50 results about "Grain boundary migration" patented technology

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 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 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 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 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 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 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.

The invention discloses a process method for cooperatively regulating and controlling the structure performance of high-toughness wind power steel through trace Ce-Nb, and belongs to the technical field of wind power structural steel. According to the invention, by compositely adding trace rare earth Ce and Nb and on the basis of a two-stage hot rolling and air cooling process, austenite grains are effectively refined, grain boundary migration is inhibited, dislocation density is enhanced, and uniform refining of ferrite and pearlite structures is realized; the high-strength and high-toughness steel is prepared from the following components in percentage by mass: 0.05 to 0.15 percent of C, 1.2 to 1.5 percent of Mn, 0.1 to 0.4 percent of Si, 0 to 0.02 percent of Nb, 0.0011 to 0.0066 percent of Ce, 0 to 0.07 percent of V and the balance of iron and impurities. Under the condition that high-cost elements such as Ti and Cr are not introduced, the performance indexes that the yield strength is larger than or equal to 460 MPa and the impact energy at the temperature of-40 DEG C is larger than or equal to 280 J are achieved, and excellent low-temperature toughness and industrialization cost control are both considered.

The invention discloses a silicon carbide electrostatic chuck based on tape casting and a preparation method of the silicon carbide electrostatic chuck. The silicon carbide electrostatic chuck comprises a base, a bonding material layer and a ceramic wafer, the ceramic chip is formed by casting, pressing and sintering silicon carbide raw powder, a volume resistance regulating agent, a sintering aid and a ball-milling additive, and comprises a heating electrode layer and an adsorption electrode layer which are prepared by silk-screen printing. The volume resistivity of silicon carbide is adjusted by adding the volume resistance regulating agent so as to meet the dielectric layer quality requirement of the electrostatic chuck, and meanwhile, by adopting the casting, pressing and sintering processes, the pressure is applied at high temperature, so that the dielectric layer quality of the electrostatic chuck is improved. According to the method, the silicon carbide ceramic wafer is sintered compactly, the layers have higher bonding degree, layering is effectively avoided, and then annealing treatment is performed, so that residual impurities in the silicon carbide ceramic can be removed, and ceramic grain boundary migration, grain growth homogenization and pore elimination are promoted, so that compactness is improved, and residual stress is released.

This invention belongs to the field of powder metallurgy technology, and relates to a high-strength and tough multi-scale hierarchical aluminum-based composite material and its powder metallurgy preparation method. The composite material uses aluminum powder, silicon powder, titanium powder, and TiO2 as raw materials. Through a combination of low-temperature powder metallurgy preparation and heat treatment, a multi-scale hierarchical microstructure is generated in situ using solid-state diffusion reactions between the components to produce micron-nano Ti5Si3 particles at grain boundaries and nano-Al2O3 particles within the grains. The preparation method includes: weighing raw materials, graded ball milling and mixing, assembling, degassing and sealing, hot isostatic pressing densification, heat treatment, and machining. This invention achieves stable synthesis of Ti5Si3 and Al2O3 particles through solid-state powder metallurgy; the load-bearing effect of micron-sized Ti5Si3 at grain boundaries and the enhancement of dislocation multiplication and storage capacity by nano-sized Ti5Si3 at grain boundaries and nano-Al2O3 within the grains hinder grain boundary migration and dislocation movement under room temperature / high temperature conditions, synergistically improving the room temperature strength, toughness, and high-temperature performance of the composite material.

The invention belongs to the technical field of magnesium alloy welding, and relates to a hybrid welding method for improving corrosion resistance of a magnesium alloy weld joint by using a carbon nanotube, which comprises the following steps: preparing a carbon nanotube dispersion liquid by using a hydroxylated carbon nanotube; the magnesium alloy plate is coated with the carbon nano tube dispersion liquid and air-dried; the magnesium alloy plate coated with the carbon nano tube dispersion liquid and another magnesium alloy plate not coated with the carbon nano tube dispersion liquid are in butt joint, assembled and fixed; the pair of assembled magnesium alloy plates are welded in an inert gas environment by adopting a laser-arc hybrid welding process, and during welding, carbon nanotubes are prevented from being agglomerated by utilizing high-frequency swing of a laser beam, so that the carbon nanotubes are uniformly dispersed; the carbon nano tube inhibits the formation of thick columnar crystals and dendrites in the solidification process of a magnesium alloy molten pool, so that a welding seam structure is converted into fine isometric crystals, and the carbon nano tube is pinned at a grain boundary, hinders grain boundary migration and grain growth, provides a heterogeneous nucleation core and promotes precipitation of a precipitated phase; and the corrosion resistance of the magnesium alloy welding seam is improved.

The invention provides a preparation method of a zirconium boride reinforced molybdenum-based alloy, which comprises the following steps: mixing molybdenum powder and nano zirconium boride powder, and carrying out ball milling, prepressing and two-stage vacuum hot pressed sintering to obtain the zirconium boride reinforced molybdenum-based alloy. A high-temperature ceramic strengthening phase ZrB2 is introduced into the molybdenum alloy, and ZrB2 can pinning a grain boundary and prevent grain boundary migration in the sintering process, so that grains are refined, the grain boundary density is improved, refined grain strengthening is caused, and the average impurity concentration of the grain boundary is reduced; and meanwhile, the secondary phase can react with impurity oxygen in a molybdenum matrix to generate zirconium oxide, the impurity concentration in the alloy is further reduced, dispersion strengthening is caused, and the prepared zirconium boride strengthened molybdenum-based alloy has high compressive yield strength and good high-temperature stability.

The invention relates to the technical field of plasma W materials, in particular to rare earth oxide ceramic / Ti microalloy composite reinforced superfine / nanocrystalline W-based composite powder, a composite material and a preparation method of the composite material. The composite powder is of a nearly spherical core-shell multi-layer structure, the core-shell multi-layer structure takes W metal as a matrix, rare earth oxide ceramic particles, Ti elementary substances and oxides are dispersed on the periphery of the matrix to serve as a coating shell layer, Ti and the W matrix form a (W, Ti) ss solid solution, the (W, Ti) ss solid solution is locally enriched in the matrix, and the (W, Ti) ss solid solution and W serve as an inner core; the composite powder provided by the invention is subjected to low-temperature short-time intensified sintering to prepare the composite material, and the rare earth oxide ceramic hinders dislocation movement in matrix grains and hinders grain boundary migration in a grain boundary to refine the grains; ti exists in the form of a solid solution, an oxide and a complex-phase oxide, an enrichment area is formed on an interface of a matrix / ceramic reinforced phase, fine grain and interface strengthening and toughening are achieved, and the high-toughness superfine / nanocrystalline W-based composite material is obtained.

This invention relates to a machine learning potential function construction method for Mg-Al-Ca and Mg-Al-Zn magnesium alloy systems. The method includes: constructing an atomic-level initial configuration dataset covering solid solutions, dislocations, grain boundaries, stacking faults, twins, precipitates, and free surfaces; performing first-principles calculations to obtain energy, atomic forces, and stress tensors; converting the data format; training a machine learning potential function model using a deep potential energy method; and verifying the accuracy to a root mean square error of less than 5 × 10⁻⁶. ‑ ²eV / atom, root mean square error of force less than 1×10 ‑ ¹eV / Å. The potential function constructed in this invention combines first-principles accuracy with molecular dynamics efficiency, accurately describing the interatomic interactions of complex defects and precipitates. It can be used to study microscopic mechanisms such as solute segregation and grain boundary migration, providing computational tools for magnesium alloy composition design and process optimization.

This invention provides a refining-strengthening agent, its preparation method, and its application, belonging to the field of aluminum alloy technology. The refining-strengthening agent provided by this invention comprises the following components by mass percentage: 5-15% nano-ceramic particles, 1-3% rare earth elements, 1-3% Zr, and the balance Al; the nano-ceramic particles include ZrB2, TiB2, and Al2O3. In this invention, the nano-ceramic particles ZrB2, Al2O3, and TiB2 can act as heterogeneous nucleation cores for α-Al within aluminum grains, pinning grain boundaries and hindering grain boundary migration. During deformation, they also impede dislocation movement, simultaneously forming fine recrystallized grains, thereby improving the refining and strengthening effects. The addition of rare earth elements enables the nanoparticles to achieve both refining and strengthening effects. The combination of Zr and rare earth elements provides excellent anti-coarsening properties, thus enabling the refining-strengthening agent to exhibit good strengthening effects at both high and room temperatures.

This invention discloses an efficient magnetic domain refinement method for ultra-low loss oriented silicon steel, relating to the field of steel material technology. The method includes: raw material preparation; hot rolling and final rolling; multi-stage thermomechanical processing; controlled suppression phase formation; secondary re-junction and magnetic field-induced selective growth; surface microstructure fabrication; low-temperature domain refinement annealing and alternating magnetic field coupling; segmented cooling and quality inspection. This invention, through controlled nanoscale suppression phase engineering, forms a high-density and uniform nanoscale suppression phase within the matrix, serving as pinning sites for grain boundaries and subgrain boundaries. This controls grain boundary migration dynamics during high-temperature secondary re-junction, overcoming the problems of abnormal grain growth and microstructure instability caused by uneven distribution and large size dispersion of traditional suppression phases. This avoids the root cause of large magnetic domains, improves the controllability and repeatability of the secondary re-junction process, obtains a more uniform orientation grain size distribution, and reduces localized magnetic domain enlargement and iron loss fluctuations caused by uneven grain size.

The application discloses a composite reinforced tungsten wire base material and a preparation method thereof, and the composite reinforcement is realized through integrated reinforcement of fine-grain reinforcement, solid solution reinforcement and second-phase reinforcement. The fine-grain reinforcement is realized through high and low two-stage sintering processes based on high grain boundary migration activation energy inflection point temperature and nanometer dispersion phase grain growth inhibition synergy of a base phase; the solid solution reinforcement is realized through tungsten-molybdenum solid solution formation; and the second-phase reinforcement is realized through zirconium-containing nanometer dispersion phase and rare earth oxide nanometer dispersion phase synergy. The nanometer dispersion phase in the tungsten wire base material has a particle size of less than 50 nm, the tungsten-molybdenum solid solution base phase has a grain size of less than 1 micrometer, and the tungsten wire base material has the remarkable characteristics of high wire drawing production efficiency, high product yield, high wire strength and low production cost.

The invention provides a diamond copper vapor chamber material and a preparation method thereof, and belongs to the technical field of vapor chambers. According to the prepared copper-chromium solid solution powder, chromium is easier to migrate to an interface and a grain boundary in the sintering process, and formation of a fine chromium-rich reaction layer and a precipitated phase is facilitated; a continuous copper layer is constructed on the surface of silicon carbide through cleaning, sensitization, activation and chemical copper plating, and the wettability of the continuous copper layer and a copper matrix is improved; diamond, surface copper-coated silicon carbide and copper-chromium solid solution powder are compounded to construct a multi-scale structure of a hard high-heat-conduction framework, medium-particle-size buffer filling particles and a metal continuous matrix, and densification, interface strengthening and matrix heat conduction purification are achieved through spark plasma sintering and heat preservation treatment; in the finally obtained diamond copper vapor chamber, diamond provides a main heat conduction path, surface copper-coated silicon carbide gives consideration to gap filling and thermal expansion buffering, and the copper-chromium solid solution powder and the chromium-rich interface layer jointly improve interface bonding and thermal cycle size stability.

The invention relates to the technical field of high-temperature alloy processing and preparation, in particular to a nickel-chromium-based alloy strip foil with high creep resistance and a preparation method. In grain boundary orientation difference distribution of the nickel-chromium-based alloy strip foil, the length fraction of a 15-45-degree large-angle grain boundary exceeds 78%, and the high-energy grain boundary network effectively disperses local stress concentration under the action of external force. The number fraction of the crystal boundaries of the coincidence dot matrix sigma 3 is limited within 12%, so that the coherent twin boundaries are prevented from being dissociated into crack initiation sources under cyclic stress. By means of the design, when the nickel-chromium-based alloy strip foil serves at the temperature of 800 DEG C or above, grain boundary migration and diffusion creep are synchronously restrained, and finally the service life of the nickel-chromium-based alloy strip foil is prolonged by 3-5 times. According to the nickel-chromium-based alloy strip foil, the creep resistance of the nickel-chromium-based alloy strip foil is improved through a component design and grain boundary synergistic effect system.

The invention discloses a high-strength Al-Zn-Mg-Cu-Mn alloy suitable for friction stir additive manufacturing and a forming process of the high-strength Al-Zn-Mg-Cu-Mn alloy. The alloy elements comprise 9.0%-11.0% of Zn, 1.8%-2.2% of Mg, 1.5%-2.0% of Mn, 2.1%-2.5% of Cu and the balance Al and inevitable impurities. The Al-Zn-Mg-Cu-Mn alloy is formed by combining friction stir additive manufacturing with a heat treatment process. According to the method, an AlCuMn phase is formed through Mn and Cu elements, grain boundary migration is inhibited, and the problem that grains grow abnormally in the solution treatment process after traditional high-strength aluminum alloy friction stir additive manufacturing is solved; mg and Zn elements are matched with a heat treatment process of solid solution and aging, so that a nanoscale MgZn2 precipitated phase is formed, and the strength is greatly improved; and finally, the Al-Zn-Mg-Cu-Mn alloy can be subjected to solid solution and aging heat treatment after friction stir additive manufacturing, so that the strength of the friction stir additive manufacturing aluminum alloy component is greatly improved, and a foundation is laid for application of the friction stir additive manufacturing technology in manufacturing of large aerospace aluminum alloy components.

The application discloses a high-strength Al-Zn-Mg-Cu-Mn alloy suitable for friction stir additive manufacturing and a forming process thereof, alloy elements including Zn: 9.0-11.0%, Mg: 1.8-2.2%, Mn: 1.5-2.0%, Cu: 2.1-2.5%, the balance of Al and inevitable impurities. The Al-Zn-Mg-Cu-Mn alloy is formed by combining friction stir additive manufacturing with a heat treatment process. The AlCuMn phase is formed by Mn and Cu elements, the grain boundary migration is inhibited, and the problem of abnormal grain growth in the solid solution treatment process after traditional high-strength aluminum alloy friction stir additive manufacturing is overcome. The MgZn2 precipitated phase of nanoscale is formed by Mg and Zn elements in cooperation with the heat treatment process of'solid solution + aging', and the strength is greatly improved. Finally, the Al-Zn-Mg-Cu-Mn alloy can be subjected to the'solid solution + aging' heat treatment after friction stir additive manufacturing, so that the strength of the friction stir additive manufacturing aluminum alloy component is greatly improved, and the application of the friction stir additive manufacturing technology in the manufacturing of large aerospace aluminum alloy components is laid a foundation.

A silk-covered wire hardness change trend prediction and evaluation method belongs to the technical field of material performance evaluation, and comprises the following steps: acquiring a surface strain value and a core strain value of a silk-covered wire in a bending process, calculating a strain difference value, synchronously acquiring bending radius, grain boundary migration distance and microcrack initiation distribution data, and constructing a comprehensive damage data set; a dislocation density cumulant mapping relation is established according to the strain difference value, and the hardening degree grade is determined; the surface damage depth is calculated by combining the grain boundary migration distance and the microcrack initiation distribution data, and the microcrack initiation probability is determined; and performing correlation analysis on the microcrack initiation probability and the bending radius, determining the position of a softening turning point, dynamically adjusting the hardness prediction range, performing bending life simulation, and outputting a residual life evaluation result. The full-chain analysis from microscopic damage to macroscopic life prediction is realized, the reliability evaluation precision of the silk-covered wire in a high-stress environment is remarkably improved, and a scientific basis is provided for preventive maintenance.