A preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material

Abstract

The application provides a preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material and belongs to the technical field of intermetallic compound-based composite materials. First, a plurality of Ti2AlNb reinforcing body skeletons in a TPMS configuration are designed by using a hidden function modeling; then, anisotropy of the TPMS configuration is studied by using finite element simulation; secondly, the Ti2AlNb reinforcing body skeleton in the TPMS configuration is prepared by using a selective laser melting process SLM; finally, the Ti2AlNb / TiAl-based interpenetrating composite material in the TPMS configuration is prepared by vacuum hot pressing sintering HPS. Thus, the strong anisotropy of a traditional fiber reinforced composite material in mechanical properties is avoided, good matching of the strength, plasticity and toughness of the composite material is realized, and a new idea and solution are provided for breaking through the application bottleneck of a TiAl in a thermal end part of a space power system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of intermetallic compound-based composite materials, and particularly relates to a preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material. BACKGROUND

[0002] In addition to inheriting the excellent properties of the TiAl matrix, the TiAl-based composite material also has excellent elastic modulus and room temperature / high temperature strength of the reinforcing body, thereby realizing good matching of the strength, plasticity and toughness of the composite material at room temperature / high temperature. At present, common TiAl-based composite materials include particle / whisker reinforced and continuous fiber reinforced TiAl-based composite materials. However, the mechanical property improvement effect of some TiAl-based composite materials is limited, and there are problems such as strong anisotropy, which still hinder the development of the TiAl-based composite materials. In order to meet the increasing performance requirements of lightweight structural materials in the field of aerospace, it is urgent to further develop and design a new TiAl-based composite material.

[0003] In recent years, researchers have tried to improve the strength and plasticity of TiAl-based composite materials by adjusting the configuration of the reinforcing body, and have made some substantial progress. For example, Wang et al. successfully prepared a Ti2AlN / TiAl-based composite material with a network distribution of reinforcing bodies by spark plasma sintering technology (Y.P. Wang, T.F. Ma, Z, X. Chen, et. al. Superior high-temperature strength-ductility of TiB2-Ti2AlN / TiAl composite with core-shell microstructure [J]. Materials Science and Engineering: A, 2024, 889: 145873.). Li et al. prepared TiNb f / TiAl-based composite materials with unidirectional, orthogonal and rice-shaped arrangements of fibers by adjusting the distribution of continuous fibers. The research results show that the fiber presents the best combination of strength and plasticity when arranged unidirectionally along the load direction, the worst performance when arranged orthogonally, and the performance between the two when arranged in a rice-shaped manner (Li Jingliang. TiNb f / TiAl composite material microstructure evolution characteristics and mechanical property control [D]. Xi'an: Northwest University of Technology, 2023: 28-53.). It can be seen that the design of the reinforcing body configuration is a crucial step to improve the mechanical properties of the composite material.

[0004] "Survival of the fittest" drives the evolution of biological structures with high specific strength, high toughness and high impact toughness. The essence is the competition between different structural forms, resulting in various toughening mechanisms. More interestingly, the biological evolution has chosen triply periodic minimal surfaces (TPMS) in the long-term evolution process. For example, TPMS structures are found in butterfly wing scales, elephant beetle exoskeletons and mantis shrimp claws (B. Winter, B. Butza, C. Dieker, et. al. Coexistence of both gyroid chiralities in individual butterfly wing scales of Callophrys rubi [J]. Proceedings of the National Academy of Science of the United States of America, 2015, 112: 12911-12916.). Inspired by nature, Sun et al. printed the skeletons of two TPMS structures of zirconia ceramic reinforcements using digital light solidification technology, and then impregnated epoxy resin in the skeletons to prepare zirconia / epoxy resin-based interpenetrating composites. The results show that the strength and fracture toughness values of TPMS structure reinforced composites with uniform structure or gradient structure are much higher than those of the reinforcement skeleton (J. X. Sun, S. X. Yu, J. W. Zhu, et. al. 3D printing of ceramic composite with biomimetic toughening design [J]. Additive Manufacturing, 2022, 58: 103027.). At the same time, high-level people prepared metal-based three-dimensional interpenetrating biomimetic composites by pressureless infiltration technology, which showed high specific strength and excellent energy absorption capacity (Gao Meng, Feng Heyang, Huo Juntao, et. al. A metal-based three-dimensional interpenetrating biomimetic composite and a preparation method thereof [P]. Publication number CN 117961032A). A large number of studies have shown that TPMS structure reinforcement skeletons have advantages in structure design, mechanical properties and forming properties. For example, it has the characteristics of smooth transition in structure, avoiding the phenomenon of stress concentration at the nodes of truss-like lattices; at the same time, in terms of mechanical properties, TPMS has more uniform stress and strain distribution under load, with weak anisotropy. In summary, in order to obtain TiAl-based composites with high strength and toughness at room temperature and isotropic mechanical properties, it is urgent to study TPMS configuration Ti2AlNb / TiAl-based interpenetrating composites. SUMMARY

[0005] The technical problems solved by the present application are to provide a preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material, and to design and prepare a high-strength and high-toughness Ti2AlNb / TiAl-based interpenetrating composite material to avoid the strong anisotropy of the mechanical properties of traditional fiber-reinforced composite materials, and to realize good matching of the strength, plasticity and toughness of the composite material in multiple directions.

[0006] To achieve the above-mentioned purposes, the technical scheme adopted by the present application is:

[0007] A preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material, as shown in the accompanying drawings, the preparation method is specifically divided into two parts: Figure 1

[0008] (I) Design and preparation of TPMS configuration Ti2AlNb reinforcing body skeleton; the specific process is:

[0009] Step 1: Implicit function modeling of TPMS configuration: design a variety of TPMS configuration Ti2AlNb reinforcing body skeletons by using implicit function modeling; the specific operation method is:

[0010] Select a typical TPMS lattice structure (for example, Gyroid, Primitive, Diamond and Split-P), use nTopology commercial software to perform implicit function modeling, thereby obtaining a CAD model of the lattice structure, as shown in Figure 2 . Among them, the model for selective laser melting process SLM forming is exported as a stl model file;

[0011] The specific parameter information of the TPMS configuration Ti2AlNb reinforcing body skeleton in the above-mentioned CAD model: the unit cell size is 5*5*5mm 3 , and the number of unit cells in x, y and z directions is 6.

[0012] Step 2: Finite element simulation of TPMS configuration Ti2AlNb reinforcing body skeleton: use finite element simulation to study the anisotropy of the TPMS configuration Ti2AlNb reinforcing body skeleton; the specific operation method is:

[0013] Based on the CAD model of the TPMS configuration Ti2AlNb reinforcing body skeleton designed in step 1, the lattice structure is meshed by using nTopology software; by using the homogenization method and finite element simulation, periodic boundary conditions are applied on the unit cells of the Ti2AlNb reinforcing body skeleton in different TPMS configurations, thereby obtaining the elastic properties of the lattice structure, as shown in Figure 3 . ​

[0014] The meshing shape is a tetrahedron with a size of 0.3 mm.

[0015] Step 3: Ti2AlNb reinforcement skeleton of TPMS configuration is prepared by using a selective laser melting process SLM; the specific process is as follows:

[0016] Step 3-1: slice processing and pre-printing treatment of the Ti2AlNb reinforcement skeleton of TPMS configuration formed by the selective laser melting process SLM

[0017] Firstly, the CAD model of the lattice structure obtained above is imported into Materialise Magics software for slice processing; then, the processed file is imported into the FF-M140C device; secondly, the titanium alloy substrate is placed in the forming cavity, and the Ti-22Al-25Nb powder is filled into the powder cavity; by adjusting the position of the substrate, a uniform and complete powder layer is formed on the upper surface of the substrate; finally, high-purity argon is used to dilute and discharge the oxygen in the forming cavity and pipeline until the oxygen content in the cavity is less than 200 ppm;

[0018] The slice thickness of the lattice structure described above is 0.03 mm.

[0019] Step 3-2: selective laser melting process SLM forming of the Ti2AlNb reinforcement skeleton of TPMS configuration

[0020] By adjusting the laser input density, mainly including laser power, scanning speed, scanning spacing and powder layer thickness, the selective laser melting process SLM forming of the lattice structure is realized; after printing, when the substrate temperature drops to room temperature, the lattice structure is cut off from the substrate surface by using an electric spark wire cutting device, and after ultrasonic cleaning and drying, the selective laser melting process SLM forming of the Ti2AlNb reinforcement skeleton is completed, as shown in Figure 4 .

[0021] The laser power is 150-250 W, the scanning speed is 800-1400 mm / s, the scanning spacing is 0.1 mm, and the powder layer thickness is 0.03 mm; the laser scanning strategy is chessboard scanning, and the scanning direction between adjacent layers is rotated by 67°; the substrate preheating temperature is controlled at 90°.

[0022] Step 3-3: surface treatment of the Ti2AlNb reinforcement skeleton of TPMS configuration

[0023] The Ti2AlNb reinforcement skeleton of TPMS configuration formed by the selective laser melting process SLM is electrolytically polished to remove the un-melted powder particles adhered to the surface of the skeleton during the forming process.

[0024] (ii) Vacuum hot-pressing sintering (HPS) of Ti2AlNb / TiAl-based interpenetrating composites; the specific process is as follows:

[0025] Step 4: Preparation of Ti2AlNb / TiAl-based interpenetrating composites with TPMS configuration by vacuum hot-pressing sintering (HPS); the specific operation process is as follows:

[0026] Step 4-1: Pre-pressing of Ti2AlNb / TiAl-based interpenetrating composites with TPMS configuration

[0027] Firstly, place the TPMS configuration Ti2AlNb reinforcing body framework in a graphite mold coated with yttria coating; then, pour a certain mass of TiAl powder into the framework, and use ultrasonic vibration to reduce the gap between the powders during filling, so as to make the powder filling compact and improve the tap density of TiAl powder; finally, place the graphite mold containing the TPMS configuration Ti2AlNb reinforcing body framework and TiAl powder in a vacuum hot-pressing sintering furnace, and apply a certain pressure to pre-press at room temperature;

[0028] Based on the CAD model designed in step 1, by controlling the offset parameter C of the TPMS structure, reinforcing body frameworks with a volume fraction of 7.5-37.5 vol.% can be obtained; the required mass of TiAl powder can be calculated by the formula m = p x (0.625-0.925) x πr 2 x h; wherein p is the density of TiAl alloy (g / cm 3 ); r is the radius of the graphite mold (mm); h is the height of the TPMS structure Ti2AlNb reinforcing body (mm);

[0029] The pre-pressing pressure at room temperature is selected to be 5-10 MPa, and the pressure holding time is 10-30 min.

[0030] Step 4-2: Vacuum hot-pressing sintering (HPS) of Ti2AlNb / TiAl-based interpenetrating composites with TPMS configuration

[0031] Place the pre-pressed compact in a vacuum hot-pressing sintering furnace and perform HPS under specific sintering parameters; after the sample cools to room temperature with the furnace, take out the block from the mold, and a Ti2AlNb / TiAl-based interpenetrating composite with a diameter of 60 mm and a height of 10 mm is obtained.

[0032] The sintering parameters of the vacuum hot press sintering HPS are as follows: the sintering temperature is 1050-1250 DEG C, the holding time is 0.5-2 h, and the pressure is 45 MPa; in the process of the vacuum hot press sintering HPS, the temperature is kept at 600 DEG C for 10 min after reaching 600 DEG C to remove the residual inclusions in the graphite mold, wherein the temperature rising rate is 5-10 DEG C / min, and the oxygen content needs to be less than 200 ppm during the whole process.

[0033] In the step 3, the chemical composition of the Ti2AlNb powder used for the selective laser melting process SLM forming is as follows: Al: 22-25 at.%, Nb: 20-30 at.%, Ta: 0-7 at.%, and the balance is Ti, and the powder particle size is 15-53 mu m; in the step 4, the chemical composition of the TiAl powder used for the composite forming is as follows: Al: 45-48 at.%, Cr: 1-3 at.%, Nb: 2-5 at.%, and the balance is Ti, and the powder particle size is 50-150 mu m.

[0034] Compared with the prior art, the application has the following advantages:

[0035] 1. The present application is aimed at the problems of poor room temperature plasticity, toughness and mechanical property anisotropy of TiAl alloy, and a high strength and toughness Ti2AlNb / TiAl-based interpenetrating composite material is designed and prepared, first, a plurality of TPMS configuration Ti2AlNb reinforcing body skeletons are designed by using implicit function modeling; then, the anisotropy of the TPMS configuration is studied by using finite element simulation; secondly, the TPMS configuration Ti2AlNb reinforcing body skeleton is prepared by using the selective laser melting process (SLM); finally, the TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material is prepared by vacuum hot press sintering (HPS), so that the strong anisotropy of the traditional fiber reinforced composite material in mechanical properties is avoided, and good matching of the strength, plasticity and toughness of the composite material is realized, thereby providing a new idea and solution for breaking through the application bottleneck of TiAl in the thermal end part of the aerospace power system;

[0036] 2. The present application first uses the SLM technology to prepare the TPMS configuration Ti2AlNb reinforcing body skeleton with isotropy, and uses the same to strengthen and toughen the TiAl-based interpenetrating composite material. Compared with the cross-layer reinforcing body used in the prior art, the TPMS configuration has high strength, low stress concentration and anisotropy degree, so that the strong anisotropy of the traditional fiber reinforced and laminated structure composite material in mechanical properties is avoided, and excellent matching of the strength, plasticity and toughness of the TiAl-based composite material in multiple directions can be realized;

[0037] 3, In the prior art of the scheme, the three-dimensional continuous structure reinforcing body framework is inevitably damaged in the high temperature and high pressure conditions in the composite forming process, reducing its toughening effect. The following measures are proposed in the scheme to reduce the collapse and deformation tendency of the framework in the HPS forming process, thereby reducing its influence on the mechanical properties:

[0038] 1) The selected TiAl powder has smooth surface, good sphericity, less satellite powder and hollow powder, and improves the bulk density of the powder;

[0039] 2) After filling the Ti2AlNb reinforcing body framework of the TPMS structure with TiAl powder, ultrasonic vibration is used to reduce the gap between the powders, so that the powder is tightly filled, thereby improving the tap density of the TiAl powder;

[0040] 3) Before HPS forming, the graphite mold containing the TPMS structure Ti2AlNb reinforcing body framework and TiAl powder is preformed by applying a pressure of 5-10 MPa, so that the TiAl matrix composite has high initial density;

[0041] By implementing the above measures, the metallographic observation of the longitudinal section structure of the HPS formed composite material shows that the reinforcing body framework is reduced along the axial direction by 0.5 mm, and the deformation degree is controlled within 5.6%-10%; In the cross-sectional structure, it is found that the framework has not been deformed. The results show that the TPMS structure Ti2AlNb reinforcing body framework prepared by the above process has little effect on the mechanical property anisotropy of the TiAl-based interpenetrating composite. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The flowchart of the present application.

[0043] Figure 2 The CAD model of the TPMS structure Ti2AlNb reinforcing body framework in the present application; Fig. a is Gyroid structure, b is Primitive structure, c is Diamond structure, d is Split P structure;

[0044] Figure 3 The elastic modulus distribution diagram of the TPMS structure Ti2AlNb reinforcing body framework in the present application in xy, xz and yz directions; Fig. a is xy direction, b is xz direction, c is yz direction;

[0045] Figure 4 The macroscopic photograph of the Ti2AlNb reinforcing body framework formed by SLM in the present application;

[0046] Figure 5The room temperature compressive stress-strain curve of the different TPMS configuration Ti2AlNb reinforced skeleton for SLM forming in the application;

[0047] Figure 6 The compressive stress-strain curve of the Ti2AlNb / TiAl-based interpenetrating composite material in different directions in the application; a, b, c and d in the figure correspond to the Gyroid, Primitive, Diamond and Split P configuration Ti2AlNb / TiAl-based composite material respectively. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the application. Figures 1-6 It should be apparent that the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0049] Embodiment one:

[0050] In view of the problems of poor plasticity and toughness at room temperature and strong anisotropy of mechanical properties of TiAl alloy, a high strength and toughness Ti2AlNb / TiAl-based interpenetrating composite material is designed and prepared in the embodiment. First, a plurality of TPMS configuration Ti2AlNb reinforced skeleton is designed by using the implicit function modeling; then, the anisotropy of the TPMS configuration is studied by using the finite element simulation; secondly, the TPMS configuration Ti2AlNb reinforced skeleton is prepared by using the SLM technology; finally, the TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material is prepared by using the HPS process, so as to avoid the strong anisotropy of mechanical properties of the traditional fiber reinforced composite material, realize the good matching of the strength, plasticity and toughness of the composite material, and provide a new idea and solution for breaking through the application bottleneck of TiAl in the thermal end part of the aerospace power system.

[0051] The chemical composition of the Ti2AlNb powder used for SLM forming in the embodiment is: Al (22-25 at. %), Nb (20-30 at. %), Ta (0-7 at. %), and the balance is Ti, and the powder particle size is 15-53 μm. The chemical composition of the TiAl powder used for composite forming is: Al (45-48 at. %), Cr (1-3 at. %) and Nb (2-5 at. %), and the balance is Ti, and the powder particle size is 50-150 μm.

[0052] The preparation process of the Ti2AlNb / TiAl-based interpenetrating composite material involved in the embodiment is specifically divided into two parts:

[0053] (I) Design and preparation of the TPMS-structured Ti2AlNb reinforcement skeleton. The specific process is as follows:

[0054] Step 1: Implicit function modeling of the TPMS-structured skeleton.

[0055] A typical TPMS lattice structure (for example, Gyroid, Primitive, Diamond and Split-P) is selected, and nTopology commercial software is used for implicit function modeling to obtain a CAD model of the lattice structure, as shown in Figure 2 . The model for SLM forming is exported as an stl model file. In this embodiment, the selected lattice structure is Gyroid, and the curved surface thereof can be described by the following expression:

[0056] φ G (x,y,z)=cos(X)·sin(Y)+cos(Y)·sin(Z)+cos(Z)·sin(X)-C (1)

[0057] where X=2πx / l, Y=2πy / l, Z=2πz / l, C is a bias parameter, and l is the unit length in the x, y and z directions. The specific parameter information of the TPMS structure in the above CAD model: the unit cell size is 5×5×5mm 3 , and the number of unit cells in the x, y and z directions is 6×6×6.

[0058] Step 2: Finite element simulation of the TPMS-structured Ti2AlNb reinforcement skeleton

[0059] Based on the CAD model of the TPMS structure designed in step 1, the lattice structure is meshed by means of nTopology software; the homogenization method and finite element simulation are used to apply periodic boundary conditions on the unit cells of different TPMS structures, so as to obtain the elastic properties of the lattice structure, as shown in Figure 3 .

[0060] The above meshing shape is a tetrahedron with a size of 0.3mm. The performance parameters of Ti2AlNb used for finite element simulation are as follows: the elastic modulus, yield strength and tensile strength are 104.2GPa, 943.0MPa and 992.6MPa respectively, the Poisson's ratio is 0.3, and the density is 5.3g / cm 3 .

[0061] Step 3: SLM preparation of the TPMS-structured Ti2AlNb reinforcement skeleton using selective laser melting process;

[0062] Step 3-1: SLM forming skeleton slicing and pre-printing processing

[0063] Firstly, the CAD model of the Gyroid lattice structure obtained above was imported into Materialise Magics software for slicing processing, wherein the diameter of the reinforcing body skeleton was 60 mm, the height was 10 mm, the slice layer thickness was 0.03 mm, and there were 400 layers in total; then, the processed file was imported into the FF-M140C device; secondly, the titanium alloy substrate was placed in the forming cavity, and Ti-22Al-25Nb powder was filled into the powder cavity; by adjusting the position of the substrate, a uniform and complete powder layer was formed on the upper surface of the substrate; finally, high-purity argon was used to dilute and discharge the oxygen in the forming cavity and pipeline until the oxygen content in the cavity was less than 200 ppm.

[0064] Step 3-2: SLM forming of TPMS configuration Ti2AlNb reinforcing body skeleton

[0065] By adjusting the laser input density, mainly including laser power, scanning speed, scanning spacing and powder layer thickness, the SLM forming of the lattice structure was realized. After printing, when the substrate temperature dropped to room temperature, the lattice structure was cut off from the substrate surface by using an electric spark wire cutting device, and after ultrasonic cleaning and drying, the SLM forming of the Ti2AlNb reinforcing body skeleton was completed, as shown in Figure 4 .

[0066] The laser power was 250 W, the scanning speed was 1200 mm / s, the scanning spacing was 0.1 mm, and the powder layer thickness was 0.03 mm. The laser scanning strategy was chessboard scanning, and the scanning direction between adjacent layers was rotated by 67°. The substrate preheating temperature was controlled at 90°.

[0067] Step 3-3: Surface treatment of TPMS configuration Ti2AlNb reinforcing body skeleton

[0068] The SLM formed TPMS configuration Ti2AlNb reinforcing body skeleton was electrolytically polished to remove the un-melted powder particles adhered to the surface of the skeleton during the forming process.

[0069] (ii) HPS composite forming of Ti2AlNb / TiAl-based interpenetrating composite material. The specific process is as follows:

[0070] Step 4: TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material was prepared by vacuum hot pressing sintering of HPS;

[0071] Step 4-1: Pre-pressing of Ti2AlNb / TiAl-based interpenetrating composite material

[0072] Firstly, the TPMS structure Ti2AlNb reinforcement skeleton was placed in a graphite mold coated with yttrium oxide; then, a certain mass of TiAl powder was poured into the skeleton, and the gap between the powders was reduced by ultrasonic vibration during the filling process to make the powders fill closely, so as to improve the tap density of the TiAl powder; finally, the graphite mold containing the reinforcement skeleton and the TiAl powder was placed in a vacuum hot-pressing sintering furnace, and a certain pressure was applied to preform at room temperature.

[0073] Based on the CAD model designed in step 1, by controlling the offset parameter C of the TPMS structure, a reinforcement skeleton with a volume fraction of 30vol.% can be obtained. The required mass of TiAl powder can be calculated by the formula m = p x 0.7 x p r 2 x h. Wherein, p is the density of TiAl alloy (g / cm 3 ); r is the radius of TPMS structure (mm); h is the height of TPMS structure Ti2AlNb reinforcement (mm).

[0074] The preforming pressure at room temperature is selected as 10 MPa, and the pressure holding time is 20 min.

[0075] Step 4-2: HPS forming of Ti2AlNb / TiAl-based interpenetrating composite

[0076] The preformed compact was placed in a vacuum hot-pressing sintering furnace, and HPS forming was carried out under specific sintering parameters. After the sample was cooled to room temperature with the furnace, the block was taken out of the mold, and a Ti2AlNb / TiAl-based interpenetrating composite with a diameter of 60 mm and a height of 10 mm was obtained.

[0077] The HPS sintering parameters are as follows: sintering temperature is 1150℃, holding time is 1h, and pressure is 45 MPa. During the HPS process, the temperature is kept at 600℃ for 10 min to remove the residual inclusions in the graphite mold. The heating rate is 5-10℃ / min, and the oxygen content is required to be less than 200ppm throughout the process.

[0078] The elastic modulus of the Gyroid skeleton prepared in this embodiment is completely coincident in the projections in the xy, xz and yz planes, all showing excellent isotropy, and the yield strength reaches 206.3 MPa; and the compression strength of the Gyroid structure Ti2AlNb / TiAl-based interpenetrating composite formed by HPS along the z-axis direction is the highest, reaching 1993.9 MPa, and the compression strength along the x-axis direction is the lowest, being 1797.8 MPa, while along the y-axis direction, it is between the two, as shown in Figure 5 and 6 .

[0079] Example Two:

[0080] In view of the problems of poor plasticity and toughness at room temperature and mechanical property anisotropy of TiAl alloy, a high-strength and high-toughness Ti2AlNb / TiAl-based interpenetrating composite material is designed and prepared. First, a plurality of Ti2AlNb reinforcing body skeletons of TPMS configurations are designed by using implicit function modeling; then, anisotropy of the TPMS configurations is studied by using finite element simulation; secondly, the Ti2AlNb reinforcing body skeletons of TPMS configurations are prepared by using SLM technology; finally, the Ti2AlNb / TiAl-based interpenetrating composite material of TPMS configuration is prepared by using HPS process, so as to avoid the strong anisotropy of the traditional fiber reinforced composite material in mechanical properties, realize good matching of the strength, plasticity and toughness of the composite material, and provide a new idea and solution for breaking through the application bottleneck of TiAl in the hot end parts of the aerospace power system.

[0081] The chemical composition of the Ti2AlNb powder used for SLM forming in the embodiment is: Al (22-25 at. %), Nb (20-30 at. %), Ta (0-7 at. %), and the balance is Ti, and the powder particle size is 15-53 μm. The chemical composition of the TiAl powder used for composite forming is: Al (45-48 at. %), Cr (1-3 at. %) and Nb (2-5 at. %), and the balance is Ti, and the powder particle size is 50-150 μm.

[0082] The preparation process of the Ti2AlNb / TiAl-based interpenetrating composite material involved in the embodiment is specifically divided into two parts:

[0083] (I) Design and preparation of Ti2AlNb reinforcing body skeleton of TPMS configuration. The specific process is:

[0084] Step 1: Implicit function modeling of TPMS configuration

[0085] A typical TPMS lattice structure (for example, Gyroid, Primitive, Diamond and Split-P) is selected, and nTopology commercial software is used for implicit function modeling, so as to obtain a CAD model of the lattice structure, as shown in Figure 2 . Among them, the model for SLM forming is exported as a stl model file. In the embodiment, the selected lattice structure is Primitive, and the surface thereof can be described by the following expression:

[0086] φ P (x,y,z)=cos(X)+cos(Y)+cos(Z)-C (2)

[0087] where X = 2πx / l, Y = 2πy / l, Z = 2πz / l, C is the bias parameter, and l is the unit length in x, y, z directions. The specific parameter information of the TPMS structure in the above CAD model: the unit cell size is 5 x 5 x 5 mm 3 , and the number of unit cells in x, y, and z directions is 6 x 6 x 6.

[0088] Step 2: Finite element simulation of TPMS configuration Ti2AlNb reinforcement framework

[0089] Based on the CAD model of the TPMS structure designed in step 1, the lattice structure is meshed by means of nTopology software; by using the homogenization method and finite element simulation, periodic boundary conditions are applied on the unit cells of different TPMS structures, so as to obtain the elastic properties of the lattice structure, as shown in Figure 3 .

[0090] The above meshing shape is tetrahedron, and the size is 0.3 mm. The performance parameters of Ti2AlNb used for finite element simulation are as follows: the elastic modulus, yield strength and tensile strength are 104.2 GPa, 943.0 MPa and 992.6 MPa respectively, the Poisson's ratio is 0.3, and the density is 5.3 g / cm 3 .

[0091] Step 3: Preparation of TPMS configuration Ti2AlNb reinforcement framework by using selective laser melting process SLM;

[0092] Step 3-1: Slice processing of SLM formed framework and pre-treatment before printing

[0093] Firstly, the CAD model of the Primitive lattice structure obtained above is imported into MaterialiseMagics software for slice processing, wherein the diameter of the reinforcement framework is 60 mm, the height is 10 mm, the slice layer thickness is 0.03 mm, and there are 400 layers in total; then, the processed file is imported into FF-M140C equipment; secondly, the titanium alloy substrate is placed in the forming cavity, and Ti-22Al-25Nb powder is filled into the powder cavity; by adjusting the position of the substrate, a powder layer with uniform and complete thickness is formed on the upper surface of the substrate; finally, high-purity argon is used to dilute and discharge the oxygen in the forming cavity and pipeline until the oxygen content in the cavity is less than 200 ppm.

[0094] Step 3-2: SLM forming of TPMS configuration Ti2AlNb reinforcement framework.

[0095] SLM forming of the lattice structure is realized by adjusting the laser input density, mainly including laser power, scanning speed, scanning pitch and powder layer thickness. After printing, the lattice structure is cut from the substrate using a wire electrical discharge cutting device when the substrate temperature drops to room temperature. After ultrasonic cleaning and drying, the SLM forming of the Ti2AlNb reinforcing body framework is completed, as shown in Figure 4 .

[0096] The laser power is 250 W, the scanning speed is 1200 mm / s, the scanning pitch is 0.1 mm, and the powder layer thickness is 0.03 mm. The laser scanning strategy is chessboard scanning, and the scanning direction is rotated by 67° between adjacent layers. The substrate preheating temperature is controlled at 90°.

[0097] Step 3-3: Surface treatment of the TPMS configuration Ti2AlNb reinforcing body framework

[0098] The SLM formed TPMS configuration Ti2AlNb reinforcing body framework is electrolytic polished to remove the un-melted powder particles adhered to the surface of the framework during the forming process.

[0099] (ii) HPS composite forming of Ti2AlNb / TiAl-based interpenetrating composites. The specific process is as follows:

[0100] Step 4: TPMS configuration Ti2AlNb / TiAl-based interpenetrating composites are prepared by vacuum hot pressing sintering of HPS;

[0101] Step 4-1: Pre-pressing of Ti2AlNb / TiAl-based interpenetrating composites

[0102] Firstly, the TPMS configuration Ti2AlNb reinforcing body framework is placed in a graphite mold coated with yttrium oxide coating; then a certain mass of TiAl powder is poured into the framework, and ultrasonic vibration is used to reduce the gap between the powders during filling to make the powder filling compact, thereby improving the tap density of the TiAl powder; finally, the graphite mold containing the reinforcing body framework and TiAl powder is placed in a vacuum hot pressing sintering furnace, and a certain pressure is applied for pre-pressing at room temperature.

[0103] Based on the CAD model designed in step 1, by controlling the offset parameter C of the TPMS structure, a reinforcing body framework with a volume fraction of 30vol.% can be obtained. The required mass of TiAl powder can be calculated by the formula m = p x 0.7 x πr 2 x h. Wherein, p is the density of TiAl alloy (g / cm 3 ); r is the radius of TPMS configuration (mm); h is the height of TPMS structure Ti2AlNb reinforcing body (mm).

[0104] The pre-pressing pressure is 10 MPa at room temperature, and the pressure holding time is 20 min.

[0105] Step 4-2: HPS forming of Ti2AlNb / TiAl-based interpenetrating composites.

[0106] After pre-pressing, the compact is placed in a vacuum hot-pressing sintering furnace for HPS forming under specific sintering parameters. After the sample cools to room temperature with the furnace, the block is removed from the mold, and a Ti2AlNb / TiAl-based interpenetrating composite with a diameter of 60 mm and a height of 10 mm is obtained.

[0107] The HPS sintering parameters are: sintering temperature is 1150℃, holding time is 1h, and pressure is 45MPa. During the HPS process, when the temperature reaches 600℃, it is kept for 10min to remove the residual inclusions in the graphite mold. The oxygen content is less than 200ppm throughout the process at a heating rate of 5-10℃ / min.

[0108] The elastic modulus of the Primitive framework prepared in the example is completely coincident in the xy, xz and yz planes, and all show weak anisotropy. When the loading direction changes from

[001] to

[011] , the elastic modulus value gradually increases. The yield strength of the Primitive framework reaches 148.2MPa. The compression strength of the Primitive configuration Ti2AlNb / TiAl-based interpenetrating composite prepared by HPS forming is the highest along the x-axis direction, reaching 2075.2MPa, and the compression strength along the y-axis direction is the lowest, being 1752.4MPa, and the compression strength along the z-axis is between the two, as shown in Figure 5 and 6 .

[0109] Example Three

[0110] In view of the problems of poor room temperature plasticity, toughness and strong anisotropy of mechanical properties of TiAl alloy, a high strength and toughness Ti2AlNb / TiAl-based interpenetrating composite is designed and prepared in this embodiment. First, a variety of TPMS configuration Ti2AlNb reinforcement frameworks are designed by using implicit function modeling; then, the anisotropy of TPMS configuration is studied by using finite element simulation; secondly, the TPMS configuration Ti2AlNb reinforcement framework is prepared by using SLM technology; finally, the TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite is prepared by HPS process, thereby avoiding the strong anisotropy of mechanical properties of traditional fiber reinforced composites, realizing good matching of strength, plasticity and toughness of the composite, and providing a new idea and solution for breaking through the application bottleneck of TiAl in the hot end parts of the aerospace power system.

[0111] The chemical composition of the Ti2AlNb powder used for SLM forming in this embodiment: Al (22-25 at. %), Nb (20-30 at. %), Ta (0-7 at. %), and the balance Ti, with a powder particle size of 15-53 μm. The chemical composition of the TiAl powder used for composite forming: Al (45-48 at. %), Cr (1-3 at. %), and Nb (2-5 at. %), and the balance Ti, with a powder particle size of 50-150 μm.

[0112] The preparation process of the Ti2AlNb / TiAl-based interpenetrating composite material involved in this embodiment is specifically divided into two parts:

[0113] (I) Design and preparation of the TPMS-structured Ti2AlNb reinforcing body framework. The specific process is as follows:

[0114] Step 1: Implicit function modeling of TPMS structure

[0115] A typical TPMS lattice structure (for example, Gyroid, Primitive, Diamond, and Split-P) is selected, and nTopology commercial software is used for implicit function modeling to obtain a CAD model of the lattice structure, as shown in Figure 2 . Among them, the model for SLM forming is exported as an stl model file. In this embodiment, the selected lattice structure is Diamond, and the curved surface thereof can be described by the following expression:

[0116] φ D (x,y,z)=sin(X)·sin(Y)·sin(Z)+cos(X)·cos(Y)·cos(Z)-C (3)

[0117] where X=2πx / l, Y=2πy / l, Z=2πz / l, and C is a bias parameter, and l is the unit length in the x, y, and z directions. The specific parameter information of the TPMS structure in the above CAD model: the unit cell size is 5×5×5 mm 3 , and the number of unit cells in the x, y, and z directions is 6×6×6.

[0118] Step 2: Finite element simulation of the TPMS-structured Ti2AlNb reinforcing body framework

[0119] Based on the CAD model of the TPMS structure designed in Step 1, the lattice structure is meshed by means of nTopology software; the homogenization method and finite element simulation are used to apply periodic boundary conditions on the unit cells of different TPMS structures, thereby obtaining the elastic properties of the lattice structure, as shown in Figure 3 .

[0120] The mesh shape is tetrahedron with size of 0.3mm. The property parameters of Ti2AlNb used in finite element simulation are as follows: elastic modulus, yield strength and tensile strength are 104.2GPa, 943.0MPa and 992.6MPa respectively, Poisson's ratio is 0.3, and density is 5.3g / cm 3 .

[0121] Step 3: preparing the Ti2AlNb reinforcing body skeleton of TPMS configuration by using selective laser melting process SLM;

[0122] Step 3-1: slice processing and pre-printing treatment of the SLM formed skeleton.

[0123] Firstly, the CAD model of the Diamond lattice structure obtained above is imported into Materialise Magics software for slice processing, wherein the diameter of the reinforcing body skeleton is 60mm, the height is 10mm, the slice layer thickness is all 0.03mm, and there are 400 layers in total; then, the processed file is imported into FF-M140C equipment; secondly, the titanium alloy substrate is placed in the forming cavity, Ti-22Al-25Nb powder is filled into the powder cavity, the position of the substrate is adjusted to make the powder layer on the upper surface of the substrate have uniform and complete thickness; finally, high-purity argon is used to dilute and discharge oxygen in the forming cavity and pipeline until the oxygen content in the cavity is less than 200ppm.

[0124] Step 3-2: SLM forming of the TPMS configuration Ti2AlNb reinforcing body skeleton.

[0125] By adjusting the laser input density, mainly including laser power, scanning speed, scanning spacing and powder layer thickness, the SLM forming of the lattice structure is realized. After printing, when the substrate temperature drops to room temperature, the lattice structure is cut off from the substrate by using electric spark wire cutting equipment, and after ultrasonic cleaning and drying, the SLM forming of the Ti2AlNb reinforcing body skeleton is completed, as shown in Figure 4 .

[0126] The laser power is 250W, the scanning speed is 1200mm / s, the scanning spacing is 0.1mm, and the powder layer thickness is 0.03mm. The laser scanning strategy is chessboard scanning, and the scanning direction between adjacent layers is rotated by 67°. The substrate preheating temperature is controlled at 90°.

[0127] Step 3-3: surface treatment of the TPMS configuration Ti2AlNb reinforcing body skeleton

[0128] The SLM formed TPMS configuration Ti2AlNb reinforcing body skeleton is electrolytically polished to remove the un-melted powder particles adhered to the surface of the skeleton during the forming process.

[0129] (ii) HPS composite forming of Ti2AlNb / TiAl-based interpenetrating composites. The specific process is as follows:

[0130] Step 4: Ti2AlNb / TiAl-based interpenetrating composites with TPMS configuration are prepared by vacuum hot pressing sintering of HPS;

[0131] Step 4-1: Pre-press forming of Ti2AlNb / TiAl-based interpenetrating composites

[0132] Firstly, the TPMS configuration Ti2AlNb reinforcing body skeleton is placed in a graphite mold coated with yttria coating; then, a certain mass of TiAl powder is poured into the skeleton, and ultrasonic vibration is used to reduce the gap between the powders during filling to make the powder fill tightly, thereby improving the tap density of the TiAl powder; finally, the graphite mold containing the reinforcing body skeleton and TiAl powder is placed in a vacuum hot pressing sintering furnace, and a certain pressure is applied for pre-press forming at room temperature.

[0133] Based on the CAD model designed in step 1, by controlling the offset parameter C of the TPMS structure, a reinforcing body skeleton with a volume fraction of 30vol.% can be obtained. The required mass of TiAl powder can be calculated by the formula m = p x 0.7 x p r 2 x h. Wherein, p is the density of TiAl alloy (g / cm 3 ); r is the radius of TPMS configuration (mm); h is the height of TPMS structure Ti2AlNb reinforcement (mm).

[0134] The pre-pressing pressure at room temperature is selected as 10 MPa, and the pressure holding time is 20 min.

[0135] Step 4-2: HPS forming of Ti2AlNb / TiAl-based interpenetrating composites.

[0136] The pre-pressed compact is placed in a vacuum hot pressing sintering furnace and HPS forming is carried out under specific sintering parameters. After the sample is cooled to room temperature with the furnace, the block is taken out from the mold, and a Ti2AlNb / TiAl-based interpenetrating composite with a diameter of 60 mm and a height of 10 mm is obtained.

[0137] The HPS sintering parameters are as follows: sintering temperature is 1150℃, holding time is 1h, and pressure is 45MPa. During the HPS process, when the temperature reaches 600℃, it is kept for 10 min to remove the residual inclusions gas in the graphite mold. The oxygen content is required to be less than 200ppm throughout the process at a heating rate of 5-10℃ / min.

[0138] The elastic modulus of the Diamond framework prepared in the embodiment is completely coincident in the projections in the xy, xz and yz planes, all showing excellent isotropy, and the yield strength reaches 209.7 MPa; and the Diamond configuration Ti2AlNb / TiAl-based interpenetrating composite material formed by HPS has the highest compressive strength along the x-axis direction, reaching 1921.6 MPa, and the lowest compressive strength along the z-axis direction, being 1820.8 MPa, and the compressive strength along the y-axis is between the two. At this time, the TiAl-based interpenetrating composite material shows isotropy, as shown in Figure 5 and 6 .

[0139] Embodiment Four

[0140] In view of the problems of poor room temperature plasticity, toughness and strong anisotropy of mechanical properties of TiAl alloy, a high strength and toughness Ti2AlNb / TiAl-based interpenetrating composite material is designed and prepared in the embodiment. First, a plurality of TPMS configuration Ti2AlNb reinforcing body frameworks are designed by using implicit function modeling; then, the anisotropy of the TPMS configuration is studied by using finite element simulation; secondly, the TPMS configuration Ti2AlNb reinforcing body framework is prepared by using SLM technology; finally, the TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material is prepared by HPS process, so as to avoid the strong anisotropy of mechanical properties of the traditional fiber reinforced composite material, realize good matching of the strength, plasticity and toughness of the composite material, and provide a new idea and solution for breaking through the application bottleneck of TiAl in the hot end part of the aerospace power system.

[0141] The chemical composition of the Ti2AlNb powder used for SLM forming in the embodiment is: Al (22-25 at. %), Nb (20-30 at. %), Ta (0-7 at. %), and the balance is Ti, and the powder particle size is 15-53 μm. The chemical composition of the TiAl powder used for composite forming is: Al (45-48 at. %), Cr (1-3 at. %) and Nb (2-5 at. %), and the balance is Ti, and the powder particle size is 50-150 μm.

[0142] The preparation process of the Ti2AlNb / TiAl-based interpenetrating composite material involved in the embodiment is specifically divided into two parts:

[0143] (I) Design and preparation of TPMS configuration Ti2AlNb reinforcing body framework. The specific process is as follows:

[0144] Step 1: Implicit function modeling of TPMS configuration

[0145] A typical TPMS lattice structure (e.g., Gyroid, Primitive, Diamond and Split-P) was selected, and implicit function modeling was performed using nTopology commercial software to obtain a CAD model of the lattice structure, as shown in FIG. 1. Among them, the model for SLM forming is exported as a stl model file. In this embodiment, the selected lattice structure is Split P, and the surface thereof can be described by the following expression: Figure 2

[0146] φ SP (x,y,z)=1.1[sin(2X)·cos(Y)·sin(Z)+sin(2Y)·cos(Z)·sin(X)+sin(2Z)cos(X)·sin(Y)]-0.2[cos(2X)·cos(2Y)+cos(2Y)·cos(2Z)+cos(2Z)·cos(2X)]-0.4[cos(2Y)+cos(2Z)+cos(2X)]-C (4)

[0147] wherein X = 2πx / l, Y = 2πy / l, Z = 2πz / l, C is a bias parameter, and l is the unit length in the x, y and z directions. The specific parameter information of the TPMS structure in the above CAD model: the unit cell size is 5 x 5 x 5 mm 3 , and the number of unit cells in the x, y and z directions is 6 x 6 x 6.

[0148] Step 2: Finite element simulation of the TPMS configuration Ti2AlNb reinforced body skeleton

[0149] Based on the CAD model of the TPMS structure designed in step 1, the lattice structure was meshed by means of nTopology software; the homogenization method and finite element simulation were used to apply periodic boundary conditions on the unit cells of different TPMS structures, so as to obtain the elastic properties of the lattice structure, as shown in FIG. 2. Figure 3

[0150] The above meshing shape is tetrahedron, and the size is 0.3 mm. The performance parameters of Ti2AlNb used for finite element simulation are as follows: the elastic modulus, yield strength and tensile strength are 104.2 GPa, 943.0 MPa and 992.6 MPa, respectively, the Poisson's ratio is 0.3, and the density is 5.3 g / cm 3 .

[0151] Step 3: SLM preparation of the TPMS configuration Ti2AlNb reinforced body skeleton by using selective laser melting process

[0152] Step 3-1: SLM forming skeleton slice processing and pre-printing processing

[0153] ​​Firstly, the CAD model of the Split P lattice structure obtained above was imported into Materialise Magics software for slicing processing, wherein the diameter of the reinforcing body skeleton was 60 mm, the height was 10 mm, the slicing layer thickness was 0.03 mm, and there were 400 layers in total; then, the processed file was imported into the FF-M140C device; secondly, the titanium alloy substrate was placed in the forming cavity, Ti-22Al-25Nb powder was filled into the powder cavity, and the position of the substrate was adjusted so that a uniform and complete powder layer was covered on the upper surface of the substrate; finally, high-purity argon was used to dilute and discharge the oxygen in the forming cavity and the pipeline until the oxygen content in the cavity was less than 200 ppm.

[0154] Step 3-2: SLM forming of the TPMS configuration Ti2AlNb reinforcing body skeleton.

[0155] By adjusting the laser input density, mainly including laser power, scanning speed, scanning spacing and powder layer thickness, the SLM forming of the lattice structure was realized. After printing, when the temperature of the substrate decreased to room temperature, the lattice structure was cut off from the substrate surface by using an electric spark wire cutting device, and after ultrasonic cleaning and drying, the SLM forming of the Ti2AlNb reinforcing body skeleton was completed, as shown in Figure 4 .

[0156] The laser power was 250 W, the scanning speed was 1200 mm / s, the scanning spacing was 0.1 mm, and the powder layer thickness was 0.03 mm. The laser scanning strategy was chessboard scanning, and the scanning direction between adjacent layers was rotated by 67°. The substrate preheating temperature was controlled at 90°.

[0157] Step 3-3: Surface treatment of the TPMS configuration Ti2AlNb reinforcing body skeleton

[0158] The SLM formed TPMS configuration Ti2AlNb reinforcing body skeleton was electrolytically polished to remove the un-melted powder particles adhered to the surface of the skeleton during the forming process.

[0159] (ii) HPS composite forming of Ti2AlNb / TiAl-based interpenetrating composite material. The specific process is as follows:

[0160] Step 4: TPMS configuration Ti2AlNb / TiAl-based interpenetrating composite material was prepared by vacuum hot pressing sintering of HPS;

[0161] Step 4-1: Pre-pressing of Ti2AlNb / TiAl-based interpenetrating composite material

[0162] Firstly, the TPMS configuration Ti2AlNb reinforcing body framework is placed in a graphite mold coated with yttrium oxide; then, a certain mass of TiAl powder is poured into the framework, and ultrasonic vibration is used to reduce the gap between the powders during the filling process, so as to make the powders fill closely and thus improve the tap density of the TiAl powder; finally, the graphite mold containing the reinforcing body framework and the TiAl powder is placed in a vacuum hot-pressing sintering furnace, and a certain pressure is applied to preform at room temperature.

[0163] Based on the CAD model designed in step 1, by controlling the offset parameter C of the TPMS structure, a reinforcing body framework with a volume fraction of 30 vol.% can be obtained. The required mass of TiAl powder can be calculated by the formula m = p x 0.7 x p r 2 x h. Wherein, p is the density of TiAl alloy (g / cm 3 ); r is the radius of the TPMS configuration (mm); h is the height of the Ti2AlNb reinforcing body of the TPMS structure (mm).

[0164] The preforming pressure at room temperature is selected to be 10 MPa, and the pressure holding time is 20 min.

[0165] Step 4-2: HPS forming of Ti2AlNb / TiAl-based interpenetrating composite

[0166] The preformed compact is placed in a vacuum hot-pressing sintering furnace, and HPS forming is performed under specific sintering parameters. After the sample is cooled to room temperature with the furnace, the block is taken out of the mold, and a Ti2AlNb / TiAl-based interpenetrating composite with a diameter of 60 mm and a height of 10 mm is obtained.

[0167] The HPS sintering parameters are: sintering temperature is 1150℃, holding time is 1h, and pressure is 45MPa. During the HPS process, when the temperature reaches 600℃, it is kept for 10 min to remove the residual inclusions in the graphite mold. The oxygen content is required to be less than 200ppm throughout the process at a heating rate of 5-10℃ / min.

[0168] The elastic modulus of the Split P framework prepared in this embodiment is completely coincident in the projections in the xy, xz and yz planes, and all exhibit excellent isotropy, and the yield strength reaches 240.9MPa; and the Split P configuration Ti2AlNb / TiAl-based interpenetrating composite formed by HPS has the highest compressive strength along the x-axis direction, reaching 2145.7MPa, and the lowest compressive strength along the z-axis direction, being 2017.9MPa, and the compressive strength along the y-axis is between the two, as shown in Figure 5 and 6 .

[0169] It will be obvious to a person skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims to the identity of the reference signs therein.

[0170] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material, characterized in that: The preparation method consists of two parts: (I) Design and fabrication of TPMS-configured Ti2AlNb reinforcing framework; the specific process is as follows: Step 1: Implicit function modeling of TPMS configurations: Various TPMS configurations of Ti2AlNb reinforcement frameworks were designed using implicit function modeling; Step 2: Finite element simulation of TPMS-configured Ti2AlNb reinforced skeleton: Anisotropy of the TPMS-configured Ti2AlNb reinforced skeleton was studied using finite element simulation; Step 3: Prepare a TPMS-configured Ti2AlNb reinforcement framework using selective laser melting (SLM); Step 3-1: Slicing and pre-printing pretreatment of the Ti2AlNb reinforcement skeleton formed by selective laser melting (SLM) process for TPMS configuration; Step 3-2: Selective laser melting (SLM) forming of the TPMS-configured Ti2AlNb reinforcement framework; Step 3-3: Surface treatment of the TPMS-configured Ti2AlNb reinforcement framework; (II) Vacuum hot pressing sintering HPS composite forming of Ti2AlNb / TiAl-based interpenetrating composite materials; the specific process is as follows: Step 4: Prepare TPMS-configured Ti2AlNb / TiAl-based interpenetrating composite materials by vacuum hot pressing sintering (HPS). Step 4-1: Pre-compression forming of TPMS-configured Ti2AlNb / TiAl-based interpenetrating composite material; Step 4-2: Vacuum hot pressing sintering HPS forming of TPMS-configured Ti2AlNb / TiAl-based interpenetrating composite material; In step 1: various TPMS configurations of Ti2AlNb reinforcement frameworks were designed using implicit function modeling. The specific operation method is as follows: A typical TPMS lattice structure is selected, and implicit function modeling is performed using nTopology software to obtain the CAD model of the lattice structure; among them, the model used for selective laser melting (SLM) forming is exported as an STL model file. In step 2: the anisotropy of the Ti2AlNb reinforcement framework of the TPMS configuration is simulated using the finite element method. The specific operation method is as follows: Based on the CAD model of the TPMS-configured Ti2AlNb reinforced skeleton designed in step 1, the lattice structure was meshed using nTopology software. Using the homogenization method and finite element simulation, periodic boundary conditions were applied to the unit cells of the Ti2AlNb reinforced skeleton with different TPMS configurations to obtain the elastic properties of the lattice structure. The specific process of step 3: Step 3-1: Slicing and pre-printing pretreatment of the Ti2AlNb reinforcement skeleton formed by selective laser melting (SLM) process for TPMS configuration. First, the CAD model of the lattice structure obtained above is imported into Materialise Magics software for slicing. Then, the processed file is imported into the FF-M140C device. Next, the titanium alloy substrate is placed in the forming cavity, and Ti-22Al-25Nb powder is filled into the powder cavity. By adjusting the position of the substrate, a uniform and complete powder layer is formed on the upper surface of the substrate. Finally, high-purity argon gas is used to dilute and remove the oxygen in the forming cavity and pipeline until the oxygen content in the cavity is lower than 200 ppm. Step 3-2: Selective laser melting (SLM) forming of the TPMS-configured Ti2AlNb reinforcement framework; By adjusting the laser input density, including laser power, scanning speed, scanning spacing and powder layer thickness, the selective laser melting (SLM) process for forming lattice structures is achieved. After printing, once the substrate temperature drops to room temperature, the lattice structure is cut off from the substrate using an electrical discharge wire cutting device. After ultrasonic cleaning and drying, the SLM process for forming the Ti2AlNb reinforcement skeleton is completed. Step 3-3: Surface treatment of the Ti2AlNb reinforcement framework with TPMS configuration; Electropolishing was performed on the TPMS-structured Ti2AlNb reinforcement skeleton formed by selective laser melting (SLM) to remove unmelted powder particles adhering to the skeleton surface during the forming process. The specific operation process of step 4: Step 4-1: Pre-compression molding of Ti2AlNb / TiAl-based interpenetrating composite material with TPMS configuration; First, the TPMS-configured Ti2AlNb reinforced skeleton is placed in a graphite mold coated with yttrium oxide. Then, a certain mass of TiAl powder is poured into the skeleton. During the filling process, ultrasonic vibration is used to reduce the gaps between the powders, making the powder fill tightly and increasing the tap density of the TiAl powder. Finally, the graphite mold containing the TPMS-configured Ti2AlNb reinforced skeleton and TiAl powder is placed in a vacuum hot pressing sintering furnace and pre-pressed at room temperature under a certain pressure. Step 4-2: Vacuum hot pressing (HPS) forming of TPMS-configured Ti2AlNb / TiAl-based interpenetrating composite material The pre-pressed compact is placed in a vacuum hot pressing sintering furnace and HPS forming is performed under specific sintering parameters. After the sample cools to room temperature with the furnace, the block is removed from the mold to obtain the Ti2AlNb / TiAl-based interpenetrating composite material. The sintering parameters for vacuum hot pressing sintering (HPS) are: sintering temperature of 1050-1250 ℃, holding time of 0.5-2 h, and pressure of 45 MPa.

2. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 1 above, the specific parameter information of the TPMS configuration Ti2AlNb reinforcement framework in the CAD model is as follows: the unit cell size is 5×5×5 mm. 3 The number of units in the x, y, and z directions is 6.

3. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 2 above, the mesh is divided into tetrahedral shapes with a size of 0.3 mm.

4. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 3-1 above, the thickness of the slice layer of the lattice structure is 0.03 mm.

5. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 3-2 above, the laser power is 150-250 W, the scanning speed is 800-1400 mm / s, the scanning spacing is 0.1 mm, and the powder layer thickness is 0.03 mm; the laser scanning strategy is checkerboard scanning, with the scanning direction between adjacent layers rotating by 67°; the substrate preheating temperature is controlled at 90°.

6. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 4-1 above, based on the CAD model designed in step 1, a reinforcing skeleton with a volume fraction of 7.5–37.5 vol.% can be obtained by controlling the median surface offset C of the TPMS structure; the required TiAl powder mass is obtained by the formula m = ρ × (0.625 - 0.925) × πr. 2 The value is calculated as ×h; where ρ is the density of the TiAl alloy in g / cm³. 3 r is the radius of the graphite mold (mm); h is the height of the TPMS structure Ti2AlNb reinforcement (mm). The pre-compression pressure at room temperature is selected as 5-10 MPa, and the pressure holding time is 10-30 min.

7. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 4-2 above, during the vacuum hot pressing sintering HPS process, after the temperature reaches 600 ℃, it is held for 10 min to remove the residual inclusion gas in the graphite mold. The heating rate is 5-10 ℃ / min, and the oxygen content must be kept below 200 ppm throughout the process.

8. The method for preparing an isotropic Ti2AlNb / TiAl-based interpenetrating composite material according to claim 1, characterized in that: In step 3 above, the chemical composition of the Ti2AlNb powder used for selective laser melting (SLM) forming is as follows: Al: 22-25 at.%, Nb: 20-30 at.%, Ta: 0-7 at.%, with the balance being Ti, and the powder particle size is 15-53 µm. In step 4 above, the chemical composition of the TiAl powder used for composite forming is: Al: 45-48 at.%, Cr: 1-3 at.%, Nb: 2-5 at.%, with the balance being Ti, and the powder particle size is 50-150 µm.

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