uniformity index and a grain boundary migration tensor index are calculated based on the feature data set, a machine learning model is input, a coarse grain layer abnormal risk level is output, and sintering process parameters are dynamically adjusted according to the coarse grain layer abnormal risk level; according to the method, the abnormal evolution of the coarse grain layer is dynamically sensed by monitoring local temperature and stress changes in real time, the abnormal risk level of the grain size of the coarse grain layer is intelligently predicted based on the characteristic data set, abnormal growth of coarse grains is inhibited in time, and the microstructure consistency and service performance stability of the neodymium-iron-boron magnet are improved.

The present invention discloses a high-precision processing method and system for multi-specification copper tubes, specifically related to the technical field of copper tube processing analysis. Raw material parameters, process timing data, and detection data during the processing of multi-specification copper tubes are collected. Through multi-source data acquisition and physical enhancement generation technology, combined with the B-spline interpolation algorithm and conditional adversarial generation network, an enhanced data set is constructed to solve the problems of sparse measured data and insufficient coverage of extreme working conditions. A grain evolution-stress coupling simulation model is established to quantify the influence of grain boundary migration on stress, and the coordinates and correction coefficients of high-stress regions are marked. A graph convolutional network is used to achieve cross-scale stress prediction, and dynamic process parameters are generated through a multi-objective optimization algorithm. Finally, real-time control is driven by digital twins, solving the technical problems of low deformation control accuracy and high defect rate caused by uneven residual stress distribution in traditional copper tube processing.

The invention relates to the technical field of nuclear fusion surface plasma W materials, in particular to nano rare earth oxide ceramic-Ti microalloy composite reinforced W powder, a composite material and a preparation method of the nano rare earth oxide ceramic-Ti microalloy composite reinforced W powder. The composite powder is of a nearly spherical core-shell hierarchical structure, and the particle size is 30-50 nm; according to the composite powder, refractory metal W serves as a matrix, nano rare earth oxide ceramic particles are evenly dispersed in matrix W crystal grains, Ti mainly forms an enrichment area on the surface of the matrix or a matrix / rare earth oxide interface in a simple substance or oxide mode, the phase interface structure is effectively improved, W crystal boundary migration and dislocation motion are hindered, W crystal grains are remarkably refined, and the composite powder is prepared. Part and W form semi-coherence, fine grain and interface strengthening and toughening are achieved, and a brand new thought and a technical method are provided for synergistically improving the strength and toughness of the W composite material. The composite powder is subjected to organic reduction synthesis and low-temperature reinforced sintering to prepare the composite material, the tensile strength at the room temperature reaches 500-610 MPa, and the ductility is 5%-8%.

The invention discloses a Si-N-O high-temperature ceramic material as well as an ultra-fast synthesis preparation method and application thereof, and relates to the technical field of inorganic non-metallic materials. The method comprises the following steps: uniformly mixing pre-oxidized Si3N4 nano ceramic powder and a sintering aid in a certain proportion, and pressing into a green body; in an inert atmosphere, the green body is heated to 1400-1800 DEG C; and keeping the temperature for 8-16 seconds to obtain the Si-N-O high-temperature ceramic material. Based on the ultrafast high-temperature sintering technology, grain growth and grain boundary migration are effectively inhibited, ceramic densification is rapidly achieved, and the microstructure is accurately regulated and controlled. The temperature and the stress gradient are reduced through rapid heating, so that the uniformity and the compactness of the material are improved, the possibility of phase change or decomposition of a crystal phase at high temperature is reduced by shortening the high-temperature exposure time, and the stability and the purity of the crystal phase are improved. The performance of the material is effectively improved by the advantages of the ultrafast high-temperature sintering process.

The invention relates to the technical field of silver alloy, in particular to a method for effectively inhibiting migration of silver ions in silver alloy, which comprises the following steps: step 1, putting electrolytic silver with the purity of more than 99.99% into a smelting furnace for smelting, covering by using a covering agent, and obtaining molten silver after smelting; 2, modified silicon dioxide is added into the silver melt in the step 1, and silver alloy melt is obtained; 3, the smelting furnace is vacuumized, then mixed gas of hydrogen and nitrogen is introduced into the smelting furnace, and heat preservation is conducted for 20-60 min; and 4, the silver alloy melt is subjected to converter casting after standing. According to the method for effectively inhibiting migration of the silver ions in the silver alloy, grains can be refined through indium in the alloy, the grain boundary structure can be improved, and migration of the silver ions along the grain boundary is inhibited; indium on the surface of the alloy can form a compact indium oxide film on the surface of the silver alloy to isolate direct contact of external moisture, electrolyte and silver, so that electrochemical dissolution and migration of silver ions are reduced.

The application discloses a diamond mosaic splicing homogeneous epitaxial growth method and system based on AI intelligent control, and belongs to the technical field of single crystal diamond material preparation. A plurality of single crystal diamond substrates are spliced into a large-size deposition base in a mosaic manner; an initial geometric shape and a micro-gap distribution of a splicing seam are identified through a pre-trained AI visual detection model; a global process parameter combination and a staged deposition strategy for promoting lateral epitaxy are generated by combining a homogeneous epitaxial growth thermodynamic database and an AI process optimization model; during the growth process, a morphology evolution image and plasma state data of the splicing seam area are collected in real time, and a gap healing trend is predicted by an AI closed-loop control model, and the global process parameters are dynamically adjusted. Through AI accurate control of the global process parameters, the lateral epitaxy and the grain boundary migration at the splicing seam can be controlled to occur, and finally a seamless integrated large-size single crystal diamond is obtained.

The preparation method comprises the following steps: weighing and mixing Na2CO3, Nb2O5, CeO2 and MgO according to a stoichiometric ratio, sintering by a solid-phase method to synthesize the ceramic, and separating out a supersaturated cerium-magnesium compound by adopting a dual heat treatment technology to obtain a dispersed CeMgO2-delta precipitated phase at a grain boundary position; on one hand, the precipitated CeMgO2-delta can leave a B-site vacancy and an oxygen vacancy in a NaNbO3 structure, so that the conductivity of crystal grains is enhanced; on the other hand, a precipitated phase is dispersed and distributed at a grain boundary position, a carrier channel is provided, formation of a space charge layer is broken, and grain boundary impedance is reduced; in addition, microstress is easily formed around a precipitated phase, so that crystal lattices are expanded, niobium-oxygen bonds are weakened, carrier grain boundary migration activation energy is further reduced, and the conductivity of oxygen ions is improved. The process is simple, the NaNbO3-based ceramic which is low in working temperature, high in oxygen ion conductivity and good in chemical stability is easy to obtain, and the NaNbO3-based ceramic has a wide application prospect in the field of solid-state ion conductors.

The invention discloses a high-efficiency semitransparent perovskite battery and a preparation method thereof, and belongs to the technical field of batteries. The solar cell comprises a packaging layer, an optical regulation and control layer, a transparent top electrode, a hole transport layer, an interface passivation layer, an activation layer and a substrate from top to bottom, the activation layer comprises Gua (0.05), Cs( 0.05), FA (0.7), MA (0.15), Pb (0.8), Sn (0.2) (I (0.77), Br (0.23) 3), and the thickness of the activation layer And the transparent top electrode comprises ITO (indium tin oxide) / AgNWs / F-IWO (indium tin oxide) of 200 to 300 nm. Visible light transmission and near-infrared absorption are balanced through a B / proportional band gap, Gu inhibits perovskite grain boundary migration and Sn < 2 + > oxidation, a transparent top electrode is ITO / AgNWs / F-IWO, AgNWs reduce sheet resistance, F-IWO improves near-infrared light transmission and prevents Ag oxidation, and the contradiction between PCE and AVT and the defects of a traditional electrode are overcome.

The invention discloses a heat treatment process for improving the grain size of a TP347H seamless steel tube with an ultra-large diameter, which is suitable for improving the grain size of the TP347H seamless steel tube with the outer diameter of more than or equal to 650 mm, the wall thickness of 80-100 mm and the length of more than 6000 mm, so as to improve the quality of the TP347H seamless steel tube. Stepped solid solution, variable-speed cooling and composite stabilization processes are effectively combined, raw NbC is sufficiently dissolved in a low-temperature stage, grain boundary migration and growth are inhibited in a high-temperature stage, an anaphylaxis interval can be quickly exceeded through variable-speed cooling, sigma phase precipitation is avoided, residual stress is relieved and reduced, multi-temperature-zone stabilization treatment can promote uniform precipitation of nanoscale NbC, pinning of grain boundaries and grain refinement, and the stability of NbC is improved. According to the TP347H seamless steel pipe produced by the method, the phenomena of mixed crystals and coarse crystals are improved, the quality is improved, and the market demand is met.

The application provides an alloy solution mechanical and electromagnetic stirring device, and mainly relates to the technical field of die steel smelting. The alloy solution mechanical and electromagnetic stirring device comprises a support frame, a stirring container is fixedly installed on the support frame, a driving motor is fixedly installed on the top of the stirring container, a solution filling hopper is arranged on the top of the stirring container, a support seat is fixedly arranged outside the stirring container, the support seat is fixedly installed on the support frame through bolts, and a buffer pad is arranged between the support seat and the support frame. The application has the beneficial effects that: the application combines mechanical stirring and electromagnetic stirring, can ensure that relative movement between liquid phase and solid phase is generated in different degrees, multi-dimensional shear flow is generated, the breaking, crushing and proliferation of dendrite arms are caused, a large number of dislocations are migrated from grain boundaries to the inside of the crystals, the purpose of refining grains is achieved, the energy consumption requirement in the stirring process can be greatly reduced, and the purposes of energy saving and emission reduction are achieved.

The application discloses a microstructure evolution prediction method in a selective laser sintering additive manufacturing process, according to the microstructure evolution characteristics of the selective laser sintering additive manufacturing, starting from the free energy density functional of the system, the time and space evolution expressions of temperature, conservative order parameter and non-conservative order parameter are derived in thermodynamic self-consistency, the Cahn-Hilliard equation containing temperature gradient driven diffusion and the determination method of model parameters are given, and numerical calculation is realized through finite element programming. Combined with powder bed laying and finite element calculation, the non-isothermal phase field model can simulate the sintering neck, grain boundary migration and other microstructure evolution in the selective laser sintering additive manufacturing process, simulate the influence of the huge temperature gradient in the selective laser sintering additive manufacturing, optimize the process parameters of the selective laser sintering additive manufacturing, reveal the influence law of the process parameters of the selective laser sintering additive manufacturing on the microstructure evolution and the final microstructure, and improve the design efficiency of the selective laser sintering additive manufacturing.

The invention discloses a method for reducing consumption of rare earth elements and preparing a high-performance sintered Nd-Fe-B magnet through a diffusion process. The method comprises the following steps: preparing a matrix; the preparation method comprises the following steps: coating a layer of film on the surface of a substrate by a spray coating method and a silk-screen printing method, and then coating a layer of Pr70Cu15Al10Ga5at.% film on the magnet substrate coated with the film; and after film coating, placing in a vacuum tube furnace for diffusion. The invention discloses a method for reducing consumption of rare earth elements and preparing a high-performance sintered Nd-Fe-B magnet through a diffusion process. Two-step grain boundary diffusion is formed by NbF5 which is easy to form intergranular precipitates and Pr70Cu15Al10Ga5 grain boundary diffusion which is used for forming high-anisotropy Pr; intergranular precipitates are formed in the magnet before grain boundary diffusion of the rare earth alloy, grain boundary migration which inevitably occurs during Pr grain boundary diffusion is inhibited, and Ta-containing intergranular precipitates and a microstructure which is used for forming a Pr-rich shell and changes Nd are formed; high coercive force can be realized in the Nd-Fe-B sintered magnet without using heavy rare earth, the process cost is low, and the problem of low rare earth diffusion rate is solved.

The invention belongs to the technical field of ceramic material preparation, and discloses a ceramic material sintering process optimization method and system based on a grain growth dynamic model, and the method comprises the following steps: quantitatively describing a deformation mechanism of a ceramic material in a sintering process based on continuum mechanics; constructing a grain growth kinetic model according to the quantitatively described deformation mechanism of the ceramic material and the grain size estimation model at the final stage of sintering; determining grain growth parameters in the final stage of sintering, and predicting the grain size by using a grain growth kinetic model; calculating the relationship between the grain size and the relative density and the sintering temperature, and verifying the calculation result of the grain growth kinetic model according to the experimental result of the grain size and the relative density; the change from low temperature to high temperature behavior is simulated through a Sigmodal function, the slope (derivative) of the function is calculated, and the temperature transition point of grain growth is obtained. And the temperature transition point of the grain boundary mobility from high to low can be accurately determined.

The invention provides a rapid and continuous preparation method of a single crystal copper foil. The method comprises the following steps: firstly, rolling the polycrystalline copper foil to generate internal stress in the copper foil, then enabling the rolled copper foil to sequentially pass through a temperature gradient area and a constant temperature area in a reducing atmosphere or an inert atmosphere, and increasing the temperature of the temperature gradient area along the advancing direction of the copper foil, and forming a plurality of abnormal crystal grains with the same orientation under the combined action of the temperature gradient and the internal stress, and growing and splicing the plurality of abnormal crystal grains with the same orientation in the constant-temperature region to obtain the single-crystal copper foil. When the method is used for preparing the single-crystallized copper foil, the preparation speed is not limited by the grain boundary migration rate, the efficiency is high, and the prepared single-crystallized copper foil is large in size and is prepared continuously.

The invention belongs to the technical field of alloys, and particularly relates to a laser additive manufacturing magnesium alloy and a preparation method and application thereof. The invention provides a magnesium alloy laser additive manufacturing method which comprises the following steps: mixing magnesium alloy powder and a high-melting-point reinforcing phase to obtain a mixed material; the melting point of the high-melting-point reinforced phase is 2800-3900 DEG C; and the mixed material is subjected to laser additive manufacturing and then subjected to heat treatment, and the magnesium alloy is obtained. Magnesium alloy powder and high-melting-point reinforcing phases are used as raw materials for laser additive manufacturing, the high-melting-point reinforcing phases are distributed in a microscopic structure or at a grain boundary of a formed alloy in the laser additive manufacturing process, and in the subsequent heat treatment process, the dispersed reinforcing phases can generate a pinning effect to hinder migration of the grain boundary and generate resistance to the grain boundary, so that the grain boundary is prevented from being damaged. Therefore, the abnormal grain coarsening behavior of the magnesium alloy in the subsequent heat treatment process is inhibited, the microscopic structure of the magnesium alloy is improved, and the mechanical property of the magnesium alloy is improved.

This invention discloses a high-performance lanthanum-cerium sintered NdFeB magnet material and its preparation method. It is prepared using LaCe NdFeB magnet alloy powder and a titanium carbide nanosheet composite as raw materials. The titanium carbide nanosheet composite contains one or more of TiC, Ti2C, and Ti3C2T, where T in Ti3C2T is an oxygen-containing functional group. In this invention, the LaCe NdFeB magnet alloy powder is modified using the titanium carbide nanosheet composite, resulting in rich chemical activity. This provides more heterogeneous nucleation sites within the magnet, acting as pinning points during grain growth to hinder the movement of magnetic domain walls, thereby enhancing the magnet's coercivity. The two-dimensional nanosheet structure, layered at the grain boundaries, hinders grain boundary migration and grain merging, effectively suppressing grain growth. Furthermore, the nanosheet structure forms continuous magnetic domain wall pinning points, preventing the nucleation and expansion of opposite magnetic domains.

The invention relates to a high-temperature alloy plastic connection method for optimizing the shape of a joint, which comprises the following steps of: processing a boss and a groove structure which are matched with each other on the to-be-connected surfaces of a pair of high-temperature alloy workpieces, carrying out mechanical processing on the to-be-connected surfaces for cleaning and shaping, and after the to-be-connected surfaces are assembled and connected through the boss and the groove structure, carrying out mechanical processing on the to-be-connected surfaces. The method comprises the following steps: carrying out plastic connection to realize a completely microscopic metallurgical bonding step in macroscopic deformation of high-temperature alloy workpieces, sequentially carrying out recrystallization annealing and stress relief annealing treatment on a pair of high-temperature alloy workpieces subjected to plastic connection, recrystallizing residual deformed grains after plastic connection, and pushing a grain boundary to migrate and cross an interface grain boundary. And the grain boundary of the interface is bridged, so that the connection quality is improved. According to the method, the connection structure of alloy plastic connection is optimized, formation and welding of an interface grain boundary are promoted, and complete microcosmic metallurgical bonding is achieved in macroscopic deformation of a high-temperature alloy workpiece.

The invention discloses a gradient sintering process for improving the elimination rate of closed pores of ceramic, and belongs to the technical field of aluminum oxide ceramic manufacturing. During sintering and glue discharging, lanthanum aluminum oxide core-shell powder is added as a sintering aid, and switching from an air atmosphere to an oxygen atmosphere is utilized, so that gradient sintering is realized, the closed pores can be greatly eliminated, and the sealing performance of the ceramic is improved. The density and mechanical strength of the ceramic material are improved, so that the ceramic material is not easy to crack; the sintering aid is lanthanum oxide aluminum core-shell powder, the structure of the sintering aid is a core-shell structure with lanthanum oxide as a shell layer and gamma-aluminum oxide as a core layer, lanthanum oxide can reduce the concentration of lattice cation filling gaps or generate a grain boundary dragging effect, so that the growth rate of crystal grains is controlled, smooth removal of air holes is ensured, and under oxygen calcination, the sintering efficiency is improved. The concentration of positive ion gaps in aluminum oxide and lanthanum oxide can be increased, the grain boundary migration rate can be controlled to a certain extent in the sintering densification process, and formation of closed pores is further reduced.

The invention discloses an endogenous rapid test method for tellurium brittleness sensitivity of a high-nickel alloy. The method comprises the following steps that S1, tellurium elements are added into the high-nickel alloy through a smelting method, and a base material with tellurium atoms preset inside is obtained; s2, processing and forming the base material into a tellurium-containing sample, and carrying out solid solution treatment on the tellurium-containing sample, so that tellurium atoms are completely and uniformly dissolved in the matrix dot matrix; s3, carrying out aging treatment on the tellurium-containing sample subjected to the solution treatment, and driving tellurium atoms subjected to solution treatment in a matrix to migrate to a grain boundary and form a segregation layer; and S4, performing quantitative characterization on the tellurium brittleness sensitivity of the tellurium-containing sample subjected to aging treatment through a mechanical test. Compared with the prior art, the method has the advantages that the damage state after long-time service is reproduced by changing a physical model and utilizing endogenous atom short-range migration, and the tellurium brittleness sensitivity of the high-nickel alloy can be accurately, quantitatively, safely and efficiently tested and evaluated.

The invention relates to an electrolytic polishing solution for in-service austenitic stainless steel and an EBSD sample preparation method, in particular to the technical field of microstructure analysis and detection of the austenitic stainless steel. And then electrolytic polishing is conducted on the grinding and polishing face for 5-25 s by adopting an electrolytic polishing solution including, by volume, 8-12% of perchloric acid, 10-15% of ethylene glycol butyl ether and the balance alcohol under the conditions that the voltage is 20-30 V and the temperature is-15 DEG C to-5 DEG C, then cleaning and drying are conducted, and EBSD characterization analysis is conducted on the electrolytic polishing face. According to the method, the deformation layer on the surface of the service-state austenitic stainless steel can be effectively removed, information such as grain boundary migration and nucleation, twin crystal types and number changes and precipitation phase precipitation characteristics is obtained, the preparation time of the sample is shortened, and the calibration rate is larger than 96%.

The invention discloses a Yb-alpha-beta-Sialon composite ceramic and a preparation method thereof, and belongs to the technical field of ceramic processing, and the Yb-alpha-beta-Sialon composite ceramic comprises the following components: Si3N4, Al2O3, AlN, Yb2O3, Lu2O3, nano SiC whisker, Ti3SiC2, a liquid metal gallium indium tin alloy, a bonding aid and a sintering aid. Double rare earth stabilizers (ytterbium and lutetium) are introduced, the radius of ytterbium ions is large, and an alpha-Sialon phase is mainly stabilized; the lutetium ions are small in radius and mainly stabilize the beta-Sialon phase, the combination can more effectively enter lattice vacancies of different crystal phases, the grain boundary migration speed is restrained, and excessive growth of grains is hindered.

This invention belongs to the field of heat exchanger technology, specifically relating to a heat treatment enhancement method and system for heat exchangers. The invention employs a three-stage magnetic field design, applying specific types, parameters, and directions of magnetic fields at three key stages: 200-400℃, 600-900℃, and 900-1100℃. In the low-temperature stage, an alternating magnetic field at a 30-60° angle to the heat transfer path is used to uniformly eliminate residual stress. In the medium-temperature stage, a high-energy pulsed strong magnetic field drives dislocation movement and grain boundary migration. In the high-temperature stage, a uniformly rotating magnetic field achieves uniform distribution of the temperature and electromagnetic fields across the entire domain. This solves the problems of stress concentration, uneven recrystallization, and abnormal grain growth caused by the single direction of the magnetic field in traditional processes. It significantly optimizes the microstructure of the substrate and effectively improves the uniformity of the austenite structure and the grain refinement effect.

The invention provides a weak-texture additive manufacturing medium-entropy alloy and a processing method thereof, and belongs to the technical field of medium-entropy alloys. The CoCrNi-based medium-entropy alloy forms orderly-arranged columnar crystals after additive manufacturing, the medium-entropy alloy subjected to additive manufacturing is subjected to heat treatment under the specific condition, crystal grains in the medium-entropy alloy grow again in a recrystallization mode, a discontinuous sigma phase and a discontinuous L12 phase are separated out, the discontinuous L12 phase separated out at the high temperature promotes grain boundary migration, and therefore the grain boundary migration is promoted. The effect of grain refinement is achieved; due to the fact that discontinuous precipitation phases are different in migration pushing direction and speed of each grain boundary, the randomness of the grain growth direction is enhanced, the generated grain orientation is more uniform, the strong texture generated by additive manufacturing is weakened, and meanwhile the strengthening effect of the precipitation phases enables the material to have the excellent mechanical property.

The invention discloses a method for inducing directional arrangement of carbon nanotubes, a carbon nanotube array and application. The method for inducing the directional arrangement of the carbon nanotubes comprises the following steps: depositing the carbon nanotubes on the surface of a metal substrate to form a combined body, wherein at least the part, used for being in contact with the carbon nanotubes, of the metal substrate consists of polycrystalline metal; and carrying out high-temperature annealing treatment on the assembly, so that the polycrystalline metal is subjected to grain boundary migration to be converted into single-crystal metal, and promoting the carbon nanotubes to be directionally arranged along the extension direction of a step formed by a high-index crystal face of the single-crystal metal. According to the method, the carbon nanotubes are deposited on the surface of the metal substrate, high-temperature annealing treatment is carried out, the grain boundary migration phenomenon of the metal substrate during high-temperature annealing treatment is used as driving force for inducing directional arrangement of the carbon nanotubes, and directional arrangement of the carbon nanotubes is caused by the step characteristic of the surface of the high-index single-crystal metal substrate; the structure of the semiconductor type carbon nanotube is not damaged in the high-temperature annealing process, operation is easy and convenient, the preparation process is fast, and the yield is high.

The invention provides a solid oxide battery and a preparation method thereof. The preparation method comprises the steps of preparing a metal support body, preparing a porous anode layer, preparing an electrolyte layer and preparing a porous cathode layer. Preparing an electrolyte layer: coating the surface of the porous anode layer with electrolyte slurry; carrying out pre-sintering treatment in an air atmosphere; and carrying out hot isostatic pressing sintering treatment in an inert gas atmosphere. Due to the fact that hot isostatic pressing sintering is carried out under inert gas, compared with sintering under the air atmosphere for a long time, oxidation of the metal supporting body is avoided, and therefore high strength and high conductivity of the metal supporting body are guaranteed. Meanwhile, the interior of the furnace is in a high-pressure environment, and uniform pressure in all directions is applied to the sample to promote grain boundary migration and discharge of closed pores in the material, so that the density of an electrolyte layer is improved, grains can be refined by high pressure in the furnace, and the thermal shock resistance and strength of the battery are improved. Compared with processes such as impregnation, the preparation time is shortened, and the energy consumption is reduced.

The present invention discloses a continuous preparation method of a large-area (100) single-crystal copper foil, wherein a polycrystalline copper foil is connected to a roll-to-roll device, a carbon-based substrate is placed under the copper foil, and a large-area (100) single-crystal copper foil is prepared by applying stress during a heat treatment process in a reducing / protective atmosphere and in an environment with a temperature gradient. The present invention applies stress to the copper foil for the first time, accurately controls its strain energy, and makes the strain energy the main influencing factor of grain boundary migration and lattice rotation, thereby achieving the control of the strain energy dominating in the growth process of the single-crystal copper foil, and a large-area (100) single-crystal copper foil can be prepared by heat treatment in a reducing atmosphere.

The present disclosure provides a method for regulating dynamic recrystallization of NiTi alloy by Ti2Ni phase, comprising: after open-die forging of the as-cast NiTi alloy, performing staged thermal mechanical treatment, first performing first-stage thermal deformation, then performing second-stage thermal deformation, and rapidly water cooling after deformation; by regulating the two-stage variable-temperature and variable-strain rate, Ti2Ni, which is originally considered as a harmful phase, is converted into a micro tool for controlling grain boundary migration; by using Ti2Ni to induce particle-induced nucleation in the low-temperature region, the critical strain required for complete recrystallization is reduced, and the limitation of traditional single thermal coupling driving is broken; this innovative mechanism not only promotes the occurrence of austenite grain dynamic recrystallization process by increasing nucleation sites, but also inhibits the organization coarsening caused by high-temperature grain boundary migration by using the pinning effect of the second phase particles, so as to realize the precise regulation of the uniformity of the organization under a lower deformation amount.