Preparation of continuous core mesh structure wire of titanium matrix composites for fused filament additive manufacturing

Abstract

The present invention discloses a method for preparing a continuous core mesh structure wire of a titanium-based composite material for use in fused filament additive manufacturing. The method comprises the following steps: using a titanium ribbon as an outer titanium shell and a fine mesh titanium-based composite powder as a filler powder; sealing and rolling the titanium shell and filler powder, and drawing and reducing the diameter to form a continuous core mesh structure wire, and then using a fused filament additive manufacturing method to prepare an in-situ self-reinforced titanium-based composite material. This method fully utilizes the in-situ self-reinforcement reaction of the reinforcement of the continuous core mesh structure wire during the solidification process, refines the matrix grains, and precisely controls the microstructure and the size and distribution of the reinforcements. This method can improve the comprehensive mechanical properties of additively manufactured titanium-based composite materials. This method has the advantages of high design freedom and high material utilization, and provides a new method for the integrated preparation of complex components made of difficult-to-deform titanium-based composite materials.

Description

Technical Field

[0001] The present invention relates to the technical field of metal-based composite materials, and in particular to a method for preparing a titanium-based composite material continuous core mesh structure wire for fused filament additive manufacturing. Background Art

[0002] The next generation of high-end aerospace equipment faces extremely harsh conditions such as ultra-high temperatures, high overloads, and severe vibrations, necessitating the development of lightweight, high-strength, and heat-resistant new materials and related integrated manufacturing technologies. Titanium-based composites (TMCs) are discontinuously reinforced titanium-based composites (TMCs) created by introducing a multi-dimensional, multi-scale whisker and / or granular ceramic reinforcement into a titanium alloy matrix and regulating their spatially ordered arrangement. These composites exhibit excellent mechanical properties such as high specific strength, high stiffness, wear resistance, and high-temperature resistance, and are therefore suitable for high-end aerospace equipment.

[0003] Additive manufacturing technology, through its layered slicing and layer-by-layer deposition process based on three-dimensional models, enables the integrated formation of parts with complex geometries, offering advantages such as high design freedom, high material utilization, and high precision. Additive manufacturing technologies for metal materials can be categorized into three types: laser, electron beam, and arc additive manufacturing, depending on the heat source. These technologies are widely used in the manufacture of large or complex components. The free-forming and near-net-shape properties of additive manufacturing technology provide a historic opportunity for the integrated material-structure-performance formation of lightweight, high-strength, and difficult-to-deform titanium-based composite components.

[0004] Currently, the raw materials used in additive manufacturing of titanium-based composites (TMCs) primarily come from powder materials, suitable for laser and electron beam additive manufacturing (EBAM). While powder materials offer the advantage of high forming precision, they also suffer from low deposition efficiency, low material utilization, and high cost. Common methods for powder pretreatment include mechanical ball milling, electrochemical deposition, and chemical vapor deposition (CVD). These methods embed or adsorb reinforcement reactants onto the surface of titanium alloy powders through physical or chemical means, aiming to form reinforcements through in-situ autogenous reactions during the AM process. However, mechanical ball milling is prone to introducing impurities such as H and O, while electrochemical deposition and CVD struggle to ensure uniformity of the reinforcements on the surface of the titanium alloy powders. These shortcomings in process preparation and powder pretreatment limit the AM of TMCs using powder materials. In comparison, fused filament AM offers advantages such as high deposition efficiency (5 kg / h) and dense microstructure, making it particularly suitable for the efficient and high-quality manufacture of large-scale structural components. However, high-strength titanium-based composite materials are almost impossible to draw into wires due to their low slip number (the α phase is an HCP structure), easy mismatch between the reinforcement interface, and low plasticity. Currently, there is little research on the design and preparation technology of titanium-based composite wires. Therefore, how to prepare high-quality titanium-based composite wires and achieve stable fused filament additive manufacturing of lightweight, high-strength, and difficult-to-deform titanium-based composite components by regulating the matrix structure and reinforcement size distribution has become a focus of researchers.

[0005] Research on fused wire additive manufacturing (FAM) of metal-based composites and alloys has made some progress. For example, patent CN115156551A discloses a method and system for arc additive manufacturing of particle-reinforced aluminum-based composites. This patent uses in-situ TiC particle-reinforced Al-6.3Cu alloy wire and ER2319 Al-6.3Cu alloy wire as additive manufacturing raw materials to produce particle-reinforced aluminum-based composites. This method prepares a particle-reinforced aluminum-based composite ingot and directly draws it into a wire raw material for FAM. However, for titanium-based composites, the α phase in the titanium alloy matrix has a close-packed hexagonal structure with few slip systems and is difficult to deform. Cracking and brittle fracture are prone to occur during the drawing process, making it difficult to directly use the "melt casting and wire drawing" method for additive manufacturing. Patent CN115781105A discloses a titanium alloy flux-cored welding wire, its flux core, and a preparation method. This method mixes corresponding powder components, including 20-30 parts aluminum powder, 50-60 parts vanadium metal, 35-45 parts chromium metal, 25-35 parts zirconium metal, 0.8-1.2 parts iron powder, and 25-35 parts molybdenum powder, as filling powder. The titanium alloy flux-cored welding wire is obtained by drying the flux core, rolling the flux coating into a U-shaped groove, filling the flux powder, closing the flux coating, reducing the diameter, drawing, and winding. However, this method can only produce titanium alloy flux-cored welding wire, and cannot produce titanium-based composite material wire. At the same time, the uniformity of the powder mixture in this method will significantly affect the uniformity of the weld composition and structure based on this welding wire. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies and provides a method for preparing continuous core mesh wires of titanium-based composite materials for use in fused filament additive manufacturing (FAM). This method facilitates the direct production of high-strength and high-toughness titanium-based composite materials and their large-scale components using FAM, and has significant application value in critical equipment applications such as aerospace.

[0007] The present invention is achieved through the following technical solutions:

[0008] The present invention provides a method for preparing a titanium-based composite material continuous core mesh structure wire for fused filament additive manufacturing, comprising the following steps:

[0009] A. Use pure titanium strip or titanium alloy strip as the outer titanium shell;

[0010] B. Use titanium-based composite material powder embedded with fine mesh reinforcement as internal filling powder;

[0011] C. Rolling the titanium shell and the inner filling powder into a sealed shape, and then drawing and reducing the diameter to form a continuous core mesh structure wire;

[0012] D. Use fused filament additive manufacturing method to prepare in-situ reinforced titanium-based composite materials.

[0013] As an embodiment of the present invention, the thickness of the titanium strip in step A is 0.04 to 0.08 mm.

[0014] As an embodiment of the present invention, the material of the titanium strip includes pure titanium and titanium alloys. In some embodiments, the material of the titanium strip is at least one of Ti6Al4V, Ti-6.5Al-1.5Zr-3.5Mo-0.3Si, and Ti-5.8Al-4Sn-3.5Zr-0.7Nb-0.5Mo-0.35Si.

[0015] As an embodiment of the present invention, in step B, the titanium-based composite material powder has a powder particle size ranging from 53 to 150 μm.

[0016] As an embodiment of the present invention, the matrix of the titanium-based composite material powder comprises pure titanium and titanium alloy, and the matrix is ​​combined with the reinforcement to form the titanium-based composite material.

[0017] As an embodiment of the present invention, the reinforcement phase includes one or more reinforcements such as TiB, TiC and La2O3.

[0018] As an embodiment of the present invention, the titanium-based composite material is TiB / Ti6Al4V, TiC / Ti-6.5Al-1.5Zr-3.5Mo-0.3Si, (TiB+TiC) / Ti6Al4V or (TiB+La2O3) / IMI834.

[0019] As an embodiment of the present invention, the reinforcing phase is distributed in a network-like manner within the titanium-based composite material powder, and the size of the fine network structure is ≤10 μm.

[0020] As an embodiment of the present invention, the volume fraction of the reinforcement phase in the titanium-based composite material wire is 0.1 to 10 vol.%, preferably 0.1 to 5 vol.%.

[0021] As an embodiment of the present invention, the diameter of the continuous core mesh structure wire in step C is 1.2 to 3.0 mm, and the diameter of the unit core mesh is ≤10 μm.

[0022] As an embodiment of the present invention, the drying temperature in the step of preparing the continuous core mesh structure wire material in step C is controlled at 200-400°C.

[0023] As an embodiment of the present invention, the drawing and reducing in step C comprises a method including roller die drawing, fixed die drawing, or a roller die and fixed die combined in series.

[0024] As an embodiment of the present invention, the powder filling rate of the titanium-based composite material in the continuous core mesh structure wire preparation step in step C is 30-45%. If the powder filling amount is too low, pores will exist inside, affecting the subsequent use of the wire. If the powder filling amount is too high, it will cause surface cracks during the wire diameter reduction process.

[0025] As an embodiment of the present invention, in step C, the preparation of the continuous core mesh structure wire material includes the following steps:

[0026] C1. Drying fine mesh titanium-based composite material powder;

[0027] C2. Use roller extrusion to curl the titanium strip into a "U" shape;

[0028] C3. Add the titanium-based composite material powder prepared in step C1 into a U-shaped titanium strip, and squeeze the two sides of the U-shaped titanium strip together to form an O-shaped titanium tube.

[0029] C4. Place the titanium tube directly into the hot rolling die for initial diameter reduction to compact the powder core inside the titanium tube;

[0030] C5. Heating the rolling wheel to 400° C. to 450° C. by online heat treatment annealing, and performing multiple hot rolling to reduce the diameter of the titanium tube filled with the titanium-based composite material powder obtained in step C4 until the diameter reaches the designed size;

[0031] C6. Perform vacuum heat treatment on the titanium tube after the diameter reduction in step C5 to obtain titanium-based composite material wire.

[0032] In step C5, multi-pass hot rolling reduction refers to continuously heating rolling wheels of different reduction sizes (such as two rolling wheels of 3.6mm, two rolling wheels of 3mm, two rolling wheels of 2.5mm, etc.) by induction heating, maintaining the set temperature, and the wire continuously passes through rolling wheels of different reduction sizes, which is a continuous rolling reduction process. The present invention designs the matrix component system and the type of additive of the in-situ self-generated titanium-based composite wire by screening titanium-based composite powders with different reinforcements and volume fractions, as well as pure titanium or titanium alloy titanium strips of different thicknesses. In combination with this process, on the one hand, diameter reduction is achieved, and on the other hand, the effect of stress relief annealing treatment is also achieved. Therefore, it is also called rolling wheel online heating annealing. In some embodiments, it is preferred to set the temperature to 400°C in the first online heating annealing pass, and the temperature increases during each pass, and the online heating annealing temperature is 450°C at the last pass. This solution can achieve a better stress relief annealing effect.

[0033] As an embodiment of the present invention, in step C5, auxiliary argon protection is used during the hot rolling and diameter reducing process.

[0034] As an embodiment of the present invention, in step C6, the vacuum heat treatment is performed at a temperature of 500 to 650° C. for a time of 10 to 30 minutes.

[0035] As an embodiment of the present invention, the fuse additive manufacturing method described in step D includes one of arc fuse additive, laser fuse additive, and electron beam fuse additive.

[0036] The present invention also provides an in-situ self-reinforced titanium-based composite material prepared by the method.

[0037] The method of the present invention designs the matrix component system and additive type of in-situ self-generated titanium-based composite wire by screening titanium-based composite powders with different reinforcements and volume fractions, as well as pure titanium or titanium alloy titanium strips of different thicknesses. The titanium strip is used as an outer shell, and a mesh-structured titanium-based composite powder is embedded therein. The titanium strip is first rolled into a "U" shape, and the titanium-based composite powder is added to the "U"-shaped titanium strip, and sealed and rolled into a titanium tube. The tube is then reduced in diameter by heat treatment, annealing, hot rolling or drawing, and this operation is combined with heat treatment, stress relief, and annealing cycles. Finally, a diameter reduction process is performed to obtain a wire of the desired size. Additive manufacturing is performed based on a continuous core mesh structure wire, and the melting characteristics are controlled by changing the energy and distribution of different heat sources. This solves the problems of expensive powder raw materials, low density of the prepared material, and anisotropy of continuous fiber-reinforced titanium-based composite materials in the existing titanium-based composite additive manufacturing methods.

[0038] In order to achieve the goal of preparing particle-reinforced titanium-based composite materials based on direct additive manufacturing of wire, the present invention adopts titanium-based composite material powder with embedded mesh reinforcement as filling powder, pure titanium or titanium alloy titanium strip as external titanium shell, and prepares titanium-based composite wire with a continuous core network structure of powder particle size based on U-tube rolling-filling powder-rolling sealing-rolling wheel online hot drawing and reducing diameter-annealing-winding and other process operations, so as to realize the preparation of titanium-based composite material components with controllable wire structure and adjustable reinforcement and alloy composition.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The present invention can design the matrix component system and the type of additive of in-situ self-generated titanium-based composite wire by screening titanium-based composite powders with different reinforcements and volume fractions, as well as pure titanium or titanium alloy strips of different thicknesses. It has the advantages of high design freedom and high material utilization rate, solves the problem of preparing titanium-based composite wires with difficult deformation and low plasticity of titanium alloys, and prepares titanium-based composite wires with a continuous core mesh structure.

[0041] (2) Compared with powder-based additive manufacturing processes, wire-based additive manufacturing has the advantages of high efficiency, high densification and low cost, and is also suitable for the integrated forming of large structural parts;

[0042] (3) The present invention is applicable to various types of unit-reinforced titanium-based composite materials, as well as titanium-based composite materials containing mixed reinforcements of different reinforcements, such as TiB, TiB+TiC and other TiB+La2O3 mixed reinforcement series;

[0043] (4) The present invention is applicable to pure titanium or titanium alloy substrates, including Ti, Ti-6Al-4V and Ti60, and has a wide range of applications;

[0044] (5) The present invention is applicable to various additive manufacturing processes carried out under high-energy heat sources, such as arc additive manufacturing, laser additive manufacturing, and electron beam additive manufacturing, and realizes the integrated design and preparation of titanium-based composite materials based on wire materials;

[0045] (6) Based on the continuous core mesh structure titanium-based composite material wire of the present invention, the melting, solidification and deposition processes are carried out layer by layer by additive manufacturing, and reinforcements of different types and sizes are generated in situ inside the titanium alloy by in-situ chemical reaction, thereby avoiding poor interface wettability and interface contaminants, improving the interface bonding strength between the reinforcement and the matrix, and obtaining an in-situ self-generated shape-controllable high-strength and tough titanium-based composite material;

[0046] (7) During the fused filament additive manufacturing process, the in-situ autogenous reaction of titanium-based composite material wire-powder is used to refine the matrix grains and reinforcement size, thereby achieving precise control of the reinforcement size distribution, thereby significantly improving the strength and toughness of the additively manufactured titanium-based composite material;

[0047] (8) The process of CN115781105A cannot overcome the problem of titanium alloy being difficult to deform. The reason is that when the filling powder is a titanium alloy powder with embedded reinforcement, its powder properties such as powder fluidity, surface hardness, and deformation are significantly different from those of the mixed powder of CN115781105A, as well as traditional low-carbon steel and aluminum alloys with good plasticity and toughness. The high yield stress of the powder leads to severe shrinkage deformation during the rolling and reducing process, which easily causes stress concentration and local fracture of the pure titanium coating. However, the present invention reduces dislocation pile-up and stress concentration during the high-temperature reducing process through online heat treatment of the rolling wheel and multiple annealing, and improves it by auxiliary multiple annealing during the online hot drawing and reducing process of the rolling wheel, including online heating annealing of the rolling wheel and overall annealing after reducing, so as to overcome the fracture problem caused by stress concentration during the deformation of the titanium alloy and achieve optimized preparation of titanium-based composite wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0049] Figure 1 Schematic diagram of the synthesis of continuous core network structure titanium-based composite wire based on the selected titanium strip and titanium-based composite powder with embedded mesh reinforcement according to the process of sealed rolling-drawing-online heat treatment-annealing;

[0050] Figure 2The prepared 2vol TiB+TiC / TC4 continuous core network structure titanium-based composite wire; (a) is the macroscopic morphology of the wire, (b) and (c) are the macroscopic morphology and local magnified images of the wire cross section, respectively, (d) is the magnified image of the filling powder, (e) and (f) are the metallographic images of the wire cross section and the distribution of the local network reinforcement, (g) is the schematic diagram of the three-dimensional morphology of the powder and the height difference distribution of the sample;

[0051] Figure 3 Schematic diagram of the fused wire additive manufacturing process for in-situ reinforced titanium-based composites using continuous core mesh titanium-based composite wire. 1- welding gun, 2- continuous core mesh titanium-based composite wire, 3- wire feed nozzle, 4- in-situ reinforced titanium-based composite, 5- substrate.

[0052] Figure 4 The internal organization diagram of the titanium-based composite material prepared based on the continuous core mesh structure titanium-based composite material wire; wherein, (a) is the internal organization in Example 2, and (b) is the internal organization in Comparative Example 2. DETAILED DESCRIPTION

[0053] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0054] Example 1

[0055] This embodiment provides a method for additive manufacturing of titanium-based composite materials based on continuous core mesh structure wire. The preparation process is shown in FIG. Figure 1 ; including the following steps:

[0056] A. First, clean a 0.04 mm thick titanium strip with a mixture of NaOH and acetone, then rinse with clean water, and then ultrasonically clean it with a mixed aqueous solution of HF and HNO3 to obtain a cleaned TA1 titanium strip; the mass fraction of NaOH in the mixed aqueous solution of NaOH and acetone used is 15%, the mass fraction of acetone is 85%, the mass fraction of HF in the mixed aqueous solution of HF and HNO3 is 5%, and the mass fraction of HNO3 is 35%. Ultrasonic cleaning is performed for 2 minutes at a frequency of 20 kHz.

[0057] B. A 2.5 vol.% TiB+2.5 vol.% TiC-reinforced TC4 composite material powder (5 vol TiB+TiC / TC4) prepared by an atomization method was selected and vibrated to select a powder with a particle size of 53 to 80 μm; the embedded network reinforcement powder was dried at 400°C for 2 h.

[0058] C. Based on the preferred 0.04mm thick titanium strip and 5vol TiB+TiC / TC4 embedded mesh reinforcement powder, the titanium-based composite material powder dried in step B is filled into a U-shaped TA1 titanium strip using a flux-cored wire making machine, and the TA1 titanium strip is closed using a forming machine (i.e., the initial diameter reduction, compacting the powder core in the titanium tube), to obtain a 2vol TiB+TiC / TC4 titanium-based composite material wire precursor with a continuous core mesh structure and a diameter of 4mm (the powder accounts for 40% of the wire, and the other 60% is titanium strip, so the overall reinforcement content of the wire is 5vol.%×40%=2vol.%). The rolling wheel is heated to 400-450℃ using an online heat treatment method, and the TA1 titanium-based composite wire precursor with a diameter of 4mm is subjected to multiple hot drawing and diameter reduction. At the same time, argon protection is used as an auxiliary during the diameter reduction process to prevent severe oxidation of the wire surface. Specifically, the rolling wheels with different diameter reduction sizes are continuously heated by induction heating, namely, two 3.6mm rolling wheels, maintained at 400℃, two 3mm rolling wheels, maintained at 415℃, two 2.5mm rolling wheels, maintained at 425℃, two 2.2mm rolling wheels, maintained at 435℃, and two 2.0mm rolling wheels, maintained at 450℃. The wire continuously passes through the rolling wheels with different diameter reduction sizes, and finally a welding wire with a diameter of 2.0mm is obtained. The overall schematic diagram of the preparation process is shown as follows Figure 1 As shown, the cross-sectional macroscopic morphology and internal network reinforcement distribution of 2vol TiB+TiC / TC4 were prepared as shown in Figure 2 Finally, the reduced wire is transferred to a vacuum furnace for annealing after reducing the diameter. The stress relief annealing time is 30 minutes at a temperature of 500°C. The oil stains on the welding wire are wiped with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, it is dried and coiled into a disc.

[0059] D. Based on the continuous core mesh structure titanium-based composite wire obtained above, the additive manufacturing is carried out by arc fusion additive manufacturing. Based on the REHM Tiger 180DC arc welding power source, the welding current is 120A, the welding speed is 3mm / s, the wire feeding speed is 12mm / s, and the reciprocating deposition strategy is adopted, that is, the deposition direction of the next layer is opposite to that of the previous layer. The processing process is as follows Figure 3As shown, the continuous core mesh structure titanium matrix composite wire 2 is fed to the arc below the welding torch 1 through the wire feeding nozzle 3, and melted and deposited to form an in-situ self-generated titanium matrix composite material 5, and finally an in-situ self-generated reinforced titanium matrix composite thin-walled part is prepared, and its internal structure is as shown in FIG. Figure 4 As shown in (a), the reinforcement is small and evenly distributed.

[0060] Example 2

[0061] This embodiment provides a method for additive manufacturing of a titanium-based composite material based on a continuous core mesh structure wire, comprising the following steps:

[0062] A. First, clean a 0.04mm thick titanium strip with a mixture of NaOH and acetone, then rinse with water. Then, ultrasonically clean the strip using a mixed aqueous solution of HF and HNO3 to obtain the cleaned TA1 titanium strip. The NaOH and acetone mixture contains 15% NaOH and 85% acetone, while the HF and HNO3 mixture contains 5% HF and 35% HNO3. Ultrasonic cleaning is performed for 2 minutes at a frequency of 20 kHz.

[0063] B. 2.5 vol.% TiB-reinforced TC4 composite material powder prepared by atomization method was selected, and powder with a particle size of 80 to 100 μm was screened out by vibration screening; the embedded network reinforcement powder was dried at a temperature of 400° C. for 2 h.

[0064] C. Based on the preferred 0.04mm thick titanium strip and 2.5vol TiB / TC4 embedded mesh reinforcement powder, the titanium-based composite material powder dried in step B was filled into a U-shaped TA1 titanium strip using a flux-cored wire making machine. The TA1 titanium strip was then closed using a forming machine (i.e., the initial diameter reduction was performed to compact the powder core within the titanium tube), resulting in a 1vol TiB / TC4 titanium-based composite wire precursor with a continuous core mesh structure and a diameter of 4mm. The rolling wheel was heated to 400-450°C using an online heat treatment method, and the 4mm diameter TA1 titanium-based composite wire precursor was subjected to multiple hot drawing and diameter reduction passes. Argon gas protection was used during the diameter reduction process to prevent severe oxidation of the wire surface. Specifically, the wire is continuously heated through induction heating using rolling wheels of different diameter reduction sizes (two 3.6mm rolling wheels maintained at 400°C, two 3mm rolling wheels maintained at 410°C, two 2.5mm rolling wheels maintained at 425°C, two 2.2mm rolling wheels maintained at 440°C, and two 2.0mm rolling wheels maintained at 450°C). The wire is continuously passed through the rolling wheels of different diameter reduction sizes to obtain a welding wire with a diameter of 2.0mm. Finally, the reduced wire is transferred as a whole to a vacuum furnace for post-reduction annealing. The stress relief annealing time is 30 minutes at a temperature of 500°C. The oil stains on the welding wire are wiped with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, it is dried and coiled into a disc.

[0065] D. Based on the continuous core mesh structure titanium-based composite material wire obtained above, laser fused wire additive manufacturing was used for additive preparation. The process parameters were 1200W laser power and 300mm / min scanning speed. Based on the RC-LDM8060 model laser additive manufacturing equipment, a reciprocating deposition strategy was adopted, that is, the deposition direction of the next deposition layer was opposite to that of the previous layer, to prepare in-situ self-reinforced titanium-based composite thin-walled parts.

[0066] Example 3

[0067] This embodiment provides a method for additive manufacturing of a titanium-based composite material based on a continuous core mesh structure wire, comprising the following steps:

[0068] A. A 0.08 mm thick titanium strip was first cleaned with a mixture of NaOH and acetone, then rinsed with water. The strip was then ultrasonically cleaned with a mixed aqueous solution of HF and HNO3 to obtain a cleaned TA1 titanium strip. The NaOH and acetone mixture contained 15% NaOH by mass and 85% acetone by mass. The HF and HNO3 mixture contained 5% HF by mass and 35% HNO3 by mass. Ultrasonic cleaning was performed for 2 minutes at a frequency of 20 kHz.

[0069] B. 5 vol.% TiB reinforced TC4 composite material powder prepared by atomization method was selected, and powder with a particle size of 100-120 μm was screened out by vibration screening; the embedded network reinforcement powder was dried at a temperature of 400° C. for 2 h.

[0070] C. Based on the preferred 0.08mm thick titanium strip and 5vol TiB / TC4 embedded mesh reinforcement powder, the titanium-based composite powder dried in step B was filled into a U-shaped TA1 titanium strip using a flux-cored wire making machine. The TA1 titanium strip was then closed using a forming machine (i.e., the initial diameter reduction was performed to compact the powder core within the titanium tube), resulting in a 2vol TiB / TC4 titanium-based composite wire precursor with a continuous core mesh structure and a diameter of 4mm. The rolling wheel was heated to 400-450°C using an online heat treatment method, and the 4mm diameter TA1 titanium-based composite wire precursor was subjected to multiple hot drawing and diameter reduction passes. Argon gas protection was used during the diameter reduction process to prevent severe oxidation of the wire surface. Specifically, the wire is continuously heated by induction heating using rolling wheels of different diameter reduction sizes: two 3.6mm rolling wheels maintained at 400°C, two 3mm rolling wheels maintained at 410°C, two 2.5mm rolling wheels maintained at 420°C, two 2.2mm rolling wheels maintained at 430°C, two 2.0mm rolling wheels maintained at 440°C, and two 1.6mm rolling wheels maintained at 450°C. The wire is continuously passed through the rolling wheels of different diameter reduction sizes to obtain a welding wire with a diameter of 1.6mm. Finally, the reduced wire is transferred as a whole to a vacuum furnace for post-reduction annealing. The stress relief annealing time is 30 minutes at a temperature of 500°C. The oil stains on the welding wire are wiped with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, it is dried and coiled into a disc.

[0071] D. Based on the continuous core mesh structure titanium-based composite material wire obtained above, arc fused wire additive manufacturing was used for additive preparation. Based on the REHM Tiger 180DC arc welding power supply, the welding current was 120A, the welding speed was 3mm / s, the wire feeding speed was 12mm / s, and a reciprocating deposition strategy was adopted, that is, the deposition direction of the next deposition layer was opposite to that of the previous layer, to prepare in-situ self-reinforced titanium-based composite thin-walled parts.

[0072] Example 4

[0073] This embodiment provides a method for additive manufacturing of a titanium-based composite material based on a continuous core mesh structure wire, comprising the following steps:

[0074] A. A 0.04 mm thick titanium strip was first cleaned with a mixture of NaOH and acetone, then rinsed with water. The strip was then ultrasonically cleaned with a mixed aqueous solution of HF and HNO3 to obtain a cleaned TA1 titanium strip. The NaOH and acetone mixture contained 15% NaOH by mass and 85% acetone by mass. The HF and HNO3 mixture contained 5% HF by mass and 35% HNO3 by mass. Ultrasonic cleaning was performed for 2 minutes at a frequency of 20 kHz.

[0075] B. 2.5 vol.% TiB+2.5 vol.% La2O3 reinforced IMI834 composite material powder prepared by a gas atomization method was selected, and a powder with a particle size of 120-150 μm was screened out by vibration screening; the embedded network reinforcement powder was dried at a temperature of 400°C for 2 hours.

[0076] C. Based on the preferred 0.04mm thick titanium strip and 5vol TiB+La2O3 / IMI834 embedded mesh reinforcement powder, the titanium-based composite powder dried in step B was filled into a U-shaped TA1 titanium strip using a flux-cored wire making machine. The TA1 titanium strip was then closed using a forming machine (i.e., the initial diameter reduction was performed to compact the powder core within the titanium tube), resulting in a 2vol TiB+La2O3 / IMI834 titanium-based composite wire precursor with a continuous core mesh structure and a diameter of 4mm. The rolling wheel was heated to 400-450°C using an online heat treatment method, and the 4mm diameter TA1 titanium-based composite wire precursor was subjected to multiple hot drawing and diameter reduction passes. Argon gas protection was used during the diameter reduction process to prevent severe oxidation of the wire surface. Specifically, the wire is continuously heated by induction heating using rolling wheels of different diameter reduction sizes: two 3.6mm rolling wheels maintained at 400°C, two 3mm rolling wheels maintained at 410°C, two 2.5mm rolling wheels maintained at 420°C, two 2.2mm rolling wheels maintained at 430°C, two 2.0mm rolling wheels maintained at 440°C, and two 1.6mm rolling wheels maintained at 450°C. The wire is continuously passed through the rolling wheels of different diameter reduction sizes to obtain a welding wire with a diameter of 1.6mm. Finally, the reduced wire is transferred as a whole to a vacuum furnace for post-reduction annealing. The stress relief annealing time is 30 minutes at a temperature of 500°C. The oil stains on the welding wire are wiped with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, it is dried and coiled into a disc.

[0077] D. Based on the continuous core mesh structure titanium-based composite material wire obtained above, laser fused wire additive manufacturing was used for additive preparation. The process parameters were 1500W laser power and 500mm / min scanning speed. Based on the RC-LDM8060 powder feeding laser additive manufacturing equipment, the continuous laser was changed to pulsed laser mode with a pulse frequency of 5Hz. The melting process was regulated by periodic solidification of the molten pool. At the same time, a 67° interlayer rotation deposition strategy was adopted, that is, the deposition direction of the next deposition layer differed by 67° from that of the previous layer, to prepare in-situ self-reinforced titanium-based composite thin-walled parts.

[0078] Example 5

[0079] This embodiment provides a method for additive manufacturing of a titanium-based composite material based on a continuous core mesh structure wire, comprising the following steps:

[0080] A. A 0.08 mm thick titanium strip was first cleaned with a mixture of NaOH and acetone, then rinsed with water. The strip was then ultrasonically cleaned with a mixed aqueous solution of HF and HNO3 to obtain a cleaned TA1 titanium strip. The NaOH and acetone mixture contained 15% NaOH by mass and 85% acetone by mass. The HF and HNO3 mixture contained 5% HF by mass and 35% HNO3 by mass. Ultrasonic cleaning was performed for 2 minutes at a frequency of 20 kHz.

[0081] B. 5 vol.% TiB reinforced TC4 composite material powder prepared by atomization method was selected, and powder with a particle size of 53 to 80 μm was screened out by vibration screening; the embedded network reinforcement powder was dried at a temperature of 400° C. for 2 h.

[0082] C. Based on the preferred 0.08mm thick titanium strip and 5vol TiB / TC4 embedded mesh reinforcement powder, the titanium-based composite powder dried in step B was filled into a U-shaped TA1 titanium strip using a flux-cored wire making machine. The TA1 titanium strip was then closed using a forming machine (i.e., the initial diameter reduction was performed to compact the powder core within the titanium tube), resulting in a 2vol TiB / TC4 titanium-based composite wire precursor with a continuous core mesh structure and a diameter of 4mm. The rolling wheel was heated to 400-450°C using an online heat treatment method, and the 4mm diameter TA1 titanium-based composite wire precursor was subjected to multiple hot drawing and diameter reduction passes. Argon gas protection was used during the diameter reduction process to prevent severe oxidation of the wire surface. Specifically, the wire is continuously heated by induction heating using rolling wheels of different diameter reduction sizes: two 3.6mm rolling wheels maintained at 400°C, two 3mm rolling wheels maintained at 410°C, two 2.5mm rolling wheels maintained at 420°C, two 2.2mm rolling wheels maintained at 430°C, two 2.0mm rolling wheels maintained at 440°C, and two 1.6mm rolling wheels maintained at 450°C. The wire is continuously passed through the rolling wheels of different diameter reduction sizes to obtain a welding wire with a diameter of 1.6mm. Finally, the reduced wire is transferred as a whole to a vacuum furnace for post-reduction annealing. The stress relief annealing time is 30 minutes at a temperature of 500°C. The oil stains on the welding wire are wiped with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, it is dried and coiled into a disc.

[0083] D. Based on the continuous core mesh structure titanium-based composite material wire obtained above, electron beam fused wire additive manufacturing was used for additive manufacturing. The additive manufacturing process parameters were an acceleration voltage of 60 kV, a beam current of 50 mA, a molten pool moving speed of 1000 mm / min, a wire feeding speed of about 3 kg / h, an overlap rate of 30%, a layer thickness of 2 mm, and a vacuum pressure of 5×10 -2 At the same time, a reciprocating deposition strategy is adopted, that is, the deposition direction of the next deposition layer is opposite to that of the previous layer, to prepare in-situ self-reinforced titanium-based composite thin-walled parts.

[0084] Comparative Example 1

[0085] This comparative example differs from Example 1 in that the titanium-based composite material powder of Example 1 is used, and multiple in-line annealing is not employed during the drawing process, instead employing conventional drawing methods currently available in the art. Based on a 2.5 vol.% TiB + 2.5 vol.% TiC reinforced TC4 composite material powder (5 vol TiB + TiC / TC4), a TA1 titanium strip is closed using a forming machine to produce a 2 vol TiB + TiC / TC4 titanium-based composite wire precursor with a continuous core mesh structure and a diameter of 4 mm. The 4 mm diameter TA1 titanium-based composite wire precursor is then further cold-drawn and reduced in diameter on a wire drawing machine, passing through reducing wheels with diameters of 3.8 mm, 3.4 mm, and 3.0 mm, respectively. After each two cold-drawing reductions, the wire is stress-relieved in a vacuum tube annealing furnace for 40 minutes at 600°C. However, this comparative example only produces a wire with a diameter of 3.0 mm; further reduction will result in cracks. Grease stains on the wire are wiped clean with a cotton cloth dipped in acetone or anhydrous ethanol, and finally dried and coiled into a disc. Based on the titanium-based composite wire obtained above, arc-fused wire additive manufacturing (AFM) was used. Using a REHM Tiger 180DC arc welding power source, the welding current was 120A, the welding speed was 3mm / s, and the wire feed speed was 12mm / s. A reciprocating deposition strategy, where the deposition direction of the next layer was opposite to that of the previous layer, was employed to prepare thin-walled in-situ reinforced titanium-based composite parts. This additive manufacturing method suffers from the problem of uneven reinforcement distribution in the in-situ reinforced titanium-based composite due to the propensity of the raw material powder to oxidize during ball milling and the difficulty in ensuring powder uniformity. Furthermore, the lack of multiple annealing treatments (including rolling, in-line hot drawing, and overall annealing) makes it difficult to further reduce the wire diameter. Consequently, the morphology of the deposited layer in additive manufacturing using large-diameter wire is difficult to precisely control, resulting in poor mechanical property stability and anisotropy, hindering the further development and application of integrated additively manufactured titanium-based composite structural parts.

[0086] Comparative Example 2

[0087] This comparative example differs from Example 1 in that titanium-based composite material powder with a particle size range of 15 to 45 μm is used as a filler material to fill the U-shaped titanium strip. The remaining steps are essentially the same as in Example 1. A forming machine is used to close the TA1 titanium strip to obtain a 4 mm diameter continuous core mesh structure 2 vol TiB+TiC / TC4 titanium-based composite wire precursor. An online heat treatment process is employed, heating the rolling wheel to 400-450°C. The 4 mm diameter TA1 titanium-based composite wire precursor undergoes multiple hot-drawing reduction passes, while argon gas protection is used during the reduction process to prevent severe oxidation of the wire surface. The specific operations are the same as in Example 1, resulting in a 2.0 mm diameter welding wire. Finally, the reduced wire is transferred to a vacuum furnace for post-reduction annealing. The stress relief annealing lasts for 30 minutes at 500°C. Oil stains on the welding wire are wiped clean with a cotton cloth dipped in acetone or anhydrous ethanol. Finally, the wire is dried and coiled into a disc. Based on the titanium-based composite material wire obtained above, the additive preparation was carried out by arc fusion additive manufacturing. Based on the REHM Tiger 180DC arc welding power source, the welding current was 120A, the welding speed was 3mm / s, the wire feeding speed was 12mm / s, and a reciprocating deposition strategy was adopted, that is, the deposition direction of the next deposition layer was opposite to that of the previous layer, to prepare in-situ self-reinforced titanium-based composite thin-walled parts. When this method is used for additive manufacturing, due to the small particle size of the raw material powder, the molecular attraction and electrostatic attraction between the powders are large, which leads to easy adsorption and aggregation of the particles, increased adhesion, poor fluidity of the filling powder, and difficulty in uniform distribution in the continuous core mesh structure titanium-based composite material wire, which leads to uneven distribution of reinforcement in the prepared in-situ self-reinforced titanium-based composite material, such as Figure 4 As shown in (b), defects such as pores and microcracks may occur, which seriously deteriorate the mechanical properties of the additive body.

[0088] In summary, the additive manufacturing method provided by the present invention refines the matrix grains and reinforcement size through the in-situ self-generated reaction during the solidification process of the continuous core mesh structure titanium-based composite material wire, and can achieve precise control of the reinforcement size distribution, thereby greatly improving the strength and toughness of the additively manufactured titanium-based composite material. Specifically, (1) Embedded mesh reinforcement design: The present invention adopts titanium-based composite material powder with embedded fine mesh reinforcement, which effectively solves the problem of poor wettability between the reinforcement and the matrix and powder agglomeration, and achieves uniform distribution and precise control of the reinforcement in the matrix. (2) Continuous core mesh structure: By rolling and drawing the titanium strip and titanium-based composite material powder, a continuous core mesh structure is formed, which improves the strength and toughness of the wire and facilitates the subsequent additive manufacturing process. (3) Process parameter optimization: The present invention optimizes the drying temperature, filling rate, diameter reduction process, heat treatment process, etc. to ensure the quality and performance of the wire. It can be seen that the method of the present invention has the advantages of high design freedom and high material utilization rate, and provides an opportunity for the integrated preparation of complex components of high-strength and tough titanium-based composite materials.

[0089] It should be understood that the present invention is not limited to the specific embodiments described above, and that those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of the present application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A method for preparing a continuous core mesh structure wire for fused filament additive manufacturing, characterized in that: The following steps are involved: A. Use titanium strip as the outer titanium shell; B. Using a fine mesh titanium-based composite material powder as the internal filling powder; the titanium-based composite material powder has a powder particle size range of 53 to 150 μm, and its matrix includes pure titanium or titanium alloy. The matrix is ​​combined with a reinforcement to form a titanium-based composite material, and the reinforcement has a mesh distribution feature in the titanium-based composite material powder, the fine mesh structure size is ≤10 μm, and the volume fraction of the reinforcement in the titanium-based composite material powder is 0.1 to 10 vol.%; C. Rolling the titanium shell and the inner filling powder into a sealed shape, and then drawing and reducing the diameter to form a continuous core mesh structure wire; D. Preparation of in-situ reinforced titanium matrix composites using fused filament additive manufacturing method; In step C, the preparation of the continuous core mesh structure wire material includes the following steps: C1. Drying fine mesh titanium-based composite material powder; C2. Use roller extrusion to curl the titanium strip into a "U" shape; C3. Add the titanium-based composite material powder prepared in step C1 to a "U"-shaped titanium strip, and squeeze the two sides of the "U"-shaped titanium strip together to form an "O"-shaped titanium tube; C4. Place the titanium tube directly into the hot rolling die for initial diameter reduction to compact the powder core inside the titanium tube; C5. Heating the rolling wheel to 400° C. to 450° C. by online heat treatment annealing, and performing multiple hot rolling to reduce the diameter of the titanium tube filled with the titanium-based composite material powder obtained in step C4 until the diameter reaches the designed size; C6. Perform vacuum heat treatment on the titanium tube after the diameter reduction in step C5 to obtain titanium-based composite material wire.

2. The method according to claim 1, characterized in that The thickness of the titanium strip in step A is 0.04-0.08 mm; the material of the titanium strip includes pure titanium or a titanium alloy; the titanium alloy includes at least one of Ti6Al4V, Ti-6.5Al-1.5Zr-3.5Mo-0.3Si, and Ti-5.8Al-4Sn-3.5Zr-0.7Nb-0.5Mo-0.35Si.

3. The method according to claim 1, characterized in that The titanium-based composite material powder includes one of the following technical features: B1, the reinforcement includes one or more of TiB, TiC and La2O3; B2. Titanium-based composite materials are TiB / Ti6Al4V, TiC / Ti-6.5Al-1.5Zr-3.5Mo-0.3Si, (TiB+TiC) / Ti6Al4V or (TiB+La2O3) / IMI834.

4. The method according to claim 1, wherein In step C, The diameter of the continuous core mesh structure wire is 1.2-3.0 mm, and the diameter of the unit core mesh is ≤10 μm; And / or, the drawing and reducing method includes roller die drawing, fixed die drawing, or a roller die and fixed die combined in series.

5. The method according to claim 1, wherein In step C5, auxiliary argon protection is provided during the hot rolling and diameter reduction process; And / or, the vacuum heat treatment temperature is 500-650° C., and the time is 10-30 min.

6. The method according to claim 1, characterized in that The fuse additive manufacturing method described in step D includes one of arc fuse additive, laser fuse additive, and electron beam fuse additive.

7. An in-situ reinforced titanium-based composite material prepared according to the method according to any one of claims 1 to 6.

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