A method for preparing high-strength, high-plasticity titanium-based composite powder and composite material

Abstract

This invention discloses a method for preparing high-strength, high-plasticity titanium-based composite powder and composite material. The method includes: 1. Selecting spherical titanium alloy powder, mineral oil and wax, and spherical copper powder; 2. Ball milling the spherical copper powder into flake copper powder, then mixing it with mineral oil and wax, and calcining to obtain Gr@Cu composite powder; 3. Ball milling and mixing the reinforcing precursor with the spherical titanium alloy powder to obtain titanium-based composite powder; 4. Obtaining Gr@Cu / titanium-based composite material by discharge plasma sintering and hot rolling. This invention uses flake copper powder as a carrier to prepare Gr@Cu composite powder, avoiding damage to graphene derivatives and improving the interfacial adhesion with the titanium matrix. In the Gr@Cu / titanium-based composite material, in-situ generated TiC and CuTi2 are distributed in a multi-level, multi-scale structure at grain boundaries and within grains, improving the material's strength. Furthermore, the scale-level structure disperses stress concentration on the matrix, preventing the material from losing plasticity while increasing strength, thus achieving a balance between strength and plasticity.

Description

Technical Field

[0001] This invention belongs to the field of in-situ loading of graphene derivatives on the surface of metal powder and preparation of metal matrix composite materials, specifically relating to a method for preparing high-strength and high-plasticity titanium-based composite powder and composite materials. Background Technology

[0002] Titanium and titanium alloys are widely used in aerospace and other fields due to their advantages such as low density, high specific strength, good corrosion resistance, and high heat resistance. However, with the rapid development of high technology, the demand for high-strength and high-toughness titanium alloy materials is increasing, and traditional titanium alloys can no longer meet the requirements. Therefore, researching and developing new titanium alloys and their composites to achieve a good strength-plasticity match is key to expanding the application fields of titanium materials and promoting their rapid industrial development. Compared with traditional titanium alloys, titanium-based composites are a new type of structural material with titanium alloys as the matrix and the introduction of suitable reinforcements. They can break through the limitations of single metal or alloy matrices and obtain superior comprehensive performance. Current research shows that although the addition of ultra-high strength graphene and its derivatives to the titanium matrix can achieve a good strength-plasticity match, demonstrating great advantages and potential in reinforcing titanium-based composites, how to improve the uniform dispersion of graphene in the titanium matrix, enhance the interfacial bonding with the titanium matrix, and achieve low-cost production of high-quality graphene remain bottleneck problems limiting the high performance of graphene / titanium-based composites.

[0003] Currently, existing technologies mainly improve the dispersion of graphene in titanium matrices through chemical methods and physical ball milling. For example, electrochemical deposition can achieve uniform dispersion of graphene in titanium matrices, but its composition is difficult to control precisely (Scientific Reports, 4(2014): 4049); in-situ growth of graphene on titanium powder using vapor phase chemical deposition has become a new technology to solve graphene agglomeration, but in practical applications, due to the high growth temperature of graphene, titanium powder is prone to sticking together, resulting in uneven graphene distribution (Materials Letters, 283(2021): 128895). In fact, the most commonly used mechanical ball milling method can improve the dispersibility of graphene to a certain extent and achieve precise control of its composition, but it often damages the structure of graphene (Carbon, 159(2020): 311-323). Therefore, improving the uniform dispersion of graphene in titanium matrices still requires further exploration and solutions.

[0004] On the other hand, in order to improve the interfacial bonding strength between graphene and the titanium matrix, the existing technology mainly relies on the principle that the wettability between metals is much greater than that between non-metals and metals. The surface of graphene is modified with metallized nanoparticles by electroless plating, and the titanium alloy matrix is strengthened by nano-composite powder to obtain a titanium matrix composite with strong plasticity matching (Journal of Alloys and Compounds, 729(2017): 293-302; Carbon, 137(2018): 146-155). It can be seen that the interfacial bonding strength between graphene and the titanium matrix can be significantly improved after graphene is modified with metal particles. However, it is very difficult to achieve uniform dispersion and tight bonding between graphene and metal particles by electroless plating technology. In addition, for large-scale commercial production, the preparation process of this technology is complex, time-consuming and expensive, and involves harmful additive solvents, which will seriously damage the interfacial bonding effect of the composite material. Therefore, the existing technology still has not solved the problem of obtaining a high-strength and high-plasticity level of titanium matrix composites by optimizing the interfacial strength between graphene and the titanium matrix, and further exploration of an energy-saving and efficient method is still needed.

[0005] In summary, there is an urgent need to propose a strategy for uniformly dispersing graphene in the titanium matrix and having a high interfacial bonding degree with it, optimize a simple and efficient graphene synthesis method, apply it to the preparation of titanium matrix composites with excellent strong plasticity matching level, and promote its industrial application. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a preparation method of a high-strength and high-plasticity titanium matrix composite powder and composite material in view of the above-mentioned deficiencies of the existing technology. In this method, flaky copper powder is used as a carrier and calcined with mineral oil and wax to prepare Gr@Cu composite powder, avoiding the destruction of graphene derivatives. Combining high-energy ball milling, graphene is uniformly coated on the titanium matrix to obtain Gr@Cu / titanium matrix composite powder, improving the interfacial adhesion with the titanium matrix. Then, through sintering and hot deformation processing, Gr@Cu / titanium matrix composite material is obtained. In this process, TiC and CuTi2 formed by in-situ solid-state reaction are distributed in a multi-level and multi-scale structure at grain boundaries and within grains, improving the strength of Gr@Cu / titanium matrix composite material, and the scale-graded structure disperses the stress concentration on the matrix, avoiding the loss of plasticity when the material improves strength, thus achieving strong plasticity matching.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: a preparation method of a high-strength and high-plasticity titanium matrix composite powder and composite material, characterized in that the method comprises the following steps:

[0008] Step 1. Selection of raw materials: Select spherical titanium alloy powder prepared by the rotating electrode method as the matrix material, and select mineral oil and wax and spherical copper powder as the raw materials for preparing the reinforcing body precursor;

[0009] Step 2: Preparation of reinforcement precursor: Place the spherical copper powder selected in Step 1 in a planetary ball mill and ball mill it into flaky copper powder. Then, mechanically stir mineral oil and wax evenly with the flaky copper powder, and then calcine it in an argon atmosphere to obtain the reinforcement precursor, that is, in-situ graphene derivative modified copper composite powder, denoted as Gr@Cu composite powder;

[0010] Step 3: Preparation of titanium-based composite powder: Place the reinforcement precursor obtained in Step 2 and the spherical titanium alloy powder selected in Step 1 in a planetary ball mill and ball mill them evenly to obtain titanium-based composite powder, that is, in-situ graphene derivative modified copper / titanium-based composite powder, denoted as Gr@Cu / titanium-based composite powder;

[0011] Step 4: Preparation of titanium-based composite material: Subject the titanium-based composite powder prepared in Step 3 to spark plasma sintering and forming, and then obtain the titanium-based composite material through hot rolling, that is, Gr@Cu / titanium-based composite material.

[0012] In this invention, mineral oil and wax are mixed evenly with flaky copper powder and then calcined to in-situ form graphene derivative modified copper composite powder. Then, it is ball milled with titanium alloy powder at high energy to prepare graphene derivative modified copper / titanium-based composite powder, and through solid-phase sintering combined with deformation processing, a high-strength and high-ductility multi-level structure titanium-based composite material is obtained.

[0013] First of all, in the preparation process of this invention, the spherical copper powder is regulated into flaky copper powder with appropriate sheet diameter and thickness through the ball milling process. Then, mineral oil and wax are dropped into the flaky copper powder for sufficient mechanical mixing, and finally, short-time calcination is carried out. By regulating the ball milling process parameters of the spherical copper powder and the content of mineral oil and wax, graphene derivative modified copper composite powder with a high specific surface area is obtained, and at the same time, the content of graphene derivatives, the thickness and size of copper sheets are precisely controlled. Based on the appropriate sheet diameter size and layer thickness of the flaky copper powder, compared with traditional graphene with the same high specific surface area, this graphene derivative modified copper composite powder increases the substantial contact area with spherical titanium alloy powder during the subsequent high-energy ball milling mixing process, and increases the coating amount of graphene derivatives. At the same time, due to the wettability between copper element and titanium element being much higher than that between carbon element and titanium element, graphene derivatives grow in-situ on the flaky copper powder and use the flaky copper powder as the contact medium between it and the spherical titanium alloy powder, effectively avoiding the phenomenon that traditional graphene is prone to agglomeration on the surface of spherical titanium alloy powder and the complete sheet layer scale is prone to fragmentation, and solving the problems of poor dispersion after mixing traditional graphene with titanium-based powder and the easy destruction of the two-dimensional sheet layer size of graphene.

[0014] Secondly, the formation characteristics of the in-situ graphene derivative modified copper / titanium-based composite powder prepared by this invention provide a prerequisite for the strength and plasticity of multi-level and multi-scale in-situ hybrid reinforcement of titanium-based composite materials. Its strengthening and toughening principle is as follows: based on solid-state diffusion reaction and the dissolution and precipitation mechanism of Ti-C and Ti-Cu, after solid-state sintering, the in-situ precipitated and pinned reinforcement TiC at the grain boundaries plays a role in inhibiting grain coarsening, hindering dislocation movement, and providing load transfer; while the copper dissolved into the grain can effectively refine the β phase structure in the matrix, and then the nano-sized CuTi2 precipitates on the β phase through a eutectoid reaction. The two always maintain a low-energy interface in the grain and restrain each other, so that the intracrystalline structure is in a relatively stable state; after hot deformation processing, the supersaturated copper also precipitates nano-sized CuTi2 particles in a diffuse distribution on the α phase in the matrix. These nanoparticles hinder the dislocation movement in the grain. Therefore, TiC at the grain boundaries and CuTi2 dispersed in the α phase within the grains improve the strength of the titanium-based composite material, while CuTi2, which is interdependent with the β phase, stabilizes the intracrystalline structure. The titanium-based composite material with a multi-level and multi-scale structure can effectively disperse the stress concentration located on each reinforcement, avoiding the loss of plasticity when the material increases its strength, thus achieving the ultimate goal of matching strength and plasticity.

[0015] The above-mentioned method for preparing a high-strength, high-plasticity titanium-based composite powder and composite material is characterized in that the spherical titanium alloy powder in step one is TA19, TC4 or Ti-1300 with a particle size of 15μm to 53μm, the mineral oil and wax are petrolatum, liquid paraffin or microcrystalline wax with C16-C21 n-alkanes as the main component, and the spherical copper powder has a particle size of 1μm to 5μm.

[0016] The preparation method of the above-mentioned high-strength and high-plasticity titanium-based composite powder and composite material is characterized in that, in step two, the ball-to-material ratio of the spherical copper powder ball milling is 15-25:1, the ball milling speed is 400 rpm-450 rpm, and the ball milling time is 4 h-6 h; the diameter of the flake copper powder is 20 μm-30 μm, and the thickness is 10 μm-20 μm; the volume ratio of the mineral oil and wax to the flake copper powder is 5-16:40, and the mechanical stirring time is 15 min-20 min; the calcination temperature is 750℃-900℃, and the calcination time is 0.5 h-1.5 h.

[0017] The preparation method of the above-mentioned high-strength and high-plasticity titanium-based composite powder and composite material is characterized in that, in step three, the mass ratio of the reinforcing precursor to the spherical titanium alloy powder is 11-50:550, the ball-to-material ratio of the ball mill is 3-6:1, the ball milling speed is 150 rpm-250 rpm, and the ball milling time is 8 h-12 h.

[0018] The preparation method of the above-mentioned high-strength and high-plasticity titanium-based composite powder and composite material is characterized in that the sintering temperature of the discharge plasma sintering in step four is 900℃~1100℃, and the holding time is 3min~6min; the hot rolling temperature is 800℃~1000℃.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. To address the disadvantages of existing metal nanoparticle-modified graphene preparation techniques, such as chemical plating, which suffer from high costs and cumbersome processes, as well as the problem of severe agglomeration and detachment of metal nanoparticles on graphene, this invention uses ball-milled sheet copper powder with controllable sheet size and thickness as a carrier. Green, non-toxic, and inexpensive mineral oil and wax are used to calcine the sheet copper powder for a short time, thereby generating a large amount of graphene derivatives in situ on the sheet copper powder. This produces in-situ graphene derivative-modified copper composite powder, which not only easily controls the content of graphene derivatives but also improves the uniformity and tightness of the graphene derivatives on the sheet copper powder. Furthermore, this preparation process is easy to implement and suitable for large-scale industrial production.

[0021] 2. Compared to dispersing graphene on a titanium matrix via stepwise low-energy ball milling, in this invention, the graphene derivative is grown in situ within flake copper powder as a carrier. The excellent ductility of the flake copper powder ensures that the two-dimensional large-sheet graphene derivative is not destroyed by high ball milling speed, thus achieving uniform graphene coating on the titanium matrix through a single high-energy ball milling step. Compared to existing technologies that use metal nanoparticles to modify graphene to improve the interfacial adhesion strength between graphene and the titanium matrix, and retain graphene by controlling the interface to obtain reinforced titanium-based composite materials, the Gr@Cu composite powder prepared in this invention benefits from the strong affinity between copper and titanium elements. The high interfacial adhesion between the graphene-modified copper and the titanium matrix is ​​directly obtained. During sintering and rolling, the in-situ solid-state reaction between the graphene-modified copper and the titanium matrix produces TiC and CuTi2, which are distributed in a multi-level, multi-scale structure at the grain boundaries and within the grains. Compared with the existing technology that attempts to suppress the strong interfacial reaction between graphene and the titanium alloy matrix to retain the graphene and only construct the surface and interfacial structure, the Gr@Cu / titanium-based composite material prepared by this invention can not only achieve high room temperature tensile strength by relying on the coexisting precipitates, but also overcome the mismatch problem of low plasticity under high tensile strength by dispersing the stress concentration on the matrix through the multi-scale hierarchical structure.

[0022] 3. The room temperature mechanical properties of the Gr@Cu / titanium-based composite material prepared by this invention are: tensile strength of 1490MPa to 1510MPa and elongation after fracture of 5% to 8%, which are far higher than the strength-plasticity matching level of existing graphene / titanium-based composite materials or metal nanoparticle-modified graphene / titanium-based composite materials.

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] Figure 1 This is a microstructure image of the Gr@Cu composite powder prepared in Example 1 of the present invention.

[0025] Figure 2 The image shows the Raman spectrum of the Gr@Cu composite powder prepared in Example 1 of this invention.

[0026] Figure 3 This is a microstructure image of the Gr@Cu / TC4 composite powder prepared in Example 1 of the present invention.

[0027] Figure 4 This is a low-magnification microstructure image of the Gr@Cu / TC4 composite material prepared in Example 1 of the present invention.

[0028] Figure 5 This is a high-magnification microstructure image of the Gr@Cu / TC4 composite material prepared in Example 1 of the present invention.

[0029] Figure 6 The images show the engineering stress-strain curves at room temperature of the Gr@Cu / TC4 composite materials prepared in Examples 1 to 3 of this invention, the TC4 material prepared in Comparative Example 1, and the Cu / TC4 composite material prepared in Comparative Example 2. Detailed Implementation

[0030] Example 1

[0031] This embodiment includes the following steps:

[0032] Step 1: Selection of raw materials: Spherical TC4 titanium alloy powder with a particle size of 15μm to 53μm prepared by the rotating electrode method is selected as the matrix material, and liquid paraffin with C16-C21 n-alkanes as the main component and spherical copper powder with a particle size of 1μm to 5μm are selected as the raw materials for the preparation of the reinforcing precursor.

[0033] Step 2: Preparation of the reinforcing precursor: The spherical copper powder selected in Step 1 was placed in a planetary ball mill and ball-to-powder ratio of 20:1, milling speed of 425 rpm, and milling time of 5 h to obtain flake copper powder with a diameter of 25 μm and a thickness of 15 μm. Then, liquid paraffin and flake copper powder were mixed at a volume ratio of 5:30. 0.5 mL of liquid paraffin was mechanically stirred evenly for 18 min. The mixture was then placed in a tube furnace and calcined at 800 °C under an argon atmosphere for 1 h to obtain the reinforcing precursor, namely, in-situ graphene derivative modified copper composite powder, denoted as Gr@Cu composite powder.

[0034] Step 3: Preparation of titanium-based composite powder: 6g of the reinforcing precursor obtained in Step 2 and 114g of the spherical TC4 titanium alloy powder selected in Step 1 were loaded into a stainless steel ball mill and placed in a planetary ball mill for ball milling and mixing. The ball-to-material ratio was 5:1, the ball milling speed was 200 rpm, and the ball milling time was 10h to obtain titanium-based composite powder, namely in-situ graphene derivative modified copper / titanium-based composite powder, denoted as Gr@Cu / TC4 composite powder;

[0035] Step 4: Preparation of titanium-based composite material: The titanium-based composite powder prepared in step 3 is subjected to discharge plasma sintering at a temperature of 1000℃ and a holding time of 5min. The titanium-based composite material, namely Gr@Cu / TC4 composite material, is obtained by hot rolling at 900℃.

[0036] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Gr@Cu / TC4 composite material prepared in this embodiment was 1504 MPa and the elongation after fracture was 6.04%.

[0037] Table 1. Comparison of mechanical properties of Gr@Cu / TC4 with existing reported graphene / titanium-based composites or X@Gr (X = metal nanoparticles) / titanium-based composites.

[0038]

[0039] References: [1] Q. Yan, et al., Improved mechanical properties in titanium matrix composites reinforced with quasi - continuously networked graphene nanosheets and in - situ formed carbides[J]. Journal of Materials Science & Technology, 96(2022)85 - 93; [2] B. Zhang, et al., Graphene - TiC hybrid reinforced titanium matrix composites with 3D network architecture: fabrication, microstructure and mechanical properties[J]. Journal of Alloys and Compounds, 859(2021)157777; [3] H. Zhang, et al., Uniform dispersion and interface analysis of nickel coated graphene nanoflakes / pure titanium matrix composites[J]. Carbon, 137(2018)146 - 155; [4] L. Dong, et al., Reduced graphene oxide nanosheets decorated with copper and silver nanoparticles for achieving superior strength and ductility in titanium composites[J]. ACS Applied Materials & Interfaces, 13(2021)43197 - 43208; [5] H. Xue, et al., In - situ synthesis of reduced graphene oxide / aluminium oxide nanopowders for reinforcing Ti - 6Al - 4V composites[J]. Journal of Alloys and Compounds, 905(2022)164198; [6] Y. Guo, et al.,Role of powder metallurgical processing on mechanical response of nickel-phosphorus-coated graphene nanoflakes / titanium matrix composites[J].AdvancedEngineering Materials, 25(2023)2201002.

[0040] As shown in Table 1, the Gr@Cu / titanium-based composite material prepared in this invention exhibits high strength and low plasticity loss at room temperature, which is far superior to the strength-plasticity matching level of existing graphene / titanium-based composite materials or metal nanoparticle-modified graphene / titanium-based composite materials.

[0041] Figure 1 This is a microstructure image of the Gr@Cu composite powder prepared in this embodiment. Figure 1 It can be seen that a large number of wrinkles have appeared on the copper sheet, combined with Figure 2 It can be seen that the wrinkles are graphene derivatives generated in situ, and in order to reduce their surface energy, the morphology of the graphene derivatives changes from two-dimensional to three-dimensional, so the wrinkles on the surface of the sheet copper powder are significantly increased.

[0042] Figure 2 The image shows the Raman spectrum of the Gr@Cu composite powder prepared in this embodiment. Figure 2 It can be seen that at 1330cm -1 and 1590cm -1 There are two obvious carbon signal characteristic peaks, which are consistent with the positions of the typical graphene D peak and G peak reported in existing literature ([1] Separation and Purification Technology, 267(2021): 118680; [2] Composites Part B, 234(2022): 109731), indicating that the graphene derivative was successfully grown in situ on the surface of a sheet of copper with controllable size and thickness.

[0043] Figure 3 This is a microstructure image of the Gr@Cu / TC4 composite powder prepared in this embodiment. Figure 3 It can be seen that the Gr@Cu composite powder is uniformly distributed on the surface of the spherical TC4 titanium alloy powder.

[0044] Figure 4 This is a low-magnification microstructure image of the Gr@Cu / TC4 composite material prepared in Example 1 of this invention. Figure 4It can be seen that after sintering and hot deformation processing, the Gr@Cu / TC4 composite powder has in-situ precipitates distributed in a network at the grain boundaries of the elongated TC4 grains.

[0045] Figure 5 This is a high-magnification microstructure image of the Gr@Cu / TC4 composite material prepared in this embodiment. Figure 5 It can be seen that CuTi2 is distributed sequentially on β-Ti and α-Ti within the crystal.

[0046] Comparative Example 1

[0047] The process of this comparative example is as follows: spherical TC4 titanium alloy powder with a particle size of 15μm to 53μm prepared by the rotating electrode method is directly subjected to discharge plasma sintering at a sintering temperature of 1000℃ and a holding time of 5min. The TC4 material is then obtained by hot rolling at 900℃.

[0048] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the TC4 material prepared in this comparative example was 1194 MPa and the elongation after fracture was 8.34%.

[0049] Comparative Example 2

[0050] The difference between this comparative example and Example 1 is that the process of mixing and calcining the sheet copper powder with liquid paraffin in step two to prepare in-situ graphene derivative modified copper composite powder is omitted. Instead, the sheet copper powder and spherical TC4 titanium alloy powder are directly ball-milled and then sintered by discharge plasma and hot-rolled to obtain Cu / TC4 composite material.

[0051] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Cu / TC4 composite material prepared in this comparative example was 1392 MPa and the elongation after fracture was 1.82%.

[0052] Figure 6 The engineering stress-strain curves at room temperature of the Gr@Cu / TC4 composite materials prepared in Examples 1 to 3 of this invention, the TC4 material prepared in Comparative Example 1, and the Cu / TC4 composite material prepared in Comparative Example 2 are shown below. Figure 6It can be seen that the tensile strength of the TC4 material prepared in Comparative Example 1 is 1194 MPa, and the elongation after fracture is 8.34%. The tensile strength of the Cu / TC4 composite material prepared in Comparative Example 2 is 1392 MPa, and the elongation after fracture is 1.82%. Compared with the TC4 material in Comparative Example 1, the CuTi2 reinforcement in Comparative Example 2 accumulates a large number of dislocations within the grains of the Cu / TC4 composite material, contributing additional strength. However, due to the strain incompatibility between the reinforcement distributed within the grains and the matrix, there is significant stress concentration near the reinforcement. Moreover, the Cu / TC4 composite material does not precipitate phases pinned at the grain boundaries, which leads to overall grain coarsening and a decrease in elongation after fracture. In contrast, the Gr@Cu / TC4 composite material prepared in Example 1 has a tensile strength of 1504 MPa and an elongation after fracture of 6.04%, which is significantly higher than the strength of the TC4 material while maintaining almost no change in plasticity. It also shows a significant improvement in both strength and plasticity compared to the Cu / TC4 composite material. Since the Gr@Cu / TC4 composite material has the characteristics of both carbon and copper sources, based on the solid-state diffusion reaction and the dissolution and precipitation mechanism of Ti-C and Ti-Cu, a mixed reinforcing phase of TiC distributed at the grain boundaries and CuTi2 within the grains is generated in situ. The Gr@Cu / titanium-based composite material prepared in this invention can not only achieve high room temperature tensile strength by relying on the coexisting TiC and CuTi2 precipitates, but also overcome the mismatch problem of low plasticity under high tensile strength by dispersing stress concentration on the matrix through a multi-scale hierarchical structure.

[0053] Example 2

[0054] The difference between this embodiment and Embodiment 1 is that 2g of the reinforcing precursor is used in step three.

[0055] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Gr@Cu / TC4 composite material prepared in this embodiment was 1250 MPa and the elongation after fracture was 9.65%.

[0056] Example 3

[0057] The difference between this embodiment and Embodiment 1 is that 10g of reinforcing precursor is used in step three.

[0058] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Gr@Cu / TC4 composite material prepared in this embodiment was 1513 MPa and the elongation after fracture was 2.11%.

[0059] Example 4

[0060] This embodiment includes the following steps:

[0061] Step 1: Selection of raw materials: Spherical TA19 titanium alloy powder with a particle size of 15μm to 53μm prepared by the rotating electrode method is selected as the matrix material, and petrolatum with C16-C21 n-alkanes as the main component and spherical copper powder with a particle size of 1μm to 5μm are selected as the raw materials for the preparation of the reinforcing precursor.

[0062] Step 2: Preparation of the reinforcing precursor: The spherical copper powder selected in Step 1 was placed in a planetary ball mill and ball-to-powder ratio of 15:1, milling speed of 400 rpm, and milling time of 4 h to obtain flake copper powder with a diameter of 30 μm and a thickness of 20 μm. Then, 0.4 mL of petrolatum and flake copper powder were measured and mechanically stirred evenly for 15 min at a volume ratio of 5:40. The mixture was then placed in a tube furnace and calcined at 750 °C under an argon atmosphere for 0.5 h to obtain the reinforcing precursor, namely, in-situ graphene derivative modified copper composite powder, denoted as Gr@Cu composite powder.

[0063] Step 3: Preparation of titanium-based composite powder: 6g of the reinforcing precursor obtained in Step 2 and 114g of the spherical TA19 titanium alloy powder selected in Step 1 were loaded into a stainless steel ball mill and placed in a planetary ball mill for ball milling and mixing. The ball-to-material ratio was 3:1, the ball milling speed was 150 rpm, and the ball milling time was 8h to obtain titanium-based composite powder, namely in-situ graphene derivative modified copper / titanium-based composite powder, denoted as Gr@Cu / TA19 composite powder;

[0064] Step 4: Preparation of titanium-based composite material: The titanium-based composite powder prepared in step 3 is subjected to discharge plasma sintering at a temperature of 900℃ and a holding time of 3 minutes. The titanium-based composite material, namely Gr@Cu / TA19 composite material, is obtained by hot rolling at 800℃.

[0065] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Gr@Cu / TA19 composite material prepared in this embodiment was 1435 MPa and the elongation after fracture was 6.2%.

[0066] Example 5

[0067] This embodiment includes the following steps:

[0068] Step 1: Selection of raw materials: Spherical Ti-1300 titanium alloy powder with a particle size of 15μm to 53μm prepared by the rotating electrode method is selected as the matrix material, and microcrystalline wax with C16-C21 n-alkane as the main component and spherical copper powder with a particle size of 1μm to 5μm are selected as the raw materials for the preparation of the reinforcing precursor.

[0069] Step 2: Preparation of the reinforcing precursor: The spherical copper powder selected in Step 1 was placed in a planetary ball mill and ball-to-powder ratio of 25:1, milling speed of 450 rpm, and milling time of 6 h to obtain flake copper powder with a diameter of 20 μm and a thickness of 10 μm. Then, 0.5 mL of microcrystalline wax was measured and mechanically stirred with the flake copper powder at a volume ratio of 16:40 for 20 min. The mixture was then placed in a tube furnace and calcined at 900 °C under an argon atmosphere for 1.5 h to obtain the reinforcing precursor, namely, in-situ graphene derivative modified copper composite powder, denoted as Gr@Cu composite powder.

[0070] Step 3: Preparation of titanium-based composite powder: 6g of the reinforcing precursor obtained in Step 2 and 114g of the spherical Ti-1300 titanium alloy powder selected in Step 1 were loaded into a stainless steel ball mill and placed in a planetary ball mill for ball milling and mixing. The ball-to-material ratio was 6:1, the ball milling speed was 250 rpm, and the ball milling time was 12h to obtain titanium-based composite powder, namely in-situ graphene derivative modified copper / titanium-based composite powder, denoted as Gr@Cu / Ti-1300 composite powder;

[0071] Step 4: Preparation of titanium-based composite material: The titanium-based composite powder prepared in step 3 is subjected to discharge plasma sintering at a temperature of 1100℃ and a holding time of 6 min. The titanium-based composite material, namely Gr@Cu / Ti-1300 composite material, is obtained by hot rolling at 1000℃.

[0072] The room temperature mechanical properties were tested using a universal testing machine. The results showed that the tensile strength of the Gr@Cu / Ti-1300 composite material prepared in this embodiment was 1481 MPa and the elongation after fracture was 4.3%.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing high-strength, high-plasticity titanium-based composite powder and composite material, characterized in that, The method includes the following steps: Step 1: Selection of raw materials: Spherical titanium alloy powder prepared by the rotating electrode method is selected as the matrix material, and mineral oil or wax and spherical copper powder are selected as the raw materials for the preparation of the reinforcing precursor. Step 2: Preparation of the reinforcing precursor: The spherical copper powder selected in Step 1 is placed in a planetary ball mill and ball-milled into flake copper powder. Then, mineral oil or wax is mechanically stirred with the flake copper powder until homogeneous, and then calcined under an argon atmosphere to obtain the reinforcing precursor, namely, in-situ graphene derivative modified copper composite powder, denoted as Gr@Cu composite powder; the mineral oil or wax is selected from petrolatum, liquid paraffin, and microcrystalline wax, with the main component being C16-C21 n-alkanes; the calcination temperature is 750℃~900℃, and the calcination time is 0.5h~1.5h; Step 3: Preparation of titanium-based composite powder: The reinforcing precursor obtained in step 2 and the spherical titanium alloy powder selected in step 1 are placed in a planetary ball mill and mixed evenly to obtain titanium-based composite powder, namely in-situ graphene derivative modified copper / titanium-based composite powder, denoted as Gr@Cu / titanium-based composite powder. Step 4: Preparation of titanium-based composite material: The titanium-based composite powder prepared in Step 3 is subjected to discharge plasma sintering and hot rolling to obtain titanium-based composite material, namely Gr@Cu / titanium-based composite material; the sintering temperature of discharge plasma sintering is 900℃~1100℃, and the holding time is 3min~6min; the hot rolling temperature is 800℃~1000℃.

2. The method for preparing a high-strength, high-plasticity titanium-based composite powder and composite material according to claim 1, characterized in that, The spherical titanium alloy powder mentioned in step one is TA19, TC4 or Ti-1300, with a particle size of 15μm~53μm, and the spherical copper powder has a particle size of 1μm~5μm.

3. The method for preparing a high-strength, high-plasticity titanium-based composite powder and composite material according to claim 1, characterized in that, In step two, the ball-to-material ratio for ball milling the spherical copper powder is 15-25:1, the ball milling speed is 400-450 rpm, and the ball milling time is 4-6 hours. The diameter of the flake copper powder is 20-30 μm, and the thickness is 10-20 μm. The volume ratio of the mineral oil or wax to the flake copper powder is 5-16:40, and the time for mechanical stirring to achieve uniformity is 15-20 minutes.

4. The method for preparing a high-strength, high-plasticity titanium-based composite powder and composite material according to claim 1, characterized in that, In step three, the mass ratio of the reinforcing precursor to the spherical titanium alloy powder is 11~50:550, the ball-to-material ratio in the ball mill is 3~6:1, the ball milling speed is 150rpm~250rpm, and the ball milling time is 8h~12h.

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