Solid solution reinforced network structure super high strength and toughness titanium matrix composite material and preparation method thereof

Abstract

The application discloses a kind of solid solution strengthening net structure super high strength and toughness titanium matrix composite and preparation method thereof, which comprises: one, sequentially with titanium alloy matrix powder of nanometer carbide containing beta stabilizing element and nanometer carbon source / boron source are mixed by multi-step low-energy ball milling;Two, after densification rapid sintering, titanium matrix composite is obtained by hot deformation processing.The application uses multi-step low-energy ball milling mixing, by carbide introduction beta stabilizing element solid solution strengthening intracrystalline titanium matrix, using nanometer carbon source / boron source and the interface reaction product of titanium is formed TiC p Or TiB w Surrounding the discontinuous net structure of grain boundary strengthens grain boundary, while high-density acicular alpha" precipitated phase is precipitated in equiaxial beta-Ti matrix during hot deformation processing, the solid solution strengthening net structure makes titanium matrix composite have super high strength and excellent room temperature elongation, realizes the matching of strength and plasticity, and the method is simple, easy to realize, suitable for aerospace titanium alloy structural materials.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, specifically relating to a solid solution reinforced network structure ultra-high strength and toughness titanium matrix composite material and its preparation method. Background Technology

[0002] With the development of the aerospace industry, there is a growing demand for structural materials with lower density, longer service life, and the ability to withstand more complex and demanding service conditions. Compared to titanium alloys, titanium-based composites possess superior strength, higher heat resistance, excellent wear resistance, and hardness, and are attracting significant attention as a novel strategic structural material. Through research on titanium-based composites over the past decade, the bottleneck problem of poor plasticity in traditional homogeneous titanium-based composites has been solved by optimizing the design of the reinforcement's spatial configuration, significantly improving the strength-plasticity balance and machinability of titanium-based composites.

[0003] Graphene and other nanomaterials are a type of carbon nanomaterials made from sp 2 Two-dimensional carbon nanomaterials composed of hybrid orbitals possess excellent mechanical properties, such as high elastic modulus and high fracture strength, and are considered one of the ideal reinforcing materials for metal matrix composites. my country attaches great importance to the research of graphene / titanium composites, with research institutions such as the Northwest Institute of Nonferrous Metals, Beijing Institute of Technology, and Southeast University successively carrying out related research. Due to the poor chemical compatibility between carbon and titanium, they are prone to chemical reactions during the molding process, leading to the destruction of the graphene nanoreinforcing phase. According to the Fick diffusion principle, the diffusion of carbon and titanium atoms can be suppressed by reducing the high-temperature residence time or using low-temperature sintering, preserving the intrinsic structure of graphene. However, lowering the sintering temperature and reducing the high-temperature residence time can lead to problems such as poor formability and low density in the composite material, resulting in numerous defects such as cracks, voids, and pores in the molded samples. Therefore, how to control the interfacial reaction between graphene and the titanium matrix has become the key to improving the performance of titanium-based composite materials. However, in many existing technologies (Mater.Des., 140 (2018) 431-441; Mater.Des., 196 (2020) 109119; Compos.Part A 136 (2020) 105971; J.Mater.Sci.Technol.96 (2022) 85–93, etc.), the graphene or a small amount of interfacial reaction product TiC is only distributed on the grain boundaries of titanium grains, and has no strengthening effect on the grains, resulting in limited synergistic strengthening effect.

[0004] To address the limitations of existing technologies in preparing graphene / titanium-based composites, which offer limited performance improvements and suffer from a severe "inversion" of strength and plasticity—particularly the failure to achieve a strength greater than 1500 MPa and an elongation greater than 5%—there is an urgent need to design and develop a titanium-based composite material with ultra-high strength and toughness. Such materials possess significant application potential, thus providing a new growth point for the development of titanium-based composite materials. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method for preparing a solid solution-reinforced network structure ultra-high strength and toughness titanium-based composite material. This method involves multi-step low-energy ball milling to sequentially and uniformly coat and disperse nano-carbide containing β-stabilizing elements and nano-carbon / boron sources onto the surface of a titanium alloy matrix powder. This promotes the uniform dispersion of the nano-carbon / boron sources on the titanium alloy matrix powder surface. Combined with densification rapid sintering and hot deformation processing, this promotes a concentration gradient distribution of metal elements in the nano-carbide to strengthen the titanium alloy grains and form TiC at the grain boundaries of the titanium alloy particles. p or TiB w The discontinuous network structure strengthens the grain boundaries, and high-density needle-like α" precipitates are formed in the equiaxed β-Ti matrix during hot deformation processing. This allows the titanium matrix composite to maintain excellent room temperature elongation while possessing ultra-high strength, achieving an excellent strength-plasticity matching level and overcoming the bottleneck of the "inverted" strength-plasticity of existing network structure titanium matrix composites.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, characterized in that the method includes the following steps:

[0007] Step 1: Selection of powder raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder prepared by the rotating electrode method is used as titanium alloy matrix powder. Nano carbides containing β-stabilizing elements and nano carbon sources / boron sources are used as intragranular solid solution strengthening phases and grain boundary network structure strengthening nano precursors, respectively. Nano carbides containing β-stabilizing elements and nano carbon sources / boron sources are added to the titanium alloy matrix powder in sequence and mixed by multi-step low-energy ball milling to obtain a titanium-based composite powder with low damage and uniform dispersion of nano carbides and nano carbon sources / boron sources.

[0008] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is densified and rapidly sintered to obtain a titanium-based composite material blank, which is then subjected to hot deformation processing to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material; the solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material has a strength greater than 1500 MPa and an elongation greater than 8%.

[0009] This invention employs a multi-step low-energy ball milling process to sequentially and uniformly encapsulate and disperse the intragranular solid solution strengthening phase (i.e., nano-carbide containing β-stabilizing elements) and the grain boundary network structure strengthening nano-precursors (i.e., nano-carbon / boron sources) onto the surface of a titanium alloy matrix powder. Rapid plasma sintering then yields a TiC matrix powder with intragranular gradient solid solution strengthening and grain boundary strengthening. p or TiB w A titanium-based composite material preform with a network structure reinforcement was prepared by hot deformation to produce a solid solution-reinforced ultra-high strength and toughness TiC. p or TiB w Mesh-structured titanium-based composite material.

[0010] Specifically, this invention first uses multi-step low-energy ball milling to uniformly coat nano-carbides containing β-stabilizing elements onto the surface of titanium alloy matrix powder. This improves the surface roughness of the titanium alloy matrix powder, providing more sites for the subsequent uniform coating of nano-carbon / boron sources. Furthermore, by forming a carbide transition layer on the surface of the titanium alloy matrix powder, the non-wetting interface between titanium and carbon is transformed into a wetting interface, improving the dispersion of the nano-carbon / boron sources on the titanium alloy matrix powder surface. This is beneficial for the formation of a network-like TiC distribution during the subsequent sintering process. p or TiB w This process acts as a grain boundary anchor, grain refinement, and load transfer mechanism. Through these two combined effects, it effectively solves the problem of uneven dispersion of carbon sources such as graphene on the titanium alloy surface in existing direct ball milling processes.

[0011] Then, this invention employs a densification rapid sintering process. Due to the short sintering time, the metal elements in the nano-carbide containing β-stabilizing elements do not have enough time to fully diffuse and homogenize within the grains. This results in a concentration gradient distribution of the metal elements within the grains, strengthening the titanium grains and increasing the volume fraction of the β phase. Furthermore, utilizing the slip system properties of the β phase helps improve the plasticity of the titanium-based composite material, ensuring the introduction of more reinforcing phases at the grain boundaries under processable plasticity conditions. Simultaneously, during the densification rapid sintering process, the nano-carbon or boron source uniformly coated on the outer layer of the titanium-based composite powder undergoes an in-situ reaction with the titanium alloy, forming a ceramic reinforcing phase TiC at the grain boundaries. p or TiB w The TiC formed at the grain boundaries exhibits a network structure, pinning the grain boundaries and limiting rapid grain growth, thus strengthening the titanium-based composite material. This structure, characterized by three-dimensional interconnected agglomerates, discretely distributed depleted reinforcement regions, and reinforcement phase encapsulation of the soft matrix, ensures excellent reinforcement performance. Furthermore, the TiC formed at the grain boundaries... p or TiB wThe ceramic phase can effectively bear the load and improve the strength of titanium matrix composites, while the soft phase matrix can passivate cracks, hinder crack propagation, and achieve plastic deformation. In particular, during the hot deformation process, the high-density needle-like α" precipitates in the equiaxed β-Ti matrix always maintain coherent twin deformation with the matrix during the loading deformation process, ensuring the plasticity of the titanium matrix composites.

[0012] Finally, this invention employs hot deformation processing to ensure that the metal elements in the nano-carbide are uniformly solid-dissolved and strengthened within the grains, while the ceramic reinforcing phase TiC at the grain boundaries... p or TiB w The particles are further dispersed and distributed in a discontinuous network along the direction of hot deformation. Simultaneously, the matrix undergoes thermal deformation strengthening, further improving the strength and density of the titanium-based composite material, with larger ceramic reinforcing phases being broken down and refined. Furthermore, hot deformation refines the intragranular α-grain size and matrix structure. With increasing deformation, the dislocation density in the titanium-based composite material continuously increases. During dislocation movement, obstacles such as dislocation pile-ups and cleavage steps easily form, hindering further dislocation movement and increasing deformation resistance. Simultaneously, the high-density needle-like α" precipitates in the equiaxed β-Ti matrix during hot deformation interact with dislocations, further enhancing the strength of the titanium-based composite material.

[0013] In summary, under the action of the above-mentioned multiple strengthening mechanisms, a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material with ultra-high strength and good room temperature elongation is obtained. This overcomes the problems of poor and uneven dispersion of nano-carbon sources or boron sources (such as graphene, TiB2, etc.) in the titanium matrix, as well as the problem that residual graphene or local reaction products in the existing technology are only distributed on the grain boundaries, resulting in insufficient strength and plasticity matching level of titanium-based composite materials.

[0014] The above-mentioned method for preparing ultra-high strength and toughness titanium-based composite materials with solid solution reinforced network structure is characterized in that the spherical TC4 pre-alloyed powder in step one is prepared by plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys"; the nano-carbide containing β-stabilizing elements is spherical Mo2C powder with a particle size of 20nm to 800nm. This invention, by using spherical Mo2C powder as nano-carbide containing β-stabilizing elements, introduces solid solution reinforced Mo2C into the grains, which is beneficial for increasing the volume fraction of the β phase and improving the plasticity of the titanium-based composite material.

[0015] The above-mentioned method for preparing ultra-high strength and toughness titanium-based composite materials with solid solution reinforced network structure is characterized in that the nano-carbon source in step one is reduced graphene oxide or carbon black particles, wherein the reduced graphene oxide has a sheet diameter of 4μm to 7μm and a thickness of 5nm, and the carbon black particles have an average size of 25nm. Selecting the above-mentioned types of nano-carbon sources is beneficial for improving their dispersibility.

[0016] The above-mentioned method for preparing ultra-high strength and toughness titanium-based composite materials with solid solution reinforced network structure is characterized in that the nano-boron source in step one is one or more of TiB2, B4C and B powder, and the average size of TiB2 powder is 40 nm.

[0017] The above-mentioned method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium matrix composite material is characterized in that, in step one, the multi-step low-energy ball milling mixing speed is 150 r / min to 250 r / min, the ball milling time is 5 h to 10 h, and the ball-to-material ratio is 5:1. More preferably, the multi-step low-energy ball milling mixing speed is 200 r / min. By controlling the speed, time, and ball-to-material ratio, the spherical morphology of the titanium alloy matrix powder is ensured to the greatest extent, and the nano-carbon source / boron source is uniformly coated on the titanium matrix powder.

[0018] The above-mentioned method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium matrix composite material is characterized in that the densification rapid sintering in step two is plasma-activated sintering, hot pressing sintering, or hot isostatic pressing sintering, and the plasma-activated sintering temperature is 800℃~1100℃, the heating rate is 100℃ / min, the holding time is 5min~10min, and the pressure is 30MPa~60MPa. More preferably, the ion-activated sintering temperature is 1000℃, the heating rate is 100℃ / min, the holding time is 5min, and the pressure is 40MPa. This sintering method and process parameters are conducive to the in-situ generation of TiC by reacting nano-carbon sources or nano-boron sources with the titanium matrix. p or TiB w .

[0019] The above-mentioned method for preparing ultra-high strength and toughness titanium-based composite materials with solid solution reinforced network structure is characterized in that the hot deformation processing in step two is rolling, and the rolling temperature is 800℃~1000℃, the holding time is 10min~30min, and the rolling deformation is 50%~90%. More preferably, the rolling temperature is 900℃, the holding time is 20min, and the rolling deformation is 75%. This hot deformation processing method and process parameters help to further improve the density of the titanium-based composite material, break up larger TiC particles and TiB whiskers, improve their distribution in the titanium matrix, and optimize its mechanical properties.

[0020] Furthermore, this invention also discloses a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, characterized in that it is prepared by the above-described method.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. This invention utilizes the compositional and structural characteristics of titanium alloys. Through multi-step low-energy ball milling, nano-carbides containing β-stabilizing elements and nano-carbon / boron sources are uniformly coated and dispersed on the surface of titanium alloy matrix powder. The carbides introduce β-stabilizing elements to strengthen the grains through solid solution and increase the volume fraction of the β phase. The slip system of the β phase is utilized to improve the plasticity of the titanium-based composite material. Combined with the interfacial reaction products between the nano-carbon / boron sources and titanium, TiC is formed at the grain boundaries of the titanium alloy particles. p or TiB w The non-continuous network structure strengthens the grain boundaries, and high-density needle-like α" precipitates are formed in the equiaxed β-Ti matrix during hot deformation processing, thus obtaining an ultra-high strength and toughness titanium-based composite material with ultra-high strength and excellent room temperature elongation. This achieves an excellent strength-plasticity matching level of titanium-based composite material, overcoming the problem that conventional powder metallurgy graphene-reinforced titanium-based composite materials have limited performance improvement and a serious "inversion" of strength and plasticity.

[0023] 2. In the multi-step low-energy ball milling process of the present invention, nano-carbides containing β-stabilizing elements are first uniformly coated on the surface of titanium alloy matrix powder, which improves the dispersion effect of nano-carbon source / boron source on the surface of titanium alloy matrix powder and provides more sites for coating, promotes the uniform dispersion of carbon source / boron source reinforcing materials on the surface of titanium alloy, solves the problem of uneven dispersion of nano-carbon source / boron source on the surface of titanium alloy, and provides a foundation for the subsequent formation of titanium-based composite materials with network structure distribution reinforcement.

[0024] 3. This invention employs a densification and rapid sintering process to promote a concentration gradient distribution of metal elements in the β-stable element nanocarbide within the grains, strengthening titanium grains. This ensures an increased grain boundary distribution of the reinforcing phase under processable plasticity conditions, while simultaneously increasing the TiC content at the grain boundaries. p or TiB w It exhibits a network structure distribution, and TiC p or TiB w It plays a role in strengthening and passivating cracks, respectively, with the high-density needle-like α" precipitates in the equiaxed β-Ti matrix interacting with dislocations. It also maintains a coherent twin relationship with the matrix during loading and deformation, ensuring both excellent reinforcement and plasticity of the titanium-based composite material.

[0025] 4. This invention promotes uniform solid solution strengthening of metal elements within the grains of nano-carbide and ceramic-reinforcing phase TiC at the grain boundaries through hot deformation processing. p or TiBw The dispersed and discontinuous network distribution, along with the fragmentation and refinement of the ceramic reinforcing phase, strengthens the matrix through thermal deformation, thereby improving the density and strength of the titanium-based composite material.

[0026] 5. The raw materials of this invention are widely available, the process is simple and easy to implement, and it has significant engineering prospects. It can be widely applied to near-α titanium alloys.

[0027] 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

[0028] Figure 1 This is a SEM image of the titanium-based composite powder prepared in Example 1 of the present invention.

[0029] Figure 2a This is a SEM image of the sintered titanium-based composite material preform prepared in Example 1 of the present invention.

[0030] Figure 2b for Figure 2a Distribution of Mo element in [the sample / material].

[0031] Figure 3a This is a SEM image of the rolled titanium-based composite material prepared in Example 1 of the present invention.

[0032] Figure 3b for Figure 3a Distribution of Mo element in [the sample / material].

[0033] Figure 4 The diagram shows a comparison of the mechanical properties of the titanium-based composite materials prepared in Examples 1-2 of this invention with those of the TC4 titanium alloy prepared in Comparative Example 1 and the titanium-based composite materials prepared in Comparative Examples 2-3. Detailed Implementation

[0034] Example 1

[0035] This embodiment includes the following steps:

[0036] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and reduced graphene oxide were used as intragranular solid solution strengthening phase and grain boundary network structure strengthening nano-precursors, respectively. 1.2g of spherical Mo2C with a particle size of 800nm ​​was added to 120g of spherical TC4 titanium alloy powder. The mixture was ball-milled for 5h at a speed of 200r / min and a ball-to-material ratio of 5:1. Then, 0.6g of reduced graphene oxide was added in portions and the mixture was ball-milled for another 10h at a speed of 200r / min and a ball-to-material ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and reduced graphene oxide.

[0037] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition met the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys"; the reduced graphene oxide had a sheet diameter of 4μm to 7μm and a thickness of 5nm;

[0038] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiC / TC4 composite material.

[0039] Figure 1 Here is a SEM image of the titanium-based composite powder prepared in this embodiment, from... Figure 1 It can be seen that the titanium-based composite powder still maintains a spherical morphology, and Mo2C and reduced graphene oxide are uniformly coated on the surface of the spherical TC4 titanium alloy powder.

[0040] Figure 2a The image shows a SEM image of the sintered titanium-based composite material preform prepared in this embodiment. Figure 2a It can be seen that after sintering, TiC p The molybdenum element is distributed in a discontinuous network structure at the grain boundaries of the titanium-based composite material preform, and the molybdenum element is distributed in a gradient. The molybdenum element is enriched at the grain boundaries and relatively less in the grains. Figure 2b for Figure 2a The distribution map of Mo element in the image, from Figure 2b It can be seen that the Mo element in the sintered titanium-based composite preform exhibits a gradient solid solution distribution characteristic.

[0041] Figure 3a The image shows a SEM image of the rolled titanium-based composite material prepared in this embodiment. Figure 3a Combination Figure 2a It can be seen that hot deformation processing promotes the growth of TiC p The dispersion is such that the grains are refined and distributed in a fibrous, discontinuous network. Figure 3b for Figure 3a The distribution map of Mo element in the image will Figure 3b Combination Figure 2b It can be seen that hot deformation processing promotes the homogenization of Mo elements, thereby further strengthening the titanium matrix through solid solution treatment.

[0042] The densification rapid sintering in this embodiment can also be replaced by hot pressing sintering or hot isostatic pressing sintering.

[0043] Comparative Example 1

[0044] This comparative example includes the following steps:

[0045] Step 1: Selection of powder raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder is used as the titanium alloy matrix powder; the spherical TC4 pre-alloyed powder is prepared by plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and the chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0046] Step 2, Preparation of TC4 Titanium Alloy: The titanium alloy matrix powder selected in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a TC4 titanium alloy billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain the TC4 titanium alloy.

[0047] Comparative Example 2

[0048] This comparative example includes the following steps:

[0049] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder, and Mo2C was used as the intragranular solid solution strengthening phase. 0.6g of spherical Mo2C with a particle size of 800nm ​​was added to 120g of spherical TC4 titanium alloy powder. The mixture was ball-milled for 5h at a speed of 200r / min and a ball-to-material ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C.

[0050] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0051] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a solid solution reinforced titanium-based composite material, namely Mo solid solution reinforced TC4 composite material.

[0052] Comparative Example 3

[0053] This comparative example includes the following steps:

[0054] Step 1: Selection of powder raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder, and reduced graphene oxide was used as the grain boundary network structure reinforcement nano precursor. 0.6g of reduced graphene oxide was added to 120g of spherical TC4 titanium alloy powder and mixed by low-energy ball milling for 5h at a rotation speed of 200r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of reduced graphene oxide.

[0055] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition met the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys"; the reduced graphene oxide had a sheet diameter of 4μm to 7μm and a thickness of 5nm;

[0056] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a network structure titanium-based composite material, namely TiC reinforced TC4 composite material.

[0057] Example 2

[0058] This embodiment includes the following steps:

[0059] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and TiB2 were used as intragranular solid solution strengthening phase and grain boundary network structure strengthening nano-precursors, respectively. 1.2g of spherical Mo2C with a particle size of 800nm ​​and 1.08g of TiB2 with an average size of 40nm were added to 120g of spherical TC4 titanium alloy powder in sequence. The mixture was ball-milled for 10h at a speed of 200r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and TiB2.

[0060] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0061] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiB / TC4 composite material.

[0062] In this embodiment, the boron nanosource can also be replaced with one or more of TiB2, B4C, and B powder, in addition to TiB2.

[0063] Figure 4 This is a comparison chart of the mechanical properties of the titanium-based composite materials prepared in Examples 1-2 of the present invention, the TC4 titanium alloy prepared in Comparative Example 1, and the titanium-based composite materials prepared in Comparative Examples 2-3. Figure 4 As can be seen, compared with the TC4 titanium alloy of Comparative Example 1, the Mo solid solution reinforced TC4 composite material of Comparative Example 2, and the TiC reinforced TC4 composite material of Comparative Example 3, the strength of the Mo solid solution reinforced network structure TiC / TC4 composite material of the present invention is significantly improved to 1500MPa~1650MPa, and the room temperature elongation is greater than 10%. It has an excellent strength-plasticity matching level, which overcomes the problem of strength-plasticity imbalance in the prior art. This shows that the preparation method of the present invention overcomes the problem of limited performance improvement and serious strength-plasticity "inversion" of conventional powder metallurgy graphene reinforced titanium-based composite materials.

[0064] Example 3

[0065] This embodiment includes the following steps:

[0066] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and carbon black were used as nano precursors for intragranular solid solution strengthening and grain boundary network structure strengthening, respectively. 0.6g of spherical Mo2C with a particle size of 20nm and 0.36g of carbon black with an average size of 25nm were added to 120g of spherical TC4 titanium alloy powder in sequence. The mixture was ball-milled for 10h at a speed of 200r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and carbon black.

[0067] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0068] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiC / TC4 composite material.

[0069] Testing showed that the titanium-based composite material prepared in this embodiment has a strength greater than 1500 MPa and an elongation greater than 8%.

[0070] Example 4

[0071] This embodiment includes the following steps:

[0072] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and TiB2 were used as intragranular solid solution strengthening phase and grain boundary network structure strengthening nano-precursors, respectively. 0.6g of spherical Mo2C with a particle size of 500nm and 0.6g of TiB2 with an average size of 40nm were added to 120g of spherical TC4 titanium alloy powder in sequence. The mixture was ball-milled for 10h at a speed of 200r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and TiB2.

[0073] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0074] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1000℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 40MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 900℃, a holding time of 20min, and a rolling deformation of 75% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiB / TC4 composite material.

[0075] Testing showed that the titanium-based composite material prepared in this embodiment has a strength greater than 1500 MPa and an elongation greater than 8%.

[0076] Example 5

[0077] This embodiment includes the following steps:

[0078] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and TiB2 were used as intragranular solid solution strengthening phase and grain boundary network structure strengthening nano-precursors, respectively. 0.6g of spherical Mo2C with a particle size of 800nm ​​and 0.36g of TiB2 with an average size of 40nm were added to 120g of spherical TC4 titanium alloy powder in sequence. The mixture was ball-milled for 5h at a speed of 150r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and TiB2.

[0079] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0080] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 800℃, a heating rate of 100℃ / min, a holding time of 10min, and a pressure of 60MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 800℃, a holding time of 10min, and a rolling deformation of 90% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiB / TC4 composite material.

[0081] Testing showed that the titanium-based composite material prepared in this embodiment has a strength greater than 1500 MPa and an elongation greater than 8%.

[0082] Example 6

[0083] This embodiment includes the following steps:

[0084] Step 1: Selection of raw materials and low-damage synthesis: Spherical TC4 pre-alloyed powder was used as the titanium alloy matrix powder. Mo2C and carbon black were used as intragranular solid solution strengthening phase and grain boundary network structure strengthening nano-precursors, respectively. 1.2g of spherical Mo2C with a particle size of 800nm ​​and 0.36g of carbon black with an average size of 25nm were added to 120g of spherical TC4 titanium alloy powder in sequence. The mixture was ball-milled for 15h at a speed of 250r / min and a ball-to-powder ratio of 5:1 to obtain a titanium-based composite powder with low damage and uniform dispersion of spherical Mo2C and carbon black.

[0085] The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm to 53μm, good sphericity and no planetary powder, and its chemical composition meets the requirements of GB / T 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys";

[0086] Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is subjected to plasma activation sintering at a temperature of 1100℃, a heating rate of 100℃ / min, a holding time of 5min, and a pressure of 30MPa to obtain a titanium-based composite material billet. The billet is then rolled at a temperature of 800℃, a holding time of 30min, and a rolling deformation of 50% to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, namely, Mo solid solution reinforced network structure TiC / TC4 composite material.

[0087] Testing showed that the titanium-based composite material prepared in this embodiment has a strength greater than 1500 MPa and an elongation greater than 8%.

[0088] 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 ultra-high strength and toughness titanium-based composite materials with solid solution reinforced network structure, characterized in that, The method includes the following steps: Step 1: Powder Raw Material Selection and Low-Damage Synthesis: Spherical TC4 pre-alloyed powder prepared by the rotating electrode method was used as the titanium alloy matrix powder. Nano-carbides containing β-stabilizing elements and nano-carbon sources / boron sources were used as intragranular solid solution strengthening phases and grain boundary network structure strengthening nano-precursors, respectively. The nano-carbides containing β-stabilizing elements and nano-carbon sources / boron sources were sequentially added to the titanium alloy matrix powder and mixed through multi-step low-energy ball milling to obtain a titanium-based composite powder with low damage and uniform dispersion of nano-carbides and nano-carbon sources / boron sources. The spherical TC4 pre-alloyed powder was prepared by the plasma rotating electrode method, with a particle size of 15μm~53μm, good sphericity, and no planetary powder. Its chemical composition conformed to GB / T standards. The requirements of 3620.1-2007 "Standard for Grades and Chemical Composition of Titanium and Titanium Alloys" are as follows: the nano carbide containing β-stabilizing elements is spherical Mo2C powder with a particle size of 20nm~800nm; the nano carbon source is carbon black particles with an average particle size of 25nm; the nano boron source is one or more of TiB2, B4C and B powder, and the average size of TiB2 powder is 40nm. Step 2: Preparation of titanium-based composite material: The titanium-based composite powder obtained in Step 1 is densified and rapidly sintered to obtain a titanium-based composite material blank, which is then subjected to hot deformation processing to obtain a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material; the solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material has a strength greater than 1500 MPa and an elongation greater than 8%.

2. The method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material according to claim 1, characterized in that, The multi-step low-energy ball milling mixing in step one has a rotation speed of 150 r / min to 250 r / min, a ball milling time of 5 h to 10 h, and a ball-to-material ratio of 5:

1.

3. The method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material according to claim 1, characterized in that, The densification rapid sintering described in step two is plasma activation sintering, hot pressing sintering, or hot isostatic pressing sintering. The temperature of plasma activation sintering is 800℃~1100℃, the heating rate is 100℃ / min, the holding time is 5min~10min, and the pressure is 30MPa~60MPa.

4. The method for preparing a solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material according to claim 1, characterized in that, The hot deformation process described in step two is rolling, and the rolling temperature is 800℃~1000℃, the holding time is 10min~30min, and the rolling deformation is 50%~90%.

5. A solid solution reinforced network structure ultra-high strength and toughness titanium-based composite material, characterized in that, Prepared by the method described in any one of claims 1 to 4.

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