56 results about "Magnesium matrix composite" patented technology

The invention discloses a preparation method of a high-capacity magnesium-based composite material based on MOF structure modification, and belongs to the technical field of hydrogen storage materials, the preparation method comprises the following steps: (1) preparing an M-MOF guest material; (2) modifying an aperture structure of the M-MOF guest material; and (3) preparing the MgH2 (at) S-M-MOF compound by a wet impregnation nano confinement method. Compared with a pure MgH2 hydrogen storage material, the MgH2 (at) S-M-MOF compound magnesium-based hydrogen storage material prepared by the nano confinement method has the advantages that the hydrogen absorption and desorption reaction temperature is obviously reduced, and the dynamics is greatly improved; compared with a traditional nano confinement hydrogen storage material preparation process, the preparation method has the advantages that the comprehensive hydrogen storage performance of a compound is enhanced by modifying a pore structure and introducing catalytic elements, the operability is high, the effective loading rate is high, the preparation period is short, and the yield is high; the required raw materials are cheap and easy to obtain, and the preparation process is low in cost, high in safety and suitable for industrial production and popularization.

The invention relates to the technical field of magnesium alloys, in particular to a low-density, high-modulus and ultrahigh-strength magnesium-based composite material and a preparation method thereof.The preparation method comprises the steps that SiC reinforcement particles are pretreated; the raw materials are proportioned according to the mass percent of the components of the magnesium alloy; melting pure magnesium, sequentially adding alloy elements, uniformly stirring, cooling to a semi-solid temperature interval, adding the pretreated SiC reinforcement particles, and casting in a preheating mold to solidify, so as to obtain a magnesium-based composite material cast ingot; the cast ingot is sequentially subjected to solution treatment and extrusion forming; carrying out secondary solution treatment on the magnesium-based composite material bar subjected to extrusion forming; and performing rotary swaging deformation and intermediate annealing treatment on the magnesium-based composite material bar subjected to secondary solution treatment to obtain the ultrahigh-strength magnesium-based composite material. Therefore, the problems that in the prior art, magnesium alloy is insufficient in strength and modulus, a magnesium-based composite material easily generates casting defects and is difficult to deform at room temperature, and the performance of the material is weakened due to grain growth during high-temperature deformation are solved.

The application discloses a magnesium-based composite material and a preparation method and application thereof. The magnesium-based composite material comprises ferroferric oxide and a magnesium alloy. The magnesium alloy comprises the following components in percentage by weight: 3wt.%-6wt.% of Zn, 0.3wt.%-0.8wt.% of Ca, and the rest of Mg and inevitable impurities. The magnesium-based composite material can effectively solve the problem that micron-sized particles are easy to agglomerate in a metal liquid when the magnesium alloy is modified, and the plasticity of the alloy is reduced and the alloy is not easy to be formed.

The application discloses a degradable fracture fixation device, which comprises a fixing part, a suture and a tensioning mechanism, one end of the suture is connected with the fixing part, the other end of the suture is connected with the tensioning mechanism after passing through a separation site and a bone body, and the tensioning mechanism is used for tightening the suture so as to fix the separation site on the bone body; the tensioning mechanism comprises a positioning cylinder, a tensioning part is movably arranged in the positioning cylinder, and the tensioning part is connected with the suture. The fixing part and the tensioning mechanism are both made of degradable materials, and the degradable materials are any one of magnesium or a magnesium alloy or a magnesium-based composite material, zinc or a zinc alloy or a zinc-based composite material, and iron or an iron alloy or an iron-based composite material. The fixing device has the advantages of simple structure, convenient use, simplified operation process, shortened operation time, favorable operation completion of doctors, good fixing effect on the separation site, prevention of tearing of the separation site, promotion of post-operation recovery of patients and the like.

The invention discloses a preparation method of a coarse / fine grain double-structure texture graphene-magnesium-based composite material, and belongs to the field of metal material preparation. According to the method, graphene forms an enrichment area and a lean area in a magnesium matrix through a powder mixing process, and then cold pressing, sintering and hot extrusion forming are performed to prepare the composite material with a coarse grain and fine grain double-structure tissue. According to the method, the problem that plasticity of a traditional graphene-magnesium-based composite material is reduced due to the fact that grains are too refined is solved, the material strength is remarkably improved, and meanwhile the ductility and toughness of the material are effectively improved. The preparation method is simple in process, low in cost and suitable for preparation of light high-strength structural materials such as low-altitude aircrafts and new energy automobiles, and has wide application prospects.

The invention discloses an in-situ generated high-entropy particle reinforced magnesium-based composite material and a preparation method thereof, the composite material comprises Mg, Y, Dy, Ho and Er elements, the atomic ratio of Mg / Y + Dy + Ho + Er is greater than 10: 1, and the atomic ratio of Y to Dy to Ho to Er is 1: 1: 1: 1. The atomic ratio of Mg / Y + Dy + Ho + Er is larger than 10: 1, the atomic ratio of Y, Dy, Ho and Er is 1: 1: 1: 1: 1, Mg24 (Y0.25 Dy0.25 Ho0.25 Er0.25) 5 high-entropy particles can be generated after rare earth atoms are subjected to solid solution, the high-entropy particles serving as reinforcements have high strength and high hardness, and the strength and hardness of the composite material can be remarkably improved; meanwhile, in-situ synthesized Mg24 (Y0. 25Dy0. 25Ho0. 25Er0. 25) 5 high-entropy particles and an Mg matrix form a coherent interface, dislocation can be extended, plastic deformation of the material is coordinated, and when the room temperature of the prepared composite material is 25 DEG C, the yield strength is 212 MPa, the tensile strength is 361 MPa, the Vickers hardness is 107 Hv, and the ductility is 10.6%; the high-entropy particle reinforced Mg-based composite material is generated in situ, so that the room-temperature strength and ductility of the alloy can be synergistically improved.

The utility model discloses a kind of magnesium-based composite material forming equipment, it is related to composite material preparation technical field, including material pipe, main feeding mechanism, auxiliary feeding mechanism, heating assembly and main push assembly;Material pipe front end is communicated with the forming cavity of die casting mould, and the length direction of material pipe is spaced and provided with at least two feeding positions;Main feeding mechanism is fed into magnesium alloy matrix to material pipe rear end;Auxiliary feeding mechanism is movably arranged and is fed into the inner cavity of material pipe with carbon fiber powder in any one feeding position;Main push assembly is used to push magnesium alloy matrix forward, so that magnesium alloy matrix is melted to form semi-solid slurry under the heating action of heating assembly, and mixed with carbon fiber powder to form semi-solid composite slurry, then semi-solid composite slurry is pushed forward to the forming cavity and is die casting formed.This scheme can control the interface reaction degree of carbon fiber and magnesium alloy matrix, effectively avoid the generation of harmful interface, so as to obtain ideal interface bonding effect.

The application discloses a numerical simulation method for particle dispersion in a molten pool of a laser surface remelting particle reinforced magnesium matrix composite, and belongs to the technical field of numerical simulation of particle dispersion in a molten pool of a composite material.The application solves the problem that the particle dispersion in a laser surface remelting (LSR) process of a particle reinforced magnesium matrix composite cannot be accurately predicted at present.The temperature gradient and the primary dendrite arm spacing in the molten pool are obtained based on experimental characterization, so that the liquidus and eutectic reaction temperature of non-equilibrium solidification are calculated.The liquidus and eutectic reaction temperature of non-equilibrium solidification are used to calculate the molten pool evolution in the LSR process of the magnesium matrix composite, so that the molten pool formation characteristics and the migration behavior of the particles in the molten pool can be more accurately predicted, the particle dispersion in the molten pool formation process of the particle reinforced magnesium matrix composite can be accurately predicted, and theoretical guidance is provided for in-depth understanding of the molten pool evolution process in the laser forming process of the composite material and process parameter optimization.The application can be applied to the prediction of the particle dispersion in the molten pool of the composite material.

The invention relates to the technical field of materials, in particular to an electronic equipment frame, a preparation method thereof and electronic equipment. The electronic equipment frame comprises a middle plate and a frame fixedly connected to the periphery of the middle plate. Wherein the frame comprises a magnesium-based composite material, a powder material reinforcement body is doped in the magnesium-based composite material, and the elastic modulus of the magnesium-based composite material is not lower than 55 GPa; the middle plate comprises magnesium alloy with the heat conductivity coefficient not lower than 90 W / m.k. According to the electronic equipment frame body, the high-modulus magnesium-based composite material serves as the frame, the high-thermal-conductivity magnesium alloy serves as the middle plate, the frame and the middle plate are fixedly connected, meanwhile, the performance of high strength, high modulus, high thermal conductivity and the like is achieved, the overall structural stability of electronic equipment can be enhanced, the overheating phenomenon can be reduced, and the service life of the electronic equipment is prolonged. The damage risk of internal elements of the electronic equipment caused by thermal stress is reduced, the service life of the electronic equipment is prolonged, and lightweight design of the electronic equipment is facilitated.

The invention provides a SiCp reinforced magnesium-based composite material casting and a casting method thereof.The casting method comprises the following steps that magnesium alloy and magnesium intermediate alloy are mixed and heated to be completely melted, and alloy melt is obtained; wherein the magnesium intermediate alloy contains rare earth elements; adding a preheated SiCp reinforced phase into the alloy melt by adopting a method of combining semi-solid stirring and liquid ultrasonic assistance, and stirring and mixing to obtain a magnesium-based composite material melt; after the magnesium-based composite material melt is heated to the target temperature, the magnesium-based composite material melt is rapidly poured into a preheated casting mold, after casting is completed, the cooling speed is controlled till the melt is cooled, and the SiCp reinforced magnesium-based composite material is obtained; and the SiCp reinforced magnesium-based composite material is put into a hot isostatic pressing process heating furnace to be treated, and the SiCp reinforced magnesium-based composite material casting is obtained. According to the casting method, the mechanical property of the magnesium-based composite material casting can be improved on the basis that the casting defects of the SiCp reinforced magnesium-based composite material casting can be remarkably reduced.

The application discloses a kind of multiphase high-strength high-modulus lightweight magnesium-based composite material and its preparation method, raw material is low-density magnesium matrix and the oxide that can be combined with magnesium alloy matrix and occur chemical reaction, raw material is mixed under vacuum ball milling and then through the method of advanced short-time discharge plasma sintering, a kind of multiphase high-strength high-modulus lightweight magnesium-based composite material can be obtained;Through the chemical reaction of combination in sintering process, oxide is converted into multiphase form, overcome the problem of high melting point of oxide sintering difficulty, and multiphase is evenly distributed in magnesium alloy matrix, the elastic modulus and strength of magnesium-based composite material are greatly improved.The composite material makes full use of the chemical reaction of combination between oxide material and magnesium matrix and the product high strength, modulus is high, thermal stability is good, while combining the advantages of low-density magnesium matrix, so as to improve the overall performance of composite material.

The invention discloses a high-rigidity graphene / magnesium-based composite material design method based on multi-modal feature fusion, and belongs to the field of calculation design of metal-based composite materials. The method comprises the following steps: collecting and preprocessing multi-source heterogeneous data; feature extraction and structure representation modeling; performing multi-modal feature fusion and performance prediction; and performing configuration parameter optimization design. According to the method, high-precision prediction of key performance indexes (elastic modulus, fracture strain, limit stress and the like) is realized by constructing a depth feature extraction network of an image mode and a text mode, unifying heterogeneous feature space representation and combining a sequence modeling and regression prediction algorithm. And finally, reversely deducing an optimal configuration parameter combination through a multi-objective optimization algorithm.

The application discloses a preparation method of high-hardness and high-wear-resistance magnesium-based composite material, which comprises the following steps: preparing materials, remelting, casting, and extruding; AZ91 alloy semi-solid-state temperature is added with B4C for stirring and cooling to form a casting rod for standby; an AZ91 alloy solution is prepared; a mold with a proper diameter is selected, the standby casting rod is placed at a center position of the mold, the AZ91 alloy solution is poured into the mold, meanwhile, the mold is placed on a vibration platform to continuously vibrate until the solution completely solidifies, so that the magnesium-based composite material is formed; and the magnesium-based composite material after complete solidification is subjected to heat treatment and cooling, and then is heated again to be extruded and deformed. The application effectively solves the extrusion difficulty of the existing composite material, greatly improves the hardness of the alloy layer, significantly reduces internal defects, improves the material density, uniformly disperses B4C particles in the matrix, avoids local agglomeration, improves the hardness and wear resistance of the composite material, and effectively reduces the cracking risk in the extrusion process.

The invention belongs to the technical field of alloy preparation, and particularly relates to a modular semi-solid forming method and system for a particle reinforced magnesium-based composite material. Modularized mixing is conducted on liquid magnesium alloy melt and reinforcement particles, mixing is conducted in a first module mixing chamber at a first rotating speed for a first time under the condition that the temperature is higher than the liquidus temperature of magnesium alloy, and then the mixture is conveyed to a preheated second module mixing chamber to be mixed at a second rotating speed for a second time; in the mixing process, the temperature is reduced to a temperature interval between a magnesium alloy liquidus and a magnesium alloy solidus, then the magnesium alloy is conveyed into a preheated third module mixing chamber to be mixed for a third time at a third rotating speed, and uniform dispersion of reinforcement particles can be achieved through synergistic mixing among the module mixing chambers; and finally, the semi-solid composite slurry prepared through mixing is subjected to die-casting forming, the high-performance particle-reinforced magnesium-based composite material can be obtained, and the semi-solid forming process which is simple in preparation process, short in production process and excellent in product mechanical property is provided.

The invention discloses a bionic structure titanium alloy frame reinforced magnesium-based composite material and a preparation method and application thereof, and belongs to the technical field of magnesium alloy composite materials. The bionic structure titanium alloy frame reinforced magnesium-based composite material comprises a magnesium alloy base body and a titanium alloy frame of a multi-layer net-shaped lamellar structure, and the titanium alloy frame of the multi-layer net-shaped lamellar structure is arranged in the magnesium alloy base body in a stacked mode. The volume of all the titanium alloy frame entity parts is 5%-50% of the total volume of the bionic structure titanium alloy frame reinforced magnesium-based composite material; the thickness of the single-layer titanium alloy frame ranges from 1 mm to 3 mm, the volume percentage of meshes ranges from 10% to 80%, and the size of a single mesh in the titanium alloy frame ranges from 0.1 mm to 0.5 mm. The magnesium-based composite material is relatively high in tissue density and uniform in component, has relatively good comprehensive mechanical properties, and is suitable for preparing structural parts such as mobile phone shells and the like.

The application discloses a kind of mechanical-shielding integrated magnesium-based composite material and preparation method thereof, it is related to metal-based composite material preparation technical field.The preparation method of mechanical-shielding integrated magnesium-based composite material of the present application is as follows: porous graphene is prepared by etching graphene with acid solution;Mix the porous graphene with magnesium powder, ball mill to obtain the powder after ball milling;The powder after ball milling is subjected to spark plasma sintering to obtain sintered block;The sintered block is subjected to hot extrusion, and the mechanical-shielding integrated magnesium-based composite material is obtained after cooling;The present application utilizes the synergistic effect of porous graphene and magnesium matrix to induce the generation of high-density nano-MgO at the interface, enhance the interfacial bonding strength and improve the mechanical properties of the composite material.The porous structure and spark plasma sintering synergistically reduce electromagnetic wave reflection, and the electromagnetic wave absorption is enhanced through multiple interface loss and polarization loss.The obtained composite material realizes efficient electromagnetic shielding dominated by absorption in the X-band, effectively inhibits secondary pollution.

The application belongs to the field of metal composite materials, and specifically discloses a preparation method of high-strength and high-toughness titanium alloy frame reinforced magnesium-based composite material, which comprises the following steps: arranging and fixing titanium alloy wires in a mold to obtain a titanium alloy frame; then injecting magnesium alloy into the titanium alloy frame, and then performing vibration and compression molding to obtain a composite material blank; and sintering the composite material blank to obtain the magnesium-based composite material. The magnesium-based composite material prepared by the preparation method has a titanium alloy frame for reinforcement, the titanium alloy frame and the magnesium alloy have a good bonding interface, the magnesium-based composite material has high mechanical properties and low density, and specifically, the yield strength is greater than or equal to 500 MPa, the tensile strength is greater than or equal to 500 MPa, the elastic modulus is greater than or equal to 80 GPa, and the density is less than or equal to 3.2 g / cm 3 , thereby significantly solving the problem of poor strength of the existing magnesium alloy.

The invention discloses an Mg / MgO magnesium-based composite material with a gradient impedance structure as well as a preparation method and application of the Mg / MgO magnesium-based composite material, and relates to the technical field of electromagnetic shielding materials. The preparation method specifically comprises the following steps: taking magnesium powder in an inert atmosphere, and carrying out ball milling treatment for different times to respectively obtain magnesium powder with different oxygen contents; paving the magnesium powder with different oxygen contents in a reaction device according to the sequence of the ball milling treatment time from short to long in an inert atmosphere; and carrying out vacuum hot pressed sintering on the reaction device, and then cooling to obtain the Mg / MgO magnesium-based composite material with the gradient impedance structure. Through the synergistic effect of gradient impedance design and hot pressing sintering, electromagnetic wave reflection on the surface of the material is remarkably reduced, and the electromagnetic wave absorption efficiency is enhanced. The electromagnetic shielding effectiveness of the prepared composite material in the X wave band is remarkably improved, efficient electromagnetic shielding dominated by absorption is achieved, and secondary electromagnetic pollution is effectively reduced.

The invention discloses a method for preparing a hydroxyapatite whisker / WE43 magnesium alloy biological composite material through a vacuum pressure impregnation method, and belongs to the technical field of new materials. The invention aims to solve the problems that the existing hydroxyapatite particle reinforced magnesium-based composite material is relatively high in hydrogen evolution rate, too high in-vitro degradation rate and low in hardness and elasticity modulus, and the hydroxyapatite whisker reinforced magnesium-based composite material is fractured and the length-diameter ratio is obviously reduced. According to the hydroxyapatite whisker / WE43 magnesium alloy biological composite material prepared by using a vacuum pressure impregnation method, good interface bonding can be formed; the added hydroxyapatite whisker effectively refines the grain structure of the WE43 magnesium alloy, and the strengthening effect of grain refinement on the magnesium-based composite material is far better than that of aluminum alloy; compared with a matrix alloy, the hydroxyapatite whisker / WE43 magnesium alloy biological composite material prepared by using a vacuum pressure impregnation method has the advantages that the elasticity modulus and the hardness are obviously improved, and the in-vitro degradation performance is good.

The application discloses a numerical simulation method for laser surface remelting microstructure of particle reinforced magnesium matrix composite, and belongs to the technical field of numerical simulation of composite microstructure.The application solves the problem that the existing numerical simulation method does not fully consider the interaction between dendrite growth and particle movement.Based on the electron probe experimental characterization result, the application takes the real solid phase composition field of the as-cast state as the initial condition of calculation, more truly reproduces the actual solidification process, simultaneously carries out coupling calculation on the microstructure evolution and particle movement, adopts the cellular automaton technology to simulate the magnesium alloy existing the reinforcing particles, considers the influence of the dendrite growth on the particle movement, can realize the numerical prediction of the microstructure of the laser surface remelting particle reinforced magnesium matrix composite, and can more accurately predict the microstructure formation and particle migration in the molten pool in the laser melting metal process.The method can be applied to the numerical simulation of the microstructure of the particle reinforced magnesium matrix composite.

The application belongs to the field of metal matrix composite material preparation, and specifically discloses a method for preparing a metal particle reinforced magnesium matrix composite material by semi-solid injection molding, which comprises the following steps: mixing and grinding magnesium alloy particles with metal particles to obtain mixed particles; heating the mixed particles to semi-solid state in the process of shear mixing to obtain a semi-solid slurry; injecting the semi-solid slurry into a mold, and then applying pressure to make the semi-solid slurry solidify and form the metal particle reinforced magnesium matrix composite material. The preparation method in the application can make the mixed particles uniformly distributed by heating the mixed particles to semi-solid slurry under the action of shear mixing, solve the common macrosegregation and local agglomeration defects of the composite material, and make the shape of the solid particles in the semi-solid slurry tend to be spherical, thereby improving the flexibility and mechanical properties of the prepared composite material at room temperature and high temperature.

The application provides a copper oxide modified graphene reinforced magnesium-based composite material and a preparation method thereof. The composite material comprises 97-99.9 wt.% of a magnesium alloy and 0.1-3 wt.% of copper oxide modified graphene. The surface of the graphene is modified by copper oxide, and the price of the copper oxide is lower than that of noble metals such as nickel and silver, so that the material cost is effectively reduced. After the surface modification of the graphene, the self-aggregation of the graphene and the interface wettability between the graphene and the metal matrix can be effectively improved, a good interface combination is formed, and the mechanical properties of the composite material are improved.

The application belongs to the technical field of metal matrix composite material, and particularly relates to a Ti reinforced phase bimodal distribution magnesium matrix composite material and a preparation method thereof. The preparation method comprises the following steps: mechanical alloying of titanium powder and magnesium matrix powder to obtain mixed powder A; mixing of the mixed powder A and titanium powder to obtain mixed powder B; forming of the mixed powder B to obtain a magnesium matrix composite material; and heat treatment of the magnesium matrix composite material to obtain the Ti reinforced phase bimodal distribution magnesium matrix composite material. The micron / submicron Ti phase dispersedly distributed at the magnesium grain boundary, the nanoscale Ti phase uniformly precipitated in the grain and at the grain boundary after heat treatment, the strength of the magnesium matrix composite material is significantly improved under the action of Orowan strengthening and load strengthening. The application has low material cost, simple preparation process flow, low requirement on equipment, high production efficiency, high product stability, and good industrialization prospect.

The application discloses a preparation method of a titanium particle reinforced magnesium matrix composite material based on semi-solid injection molding, and comprises the following steps: 1) mixing magnesium alloy particles with titanium particles to obtain mixed particles; 2) heating the mixed particles to semi-solid state to obtain semi-solid slurry; and 3) applying shearing force to the semi-solid slurry to move the semi-solid slurry to a nozzle, and applying pressure to inject the semi-solid slurry into a mold to solidify and form. The application pre-disperses the composite material particles before semi-solid injection molding, in-situ melts the mixed composite material particles during the semi-solid injection molding process, combines the shearing force provided by a rotating screw and the pressure to perform injection, effectively solves the macro-branching segregation and local reinforcement segregation problems of the as-cast titanium particle reinforced magnesium matrix composite material, makes the titanium particles uniformly distributed in the magnesium matrix, and avoids the performance fluctuation caused by particle agglomeration and uneven dispersion in the traditional melting casting method, and the defects of high cost and complex process in the powder metallurgy method.

The magnesium-based composite material preparation device comprises a preparation smelting furnace, a heating component, a vacuum system, a stirring mechanism and a mold, and the preparation smelting furnace comprises a shell capable of being sealed and a crucible arranged in the shell; the heating part is used for heating the magnesium material ingot blank in the crucible to enable the magnesium material ingot blank to be liquefied to form magnesium melt; the vacuum system is used for forming a vacuum state in the preparation smelting furnace; the stirring mechanism is used for stirring the magnesium melt to form turbulent flow, and the turbulent flow can roll up the high-strength particles in the crucible and uniformly distribute the high-strength particles in the magnesium melt to form a magnesium-based composite material; a mold is disposed within the housing. According to the magnesium-based composite material preparation device, high-strength particles can be uniformly distributed in magnesium melt, so that the performance of the magnesium-based composite material is effectively improved.

The application belongs to the technical field of alloy preparation, and more particularly relates to a modular semi-solid forming method and system of a particle-reinforced magnesium-based composite material. By modular mixing a liquid magnesium alloy melt and reinforcing body particles, the particles are mixed in a first module mixing chamber at a first rotating speed for a first time at a temperature higher than the liquidus temperature of the magnesium alloy, then are transported to a preheated second module mixing chamber to be mixed at a second rotating speed for a second time, and are cooled to a temperature range between the liquidus and solidus of the magnesium alloy during the mixing, and then are transported to a preheated third module mixing chamber to be mixed at a third rotating speed for a third time. Through the collaborative mixing between the module mixing chambers, the reinforcing body particles can be uniformly dispersed. Finally, the semi-solid composite slurry prepared by mixing is pressure die cast, and a high-performance particle-reinforced magnesium-based composite material is obtained. The semi-solid forming process has the advantages of simple preparation process, short production process, and excellent mechanical properties of the product.

The application belongs to the technical field of non-ferrous composite material preparation and application, and more particularly relates to a semi-solid die casting method and system of ceramic particle premixed reinforced magnesium-based composite material. The application adds a preparation step of pre-prepared composite particles in front of the inlet of a semi-solid hydraulic casting slurry machine. The pre-prepared composite particles are obtained by heating, melting, premixing and cooling and crushing of interface-optimized ceramic particles and magnesium-based alloy particles. The ceramic particles are interface-optimized and further premixed with the magnesium-based alloy through a specific premixing process. The two cooperate to prepare the pre-prepared composite particles, which form a high-quality metallurgical bonding interface under controllable conditions. The pre-prepared composite particles are used as the feedstock of the semi-solid die casting process, which completely changes the raw material basis of the semi-solid die casting and ensures the uniformity and excellent interface of the final composite material product, thereby significantly improving the mechanical properties of the composite material.

The invention provides a lacquering mold for a horizontal enameled flat wire and a preparation method of the lacquering mold, and relates to the technical field of mold material processing. The material used by the painting mold is an aluminum-based or magnesium-based composite material reinforced by ceramic particles, and the ceramic technology is one or more of SiC, TiC, TiB2, Al2O3 particles or whiskers. The mold is manufactured by adopting a powder injection molding process. The lacquering mold for the horizontal type enameled flat wire has the advantages of being low in thermal expansion coefficient, high in hardness and elasticity modulus and good in abrasion resistance, can stably float at the design position in a paint box, and solves the problem that due to the fact that a traditional mold is large in weight and deviates from the center, the thicknesses of paint films on the upper side and the lower side of the enameled flat wire are not consistent.

The present application relates to a kind of nanoparticle reinforced magnesium-based composite material and its preparation method, the method includes the following steps: nanoparticle is uniformly dispersed with salt with water, obtain nanoparticle salt solution;Nanoparticle salt solution is dried, obtain the mixture of nanoparticle and salt;Nanoparticle and salt mixture are placed under high temperature condition to make salt melt, obtain molten salt-based nanofluid;Magnesium is added to molten salt-based nanofluid and melts, forms smelting system;Smelting system is carried out high-temperature heat preservation treatment, then after solidification, nanoparticle reinforced magnesium-based composite material is prepared.The present application is based on liquid metallurgy method, at high temperature, without using protective gas, also can avoid the oxidation combustion of nanoparticle and magnesium melt at high temperature, without mechanical stirring, also can realize the good compounding of nanoparticle and magnesium melt, can avoid the problem that more pore, inclusion defects are in composite material, is favorable to improve the mechanical properties of material.

This invention discloses a method for preparing biomedical layered heterogeneous graphene-magnesium-based composite materials. The method involves depositing graphene oxide onto magnesium-based alloy sheets using electrophoretic deposition. By varying the deposition time and the initial graphene thickness, layered graphene-magnesium-based composite materials with different structural parameters are constructed. The composite materials are then subjected to spark plasma sintering and multiple rolling steps to obtain the biomedical layered heterogeneous graphene-magnesium-based composite material. This method can reduce the degradation rate of bio-magnesium alloys in vivo, increase the service life of biomedical magnesium alloys in the human body environment, and simultaneously improve the strength and toughness of the material itself.