An integrally formed composite structure based on three-dimensional printing and casting processes and a method of making the same

Abstract

The application discloses an integrally formed composite material structure based on a three-dimensional printing and casting process and a preparation method thereof, and relates to the technical field of composite material manufacturing. The integrally formed composite material structure preparation method is prepared through three steps, that is, first, a first metal material is three-dimensionally printed to obtain a metal insert; then, post-processing is performed; and finally, a second metal material is heated to a molten state to finally obtain the integrally formed composite material structure. The application connects the 3D printed metal insert with a traditional casting process through accurate design, forms an integrated composite metal structure, and ensures the precision and sealing performance of mold assembly. Moreover, the application can realize complex material forming which is difficult to be completed by traditional manufacturing processes through 3D printing of complex shape materials, meets the demand of manufacturing complex shape metal materials in different fields, and breaks through the limitations of traditional titanium-aluminum composite processes. The integrally formed composite material structure has high precision, high strength and good surface finish.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material science and engineering, and particularly relates to an integrally formed composite structure based on three-dimensional printing and casting process and a preparation method thereof. BACKGROUND

[0002] Current material forming technologies mainly include three kinds, traditional casting process, plastic forming technology and three-dimensional printing forming technology. The traditional casting process is a production method that melts the metal into a casting cavity with a shape and size suitable for the material, and then cools and solidifies to obtain the material, which is commonly known as metal melting state forming or casting. Casting, as a common metal forming process, has significant advantages in producing a large number of high-precision and complex-shaped metal materials. However, the manufacturing process of the traditional casting mold has many limitations. For example, it is difficult to achieve complex crystal structures and lattice structures in the mold, which leads to uneven temperature distribution in the mold during the casting process, and easily causes defects such as deformation and shrinkage holes in the casting, affecting the quality of the casting. At the same time, the manufacturing cycle of the casting mold is long and the cost is high. For some small-batch and customized product production, the economic efficiency of the traditional casting process is poor, and it is difficult to achieve complex internal structures. Plastic forming technology is a processing method that uses the plasticity of metal materials to produce plastic deformation under the action of a certain external force of tools and molds, thereby obtaining materials with certain shape, size and mechanical properties. There are many types of plastic forming, mainly including forging, rolling, extrusion, drawing, stamping, etc. However, plastic forming requires metal materials to have good plasticity, and it is difficult to use plastic forming for some metal materials with poor plasticity, such as some high-strength alloy steels, titanium alloys, etc. Special processes and equipment are needed. The mold is an indispensable tool in plastic forming, and the design and manufacturing of the mold require high technical level and cost. Especially for complex-shaped parts, the design and manufacturing of the mold are more difficult and costly. Three-dimensional printing forming technology is a rapid prototyping technology that can effectively solve the problem of complex shape manufacturing. 3D printing technology can manufacture various complex-shaped objects by layer-by-layer accumulation of materials according to a three-dimensional model. It has the advantages of high design freedom, short manufacturing cycle, no need for molds, etc., and is especially suitable for manufacturing materials with complex crystal structures. However, 3D printing has certain limitations in material selection and forming efficiency. For some metal materials that need to be mass-produced, the cost of using 3D printing alone is too high and the efficiency is low, and the strength and durability may not be sufficient in some applications. Moreover, although three-dimensional printing technology can manufacture complex structures, it has limitations in material performance and production efficiency. At present, the independent application of 3D printing and casting process is more common, but the technical solution of effectively combining the two still needs to be further improved and innovated. The existing preparation technology cannot meet the needs of complex structure manufacturing, high-quality material production, and low cost and short cycle.

[0003] Composite metal material refers to a material with new properties formed by metallurgical bonding of two or more metals with different chemical and mechanical properties at the interface by using composite technology. The common composite metal material preparation processes at present include powder metallurgy, diffusion bonding and in-situ synthesis, etc., but all have obvious shortcomings, for example, the powder metallurgy has strict requirements on the quality and particle size of the powder, the powder preparation cost is high, and high pressure and high temperature conditions are needed in the preparation process, so the process control is difficult. The diffusion bonding has very high requirements on the flatness and cleanliness of the connecting surface, the pretreatment process is complex, batch production is difficult to achieve, which limits its application in large-scale industrial production, and the in-situ synthesis is difficult to accurately control the reaction, and harmful phases are easily generated. And the in-situ synthesis method is mostly in the laboratory research stage, and some technical problems still exist in realizing large-scale industrial production.

[0004] Therefore, in view of the deficiencies of the prior art, it is very necessary to provide an integrally formed composite material structure based on a three-dimensional printing and casting process and a preparation method thereof to solve the deficiencies of the prior art. SUMMARY

[0005] A first object of the present application is to provide a preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process to avoid the deficiencies of the prior art. The preparation method of the integrally formed composite material structure overcomes the limitations of the traditional casting process, can manufacture a complex shape composite material structure, and has the advantages of high precision and high strength. In addition, the production cycle can be shortened and the cost can be reduced.

[0006] The above object of the present application is achieved by the following technical measures:

[0007] The present application provides a preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process, comprising the following steps:

[0008] S1, three-dimensional printing of a first metal material to obtain a metal insert, the metal insert being a porous structure;

[0009] S2, post-treatment of the metal insert obtained in S1 to obtain a treated metal insert;

[0010] S3, heating a second metal material to a molten state, then injecting the second metal material in a molten state into the treated metal insert obtained in S2, and then cooling, to finally obtain the integrally formed composite material structure with the treated metal insert as a shell.

[0011] Preferably, the melting point of the second metal material is lower than the melting point of the first metal material.

[0012] Preferably, the metal insert is composed of a plurality of unit cell structures.

[0013] Preferably, the unit cell structure is a triply periodic minimal surface (TPMS) lattice structure.

[0014] Preferably, the triply periodic minimal surface (TPMS) lattice structure is a Gyroid structure, a Diamond structure or a Schwarz structure.

[0015] Preferably, the S2 is performed by the following steps:

[0016] S2.1, ultrasonic oil removal treatment is performed on the metal insert, and then S2.2 is entered;

[0017] S2.2, pickling treatment is performed on the metal insert, and then S2.3 is entered;

[0018] S2.3, plasma cleaning treatment is performed on the metal insert, and then S2.4 is entered;

[0019] S2.4, magnetic force grinding treatment is performed on the metal insert, and then S2.5 is entered;

[0020] S2.5, sand blasting treatment is performed on the metal insert to obtain the treated metal insert.

[0021] Preferably, the S2 is performed by the following steps:

[0022] S2.1, the oil removal powder and water are mixed and then added into an ultrasonic cleaner, and then the metal insert is added into the ultrasonic cleaner, the temperature is controlled to be 30-70°C, the current is controlled to be 2-5A, and ultrasonic cleaning is performed for 2-8 minutes, and then S2.2 is entered after the ultrasonic oil removal is completed, the amount of the oil removal powder is 40-80g / L;

[0023] S2.2, the metal insert is added into pickling liquor, the temperature is controlled to be 40-90°C, air is introduced and the aeration amount is 0.2-1.0m³ / H, and the treatment time is 2-8 minutes, and then S2.3 is entered after the pickling is completed, the pickling liquor is a mixture of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 2-10:1;

[0024] S2.3, the metal insert is placed into a plasma cleaner for cleaning, the gas flow is 100-500mL / min, the gas cleaning time is 150-350s, and then S2.4 is entered after the plasma cleaning is completed; the gas is at least one of argon, oxygen or hydrogen;

[0025] S2.4, put the metal insert into the magnetic grinding machine and add grinding liquid and magnetic grinding needles for grinding, and after the magnetic grinding treatment is completed, enter S2.5; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 20-40 min, and the grinding frequency is 50-60 Hz;

[0026] S2.5, the metal insert is subjected to sand blasting treatment, and the treated metal insert is obtained after the sand blasting treatment is completed, the parameters of the sand blasting treatment are that the sand particle size is 150-320 mesh, the sand blasting pressure is 0.1-0.8 MPa, the distance of the sand blasting gun is 30-200 mm, and the sand blasting angle is 15-45°.

[0027] Preferably, S2.3 is specifically as follows:

[0028] S2.3.1, the metal insert is put into the plasma cleaning machine, and S2.3.2 is entered;

[0029] S2.3.2, the gas flow is controlled to be 100-300 mL / min, the gas is argon and oxygen, the volume ratio of argon and oxygen is 1:0.3-0.5, the gas cleaning time is 70-150 s, and S2.3.3 is entered;

[0030] S2.3.3, the gas flow is controlled to be 300-500 mL / min, the gas is argon, the gas cleaning time is 10-50 s, and S2.3.4 is entered;

[0031] S2.3.4, the gas flow is controlled to be 100-300 mL / min, the gas is argon and oxygen, the volume ratio of argon and hydrogen is 1:1.5-2.0, the gas cleaning time is 70-150 s, and S2.4 is entered after completion.

[0032] Preferably, S1 is specifically as follows: the powder of the first metal material is laid layer by layer by a laser selective melting 3D printing process, and finally the metal insert is obtained by laser melting accumulation.

[0033] Preferably, the printing parameters of the laser selective melting 3D printing process are as follows: the laser power is 120-250 W; the scanning speed is 1000-1500 mm / s, the layer thickness is controlled to be 30-60 μm; the gas protection is argon, and the purity of the argon is ≥99.99%, and the oxygen content is <0.1%.

[0034] Preferably, S3 is performed as follows:

[0035] S3.1. Heat the second metal material to 410℃~750℃ to make the second metal material melt, and at the same time heat the treated metal insert obtained in S2 to 250℃~350℃. Then, under a vacuum of 150 mbar~350 mbar and an injection speed of 0.1m / s~0.6m / s, inject the molten second metal material into the treated metal insert obtained in S2.

[0036] S3.2 Cooling: After cooling, the material is cut to obtain the integrally molded composite material structure. The cutting process parameters are: cutting speed of 20 m / min to 60 m / min, feed rate of 0.05 mm / r to 0.25 mm / r, and cutting depth of 0.1 mm to 2 mm.

[0037] Preferably, the first metallic material is titanium or stainless steel.

[0038] Preferably, the second metallic material is aluminum, zinc, or magnesium.

[0039] The second metallic material is aluminum, zinc, or magnesium;

[0040] When the second metallic material is aluminum, the lattice constant of the unit cell structure is 2.8 Å to 3.2 Å, the surface offset of the unit cell structure is 0.1 mm to 0.3 mm, the unit size of the unit cell structure is 0.5 mm to 2.0 mm, the relative density of the unit cell structure is 0.3 to 0.6, the Poisson's ratio of the unit cell structure is 0.3 to 0.35, and the Young's modulus of the unit cell structure is 100 GPa to 160 GPa.

[0041] When the second metallic material is zinc, the lattice constant of the unit cell structure is 2.9 Å to 3.3 Å, the surface offset of the unit cell structure is 0.2 mm to 0.5 mm, the unit size of the unit cell structure is 0.8 mm to 3.0 mm, the relative density of the unit cell structure is 0.4 to 0.7, the Poisson's ratio of the unit cell structure is 0.28 to 0.33, and the Young's modulus of the unit cell structure is 80 GPa to 140 GPa.

[0042] When the second metallic material is magnesium, the lattice constant of the unit cell structure is 2.8 Å to 3.1 Å, the surface offset of the unit cell structure is 0.3 mm to 0.6 mm, the unit size of the unit cell structure is 0.6 mm to 2.5 mm, the relative density of the unit cell structure is 0.25 to 0.55, the Poisson's ratio of the unit cell structure is 0.32 to 0.38, and the Young's modulus of the unit cell structure is 45 GPa to 110 GPa.

[0043] The second object of the present application is to provide an integrally formed composite material structure to avoid the shortcomings of the prior art. The integrally formed composite material structure can have a complex shape composite material structure, and has the advantages of high precision, high strength and good surface finish.

[0044] The above object of the present application is achieved by the following technical measures:

[0045] An integrally formed composite material structure is provided, which is prepared by the above-mentioned integrally formed composite material structure preparation method based on three-dimensional printing and casting process.

[0046] The shear resistance of the integrally formed composite material structure is greater than 200 MPa.

[0047] The integrally formed composite material structure based on three-dimensional printing and casting process and the preparation method thereof, wherein the integrally formed composite material structure preparation method comprises the following steps: S1, three-dimensional printing of a first metal material to obtain a metal insert, the metal insert is a porous structure; S2, post-treatment of the metal insert obtained in S1 to obtain a treated metal insert; S3, heating the second metal material to a molten state, then injecting the second metal material in a molten state into the treated metal insert obtained in S2, and then cooling, finally obtaining the integrally formed composite material structure with the treated metal insert as the shell; the melting point of the second metal material is lower than the melting point of the first metal material. The present application precisely designs the 3D printed metal insert and connects with the traditional casting process to form an integrated composite metal structure, ensuring the precision and sealing performance of the mold assembly. Moreover, the present application can realize the complex material forming which is difficult to be completed by traditional manufacturing process by manufacturing complex shape materials through 3D printing, meet the demand of manufacturing complex shape metal materials in different fields, and break through the limitations of traditional titanium-aluminum composite process. The integrally formed composite material structure obtained by the present application has high precision, high strength and good surface finish. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The flowchart of the integrally formed composite material structure based on three-dimensional printing and casting process of the present application.

[0049] Figure 2 The detection diagram of the composite material structure obtained when the unit cell structure of the metal insert is Gyroid structure.

[0050] Figure 3 The enlarged view of Figure 2 . DETAILED DESCRIPTION

[0051] The technical solutions of the present application are further described in combination with the following examples. The experimental methods in the following examples are all conventional methods unless otherwise specified. The raw materials, reagent materials, etc. used in the following examples can be purchased from conventional biochemical reagent stores or pharmaceutical business enterprises unless otherwise specified. The model of the oil powder is SY-W301B and is purchased from Shenzhen Yinhaida Chemical Co., Ltd.

[0052] Example 1: A preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process, like Figures 1 to 3 , comprising the following steps:

[0053] S1, three-dimensional printing a first metal material to obtain a metal insert, the metal insert being a porous structure;

[0054] S2, post-processing the metal insert obtained in S1 to obtain a processed metal insert;

[0055] S3, heating a second metal material to a molten state, then injecting the second metal material in the molten state into the processed metal insert obtained in S2, and then cooling, to finally obtain the integrally formed composite material structure with the processed metal insert as a shell.

[0056] The metal insert of the present application is designed in a computer-aided design software, such as UG, to obtain a model of the metal insert and add the required unit cell structure, the metal insert model is sliced into thin layers by using a slicing software Magics to generate a printing path and a support structure, the sliced file is imported into an SLM device for three-dimensional printing.

[0057] It should be noted that the purpose of the porous structure of the metal insert of the present application is: 1, to increase the surface area of the metal insert, thereby increasing the contact area between the metal insert and the second metal material, thereby improving the strength of the integrally formed composite material structure; 2, after the surface area of the metal insert is increased, it is beneficial for cooling and heat dissipation during casting with the second metal material; 3, the porous structure of the present application is also beneficial for reducing the material usage during three-dimensional printing, thereby reducing the three-dimensional printing cost.

[0058] The porous structure is further designed as a triple periodic minimal surface (TPMS) lattice structure, which can further reduce the material usage in 3D printing and thus reduce the weight of the metal insert, wherein the lightweight ratio of the TPMS can reach 60% to 90%, while maintaining a relatively high volume ratio. The metal insert of the first metal is formed by 3D printing to have the triple periodic minimal surface TPMS lattice structure, which can greatly reduce the usage of the first metal, further lightweight the metal insert, and further increase the surface area of the metal insert, so as to further increase the contact area with the molten second metal material in the casting process of S2, thereby improving the strength of the integrally formed composite structure. The weight of the integrally formed composite structure can be further reduced. The surface curvature of the triple periodic minimal surface TPMS lattice structure is uniformly distributed, the stress transmission is more balanced, and the stress concentration problem of the traditional porous structure such as the cubic grid is avoided. When the second metal material is injected into the metal insert composed of the TPMS, the applicant finds that the strength of the final product can be significantly improved. The triple periodic minimal surface TPMS lattice structure of the application can be a Gyroid structure, a Diamond structure or a Schwarz structure, etc., which can be determined according to actual conditions. The triple periodic minimal surface TPMS lattice structure of the embodiment is specifically a Gyroid structure.

[0059] S1 of the application is specifically a laser selective melting 3D printing process, which is used to layer by layer spread powder and laser melt and accumulate the powder of the first metal material to finally obtain a metal insert. The printing parameters of the laser selective melting 3D printing process are as follows: the laser power is 120 W to 250 W; the scanning speed is 1000 mm / s to 1500 mm / s, the layer thickness is controlled to be 30 μm to 60 μm; the gas protection is argon, and the purity of the argon is greater than or equal to 99.99%, and the oxygen content is less than 0.1%. It should be noted that the laser selective melting 3D printing process and the printing parameters of the application can be used to print a more delicate and complex porous structure, while effectively preventing the oxidation of the first metal material in the printing process, thereby improving the strength of the metal insert. The density of the first metal material in the application is greater than the density of the second metal material, so that the porous structure of the metal insert can increase the proportion of the second metal material under the same volume, thereby further reducing the weight of the integrally formed composite structure.

[0060] The printing parameters of the laser selective melting 3D printing process of the embodiment are as follows: the laser power is 250 W; the scanning speed is 1500 mm / s, the layer thickness is controlled to be 60 μm; the gas protection is argon, and the purity of the argon is greater than or equal to 99.99%, and the oxygen content is less than 0.1%.

[0061] The first metal material of the embodiment is titanium, the second metal material is aluminum, the lattice constant of the unit cell structure is 2.8 Å, the surface offset of the unit cell structure is 0.3 mm, the unit size of the unit cell structure is 2.0 mm, the relative density of the unit cell structure is 0.6, the Poisson's ratio of the unit cell structure is 0.35, and the Young's modulus of the unit cell structure is 160 GPa.

[0062] The lattice constant is the repeating period length (mm) of a single TPMS unit in space. The offset needs to meet tmin = minimum wall thickness / lattice constant. Since the second metal liquid needs to penetrate into the metal insert composed of TPMS, when the larger lattice constant facilitates the penetration of the second metal liquid, although the smaller lattice constant can improve the local stiffness, it needs to be combined with the optimization of the relative density and the minimum forming size of the printer to balance the comprehensive conditions such as the relative density, the printer feasibility, the local stiffness, etc. within the above range of the application. The surface offset t is a parameter for controlling the thickness of the TPMS curved surface, and t directly determines the density (in Gyroid: ρ∝ t). The minimum wall thickness needs to meet the lightweight and strength requirements after space filling: metal printing wall thickness ≥ 0.1 mm (depending on the material and the printer). The lattice constant range of the application is determined jointly based on the composition of the second metal material and the performance requirements of the integrally formed composite structure; the surface offset range is determined based on the printing equipment precision and process adjustment to ensure size accuracy and quality; the unit size range is selected according to the mechanical properties of the integrally formed composite structure and the printing efficiency requirements; the relative density range is determined according to the specific application requirements and the structure design; the Poisson's ratio range is affected by the composition of the second metal material and the structural complexity of the integrally formed composite structure; and the Young's modulus range is adjusted by adjusting the composition of the second metal material and the parameters of the integrally formed composite structure.

[0063] It also needs to be emphasized that since the metal insert is composed of these complex structure triple periodic minimal surface TPMS lattice structures, the traditional casting process cannot prepare the metal insert of the application, so the metal insert of the application can only be realized through three-dimensional printing. Even without considering that the metal insert has a micro-porous structure, in the macroscopic aspect, the complex shape of the metal insert can be manufactured through three-dimensional printing, thereby improving the shape diversity design of the integrally formed composite structure.

[0064] The first metal material and the second metal material of the application are two different materials, and there is a difference in color between different materials. Moreover, the metal insert of the application is a porous structure and serves as a shell, and the molten second metal material will flow to the surface of the metal insert through the porous structure, so that the integrally formed composite structure obtained by the application has a specific and unique texture structure, thereby improving the aesthetics of the integrally formed composite structure.

[0065] The S2 of the present application is performed by the following steps:

[0066] S2.1, the metal insert is subjected to ultrasonic degreasing treatment, and then enters S2.2;

[0067] S2.2, the metal insert is subjected to pickling treatment, and then enters S2.3;

[0068] S2.3, the metal insert is subjected to plasma cleaning treatment, and then enters S2.4;

[0069] S2.4, the metal insert is subjected to magnetic force grinding treatment, and then enters S2.5;

[0070] S2.5, the metal insert is subjected to sand blasting treatment, and a treated metal insert is obtained.

[0071] It should be noted that in S2, the metal insert is sequentially subjected to ultrasonic degreasing treatment, pickling treatment, plasma cleaning treatment, magnetic force grinding treatment and sand blasting treatment. The purpose of the ultrasonic degreasing treatment is to remove lubricating oil, release agent, hand sweat or other organic contaminants from the metal insert, so as to prevent grease from hindering the effective contact of the subsequent pickling, plasma cleaning and other processes with the metal surface. The purpose of the pickling treatment is to remove the oxide layer formed on the surface of the metal insert during the 3D printing process at high temperature, and to remove residual powder. The purpose of the plasma cleaning treatment is to further remove micron-sized contaminants, extremely thin oxide layers and trace amounts of organic matter. The purpose of the magnetic force grinding treatment is to remove small burrs and support structure residues from the edges and orifices of the metal insert, so that the metal insert becomes smooth in surface, so that the molten second metal material can more easily enter the interior of the metal insert; and the magnetic force grinding treatment also avoids the existence of closed pores in the porous structure in the microstructure, because if there are closed pores, the liquid metal cannot penetrate into the interior, forming a hollow structure, which reduces the strength of the integrally formed composite structure. The purpose of the sand blasting treatment is to completely remove the oxide scale, residual or severely adhered first metal powder, form a micro concave-convex structure by high-speed sand particle impact, increase the surface area, and improve the adhesion of the molten second metal material.

[0072] Specifically, S2 is performed by the following steps:

[0073] S2.1, the degreasing powder and water are mixed, then the metal insert is added into the ultrasonic cleaner, the temperature is controlled at 30℃, the current is 5A, and the ultrasonic cleaning is performed for 2min, after the ultrasonic degreasing is completed, S2.2 is entered, and the amount of the degreasing powder is 40g / L;

[0074] S2.2, add the metal insert into the pickling liquor, control the temperature to be 40 DEG C, and air is introduced and the aeration amount is 1.0 m3 / H, the treatment time is 8 min, after pickling, enter S2.3, the pickling liquor is a mixed solution of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 10:1;

[0075] S2.3 is specifically as follows:

[0076] S2.3.1, the metal insert is placed into the plasma cleaning machine, and S2.3.2 is entered;

[0077] S2.3.2, the gas flow is controlled to be 300 mL / min, the gas is argon and oxygen, and the volume ratio of argon to oxygen is 1:0.5, the gas cleaning time is 150 s, and S2.3.3 is entered;

[0078] S2.3.3, the gas flow is controlled to be 500 mL / min, the gas is argon, the gas cleaning time is 50 s, and S2.3.4 is entered;

[0079] S2.3.4, the gas flow is controlled to be 300 mL / min, the gas is argon and oxygen, and the volume ratio of argon to hydrogen is 1:2.0, the gas cleaning time is 150 s, and S2.4 is entered after completion;

[0080] S2.4, the metal insert is placed into the magnetic grinding machine and the grinding liquid and the magnetic grinding needle are added to enter grinding, and S2.5 is entered after the magnetic force grinding treatment is completed; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 20 min, and the grinding frequency is 60HZ;

[0081] S2.5, the metal insert is subjected to sand blasting treatment, and the treated metal insert is obtained after the sand blasting treatment is completed, and the sand blasting treatment parameters are that the sand particle size is 320 meshes, the sand blasting pressure is 0.8 Mpa, the spray gun distance is 200 mm, and the sand blasting angle is 45 DEG.

[0082] S3 of the application is performed by the following steps:

[0083] S3.1, the second metal material is heated to 750 DEG C, so that the second metal material is in a molten state, and the treated metal insert obtained in S2 is heated to 350 DEG C, and then the molten second metal material is injected into the treated metal insert obtained in S2 under the condition that the vacuum degree is 150 mbar and the injection speed is 0.1 m / s;

[0084] S3.2, then cooling, and cutting treatment is performed after cooling, and finally an integrally formed composite material structure is obtained; the process parameters of the cutting treatment are that the cutting speed is 20 m / min, the feed amount is 0.05 mm / r, and the cutting depth is 0.1 mm.

[0085] The preparation method of the integrally formed composite material structure based on the three-dimensional printing and casting process is characterized in that: the 3D printing metal insert is accurately designed to be connected with the traditional casting process, so that an integrated composite metal structure is formed, and the precision and sealing performance of the mold assembly are ensured.

[0086] In embodiment 2, the preparation method of the integrally formed composite material structure based on the three-dimensional printing and casting process is the same as that in embodiment 1, and the difference lies in that: S1 is specifically a 3D printing process of laser selective melting, in which the powder of the first metal material is laid layer by layer and laser melted and accumulated to finally obtain the metal insert.

[0087] The printing parameters of the laser selective melting 3D printing process are as follows: the laser power is 250 W; the scanning speed is 1500 mm / s, the layer thickness is controlled to be 60 μm; the gas protection is argon, and the purity of the argon is greater than or equal to 99.99%, and the oxygen content is less than 0.1%.

[0088] The first metal material is specifically titanium, the second metal material is aluminum, the lattice constant of the unit cell structure is 3.2 Å, the surface offset of the unit cell structure is 0.1 mm, the unit size of the unit cell structure is 0.5 mm, the relative density of the unit cell structure is 0.3, the Poisson's ratio of the unit cell structure is 0.30, and the Young's modulus of the unit cell structure is 100 Gpa.

[0089] S2 is performed by the following steps:

[0090] S2.1, the oil removal powder and water are mixed and then added to an ultrasonic cleaner, then the metal insert is added to the ultrasonic cleaner, the temperature is controlled to be 70 DEG C, the current is 2 A, and the ultrasonic cleaning is performed for 8 min, after the ultrasonic oil removal is completed, S2.2 is entered, and the dosage of the oil removal powder is 80 g / L;

[0091] S2.2, the metal insert is added to the pickling liquor, the temperature is controlled to be 90 DEG C, air is introduced and the aeration amount is 0.2 m³ / H, and the treatment time is 2 min, after the pickling is completed, S2.3 is entered, the pickling liquor is a mixture of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 2:1;

[0092] S2.3 is specifically as follows:

[0093] S2.3.1, the metal insert is placed in the plasma cleaning machine, and S2.3.2 is entered;

[0094] S2.3.2, control the gas flow to be 100 mL / min, the gas is argon and oxygen, the volume ratio of argon and oxygen is 1:0.3, the gas cleaning time is 70s, and S2.3.3 is entered;

[0095] S2.3.3, control the gas flow to be 300 mL / min, the gas is argon, the gas cleaning time is 30s, and S2.3.4 is entered;

[0096] S2.3.4, control the gas flow to be 100 mL / min, the gas is argon and oxygen, the volume ratio of argon and hydrogen is 1:1.5, the gas cleaning time is 70s, and S2.4 is entered after the process is completed;

[0097] S2.4, the metal insert is placed into a magnetic grinding machine, and a grinding liquid and a magnetic grinding needle are added to enter the grinding, and S2.5 is entered after the magnetic grinding treatment is completed; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 40 min, and the grinding frequency is 50HZ;

[0098] S2.5, the metal insert is subjected to sand blasting treatment, and the treated metal insert is obtained after the sand blasting treatment is completed, and the sand blasting treatment parameters are that the sand particle size is 150 mesh, the sand blasting pressure is 0.1 Mpa, the spray gun distance is 30 mm, and the sand blasting angle is 45°.

[0099] The S3 of the application is performed by the following steps:

[0100] S3.1, the second metal material is heated to 650 DEG C, so that the second metal material is in a molten state, and the treated metal insert obtained in S2 is heated to 250 DEG C, and then the molten second metal material is injected into the treated metal insert obtained in S2 under the condition that the vacuum degree is 350 mbar and the injection speed is 0.6 m / s;

[0101] S3.2, then cooling, and cutting treatment is performed after cooling, and finally an integrally formed composite material structure is obtained; the process parameters of the cutting treatment are that the cutting speed is 60 m / min, the feed amount is 0.25 mm / r, and the cutting depth is 0.1 mm.

[0102] Embodiment 3: a preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process, other features are the same as those of embodiment 1, and the difference lies in that S1 is specifically that the powder of the first metal material is laid layer by layer by a laser selective melting 3D printing process, and finally a metal insert is obtained by laser melting accumulation;

[0103] The printing parameters of the laser selective melting 3D printing process are that the laser power is 200 W, the scanning speed is 1200 mm / s, the layer thickness control is 40 μm, the gas protection is argon, and the purity of the argon is greater than or equal to 99.99%, and the oxygen content is less than 0.1%.

[0104] The first metal material is titanium, the second metal material is aluminum, the lattice constant of the unit cell structure is 3.0 Å, the surface offset of the unit cell structure is 0.2 mm, the unit size of the unit cell structure is 1.2 mm, the relative density of the unit cell structure is 0.4, the Poisson's ratio of the unit cell structure is 0.32, and the Young's modulus of the unit cell structure is 130 GPa.

[0105] S2 is performed by the following steps:

[0106] S2 is performed by the following steps:

[0107] S2.1, the oil removal powder and water are mixed and then added to an ultrasonic cleaner, then the metal insert is added to the ultrasonic cleaner, the temperature is controlled at 45 DEG C, the current is 3 A, and ultrasonic cleaning is performed for 5 min, after the ultrasonic oil removal is completed, S2.2 is entered, the dosage of the oil removal powder is 60 g / L;

[0108] S2.2, the metal insert is added to the pickling liquor, the temperature is controlled at 63 DEG C, air is introduced and the aeration amount is 0.6 m3 / H, and the treatment time is 5 min, after the pickling is completed, S2.3 is entered, the pickling liquor is a mixture of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 6:1;

[0109] S2.3 is specifically:

[0110] S2.3.1, the metal insert is placed in a plasma cleaning machine, and S2.3.2 is entered;

[0111] S2.3.2, the gas flow is controlled at 200 mL / min, the gas is argon and oxygen, and the volume ratio of argon to oxygen is 1:0.4, the gas cleaning time is 110 s, and S2.3.3 is entered;

[0112] S2.3.3, the gas flow is controlled at 400 mL / min, the gas is argon, the gas cleaning time is 30 s, and S2.3.4 is entered;

[0113] S2.3.4, the gas flow is controlled at 200 mL / min, the gas is argon and oxygen, and the volume ratio of argon to hydrogen is 1:1.7, the gas cleaning time is 110 s, and S2.4 is entered after completion;

[0114] S2.4, the metal insert is placed in a magnetic grinding machine and grinding liquid and magnetic grinding needles are added for grinding, and S2.5 is entered after the magnetic grinding treatment is completed; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 30 min, and the grinding frequency is 60 Hz;

[0115] S2.5, the metal insert is subjected to sand blasting treatment, and a treated metal insert is obtained after the sand blasting treatment, and parameters of the sand blasting treatment are as follows: sand granularity is 250 meshes, sand blasting pressure is 0.5 Mpa, a distance of a sand blasting gun is 100 mm, and a sand blasting angle is 30°.

[0116] S3 of the application is performed by the following steps:

[0117] S3.1, the second metal material is heated to 700 DEG C to reach a molten state, and the treated metal insert obtained in S2 is heated to 300 DEG C, and then the molten second metal material is injected into the treated metal insert obtained in S2 under the condition of a vacuum degree of 250 mbar and an injection speed of 0.4 m / s.

[0118] S3.2, then cooling, and cutting treatment is performed after the cooling, and finally an integrally formed composite material structure is obtained; process parameters of the cutting treatment are as follows: a cutting speed is 40 m / min, a feed amount is 0.15 mm / r, and a cutting depth is 1 mm.

[0119] Embodiment 4: a preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process, other features are the same as those in Embodiment 3, and the difference lies in that the triple periodic minimal surface TPMS lattice structure is a Schwarz structure.

[0120] Embodiment 5: an integrally formed composite material structure based on a three-dimensional printing and casting process, other features are the same as those in Embodiment 3, and the difference lies in that the triple periodic minimal surface TPMS lattice structure is a Diamond structure.

[0121] Embodiment 6: an integrally formed composite material structure based on a three-dimensional printing and casting process, other features are the same as those in Embodiment 3, and the difference lies in that the first metal material is titanium, the second metal material is zinc, a lattice constant of the unit cell structure is 3.3 Å, a surface offset of the unit cell structure is 0.5 mm, a unit size of the unit cell structure is 3.0 mm, a relative density of the unit cell structure is 0.7, a Poisson's ratio of the unit cell structure is 0.33, and a Young's modulus of the unit cell structure is 140 Gpa.

[0122] S3.1, the second metal material is heated to 450 DEG C to reach a molten state, and the treated metal insert obtained in S2 is heated to 300 DEG C, and then the molten second metal material is injected into the treated metal insert obtained in S2.

[0123] Example 7: An integrally formed composite structure based on a three-dimensional printing and casting process, other features being the same as example 6, except that the first metal material is specifically titanium, the second metal material is zinc, the lattice constant of the unit cell structure is 2.9 Å, the surface offset of the unit cell structure is 0.2 mm, the unit size of the unit cell structure is 0.8 mm, the relative density of the unit cell structure is 0.4, the Poisson's ratio of the unit cell structure is 0.28, and the Young's modulus of the unit cell structure is 80 GPa.

[0124] Example 8: An integrally formed composite structure based on a three-dimensional printing and casting process, other features being the same as example 6, except that the first metal material is specifically titanium, the second metal material is zinc, the lattice constant of the unit cell structure is 3.1 Å, the surface offset of the unit cell structure is 0.3 mm, the unit size of the unit cell structure is 1.8 mm, the relative density of the unit cell structure is 0.6, the Poisson's ratio of the unit cell structure is 0.31, and the Young's modulus of the unit cell structure is 100 GPa.

[0125] Example 9: An integrally formed composite structure based on a three-dimensional printing and casting process, other features being the same as example 3, except that the first metal material is specifically titanium, the second metal material is magnesium, the lattice constant of the unit cell structure is 2.8 Å, the surface offset of the unit cell structure is 0.3 mm, the unit size of the unit cell structure is 2.5 mm, the relative density of the unit cell structure is 0.55, the Poisson's ratio of the unit cell structure is 0.38, and the Young's modulus of the unit cell structure is 110 GPa.

[0126] S3.1, heat the second metal material to 600°C to bring the second metal material to a molten state, while heating the treated metal insert obtained in S2 to 300°C, and then injecting the second metal material in a molten state into the treated metal insert obtained in S2 under a vacuum degree of 250 mbar and an injection speed of 0.4 m / s.

[0127] Example 10: An integrally formed composite structure based on a three-dimensional printing and casting process, other features being the same as example 9, except that the first metal material is specifically titanium, the second metal material is magnesium, the lattice constant of the unit cell structure is 3.1 Å, the surface offset of the unit cell structure is 0.6 mm, the unit size of the unit cell structure is 0.6 mm, the relative density of the unit cell structure is 0.25, the Poisson's ratio of the unit cell structure is 0.32, and the Young's modulus of the unit cell structure is 45 GPa.

[0128] Example 11: An integrally formed composite structure based on a three-dimensional printing and casting process, other features are the same as example 9, the difference is that the first metal material is titanium, the second metal material is magnesium, the lattice constant of the unit cell structure is 3.0 Å, the surface offset of the unit cell structure is 0.4 mm, the unit size of the unit cell structure is 1.5 mm, the relative density of the unit cell structure is 0.35, the Poisson's ratio of the unit cell structure is 0.35, and the Young's modulus of the unit cell structure is 80 Gpa.

[0129] Comparative Example 1: A preparation method of an integrally formed composite structure based on a three-dimensional printing and casting process, other features are the same as example 3, the difference is that the plasma cleaning step is omitted.

[0130] Comparative Example 2: A preparation method of an integrally formed composite structure based on a three-dimensional printing and casting process, other features are the same as example 3, the difference is that the magnetic force grinding step is omitted.

[0131] Comparative Example 3: A preparation method of an integrally formed composite structure based on a three-dimensional printing and casting process, other features are the same as example 3, the difference is that the sand blasting step is omitted.

[0132] Comparative Example 4: A preparation method of an integrally formed composite structure based on a three-dimensional printing and casting process, other features are the same as example 3, the difference is that S2 is carried out as follows:

[0133] S2.1, mix the oil removal powder and water, then add the metal insert into the ultrasonic cleaner, control the temperature to be 45℃, the current to be 3A, and carry out ultrasonic cleaning for 5min, after the ultrasonic oil removal is completed, enter S2.2, the dosage of the oil removal powder is 20g / L;

[0134] S2.2, add the metal insert into the pickling liquor, control the temperature to be 35℃, and pass in air with an aeration amount of 0.6m³ / H, the treatment time is 5min, after the pickling is completed, enter S2.3, the pickling liquor is a mixture of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 13:1;

[0135] S2.3 is specifically:

[0136] S2.3.1, place the metal insert into the plasma cleaning machine, enter S2.3.2;

[0137] S2.3.2, control the gas flow to be 300mL / min, the gas is argon and oxygen, and the volume ratio of argon to oxygen is 1:0.2, the gas cleaning time is 110s, enter S2.3.3;

[0138] S2.3.3, control the gas flow to be 300 mL / min, the gas is argon, and the gas purging time is 30 s, and then enter S2.3.4;

[0139] S2.3.4, control the gas flow to be 300 mL / min, the gas is argon and oxygen, and the volume ratio of argon and hydrogen is 1:1, the gas purging time is 110 s, and then enter S2.4 after the process is completed;

[0140] S2.4, place the metal insert into the magnetic grinding machine and add the grinding liquid and the magnetic grinding needle to enter the grinding, and then enter S2.5 after the magnetic grinding treatment is completed; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 30 min, and the grinding frequency is 60 HZ;

[0141] S2.5, perform sand blasting treatment on the metal insert, and obtain the treated metal insert after the sand blasting treatment is completed; the parameters of the sand blasting treatment are that the sand particle size is 400 meshes, the sand blasting pressure is 1.0 Mpa, the spray gun distance is 100 mm, and the sand blasting angle is 30°.

[0142] S3 of the application is performed by the following steps:

[0143] S3.1, heat the second metal material to 700 DEG C, so that the second metal material is in a molten state, and meanwhile, heat the treated metal insert obtained in S2 to 230 DEG C, and then inject the molten second metal material into the treated metal insert obtained in S2 under the condition that the vacuum degree is 100 mbar and the injection speed is 0.8 m / s;

[0144] S3.2, then cool, and perform cutting treatment after the cooling, and finally obtain the integrally formed composite material structure; the process parameters of the cutting treatment are that the cutting speed is 80 m / min, the feed amount is 0.15 mm / r, and the cutting depth is 1 mm.

[0145] Comparative Example 5: a preparation method of an integrally formed composite material structure based on a three-dimensional printing and casting process, other features are the same as those of Example 3, and the difference lies in that:

[0146] S2 is performed by the following steps:

[0147] S2.1, mix the oil removal powder and water, then add the metal insert into the ultrasonic cleaning machine, control the temperature to be 45 DEG C, and the current to be 3 A, and perform ultrasonic cleaning for 5 min, and then enter S2.2 after the ultrasonic oil removal is completed; the dosage of the oil removal powder is 20 g / L;

[0148] S2.2, the metal insert is added to the pickling liquor, the temperature is controlled to be 90 DEG C, air is introduced and the aeration amount is 0.6 m3 / H, and the treatment time is 5 min, after pickling, S2.3 is entered, the pickling liquor is a mixed solution of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 1:1;

[0149] S2.3 is specifically:

[0150] S2.3.1, the metal insert is placed into a plasma cleaning machine, and S2.3.2 is entered;

[0151] S2.3.2, the gas flow is controlled to be 300 mL / min, the gas is argon and oxygen, the volume ratio of argon to oxygen is 1:1, the gas cleaning time is 110 s, and S2.3.3 is entered;

[0152] S2.3.3, the gas flow is controlled to be 300 mL / min, the gas is argon, the gas cleaning time is 30 s, and S2.3.4 is entered;

[0153] S2.3.4, the gas flow is controlled to be 300 mL / min, the gas is argon and oxygen, the volume ratio of argon to hydrogen is 1:3.0, the gas cleaning time is 110 s, and S2.4 is entered after completion;

[0154] S2.4, the metal insert is placed into a magnetic grinding machine and grinding liquid and magnetic grinding needles are added to enter grinding, and S2.5 is entered after completion of the magnetic grinding treatment; the magnetic grinding needle is a 304 stainless steel needle, the grinding time is 30 min, and the grinding frequency is 60 HZ;

[0155] S2.5, the metal insert is subjected to sand blasting treatment, and the treated metal insert is obtained after completion of the sand blasting treatment, the sand blasting treatment parameters are that the sand particle size is 100 meshes, the sand blasting pressure is 1.0 Mpa, the spray gun distance is 100 mm, and the sand blasting angle is 30 DEG.

[0156] S3 of the application is performed by the following steps:

[0157] S3.1, the second metal material is heated to 700 DEG C, so that the second metal material is in a molten state, and the treated metal insert obtained in S2 is heated to 400 DEG C, then the molten second metal material is injected into the treated metal insert obtained in S2 under the condition that the vacuum degree is 400 mbar and the injection speed is 0.8 m / s;

[0158] S3.2, then cooling, and cutting treatment is performed after cooling, and finally an integrally formed composite material structure is obtained; the process parameters of the cutting treatment are that the cutting speed is 80 m / min, the feed amount is 0.15 mm / r, and the cutting depth is 1 mm.

[0159] Comparative Example 6: A method for preparing an integral composite material structure based on 3D printing and casting processes. Other features are the same as in Example 3, except that: the first metal material is titanium, the second metal material is aluminum, the lattice constant of the unit cell structure is 3.5 Å, the surface offset of the unit cell structure is 0.5 mm, the unit size of the unit cell structure is 0.4 mm, the relative density of the unit cell structure is 0.7, the Poisson's ratio of the unit cell structure is 0.28, and the Young's modulus of the unit cell structure is 170 GPa.

[0160] Comparative Example 7: A method for preparing an integral composite material structure based on three-dimensional printing and casting processes, which is the same as Example 8 in other aspects, except that: the first metal material is titanium, the second metal material is zinc, the lattice constant of the unit cell structure is 2.8 Å, the surface offset of the unit cell structure is 0.6 mm, the unit size of the unit cell structure is 0.6 mm, the relative density of the unit cell structure is 0.8, the Poisson's ratio of the unit cell structure is 0.34, and the Young's modulus of the unit cell structure is 150 GPa.

[0161] Comparative Example 8: A method for preparing an integral composite material structure based on three-dimensional printing and casting processes, which is the same as Example 11 in other features, except that: the first metal material is titanium, the second metal material is magnesium, the lattice constant of the unit cell structure is 3.2 Å, the surface offset of the unit cell structure is 0.2 mm, the unit size of the unit cell structure is 2.6 mm, the relative density of the unit cell structure is 0.24, the Poisson's ratio of the unit cell structure is 0.30, and the Young's modulus of the unit cell structure is 120 GPa.

[0162] Comparative Example 9: A method for preparing an integral composite material structure based on three-dimensional printing and casting processes. Other features are the same as in Example 3, except that the unit cell structure is a Kagome lattice structure.

[0163] Comparative Example 10: A method for preparing an integral composite material structure based on three-dimensional printing and casting processes. Other features are the same as in Example 3, except that the unit cell structure is a Neovius lattice structure.

[0164] Test case

[0165] According to ASTM D5379 / D5379M standards, the integrally molded composite material structures obtained in Examples 1 to 11 and Comparative Examples 1 to 10 were tested. In the integrally molded composite material structure, the first metal material and the second metal material form a plate-shaped protrusion. The shear force of the integrally molded composite material structure was tested through the plate-shaped protrusion using a universal testing machine, and the results are shown in Table 1.

[0166] Table 1. Shear resistance of integrally molded composite material structures

[0167] Porous structure Second metal material Shear resistance / MPa Example 1 Gyroid structure Aluminium 226 Example 2 Gyroid structure Aluminium 214 Example 3 Gyroid structure Aluminium 235 Example 4 Schwarz structure Aluminium 201 Example 5 Diamond structure Aluminium 208 Example 6 Gyroid structure Zinc 160 Example 7 Gyroid structure Zinc 156 Example 8 Gyroid structure Zinc 166 Example 9 Gyroid structure Magnesium 88 Example 10 Gyroid structure Magnesium 86 Example 11 Gyroid structure Magnesium 93 Comparative Example 1 Gyroid structure Aluminium 116 Comparative Example 2 Gyroid structure Aluminium 146 Comparative Example 3 Gyroid structure Aluminium 164 Comparative Example 4 Gyroid structure Aluminium 188 Comparative Example 5 Gyroid structure Aluminium 173 Comparative Example 6 Gyroid structure Aluminium 204 Comparative Example 7 Gyroid structure Zinc 143 Comparative Example 8 Gyroid structure Magnesium 77 Comparative Example 9 Kagome lattice structure Aluminium 134 Comparative Example 10 Neovius lattice structure Aluminium 156

[0168] As shown in Table 1, the shear strength of the integrally molded composite material structure obtained by this invention is greater than 200 MPa. Furthermore, when the triple periodic minimal surface TPMS lattice structure is a Gyroid structure, its shear strength reaches a maximum of 235 MPa. This indicates that the shear strength of the Gyroid structure is higher than that of the Schwarz and Diamond structures. Compared with other triple periodic minimal surface TPMS lattice structures, the Gyroid structure does not have obvious stress concentration points, and its mechanical properties are more consistent in different directions, resulting in uniform strength of the integrally molded composite material. Moreover, the Gyroid structure has a continuous and regular curved surface, allowing for more uniform heat conduction in all directions during the S2 casting process, avoiding localized overheating or undercooling.

[0169] As can be seen from Examples 3 and Comparative Examples 1 to 5, the metal insert of the present invention can be fully bonded to the second metal material only under specified post-processing operations and casting conditions, and the resulting integrally molded composite material structure has the highest shear force.

[0170] Since aluminum, zinc, and magnesium have different physical properties, such as elongation and impact toughness, through Examples 3 and 6, 8 and 7, and 11 and 8 of the present invention, under the same conditions, the range of lattice constant, surface offset, unit size, relative density, Poisson's ratio, and Young's modulus of the corresponding unit cell structure also affects the shear resistance of the composite material structure. Within the specific range of lattice constant, surface offset, unit size, relative density, Poisson's ratio, and Young's modulus of the present invention, its shear resistance is relatively high.

[0171] Example 12: An integrally molded composite material structure was prepared by the integrally molded composite material structure preparation method based on three-dimensional printing and casting process described in Examples 1 to 11.

[0172] Based on the above test data, the shear strength of the integrally molded composite material structure of the present invention is greater than 200 MPa.

[0173] This one-piece molded composite material structure achieves seamless integration of precisely designed 3D-printed metal inserts with traditional casting processes, forming a unified composite metal structure that ensures the precision and sealing of mold assembly. Furthermore, this invention enables the fabrication of complex shapes using 3D printing, achieving the molding of complex materials that is difficult to accomplish with traditional manufacturing processes. This meets the needs of various fields for manufacturing complex-shaped metal materials and overcomes the limitations of traditional titanium-aluminum composite processes. The one-piece molded composite material structure obtained by this invention possesses high precision, high strength, and excellent surface finish.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an integral composite material structure based on three-dimensional printing and casting processes, characterized in that, Includes the following steps: S1. A metal insert is obtained by three-dimensional printing of the first metal material, wherein the metal insert has a porous structure; S2. Perform post-processing on the metal insert obtained in S1 to obtain the processed metal insert; S3. The second metal material is heated to a molten state, and then the molten second metal material is injected into the treated metal insert obtained in S2. Then it is cooled to finally obtain the integrally molded composite material structure with the treated metal insert as the shell. The melting point of the second metal material is lower than that of the first metal material; The S2 process is performed by the following steps: S2.

1. Perform ultrasonic degreasing on the metal inserts, and then proceed to S2.2; S2.

2. Pickling is performed on the metal inserts, and then proceeds to S2.3; S2.

3. Perform plasma cleaning on the metal inserts, and then proceed to S2.4; S2.

4. Perform magnetic abrasive treatment on the metal insert, and then proceed to S2.5; S2.

5. The metal insert is sandblasted to obtain the treated metal insert; Step S2.1 includes: mixing degreasing powder and water and adding it to an ultrasonic cleaner, then adding the metal insert to the ultrasonic cleaner, controlling the temperature to 30℃~70℃, the current to 2A~5A, and performing ultrasonic cleaning for 2min~8min. After ultrasonic degreasing is completed, proceed to S2.

2. The amount of degreasing powder used is 40 g / L~80 g / L. Step S2.2 includes: adding the metal insert to the pickling solution, controlling the temperature at 40℃~90℃, and introducing air with an aeration rate of 0.2m³ / H~1.0m³ / H, and processing for 2min~8min. After pickling, proceed to S2.

3. The pickling solution is a mixture of phosphoric acid and sulfuric acid, and the weight ratio of phosphoric acid to sulfuric acid is 2~10:

1. Step S2.3 includes: placing the metal insert into a plasma cleaner for cleaning, with a gas flow rate of 100 mL / min to 500 mL / min and a gas cleaning time of 150 s to 350 s; after the plasma cleaning is completed, proceed to step S2.4; the gas is at least one of argon, oxygen, or hydrogen. Step S2.4 includes: placing the metal insert into a magnetic polishing machine and adding polishing fluid and a magnetic polishing needle for polishing; after the magnetic polishing process is completed, proceed to S2.5; the magnetic polishing needle is a 304 stainless steel needle, the polishing time is 20 min to 40 min, and the polishing frequency is 50 Hz to 60 Hz. Step S2.5 includes: sandblasting the metal insert, and obtaining the treated metal insert after sandblasting. The parameters of the sandblasting are: a sand particle size of 150-320 mesh, a sandblasting pressure of 0.1 MPa-0.8 MPa, a spray gun distance of 30 mm-200 mm, and a sandblasting angle of 15°-45°. Specifically, S2.3 refers to: S2.3.1 Place the metal insert into the plasma cleaner and proceed to S2.3.2; S2.3.2, Control the gas flow rate to 100mL / min~300mL / min, the gas is argon and oxygen, and the volume ratio of argon to oxygen is 1:0.3~0.5, the gas cleaning time is 70s~150s, then proceed to S2.3.3; S2.3.3, control the gas flow rate to 300mL / min~500mL / min, the gas is argon, the gas cleaning time is 10s~50s, then proceed to S2.3.4; S2.3.4 Control the gas flow rate to 100 mL / min to 300 mL / min. The gas is argon and oxygen, and the volume ratio of argon to hydrogen is 1:1.5 to 2.

0. The gas cleaning time is 70 s to 150 s. After completion, proceed to S2.

4.

2. The method for preparing an integral composite material structure based on three-dimensional printing and casting processes according to claim 1, characterized in that: The metal insert is composed of multiple unit cell structures.

3. The method for preparing an integrally molded composite material structure based on three-dimensional printing and casting processes according to claim 2, characterized in that: The unit cell structure is a triple periodic minimal surface TPMS lattice structure.

4. The method for preparing an integral composite material structure based on three-dimensional printing and casting processes according to claim 3, characterized in that: The triple periodic minimal surface TPMS lattice structure is a Gyroid structure, a Diamond structure, or a Schwarz structure.

5. The method for preparing an integrally molded composite material structure based on three-dimensional printing and casting processes according to any one of claims 1 to 4, characterized in that: S1 specifically involves using a laser selective melting 3D printing process to lay powder of the first metal material layer by layer, and then laser melting and stacking the powder to finally obtain the metal insert. The printing parameters of the laser selective melting 3D printing process are as follows: laser power is 120 W to 250 W; scanning speed is 1000 mm / s to 1500 mm / s; layer thickness is controlled at 30 μm to 60 μm; the gas protection is argon, and the purity of argon is ≥99.99%, and the oxygen content is <0.1%.

6. The method for preparing an integral composite material structure based on three-dimensional printing and casting processes according to any one of claims 2 to 4, characterized in that: The first metallic material is titanium or stainless steel; The lattice constant of the unit cell structure is 2.8 Å to 3.3 Å, the surface offset of the unit cell structure is 0.1 mm to 0.6 mm, the unit cell size of the unit cell structure is 0.5 mm to 3.0 mm, the relative density of the unit cell structure is 0.25 to 0.7, the Poisson's ratio of the unit cell structure is 0.28 to 0.38, and the Young's modulus of the unit cell structure is 45 GPa to 160 GPa. The second metallic material is aluminum, zinc, or magnesium; When the second metallic material is aluminum, the lattice constant of the unit cell structure is 2.8 Å to 3.2 Å, the surface offset of the unit cell structure is 0.1 mm to 0.3 mm, the unit size of the unit cell structure is 0.5 mm to 2.0 mm, the relative density of the unit cell structure is 0.3 to 0.6, the Poisson's ratio of the unit cell structure is 0.3 to 0.35, and the Young's modulus of the unit cell structure is 100 GPa to 160 GPa. When the second metallic material is zinc, the lattice constant of the unit cell structure is 2.9 Å to 3.3 Å, the surface offset of the unit cell structure is 0.2 mm to 0.5 mm, the unit size of the unit cell structure is 0.8 mm to 3.0 mm, the relative density of the unit cell structure is 0.4 to 0.7, the Poisson's ratio of the unit cell structure is 0.28 to 0.33, and the Young's modulus of the unit cell structure is 80 GPa to 140 GPa. When the second metallic material is magnesium, the lattice constant of the unit cell structure is 2.8 Å to 3.1 Å, the surface offset of the unit cell structure is 0.3 mm to 0.6 mm, the unit size of the unit cell structure is 0.6 mm to 2.5 mm, the relative density of the unit cell structure is 0.25 to 0.55, the Poisson's ratio of the unit cell structure is 0.32 to 0.38, and the Young's modulus of the unit cell structure is 45 GPa to 110 GPa.

7. A one-piece molded composite material structure, characterized in that: The composite material structure was prepared by the method for preparing an integrally molded composite material structure based on three-dimensional printing and casting process as described in any one of claims 1 to 6. The shear strength of the integrally molded composite material structure is greater than 200 MPa.

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