Preparation method of metal-based composite component with spatial multi-stage reinforced heterostructure based on metal fused deposition

Abstract

The invention provides a preparation method of a metal-based composite component with a spatial multistage reinforced heterostructure based on metal fused deposition, which comprises the following steps: firstly, optimizing printing raw material powder, obtaining metal-based composite powder with a spatial multistage network structure formed by a reinforced phase through two-stage treatment, and meanwhile, preparing a metal-based composite component with a spatial multistage reinforced heterostructure through two-stage treatment; in the process, a metal fused deposition technology is adopted for printing and forming, the processing temperature is reduced, and a grid structure of a reinforced phase in a component and at a grain boundary is reserved and cannot be damaged. According to the method, printing is conducted in the mode that the metal layers and the metal-based composite material layers are alternately circulated, so that a reinforcing phase effectively plays a role, and good high-temperature resistance and toughness are guaranteed while the high-strength requirement of the component is met.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a method for preparing a metal-based composite component with a spatial multi-level reinforced heterogeneous structure based on metal molten deposition. Background Art

[0002] The skin materials of flight equipment are required to have good mechanical properties and beneficial surface properties, such as high strength, high plasticity, good wear resistance, good corrosion resistance, good high temperature resistance, etc. Currently, high-strength aluminum, magnesium alloys and other materials are generally used, but the mechanical properties of these materials are insufficient.

[0003] Metal Matrix Composites (MMCs) are a type of material that combines reinforcements with metal matrices, combining the advantages of metal matrices and reinforcements to achieve the development of material toughness. Metal matrix composites have the advantages of high hardness, low thermal expansion coefficient, high temperature resistance, high wear resistance and corrosion resistance, and have long been considered as an important potential structural material for future aerospace and weapon equipment.

[0004] In the prior art, the desired component is generally obtained by simply mixing the reinforcing phase and metal powder, and then using a high-energy input preparation process such as powder metallurgy. In this process, a series of problems are prone to occur, such as excessive melting, agglomeration, cracks and defects of the reinforcing phase due to high energy, the generation of a large number of brittle interface reactants, and large thermal stress at the interface, which results in the inability of the reinforcement to play a reinforcing role, affecting the high temperature resistance and mechanical properties of the final component. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a metal-based composite component with a spatial multi-level reinforced heterogeneous structure based on metal molten deposition, by preparing a metal-based composite material with a spatial multi-level network structure formed by a reinforcing phase, and further preparing a metal-based composite wire by drawing or extrusion. The spatial multi-level network structure is retained in the printed composite component by using metal molten deposition technology, and the metal layer and the metal-based composite layer are printed in an alternating cycle so that the reinforcing phase with a multi-level spatial network distribution can play an effective role, thereby meeting the high strength requirements of the component while ensuring good high temperature resistance and toughness.

[0006] According to the first aspect of the present invention, a method for preparing a metal-based composite component having a spatial multi-level reinforced heterogeneous structure based on metal molten deposition is proposed, comprising the following steps:

[0007] S1. Raw material preparation

[0008] The pretreated first metal powder is mechanically mixed with the first reinforcement phase powder, and a cast metal-based composite rod blank is prepared by vacuum autoclave smelting (VAR); the cast metal-based composite rod blank is then used as a raw material for PREP powder making to obtain a first composite powder, wherein the first reinforcement phase is refined and distributed at the grain boundaries of the matrix through PREP powder making to form a first network structure;

[0009] Mechanically mixing and ball-milling the first composite powder and the pretreated second reinforcement phase powder so that the surface of the first composite powder is covered with the nano-scale second reinforcement phase powder to obtain a second composite powder;

[0010] The second composite powder and the first binder are mixed and kneaded in proportion, so that the second reinforcing phase powder forms a second network structure on the surface of the second composite powder, thereby obtaining a metal-based composite material having a spatial multi-level network structure, wherein the spatial multi-level network structure is formed by the first network structure and the second network structure;

[0011] Using the metal-based composite material with a spatial multi-level network structure to make wires, to obtain metal-based composite wires;

[0012] The pretreated second metal powder is mixed with the second binder in a certain proportion to prepare a metal wire material;

[0013] S2, Metal Melt Deposition Additive

[0014] Using the metal wire and the metal-based composite wire as raw materials, adopting a metal melting deposition process, depositing layer by layer from the first layer to the last layer on the substrate in a metal layer-metal-based composite layer or metal-based composite layer-metal layer alternating cycle according to a preset program, to obtain a composite green body;

[0015] S3, post-processing

[0016] The composite green body is subjected to thermal degreasing, sintering and hot isostatic pressing treatments in sequence to obtain a metal-based composite component.

[0017] As an optional implementation, the first reinforcement phase powder is of micron scale; the second reinforcement phase powder is of nano scale.

[0018] As an optional embodiment, the mass ratio of the first reinforcing phase powder to the first metal powder is 1:(9-49), wherein the type of the first reinforcing phase powder is selected based on the principle that it can form a solid solution with the first metal powder to generate a reinforcing phase.

[0019] As an optional embodiment, the mass ratio of the second reinforcing phase powder to the first composite powder is 1:(9-49), wherein the type of the second reinforcing phase powder is selected based on the principle that it can be solid-dissolved with the first composite powder to generate a reinforcing phase.

[0020] As an optional embodiment, the type of the first reinforcing phase powder includes one or more of borides, carbides, nitrides, oxides, and in particular, the first reinforcing phase powder is one or more of TiC, TiB2 and WC.

[0021] As an optional embodiment, the type of the second reinforcement phase powder includes one or more of borides, carbides, nitrides, oxides, and in particular, the second reinforcement phase powder is one or more of TiC, TiB2 and WC.

[0022] As an optional embodiment, the first reinforcement phase powder and the second reinforcement phase powder are the same type of powder.

[0023] As an optional embodiment, the first metal powder and the second metal powder are preferably made of the same brand of metal powder, for example, both are selected from titanium alloys, including but not limited to TC4, Ti60, Ti65, etc.

[0024] As an optional implementation, the first binder and the second binder are both selected from at least one of polyoxymethylene (POM), ethylene (PE) or stearic acid (SA).

[0025] According to the method for preparing a metal-based composite component with a spatial multi-level reinforced heterogeneous structure based on metal molten deposition of the present invention, the printing raw material powder is first optimized, and a metal-based composite filament with a spatial multi-level network structure formed by a reinforcement phase is obtained through a two-stage treatment. At the same time, metal molten deposition technology is used for printing and molding in the process to reduce the processing temperature, so that the grid structure of the reinforcement phase inside the component and at the grain boundary is retained and will not be destroyed.

[0026] In the FDM printing process using the metal-based composite wire prepared by the present invention, the metal wire and the metal-based composite wire prepared by the present invention are used as raw materials, and the metal layer and the metal-based composite layer are printed in an alternating cycle, so that the toughening effect of the metal and the reinforcement effect of the composite material are fully exerted, the performance of the component is significantly improved, and the crack propagation can be effectively prevented, so that the reinforcement phase can play an effective role. The multi-scale reinforcement phase structure of the metal-based composite wire can achieve more efficient load transfer and stress dispersion, and further improve the performance of the material, thereby ensuring good high temperature resistance and toughness while meeting the high strength requirements of the component.

[0027] The composite component prepared according to the method of the present invention has a spatial multi-level reinforced heterogeneous structure. By introducing structural designs of different scales and different components, it can effectively combine the excellent properties of different materials, achieve the unity of high strength, high toughness and high temperature resistance, and realize the multi-objective performance requirements of materials for extreme service environment conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a process flow chart of the method for preparing a metal-based composite component with a spatial multi-level reinforced heterogeneous structure based on metal molten deposition of the present invention.

[0029] Figure 2 It is a schematic diagram of the preparation method of the present invention for a metal-based composite component having a spatial multi-level reinforced heterogeneous structure based on metal molten deposition.

[0030] Figure 3 3A is a schematic diagram of the spatial multi-level network structure of the present invention; wherein 3A is the first composite powder; and 3B is the second composite powder. DETAILED DESCRIPTION

[0031] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0032] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways.

[0033] Fused Deposition Metal (FDM) additive manufacturing technology is a technology that integrates digital technology, powder metallurgy and 3D printing technology. It slices the part model and stacks a mixture of metal powder and binder (wire) layer by layer to prepare metal parts with complex shapes and structures. It can achieve integrated molding of complex structures. This technology has high manufacturing efficiency and a flexible and energy-saving design and manufacturing process.

[0034] According to an embodiment of the present invention, the metal-based composite components designed in the prior art are designed to introduce a reinforcement phase into the metal matrix to cause internal organizational properties and high temperature resistance problems. For example, in the process of preparing composite components by powder metallurgy or laser melting additive manufacturing process, due to the input of high energy (high temperature sintering, laser melting), the reinforcement phase is excessively melted, agglomerated, and other defects occur, resulting in cracks inside the prepared component, precipitation of a large number of brittle interface reactants, and defects such as large thermal stress at the interface position, thereby weakening the effect of the reinforcement phase and affecting the mechanical properties and high temperature resistance of the component. To this end, the present invention aims to construct a preparation method for a metal spatial multi-level reinforced heterogeneous structure, through the composite material design of a multi-level heterogeneous network structure, introducing a reinforcement phase design of different scales and different components, and obtaining a high-quality composite wire, which has a spatial multi-level reinforced grid structure, effectively combining the excellent properties of different reinforcement phases, and combining the metal molten deposition (FDM) printing process. The composite wire and the metal wire are combined for alternate printing and molding, so that the complete reinforcement phase grid structure is retained in the molded component, which not only meets the high strength requirements, but also ensures good high temperature performance and toughness, and significantly improves the mechanical properties and high temperature resistance of the component.

[0035] As an example, a method for forming a metal spatial multi-level reinforced heterostructure based on metal molten deposition (FDM) according to an embodiment of the present invention comprises the following steps:

[0036] S1. Raw material preparation

[0037] The pretreated first metal powder is mechanically mixed with the first reinforcement phase powder, and a cast metal-based composite rod blank is prepared by vacuum autoclave smelting (VAR); the cast metal-based composite rod blank is then used as a raw material for PREP powder making to obtain a first composite powder, wherein the first reinforcement phase is refined and distributed at the grain boundaries of the matrix through PREP powder making to form a first network structure;

[0038] Mechanically mixing and ball-milling the first composite powder and the pretreated second reinforcement phase powder so that the surface of the first composite powder is covered with the nano-scale second reinforcement phase powder to obtain a second composite powder;

[0039] The second composite powder and the first binder are mixed and kneaded in proportion, so that the second reinforcing phase powder forms a second network structure on the surface of the second composite powder, thereby obtaining a metal-based composite material having a spatial multi-level network structure, wherein the spatial multi-level network structure is formed by the first network structure and the second network structure;

[0040] Using the metal-based composite material with a spatial multi-level network structure to prepare wires, to obtain metal-based composite wires;

[0041] The pretreated second metal powder is mixed with the second binder in a certain proportion to prepare a metal wire material;

[0042] S2, Metal Melt Deposition Additive

[0043] Using the metal wire and the metal-based composite wire as raw materials, adopting a metal melting deposition process, depositing layer by layer from the first layer to the last layer on the substrate in a metal layer-metal-based composite layer or metal-based composite layer-metal layer alternating cycle according to a preset program, to obtain a composite green body;

[0044] S3, post-processing

[0045] The composite green body is subjected to thermal degreasing, sintering and hot isostatic pressing treatments in sequence to obtain a metal-based composite component.

[0046] As an optional embodiment, in the aforementioned step S1, the pretreatment of the metal powder and the reinforcing phase powder mainly controls the heating and water removal treatment to obtain high-quality powder.

[0047] As an optional embodiment, the first reinforcement phase powder is micron-sized, and the types of powder include one or more of borides, carbides, nitrides, oxides, for example, one or more of TiC, TiB2 and WC.

[0048] As an optional embodiment, the second reinforcement phase powder is nano-scale, and its types include one or more of borides, carbides, nitrides, oxides, for example, one or more of TiC, TiB2 and WC.

[0049] As an optional implementation, the mass ratio of the first reinforcing phase powder to the first metal powder is 1:(9-49), wherein the type of the first reinforcing phase powder is selected based on the principle that it can form a solid solution with the first metal powder to generate a reinforcing phase.

[0050] As an optional implementation, the mass ratio of the second reinforcement phase powder to the first composite powder is 1:(9-49), wherein the type of the second reinforcement phase powder is selected based on the principle that it can be solid-solutioned with the first composite powder to generate a reinforcement phase.

[0051] As an optional embodiment, the first metal powder and the second metal powder can be metal powder of the same brand, for example, the metal types are both selected from titanium alloys, including but not limited to titanium alloy powders of brands TC4, Ti60, Ti65, etc., and the particle size range is selected between 50 and 250 μm.

[0052] In the embodiments of the present invention, it should be understood that due to the VAR and PREP processes in the preparation of the metal powder raw material of the present invention, the permissible range of the particle size selection of the metal powder is relatively wide, and the powder is not limited to a specific particle size.

[0053] As an optional embodiment, the first binder and the second binder are both selected from at least one of polyoxymethylene (POM), ethylene (PE) or stearic acid (SA), and a combination of at least two of them is particularly preferred.

[0054] In a further embodiment, in combination with Figure 1 , 2 As shown, taking titanium alloy powder as the metal substrate powder as an example, a method for preparing a metal-based composite component with a spatial multi-level reinforced heterogeneous structure based on metal molten deposition (FDM) includes powder pretreatment, titanium-based composite material preparation, composite wire preparation, FDM printing and post-processing process.

[0055] (1) Powder pretreatment: The titanium alloy powder and two reinforcing phase powders with different particle sizes (micrometer and nanometer) are heated to eliminate moisture in the powder.

[0056] (2) Preparation of titanium-based composites: Micron-scale reinforcement phase powder and partially pretreated titanium alloy powder (TC4 in this example) are mixed in a mass ratio of 1:(9-49), mechanically mixed by a planetary ball mill, and a cast composite material blank is prepared by a vacuum autoclave melting process (VAR) to form a rod blank;

[0057] Then, a plasma rotating electrode atomization powder making method is used to prepare powder to prepare a first composite material powder;

[0058] Then, the nano-scale reinforcement phase powder (i.e., the second reinforcement phase powder) is mixed with the obtained first composite powder in a mass ratio of 1:(9-49), and then the nano-scale reinforcement phase powder is coated on the surface of the first composite powder by planetary ball milling to obtain the second composite powder;

[0059] The second composite powder prepared in step (2) is then mixed and kneaded with the first binder in a mass ratio of (8:1) to (17:3). The nanoscale second reinforcement phase powder forms a layer of macroscopic network structure on the surface of the second composite powder through mixing. Thus, the obtained metal-based composite (i.e., titanium-based composite mixture) has a spatial multi-level network structure formed by the first network structure and the second network structure.

[0060] It should be understood that in step (2), after the nano-scale reinforcement phase powder and the first composite powder are ball-milled, the nano-scale reinforcement phase powder is coated on the surface of the composite powder, and the nano-powder on the surface forms a network structure by applying temperature and pressure during mixing. It should be understood that the temperature applied during the mixing process is far from the melting point of the nano-powder (for example, the melting point of TiC is above 3000 degrees Celsius), so it will not react with the composite, but the surface nano-reinforcement phase undergoes a solid phase transition.

[0061] Through the above method, the reinforcing phase can be distributed at the grain boundary position, thereby forming a spatial multi-level network structure; the network-distributed reinforcing phase precipitated at the grain boundary can improve the grain boundary strengthening effect, effectively inhibit the high-temperature grain boundary weakening effect, thereby effectively inhibiting the grain growth during high-temperature heat treatment and high-temperature service, and improving the high-temperature resistance of the component.

[0062] At the same time, the whisker-like reinforcement phase plays the role of pins, effectively connecting adjacent matrix particles, increasing the coordinated deformation ability between small units, effectively inhibiting necking, and improving the plasticity and deformation ability of composite materials. The grain boundary strengthening effect of the micron-scale reinforcement phase distributed at the grain boundary and the pinning effect of the nano-scale reinforcement phase at the grain boundary work together to achieve better grain boundary strengthening and effectively inhibit grain growth.

[0063] The metal-based composite material in which nanoscale and microscale coexist is prepared by the method of the present invention. On the one hand, when the first metal powder (such as TC4) is mixed with the first reinforcing phase powder (such as TiB2, TiC) and then a cast metal-based composite rod is prepared by VAR, the reinforcing phase grains inside the metal matrix (TC4) are relatively coarse and cannot achieve an ideal uniform distribution; further, through the plasma rotating electrode atomization powder making process, the heat melting, centrifugal force, rapid solidification and other effects in the powder making process are utilized to make the size of the reinforcing phase further reduced and distributed at the grain boundary to form a primary network structure, wherein the radial migration of the reinforcing phase is driven by centrifugal force in the PREP powder making process, while the rapid solidification inhibits the re-diffusion of particles, and the two together realize the spatial locking of the reinforcing phase; on the other hand, based on the composite powder obtained by powder making, after further ball milling and mixing with the nanoscale second reinforcing phase powder, a layer of nanoscale second reinforcing phase powder is coated on the surface of the composite powder. During mixing, the nanoscale reinforcing phase powder forms a layer of macroscopic second mesh structure on the surface of the composite powder to realize a spatial multi-level network structure.

[0064] Thus, in the metal-based composite material obtained by the present invention in which nano-scale and micro-scale coexist, the large number of pinning points of the nano-scale reinforcement phase can prevent the migration of the grain boundary, and the position of the micron-scale reinforcement phase at the grain boundary is more stable, and it is not easy to change position or be destroyed due to the movement of the grain boundary, so as to better play its grain boundary strengthening role; at the same time, the nano-scale reinforcement phase hinders the dislocation movement mechanism, so that the material forms more crystal nuclei during solidification or heat treatment, thereby refining the grains, so that the micron-scale reinforcement phase has more opportunities to be distributed on the grain boundary, thereby increasing the area and opportunity for the micron-scale reinforcement phase to play a role, and further indirectly promotes the role of the micron-scale reinforcement phase. At the same time, the presence of the nano-scale reinforcement phase will further increase the difficulty of dislocations bypassing or passing through the micron-scale reinforcement phase, making the micron-scale reinforcement phase more effective in hindering dislocation movement, thereby improving the mechanical properties of the material such as strength and hardness.

[0065] In this way, the mechanical properties of the material can be significantly improved.

[0066] (3) Wire making: The titanium-based composite material mixture prepared in step (2) is passed through a granulator to obtain a feed material, and the obtained feed material is subjected to a drawing or extrusion process to prepare a titanium-based composite wire material for subsequent FDM printing.

[0067] At the same time, the titanium alloy powder pretreated in step (1) is mixed and kneaded with the second binder in a mass ratio of (8:1) to (17:3), and then passed through a granulator to obtain a feed material, and the obtained feed material is further prepared into a titanium alloy wire through a drawing or extrusion process.

[0068] It should be understood that the granulation, drawing and extrusion processes can be implemented according to existing equipment and processes.

[0069] (4) FDM printing: Use a dual-nozzle multi-channel wire feeding device for metal molten deposition additive manufacturing, that is, the dual nozzles respectively feed the titanium alloy wire and titanium-based composite wire prepared above, and print in an alternating cycle of titanium alloy layer-titanium-based composite layer to prepare a green body layer by layer on the substrate.

[0070] In this example, the alternating cycle of titanium alloy layer and titanium-based composite material layer is taken as an example for implementation.

[0071] In the embodiment of the present invention, the processing temperature of the FDM process is low and does not reach the melting point of the material, so the spatial multi-level grid structure will not be destroyed, so that the reinforcement phase can retain the formed grid structure in the printed component.

[0072] Moreover, the metal layer has good ductility and toughness, and can absorb a large amount of energy when subjected to external force, thereby effectively preventing the expansion of cracks. The reinforcement phase in the metal-based composite layer can effectively transfer the load to the matrix, thereby improving the strength and stiffness of the material. Therefore, through the multi-scale spatial network distribution reinforcement phase structure designed by the present invention, more efficient load transfer and stress dispersion can be achieved, further improving the performance of the material;

[0073] In the embodiment of the present invention, FDM printing can give full play to the toughening effect of metal and the strengthening effect of composite materials by printing in an alternating cycle of metal layers and metal-based composite layers, significantly improving the performance of components, and at the same time effectively preventing crack propagation, so that the reinforcement can play an effective role, ensuring good high temperature resistance and toughness while meeting the high strength requirements of the components.

[0074] (5) Post-processing: The substrate and the green body formed by FDM printing are subjected to thermal debinding, sintering, and hot isostatic pressing in sequence.

[0075] Among them, the binder in the molded blank is removed by degreasing, and then the internal structure of the blank is improved by sintering to enhance the density and strength of the structure.

[0076] After sintering, hot isostatic pressing treatment is carried out. Through the combination of high temperature and high pressure, the pores that still exist after sintering can be effectively closed, the defects inside the material can be reduced, the densification of the material can be further promoted, and the grains can be refined, thereby significantly improving the overall performance of the material and making it more suitable for applications in harsh environments such as high temperature and high pressure.

[0077] Finally, the substrate is cut to obtain a complete metal matrix composite component.

[0078] It can be understood that the aforementioned metal types include but are not limited to titanium alloys.

[0079] As an optional example, the types of the two reinforcing phase powders with different particle sizes may be the same or different, but both are substances that can form a solid solution with the metal powder.

[0080] In a more specific example, the types of the first reinforcing phase include one or more of borides, carbides, nitrides, oxides, for example, one or more of TiC, TiB2 and WC, and the particle size range of the first reinforcing phase powder is micron level, and the particle size is particularly selected to be 10μm to 15μm.

[0081] In a more specific example, the types of the second reinforcing phase include one or more of borides, carbides, nitrides, oxides, for example, one or more of TiC, TiB2 and WC, and the particle size range of the second reinforcing phase powder is nanometer scale, and the particle size is particularly selected to be 30nm to 50nm.

[0082] As an optional example, the first binder includes at least one of polyoxymethylene (POM), ethylene (PE) or stearic acid (SA), wherein the mass ratio of POM, PE and SA is (12-16):(2-6):(1-2);

[0083] As an optional example, the second binder includes at least one of polyoxymethylene (POM), ethylene (PE) or stearic acid (SA), wherein the mass ratio of POM, PE and SA is (12-16):(2-6):(1-2).

[0084] In an optional embodiment, the components of the first binder and the second binder may be the same components and / or proportions, or different components and / or proportions may be selected according to actual conditions.

[0085] As an optional example, the metal molten deposition process is configured to determine parameters according to the parameters of the titanium alloy component, and to set a printing program accordingly to perform printing and molding of the component.

[0086] In a more specific example, specific parameters of the metal molten deposition process include:

[0087] Metal layer printing parameters: nozzle diameter 0.4mm, nozzle temperature 200℃~250℃, printing speed 10mm / s~30mm / s;

[0088] Printing parameters of metal-based composite layer: nozzle diameter 0.4mm, nozzle temperature 170℃~190℃, printing speed 30mm / s~70mm / s.

[0089] It is understandable that the metal molten deposition equipment can be a commercially available FDM equipment. Particularly preferably, in order to improve production efficiency, a dual-nozzle multi-channel wire feeding FDM printing equipment can also be directly used.

[0090] As an optional example, the substrate used in the FDM process particularly needs to be pre-treated by placing the substrate in an ultrasonic cleaner, polishing and cleaning the substrate with anhydrous ethanol, and sandblasting the substrate.

[0091] In various embodiments of the present invention, unless otherwise specified, the aforementioned powder particle size refers to the median particle size of the powder.

[0092] For better understanding, the present invention is further described below in conjunction with specific examples, but the preparation process is not limited thereto, and the content of the present invention is not limited thereto.

[0093] Unless otherwise specified, the materials in the examples were prepared according to existing methods or directly purchased from the market.

[0094] In the following example, the printed component is a cuboid with dimensions of 100mm*15mm*10mm (length*width*height).

[0095] Example 1

[0096] (1) TC4 powder (as the first metal powder, the particle size is selected between 75 μm and 150 μm, which is insensitive to the particle size tolerance of the raw material powder) and TiC powder (micron-grade powder particle size: 10 μm to 15 μm, nano-grade powder particle size: 30 nm to 50 nm) are heated at 120°C for 4 h to eliminate moisture in the powder.

[0097] (2) The pretreated part of TC4 powder was mixed with micron-sized TiC powder (mass ratio 9:1) by a planetary ball mill at a speed of 230 rpm for 5 h (powder-ball ratio 1:10), and a cast composite material blank was prepared by a vacuum consumable melting process (parameters are shown in Table 1), and a rod blank with a diameter of 50 mm was made. The first composite powder was obtained by using a plasma rotating electrode atomization powder making technology (parameters are shown in Table 2). The first composite powder was then mixed with nanoscale TiC powder (mass ratio 9:1) by a planetary ball mill at a speed of 230 rpm for 5 h (powder-ball ratio 1:10) to obtain a second composite powder coated with nanoscale TiC powder.

[0098] The second composite powder and the binder (the mass ratio of POM, PE and SA is 6:3:1) are mixed in a ratio of 85:15, the mixing temperature is 190°C, the mixing time is 120min, and the rotation speed is 145r / min to obtain a titanium-based composite with a spatial multi-level network structure.

[0099] Table 1

[0100] Melting current 20kA Melting voltage 33V Arc stability 6A Vacuum degree <![CDATA[<1*10 -2 Well]]>

[0101] Table 2

[0102] Electrode speed 2000rpm Plasma power 50kW Atomizing gas High purity argon (purity ≥ 99.999%) Atomizing gas flow 45L / min Atomizing gas pressure 1.3mm / min

[0103] (3) The titanium-based composite material obtained by mixing was extruded through a single screw extruder at an extrusion temperature of 185°C, and pelletized after extrusion to obtain feed; the obtained feed was prepared into titanium-based composite wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0104] The TC4 powder pretreated in (1) and the binder (POM, PE and SA in a mass ratio of 6:3:1) were added to a kneader in a ratio of 85:15 for mixing at a mixing temperature of 190°C, a mixing time of 120 min and a rotation speed of 145 r / min; the mixed mixture was then extruded through a single screw extruder at an extrusion temperature of 185°C, and pelletized after extrusion to obtain a feed; the obtained feed was prepared into a titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0105] (4) Pre-treating the TC4 substrate, placing the substrate in an ultrasonic cleaner, polishing and cleaning the substrate with anhydrous ethanol, and sandblasting the substrate. After that, using a dual-nozzle multi-channel wire feeding method for metal molten deposition additive manufacturing, the dual nozzles are used to respectively deliver the TC4 wire and the titanium-based composite wire obtained in the above steps, and a spiral filling path is used on the substrate to print the component with a layer height of 0.2 mm. The green body is obtained by printing layer by layer in an alternating cycle of TC4 wire and titanium-based composite wire.

[0106] Metal layer printing parameters: nozzle diameter 0.4mm, nozzle temperature 200℃, printing speed 30mm / s;

[0107] Printing parameters of the metal-based composite layer: nozzle diameter 0.4 mm, nozzle temperature 170 °C, printing speed 50 mm / s.

[0108] (5) The TC4 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After the treatment, the substrate and the component are separated using a wire cutting machine.

[0109] Table 3

[0110] step temperature Pressure / Atmosphere time Thermal degreasing 400℃ <![CDATA[Ar / vacuum (10 -2 Pa)]]> 4h sintering 1200℃ <![CDATA[Vacuum (10 -3 Pa)]]> 6h Hot Isostatic Pressing (HIP) 980℃ 120MPa (Ar medium) 3h

[0111] Example 2

[0112] (1) Ti65 powder (particle size: 75 μm to 150 μm) and TiB2 powder (micron-sized powder particle size: 10 μm to 15 μm, nano-sized powder particle size: 30 nm to 50 nm) were heated at 120°C for 4 h to eliminate moisture in the powder.

[0113] (2) The pretreated Ti65 powder and micron-sized TiB2 powder (mass ratio 9:1) were mixed by a planetary ball mill at a speed of 230 rpm for 5 h (powder-ball ratio 1:10), and a cast composite material blank was prepared by a vacuum consumable melting process (parameters are shown in Table 1) to make a composite rod blank with a diameter of 50 mm; then the plasma rotating electrode atomization powder making technology was used to make powder (parameters are shown in Table 2) to obtain the first composite powder; then the obtained first composite powder was mixed with nanoscale TiB2 powder (mass ratio 9:1) by a planetary ball mill at a speed of 230 rpm for 5 h (powder-ball ratio 1:10) to obtain a second composite powder coated with nanoscale TiB2 powder.

[0114] The second composite powder and the binder (the mass ratio of POM, PE and SA is 6:3:1) are added to a kneader in a ratio of 85:15 for mixing. The mixing temperature is 190°C, the mixing time is 120min, and the rotation speed is 145r / min to obtain a titanium-based composite (mixture) with a spatial multi-level network structure.

[0115] (3) The kneaded titanium-based composite mixture was extruded through a single screw extruder at an extrusion temperature of 185°C, and pelletized to obtain feed material after extrusion; the obtained feed material was prepared into titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0116] The Ti65 powder pretreated in (1) and the binder (POM, PE and SA in a mass ratio of 6:3:1) were added to a kneader in a ratio of 85:15 for mixing. The mixing temperature was 190°C, the mixing time was 120 min, and the rotation speed was 145 r / min. The mixed mixture was extruded through a single screw extruder at an extrusion temperature of 185°C. After extrusion, the mixture was granulated to obtain a feed material. The obtained feed material was prepared into a titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0117] (4) A Ti65 substrate was placed in an ultrasonic cleaner, and anhydrous ethanol was used to polish and clean the substrate, and the substrate was sandblasted. After that, a double nozzle multi-channel wire feeding was used for metal molten deposition additive manufacturing. The double nozzles were used to respectively deliver the Ti65 wire and titanium-based composite wire prepared above, and a serpentine reciprocating filling path was used on the substrate to print the component with a layer height of 0.2 mm. The green body was obtained by printing layer by layer in an alternating cycle of Ti65 wire and titanium-based composite wire.

[0118] Metal layer printing parameters: nozzle diameter 0.4mm, nozzle temperature 200℃, printing speed 30mm / s;

[0119] Printing parameters of the metal-based composite layer: nozzle diameter 0.4 mm, nozzle temperature 170 °C, printing speed 50 mm / s.

[0120] (5) The Ti65 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After treatment, the substrate and the component are separated using a wire cutting machine.

[0121] Example 3

[0122] (1) Ti65 powder (particle size: 75 μm to 150 μm) and WC powder (micron-sized powder particle size: 10 μm to 15 μm, nano-sized powder particle size: 30 nm to 50 nm) were heated at 120 °C for 4 h to eliminate moisture in the powder.

[0123] (2) The pretreated Ti65 powder was mixed with micron-sized WC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10), and a cast composite material blank was prepared by vacuum consumable smelting (parameters are shown in Table 1) to make a rod blank with a diameter of 50 mm; the plasma rotating electrode atomization powder making technology was used to make powder (parameters are shown in Table 2) to obtain a composite powder; the obtained composite powder was then mixed with nano-scale WC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10) to obtain a composite powder with a surface coated with nano-WC powder.

[0124] Then, the composite powder coated with nano WC powder on the surface and the binder (the mass ratio of POM, PE and SA is 6:3:1) are added to the kneader in a ratio of 85:15 for mixing. The mixing temperature is 190°C, the mixing time is 120min, and the rotation speed is 145r / min to obtain a titanium-based composite mixture with a multi-level grid structure.

[0125] (3) The kneaded titanium-based composite mixture was extruded through a single screw extruder at an extrusion temperature of 185°C, and pelletized to obtain feed material after extrusion; the obtained feed material was prepared into titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0126] The Ti65 powder pretreated in (1) and the binder (POM, PE and SA in a mass ratio of 6:3:1) were added to a kneader in a ratio of 85:15 for mixing. The mixing temperature was 190°C, the mixing time was 120 min, and the rotation speed was 145 r / min. The mixed mixture was extruded through a single screw extruder at an extrusion temperature of 185°C. After extrusion, the mixture was granulated to obtain a feed material. The obtained feed material was prepared into a titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0127] (4) A Ti65 substrate was placed in an ultrasonic cleaner, and anhydrous ethanol was used to polish and clean the substrate, and the substrate was sandblasted. After that, a double nozzle multi-channel wire feeding was used for metal molten deposition additive manufacturing. The double nozzles were used to deliver TC4 wire and titanium-based composite wire respectively. A serpentine reciprocating filling path was used on the substrate to print the component with a layer height of 0.2 mm. The green body was obtained by printing layer by layer in an alternating cycle of Ti65 wire and titanium-based composite wire.

[0128] Metal layer printing parameters: nozzle diameter 0.4mm, nozzle temperature 200℃, printing speed 30mm / s;

[0129] Printing parameters of the metal-based composite layer: nozzle diameter 0.4 mm, nozzle temperature 170 °C, printing speed 50 mm / s.

[0130] (5) The Ti65 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After treatment, the substrate and the component are separated using a wire cutting machine.

[0131] Comparative Example 1

[0132] (1) TC4 powder (particle size: 75 μm to 150 μm) and TiC powder (micron-sized powder particle size: 10 μm to 15 μm, nano-sized powder particle size: 30 nm to 50 nm) were heated at 120°C for 4 h to eliminate moisture in the powder.

[0133] (2) The pretreated TC4 powder and micron-sized TiC powder (mass ratio 9:1) were mixed by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10), and the obtained mixed powder was mixed with nano-sized TiC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10), and then the obtained composite powder and binder (POM, PE and SA mass ratio of 6:3:1) were added to a kneader at a ratio of 85:15 for mixing, and the mixing temperature was 190 ° C, the mixing time was 120 min, and the speed was 145 r / min. Then, the mixed mixture was extruded by a single screw extruder at an extrusion temperature of 185 ° C, and pelletized after extrusion to obtain feed; the obtained feed was prepared into titanium-based composite wire (diameter 1.75 mm, tolerance ± 0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300 ° C, sizing band 2 mm).

[0134] The TC4 powder pretreated in (1) and a binder (POM, PE and SA in a mass ratio of 6:3:1) were added to a kneader in a ratio of 85:15 for mixing. The mixing temperature was 190°C, the mixing time was 120 min, and the rotation speed was 145 r / min. The mixed mixture was extruded through a single screw extruder at an extrusion temperature of 185°C. After extrusion, the mixture was granulated to obtain a feed material. The obtained feed material was prepared into a titanium alloy wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0135] (3) A TC4 substrate was placed in an ultrasonic cleaner, and anhydrous ethanol was used to polish and clean the substrate, and the substrate was sandblasted. After that, a double nozzle multi-channel wire feeding was used for metal molten deposition additive manufacturing, that is, the double nozzles respectively delivered TC4 wire and titanium-based composite wire, and a spiral filling path was used on the substrate to print the component with a layer height of 0.2 mm. The green body was obtained by printing layer by layer in an alternating cycle of Ti65 wire and titanium-based composite wire.

[0136] Metal layer printing parameters: nozzle diameter 0.4mm, nozzle temperature 200℃, printing speed 30mm / s;

[0137] Printing parameters of the metal-based composite layer: nozzle diameter 0.4 mm, nozzle temperature 170 °C, printing speed 50 mm / s.

[0138] (4) The TC4 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After the treatment, the substrate and the component are separated using a wire cutting machine.

[0139] Comparative Example 2

[0140] (1) TC4 powder (particle size: 75 μm to 150 μm) and TiC powder (micron-sized powder particle size: 10 μm to 15 μm, nano-sized powder particle size: 30 nm to 50 nm) were heated at 120°C for 4 h to eliminate moisture in the powder.

[0141] (2) The pretreated TC4 powder was mixed with micron-sized TiC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10), and a cast composite material blank was prepared by vacuum consumable smelting (parameters are shown in Table 1) to make a rod blank with a diameter of 50 mm; then the plasma rotating electrode atomization powder making technology was used to make powder (parameters are shown in Table 2) to obtain a composite powder; then the obtained composite powder was mixed with nano-scale TiC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10) to obtain a titanium-based composite powder with a layer of nano-scale reinforced powder on the surface.

[0142] The titanium-based composite powder coated with a layer of nano-scale reinforced powder on the surface was mixed with a binder (the mass ratio of POM, PE and SA was 6:3:1) in a ratio of 85:15, the mixing temperature was 190°C, the mixing time was 120 min, and the rotation speed was 145 r / min to obtain a titanium-based composite with a spatial multi-level network structure.

[0143] (3) A TC4 substrate was placed in an ultrasonic cleaner, polished and cleaned with anhydrous ethanol, and sandblasted. Then, a powder feeding laser cladding process was used, and a spiral filling path was used with a layer height of 0.2 mm to alternately deposit a metal layer (printed with pretreated TC4 powder) and a composite layer (printed with titanium-based composite powder having a spatial multi-level network structure) on the TC4 substrate until a green body was obtained.

[0144] The specific process parameters of printing are: laser power 2000W, scanning speed 20mm / s, overlap rate 40%, and powder feeding rate 35g / min.

[0145] (4) The TC4 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After the treatment, the substrate and the component are separated using a wire cutting machine.

[0146] Comparative Example 3

[0147] (1) TC4 powder (particle size: 75 μm to 150 μm) and TiC powder (micron-sized powder particle size: 10 μm to 15 μm, nano-sized powder particle size: 30 nm to 50 nm) were heated at 120°C for 4 h to eliminate moisture in the powder.

[0148] (2) The pretreated TC4 powder was mixed with micron-sized TiC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10), and a cast composite material blank was prepared by vacuum consumable smelting (parameters are shown in Table 1), and a rod blank with a diameter of 50 mm was made. The powder was powdered using plasma rotating electrode atomization powder making technology (parameters are shown in Table 2), and the obtained composite powder was mixed with nano-scale TiC powder (mass ratio 9:1) by a planetary ball mill at 230 rpm for 5 h (powder-ball ratio 1:10) to obtain a titanium-based composite powder with a layer of nano-scale reinforced powder on the surface.

[0149] The titanium-based composite powder and the binder (the mass ratio of POM, PE and SA is 6:3:1) are added to a kneader in a ratio of 85:15 for mixing. The mixing temperature is 190°C, the mixing time is 120 min, and the rotation speed is 145 r / min to prepare a titanium-based composite with a multi-level grid structure.

[0150] (3) The kneaded mixture was extruded through a single screw extruder at an extrusion temperature of 185°C, and pelletized after extrusion to obtain a feed; the obtained feed was prepared into a titanium-based composite wire (diameter 1.75 mm, tolerance ±0.02 mm) by drawing (drawing speed 20 mm / s, drawing temperature 300°C, sizing band 2 mm).

[0151] (4) A TC4 substrate was placed in an ultrasonic cleaner, and the substrate was polished and cleaned with anhydrous ethanol, and the substrate was sandblasted. After that, metal molten deposition additive manufacturing was performed, and titanium-based composite wire was delivered. A spiral filling path was used on the substrate to print the component with a layer height of 0.2 mm to obtain a green body.

[0152] Printing parameters of the metal-based composite layer: nozzle diameter 0.4 mm, nozzle temperature 170 °C, printing speed 50 mm / s.

[0153] (6) The TC4 substrate and the green body are subjected to thermal debinding, sintering, and hot isostatic pressing treatment in sequence (parameters are shown in Table 3). After the treatment, the substrate and the component are separated using a wire cutting machine.

[0154] Performance Testing

[0155] The performance tests were performed on the samples obtained from Examples 1-3 and Comparative Examples 1-3, and the results are shown in Table 4.

[0156] Table 4

[0157]

[0158] It can be seen from the test results that the metal-based composite components prepared by the method of the present invention have better strength, high temperature resistance and toughness, and can meet the needs of components that serve at high temperatures and require high strength.

[0159] At the same time, by comparing Comparative Example 1 with Example 1, it can be seen that the conventional method of mixing the reinforcing phase does not form a multi-level network structure, resulting in weak interface bonding between the matrix and the reinforcing phase, low stress transfer efficiency, and significantly reduced mechanical properties. Moreover, the lack of reinforcing phase at the grain boundary at high temperature inhibits grain growth and has poor heat resistance.

[0160] By comparing Comparative Example 2 with Example 1, it can be seen that high-temperature printing causes the reinforcing phase to remelt and agglomerate, destroying the spatial multi-level grid, resulting in strength loss and reduced toughness, and the high-temperature performance deteriorates due to the failure of grain boundary strengthening.

[0161] By comparing Example 3 with Example 1, it can be seen that the single composite layer structure has insufficient effect of dispersing thermal stress and insufficient interlayer bonding strength, and cannot fully exert the toughening effect of the metal and the strengthening effect of the composite material, resulting in reduced toughness and reduced high temperature stability.

[0162] In summary, the present invention significantly improves the comprehensive performance of the metal matrix composite material by optimizing the multi-level network structure and preparation process of the reinforcement, especially showing excellent effects in high temperature strength and toughness.

[0163] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for preparing a metal-based composite component having a spatial multi-level reinforced heterogeneous structure based on metal molten deposition, characterized in that: The following steps are involved: S1. Raw material preparation The pretreated first metal powder is mechanically mixed with the first reinforcement phase powder, and a cast metal-based composite rod blank is prepared by vacuum autoclave smelting (VAR); the cast metal-based composite rod blank is then used as a raw material for PREP powder making to obtain a first composite powder, wherein the first reinforcement phase is refined and distributed at the grain boundaries of the matrix through PREP powder making to form a first network structure; Mechanically mixing and ball-milling the first composite powder and the pretreated second reinforcement phase powder, so that the surface of the first composite powder is covered with the nano-scale second reinforcement phase powder, to obtain a second composite powder; The second composite powder and the first binder are mixed and kneaded in proportion, so that the second reinforcement phase forms a second network structure on the surface of the second composite powder, thereby obtaining a metal-based composite material having a spatial multi-level network structure, wherein the spatial multi-level network structure is formed by the first network structure and the second network structure; Using the metal-based composite material with a spatial multi-level network structure to make wires, to obtain metal-based composite wires; The pretreated second metal powder is mixed with the second binder in a certain proportion to prepare a metal wire material; S2, Metal Melt Deposition Additive Using the metal wire and the metal-based composite wire as raw materials, adopting a metal melting deposition process, depositing layer by layer from the first layer to the last layer on the substrate in a metal layer-metal-based composite layer or metal-based composite layer-metal layer alternating cycle according to a preset program, to obtain a composite green body; S3, post-processing The composite green body is subjected to thermal degreasing, sintering and hot isostatic pressing treatments in sequence to obtain a metal-based composite component.

2. The preparation method according to claim 1, characterized in that: The first reinforcement phase powder is micron-sized.

3. The preparation method according to claim 1, characterized in that: The second reinforcement phase powder is nanometer-sized.

4. The preparation method according to claim 1, characterized in that: The mass ratio of the first reinforcing phase powder to the first metal powder is 1:(9-49), wherein the type of the first reinforcing phase powder is selected based on the principle that it can be dissolved with the first metal powder to form a reinforcing phase.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the second reinforcing phase powder to the first composite powder is 1:(9-49), wherein the type of the second reinforcing phase powder is selected based on the principle that it can be solid-dissolved with the first composite powder to generate a reinforcing phase.

6. The preparation method according to claim 1, characterized in that: The types of the first reinforcement phase powder and the second reinforcement phase powder include one or more of borides, carbides, nitrides, and oxides.

7. The preparation method according to claim 6, characterized in that: The first reinforcement phase powder and the second reinforcement phase powder are one or more of TiC, TiB2 and WC.

8. The preparation method according to claim 1, characterized in that: The first metal powder and the second metal powder are metal powders of the same brand.

9. The preparation method according to claim 1 or 8, characterized in that: The metal types of the first metal powder and the second metal powder are both selected from titanium alloys.

10. The preparation method according to claim 1, characterized in that: The first binder and the second binder are both selected from at least one of polyoxymethylene (POM), ethylene (PE) or stearic acid (SA).

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