A solid-phase additive device of a medium-high volume fraction aluminum matrix composite material and a preparation method thereof

Abstract

The application provides a solid-phase additive device of a medium-high volume fraction aluminum matrix composite material and a preparation method thereof, and belongs to the field of additive manufacturing. The application solves the problems of poor combination of ceramic particles and aluminum matrix, easy occurrence of harmful interface reaction, serious wear of additive tools and difficulty in preparing medium-high volume fraction aluminum matrix composite materials by solid-phase additive in the prior art. The application comprises a friction stir welding machine, a composite material powder core wire, an additive tool, a water cooling assembly and a laser auxiliary heat source assembly. The additive tool comprises a stirring head and a static shoulder, and the static shoulder is sleeved outside the stirring head. The static shoulder side wall is provided with a radial wire feeding hole, and the composite material powder core wire is fed in through the wire feeding hole. The water cooling assembly and the laser auxiliary heat source assembly form a closed-loop temperature control through a computer control system. The application precisely controls the volume fraction of the reinforcing body through the powder core wire, reduces tool wear and aluminum adhesion by using a wear-resistant coating, and realizes continuous and stable forming through the synergistic temperature control of laser preheating and water cooling.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a solid-phase additive manufacturing device and its preparation method for medium-to-high volume fraction aluminum-based composite materials. Background Technology

[0002] Aluminum-based composites have broad application prospects in aerospace, electronic packaging, and transportation due to their advantages such as lightweight, high specific strength, and adjustable performance. Ceramic particles such as SiC, with their high melting point, high elastic modulus, high hardness, and low coefficient of linear expansion, have become one of the most commonly used reinforcements in aluminum-based composites. When the volume fraction of the reinforcement reaches 30% to 50% (i.e., medium to high volume fraction), the composite material can significantly improve its elastic modulus, wear resistance, and dimensional stability, while maintaining a low density, meeting the urgent needs of high-end equipment for lightweighting and precision.

[0003] However, existing preparation technologies face three major challenges. First, harmful interfacial reactions lead to poor bonding between ceramic particles and the aluminum matrix. Traditional liquid-phase preparation methods (such as stirred casting and pressure infiltration) require heating the aluminum matrix above its melting point and mixing it with SiC particles in a high-temperature molten state. Thermodynamically unstable, SiC and liquid aluminum are prone to violent interfacial reactions, generating the brittle phase Al4C3. This brittle phase not only weakens the interfacial bonding strength between the reinforcement and the matrix but is also prone to hydrolysis in humid environments, becoming a source of early material failure. Furthermore, at medium to high volume fractions, particles are highly susceptible to agglomeration and sedimentation, making uniform distribution difficult and further deteriorating mechanical properties. Second, existing solid-phase additive manufacturing technologies struggle to prepare medium to high volume fraction aluminum-based composites. To avoid interfacial reactions in liquid-phase methods, the academic community has attempted to use solid-phase additive manufacturing technology to achieve bonding between the matrix and reinforcement in the solid state. However, most existing solid-phase additive solutions use a single aluminum wire or rod as the matrix material, introducing ceramic reinforcement through pre-fabricated powder layers, the addition of loose powder, or the attachment of a small number of particles to the wire surface. These methods have fundamental limitations in preparing medium-to-high volume fraction (30%~50%) composite materials: the powder feed rate is limited by the physical space between the filament and the powder, making it difficult to achieve a high proportion, stable and controllable particle addition; simultaneously, at medium-to-high volume fractions, the mixed powder has poor flowability, insufficient heat input, and is prone to clogging the feed channel, resulting in uneven particle distribution, frequent porosity and incomplete fusion defects within the deposited layer, and the density is difficult to meet engineering requirements. Therefore, there is currently no solid-phase additive manufacturing process that can stably prepare medium-to-high volume fraction aluminum-based composite materials. Third, high-hardness ceramic particles exacerbate wear on additive manufacturing tools, and the reaction between aluminum and iron causes aluminum alloy to adhere to the tool surface, severely hindering continuous additive manufacturing. In the solid-phase additive manufacturing process of medium-to-high volume fraction aluminum-based composite materials, the large number of dispersed reinforcing particles and additive manufacturing tools (stirring head, stationary shoulder, etc.) experience severe wear, which can easily lead to tool failure. Meanwhile, aluminum alloys have a natural chemical affinity for iron-based materials. Under the high temperature and pressure conditions generated by stirring friction, aluminum reacts with the iron in the tool steel, causing the aluminum alloy material to strongly adhere to the tool surface, forming an aluminum deposit. This not only affects the flow and deposition of subsequent materials but also causes instability in the additive manufacturing process, forcing frequent shutdowns for cleaning and making it difficult to achieve long-term continuous additive manufacturing. These three problems are particularly prominent under medium-to-high volume fraction conditions, becoming key bottlenecks restricting the engineering application of this technology.

[0004] In summary, developing a solid-phase additive manufacturing method that can avoid harmful interfacial reactions while achieving stable addition and good bonding of medium-to-high volume fraction ceramic particles has become a pressing technical challenge in this field. Summary of the Invention

[0005] To address the problems in the prior art, such as poor bonding between ceramic particles and aluminum matrix leading to harmful interfacial reactions, severe wear of additive tools, and the difficulty in preparing medium-to-high volume fraction aluminum-based composite materials using existing solid-phase additive manufacturing, this invention provides a solid-phase additive manufacturing device and preparation method for medium-to-high volume fraction aluminum-based composite materials.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: In a first aspect, the present invention provides a solid-phase additive manufacturing device for medium-to-high volume fraction aluminum-based composite materials, comprising a friction stir welding machine, a composite material core wire, and an additive manufacturing tool. The additive manufacturing tool includes a stirring head and a stationary shoulder, the stationary shoulder being sleeved outside the stirring head. The stirring head includes a clamping part, a transition part, a screw part, and a stirring needle part connected sequentially from top to bottom. The stationary shoulder includes a clamping part and a shoulder body connected sequentially from top to bottom. The side wall of the shoulder body is provided with a radial wire feeding hole, through which the composite material core wire is continuously fed. The composite material core wire includes an aluminum alloy shell, and the aluminum alloy shell contains a mixture of reinforcement and aluminum alloy powder.

[0007] Furthermore, the inner surface of the stationary shoulder 302 and the outer surface of the screw portion 30103 are both provided with a wear-resistant coating.

[0008] Furthermore, the wear-resistant coating includes, but is not limited to, a Ni-Cr-B-Si based composite material reinforced with WC particles. The composite material uses a Ni-Cr-B-Si alloy as the matrix and WC particles as the reinforcing phase. The composition, by weight percentage, is Cr 5-15%, Co 5-10%, Si 2-5%, W 3-6%, Pd 1-4%, with the balance being Ni. The WC particles account for 10-20% of the total weight.

[0009] Furthermore, the thickness of the wear-resistant coating is 0.1-1.0 mm.

[0010] Furthermore, the wear-resistant coating also includes 0.5 to 2.0% of rare earth oxides by weight of the total coating, wherein the rare earth oxides are selected from at least one of CeO2, Y2O3, and La2O3.

[0011] Furthermore, the device also includes a water-cooling component 4 and a laser-assisted heat source component 5. The water-cooling component is sleeved on the lower part of the shoulder body 30203, and the laser-assisted heat source component 5 is located in front of the shoulder body 30203 in the direction of travel. The laser-assisted heat source component 5 includes a laser heating structure 501 and an infrared temperature measuring structure 502. The infrared temperature measuring structure monitors the temperature of the material at the bottom of the stationary shoulder in real time. The computer control system adjusts the laser power in real time according to the temperature signal, and simultaneously controls the coolant flow rate of the water-cooling component, forming a closed-loop temperature control system of laser preheating and water cooling heat dissipation, so that the material at the bottom of the stationary shoulder is always within the preset plastic forming temperature range.

[0012] Furthermore, the water-cooling assembly includes a flow channel 401 and a housing 402. The housing 402 is fitted onto the lower part of the outer wall of the shoulder body 30203, and the flow channel 401 is provided inside the housing.

[0013] Secondly, this invention proposes a method for preparing triboelectric additive materials, which is implemented using a solid-phase additive manufacturing device based on the aforementioned high-volume-fraction aluminum-based composite material. The method includes the following steps: S1: Preparation of metal matrix composite powder Take a certain amount of metal powder and reinforcing powder, with a mass ratio of metal powder to reinforcing powder of 0 or 1:4 (when the mass ratio of metal powder is 0, the metal matrix of the composite material is entirely provided by the aluminum alloy hollow tube, and the reinforcing powder is entirely from the reinforcing powder, thereby achieving precise control of the volume fraction of the reinforcing powder), and mix them mechanically by ball milling for 2 to 20 hours to prepare a uniformly dispersed mixed powder. S2: Preparation of metal matrix composite powder core wire The mixed powder prepared in S1 is injected into a hollow aluminum alloy tube of the same type in a certain proportion by means of vibration or airflow guidance. The mass ratio of the mixed powder to the aluminum alloy tube is 1~4:4. The hollow tube after being injected with the mixed powder is mechanically vibrated to make the powder evenly distributed in the tube, forming a powder core wire. The volume fraction of the reinforcement in the powder core wire is between 30% and 50%. S3: Additive Deposition Molding The friction stir additive manufacturing tool and laser-assisted heat source are activated to push the powder core wire obtained in S2... f The material is fed into the feed hole along the side wall of the stationary shaft shoulder at a feeding speed of 100~300 mm / min for additive manufacturing. The rotation speed of the stirring head is ω=100~1000 rpm. Under the extrusion action of the feeding screw, the material moves downward to the vicinity of the stirring needle, deposits at the bottom of the stationary shaft shoulder, and travels at a speed of... v Deposition is carried out at a speed of 50-2000 mm / min along a designated path. A laser heating structure preheats the material at the bottom of the stationary shoulder, while an infrared temperature measurement structure monitors the temperature of the material in real time and feeds it back to the computer control system. The control system adjusts the laser power in real time using a PID algorithm and dynamically adjusts the coolant flow rate of the water-cooling device based on temperature deviations, ensuring that the temperature of the material at the bottom of the stationary shoulder is always controlled within a preset range. The preset temperature is selected according to the type of aluminum alloy.

[0014] S4: Heat treatment of composite materials The composite material was subjected to solution aging treatment at a temperature of 450~550 ℃ for 0~2 h. After the solution treatment, water quenching was performed within 15 s, with an aging temperature of 120~190 ℃ for 0~24 h.

[0015] Furthermore, the reinforcing powders used in step 1 to prepare the metal matrix composite material include, but are not limited to, SiC, TiC, TiB2, Al2O3, and CNT.

[0016] Furthermore, the types of aluminum alloys that are compatible with the specified temperature controlled by the laser-assisted heat source component 5 in step 3 include, but are not limited to, 1-series aluminum alloys, 2-series aluminum alloys, 3-series aluminum alloys, 4-series aluminum alloys, 5-series aluminum alloys, 6-series aluminum alloys, and 7-series aluminum alloys.

[0017] The beneficial effects of this invention are: 1. This invention achieves precise control of the reinforcing content by preparing powder core filaments, thereby realizing the uniform distribution of the reinforcing phase during molding; 2. This invention reduces the wear of reinforcing particles on the tool and extends its service life by cladding a coating on the surface of the screw and stationary shoulder; the Cr element in the coating forms a dense Cr2O3 oxide film at high temperature, which reduces the chemical affinity between aluminum and iron, thereby inhibiting aluminum adhesion and ensuring the continuous forming of the composite material. 3. This invention achieves precise temperature control (with an accuracy of ±5℃) in the bottom forming area of ​​the stationary shoulder through a closed-loop collaborative temperature control system of a water-cooling component and a laser-assisted heat source component: laser preheating reduces material flow stress and additive manufacturing resistance; water cooling prevents overheating of the stationary shoulder, avoiding coating softening and aluminum alloy adhesion. The two components are linked through a computer control system with positive and negative feedback, ensuring the additive manufacturing process remains in optimal thermal equilibrium, thus guaranteeing continuous and stable forming of medium-to-high volume fraction aluminum-based composite materials. This solves the problems of poor interlayer bonding and tool failure caused by heat input fluctuations in existing technologies. 4. This invention has a wide range of applications and can be applied to the reliable solid-phase deposition fabrication of various medium-to-high volume fraction aluminum-based composite materials, such as SiC / 2024Al, TiC / 7075Al, and TiB2 / 7075Al composite materials. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the working principle of the friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials according to the present invention.

[0019] Figure 2 This is a structural diagram of the additive manufacturing tool for a friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials according to the present invention.

[0020] Figure 3 This is a structural diagram of the additive tool for a friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials according to the present invention.

[0021] Figure 4This is a structural diagram of the stirring head of the friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials according to the present invention.

[0022] Figure 5 The static shoulder structure diagram of the friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials described in this invention.

[0023] Figure 6 This is a structural diagram of the water cooling device for a friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials according to the present invention.

[0024] Figure 7 This is a structural diagram of the laser-assisted heat source component of the friction stir additive manufacturing apparatus and method for medium-high volume fraction aluminum-based composite materials described in this invention.

[0025] In the diagram, 1 - Friction stir welding machine; 2-Composite core wire, 201-Aluminum alloy shell, 202-Reinforcing body and aluminum alloy powder mixture; 3-Additive tool, 301-Stirring head, 30101-Stirring head clamping part, 30102-Stirring head transition part, 30103-Stirring head screw part, 30104-Stirring needle, 302-Stationary shaft shoulder, 30201-Stationary shaft shoulder clamping part, 30202-Side wall wire feeding hole, 30203-Shoulder body; 4-Water-cooled components, 401-Water-cooled device flow channel, 402-Water-cooled device housing; 5-Laser-assisted heat source component, 501-Laser heating structure, 502-Infrared temperature measurement structure; 6- Computer control system; 7-Depositional components. Detailed Implementation

[0026] Specific implementation method one: As follows Figures 1 to 5 As shown, this embodiment provides a solid-phase additive manufacturing device for medium-to-high volume fraction aluminum-based composite materials, including a friction stir welding machine 1, a composite material core wire 2, and additive manufacturing tools.

[0027] like Figure 3 As shown, the additive tool 3 includes a mixing head 301 and a stationary shoulder 302, with the stationary shoulder 302 sleeved on the outside of the mixing head 301.

[0028] like Figure 4As shown, the stirring head 301 includes a clamping part 30101, a transition part 30102, a screw part 30103, and a stirring needle part 30104 connected sequentially from top to bottom. The clamping part 30101 is fixedly connected to the rotating part of the rotating main shaft of the friction stir welding machine 1 and has a side milled surface for clamping. The transition part 30102 connects the clamping part 30101 and the screw part 30103 and has a conical surface for axial positioning. The screw part 30103 is cylindrical in shape, and the cylindrical surface has a right-hand rectangular thread groove from top to bottom. Its pitch is 20~40 mm, and the number of turns is 1.5-3.0 turns. The bottom of the thread is provided with an arc transition tangent to the bottom plane, and it conveys thermoplastic material downwards during the counterclockwise rotation of the main shaft. The stirring needle 30104 is an eccentrically arranged cylindrical protrusion located in the area where the thread and the bottom plane of the screw are tangent. Its diameter is 1.5~3.5 mm and its length is 1.0~2.5 times the height of the additive layer, which ensures the stirring effect on the deposition component 7 and improves the interlayer bonding strength.

[0029] like Figure 5 As shown, the stationary shoulder 302 includes a clamping part 30201 and a shoulder body 30203 connected sequentially from top to bottom. The side wall of the shoulder body 30203 is provided with a radial wire feeding hole 30202. The clamping part 30201 is installed on the stationary part of the rotating spindle of the friction stir welding machine 1, and is provided with a conical surface to ensure axial positioning with the stirring head 301. After installation, the bottom of the shoulder body 30203 should be flush with the bottom of the screw part 30103. The stationary shoulder 301 moves synchronously with the stirring head 301 but does not rotate.

[0030] The diameter of the wire feeding hole 30202 is 1.0-3.0 mm larger than the diameter of the core wire, and the outer side has a chamfer to facilitate the entry of the composite core wire 2. The main body of the 30203 shoulder is a ring-shaped cylindrical structure, with an inner diameter slightly larger than the diameter of the screw part 30103. The bottom plane has a chamfer to constrain the additive raw material and apply pressure to the deposition component 7 to ensure the dense forming of the component.

[0031] like Figure 2 As shown, the composite material core wire 2 includes an aluminum alloy shell 201 and a mixture of reinforcing material and aluminum alloy powder 202. The aluminum alloy shell 201 contains the mixture of reinforcing material and aluminum alloy powder 202. The composite material core wire 2 is continuously fed in through a wire feeding hole 30202. The aluminum alloy shell 201 has a tubular structure with an outer diameter typically between 4 and 8 mm and an inner diameter typically between 2 and 5 mm. The composition of the aluminum alloy powder in the mixture of reinforcing material and aluminum alloy powder 202 is approximately the same as that in the shell 201. It is uniformly mixed with the reinforcing material powder through ball milling and then filled into the shell 201. The volume fraction of the reinforcing material is determined by the inner and outer diameters of the shell 201, the ratio of reinforcing material to aluminum alloy powder in the mixture, and the filling ratio of the mixture 202 to the shell 201.

[0032] The preparation of the metal matrix composite powder core wire 2 includes: Take a certain amount of metal powder and reinforcing powder, with a mass ratio of metal powder to reinforcing powder of 0 or 1:4 (when the mass ratio of metal powder is 0, the metal matrix of the composite material is entirely provided by the aluminum alloy hollow tube, and the reinforcing powder is entirely from the reinforcing powder, thereby achieving precise control of the volume fraction of the reinforcing powder), and mix them mechanically by ball milling for 2 to 20 hours to prepare a uniformly dispersed mixed powder. The prepared mixed powder is injected into a hollow aluminum alloy tube of the same type in a certain proportion by means of vibration or airflow guidance. The mass ratio of mixed powder to aluminum alloy tube is 1~4:4. The hollow tube after being injected with mixed powder is mechanically vibrated to make the powder evenly distributed in the tube to form powder core wire. The volume fraction of the reinforcement in the powder core wire is between 30% and 50%. Specific Implementation Method Two: This implementation method differs from Implementation Method One in that the inner surface of the stationary shoulder 302 and the outer surface of the screw portion 30103 are both provided with a wear-resistant coating. The coating on the screw portion 30103 of the stirring head has a spiral stripe structure; wherein, the stripes of the coating extend in a spiral shape along the axial direction of the stirring head, and the spiral direction of the stripes is right-handed.

[0033] The wear-resistant coating is produced using laser cladding, employing Ni-Cr-B-Si self-fluxing alloy powder as the matrix material and WC ceramic particles as the hard reinforcing phase. By weight percentage, WC particles account for 10%–20% of the total weight; the composition of the laser-clad alloy, by weight percentage, is: Cr 5–15%, Co 5–10%, Si 2–5%, W 3–6%, Pd 1–4%, with the balance being Ni. The purity of each component powder is ≥99.5%, and the powder particle size ranges from 100 to 300 mesh.

[0034] Preferably, the cladding process for the wear-resistant coating includes, but is not limited to, laser cladding, induction cladding, plasma cladding, argon arc cladding, supersonic flame spraying, and composite processes combining them with induction cladding.

[0035] Preferably, during the preparation of the cladding powder, 0.5% to 2.0% of rare earth oxide CeO2 by weight of the total coating powder is added to the mixed powder. The addition of CeO2 has a synergistic effect of deoxidation and purification, grain refinement, improved wear resistance and high-temperature oxidation resistance: on the one hand, CeO2, as a strong deoxidizer, removes oxygen and impurities from the molten pool, reduces the porosity of the coating, and at the same time inhibits columnar crystal growth, promotes equiaxed crystal formation, and refines the microstructure of the coating; on the other hand, the wear resistance of the coating after adding CeO2 can be increased by more than 20% compared with that without adding it, and it is beneficial to form a dense oxide film on the coating surface, thus improving the high-temperature oxidation resistance.

[0036] After weighing the above components according to the specified ratio, they are mixed in a three-dimensional mixer for 4-6 hours until the powder is uniformly mixed. The mixed powder is then placed in an oven and dried at 120°C for 2 hours to remove adsorbed moisture and prevent porosity defects during the cladding process. In this embodiment, a fiber laser is used as the cladding heat source, and a coaxial powder feeding method is used for laser cladding. The stirring head is clamped on a CNC rotary table, and the laser head position is adjusted so that the laser beam is focused on the shoulder of the stirring head and the area to be clad by the stirring needle. The laser cladding process parameters are set as follows: laser power 1.6-2.5 kW, spot diameter 1.2-4 mm, scanning speed 180-300 mm / min (or 2-5 mm / s), powder feeding speed 10-15 g / min, and overlap rate 30%-50%. Argon is used as the protective gas and powder carrier gas, with a gas flow rate of 4-8 L / min to prevent oxidation of the molten pool at high temperatures. To ensure the density and uniformity of the cladding layer, the cladding process was carried out in an argon-protected chamber with the oxygen content controlled below 100 ppm. After laser cladding, the coated stirring head was allowed to cool naturally to room temperature. Then, grinding and polishing were performed to remove trace amounts of oxide layer and spatter particles from the cladding surface, achieving a surface roughness of Ra ≤ 0.8 μm to ensure good material flowability during friction stir welding. Finally, dye penetrant testing was used to detect surface cracks in the cladding layer, ensuring the coating was free of macroscopic defects such as cracks and porosity. The laser cladding composite coating prepared using this embodiment showed a microhardness exceeding HRC60.

[0037] The other components and connections in this embodiment are the same as in Specific Embodiment 1.

[0038] Specific implementation method three: such as Figure 1 As shown, this embodiment also includes a water-cooling component 4 and a laser-assisted heat source component 5, such as... Figure 6 As shown, the water-cooling assembly includes a flow channel 401 and a housing 402. The housing 402 is fitted onto the lower part of the outer wall of the shoulder body 30203, and the flow channel 401 is provided inside the housing. Preferably, the housing 402 is an annular shape, fitted onto the lower part of the shoulder body 30203. Two parallel support arms extend from both ends of the annular shape, and the flow channels of the support arms are connected to the flow channels of the annular shape. The coolant enters through the inlet of one support arm, flows through the annular shape, and exits through the outlet of the other support arm. The water-cooling assembly 4 uses the circulating coolant in the flow channel 401 to forcibly cool the stationary shoulder body 30203, preventing the stationary shoulder from overheating due to frictional heat and laser preheating during continuous additive manufacturing, thereby avoiding softening of the coating on the inner surface of the stationary shoulder and excessive adhesion of the aluminum alloy. The computer control system 6 dynamically adjusts the coolant flow rate according to the temperature signal fed back by the infrared temperature measuring structure 502, so that the temperature of the stationary shoulder is always maintained within a preset range.

[0039] The laser-assisted heat source assembly 5 is positioned in front of the stationary shaft shoulder clamping part 30202 in the direction of travel. For example... Figure 7 As shown, the laser-assisted heat source component 5 includes a laser heating structure 501 and an infrared temperature measurement structure 502. The laser heating structure 501 preheats the material at the bottom of the stationary shoulder, bringing the local material to a plastic state, reducing the flow stress of the material, and reducing the mechanical resistance during the additive manufacturing process. The infrared temperature measurement structure 502 collects the temperature data of this area in real time and transmits it to the computer control system 6. The control system compares the measured temperature with the preset target temperature (determined according to different types of aluminum alloys, usually between 300 and 450°C), and automatically adjusts the laser power through a PID algorithm to achieve closed-loop temperature control. When the measured temperature is higher than the target temperature, the system can simultaneously increase the coolant flow rate of the water cooling device 4 to accelerate heat dissipation and prevent overheating that could lead to coating peeling or aluminum alloy overflow.

[0040] Specific implementation method four: such as Figure 1 , Figure 7 As shown, this embodiment is a method for preparing medium-to-high volume fraction aluminum-based composite materials through friction stir additive manufacturing. The specific method is as follows: S1: Take a certain amount of metal powder and reinforcing powder, with a mass ratio of metal powder to reinforcing powder of 0 or 1:4 (when the mass ratio of metal powder is 0, the metal matrix of the composite material is entirely provided by the aluminum alloy hollow tube, and the reinforcing powder is entirely from the reinforcing powder, thereby achieving precise control of the volume fraction of the reinforcing powder), and mix them mechanically by ball milling for 2 to 20 hours to prepare a uniformly dispersed mixed powder. The reinforcing powders for preparing the metal matrix composite material in step S1 include, but are not limited to, SiC, TiC, TiB2, Al2O3, and CNT.

[0041] S2: The mixed powder prepared in S1 is injected into a hollow aluminum alloy tube of the same type in a certain proportion by means of vibration or airflow guidance. The mass ratio of the mixed powder to the aluminum alloy tube is 1~4:4. The hollow tube after being injected with the mixed powder is mechanically vibrated to make the powder evenly distributed in the tube to form a powder core wire. The volume fraction of the reinforcement in the powder core wire is between 30% and 50%. S3: Activate the friction stir additive manufacturing tool 3 and the laser-assisted heat source assembly 5 to heat the powder core wire obtained in S2. f The material is fed into the feed hole 30202 on the side wall of the stationary shoulder at a feeding speed of 100~300 mm / min for additive manufacturing. The rotation speed of the stirring head 301 is ω=100~1000 rpm. Under the extrusion action of the feeding screw 30103, the material moves downward to the vicinity of the stirring needle 30104, deposits at the bottom of the stationary shoulder 302, and travels at a speed of ω. vThe laser heats the material at the bottom of the stationary shoulder 302 at a speed of 50-2000 mm / min along a designated path. The laser heating structure 501 preheats the material at the bottom of the stationary shoulder 302. The infrared temperature measuring structure 502 monitors the temperature of the material at the bottom of the stationary shoulder 302 in real time and feeds it back to the computer control system 6. The computer control system 6 adjusts the laser power in real time through a PID algorithm and dynamically adjusts the coolant flow rate of the water cooling component according to the temperature deviation, so that the temperature of the material at the bottom of the stationary shoulder 302 is always controlled within the preset range. The preset temperature is selected according to different types of aluminum alloys.

[0042] The temperature control accuracy of the laser-assisted heat source component 5 is ±5℃; the specified temperature controlled by the laser-assisted heat source component 5 is related to the type of aluminum alloy, including but not limited to 1-series aluminum alloys, 2-series aluminum alloys, 3-series aluminum alloys, 4-series aluminum alloys, 5-series aluminum alloys, 6-series aluminum alloys, and 7-series aluminum alloys.

[0043] S4: Perform solution aging treatment on the composite material at a temperature of 450~550 ℃ for 0~2 h. After solution treatment, perform water quenching treatment within 15 s at an aging temperature of 120~190 ℃ for 0~24 h.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A solid-phase additive manufacturing device for medium-to-high volume fraction aluminum-based composite materials, comprising a friction stir welding machine (1), characterized in that: The device also includes a composite material core wire (2) and an additive manufacturing tool (3). The additive manufacturing tool (3) includes a stirring head (301) and a stationary shoulder (302). The stationary shoulder (302) is sleeved on the outside of the stirring head (301). The stirring head (301) includes a clamping part (30101), a transition part (30102), a screw part (30103), and a stirring needle part (30104) connected from top to bottom. The stationary shoulder (302) includes a clamping part (30201) and a shoulder body (30203) connected from top to bottom. The side wall of the shoulder body (30203) is provided with a radial wire feeding hole (30202). The composite material core wire (2) is continuously fed in through the wire feeding hole (30202). The composite material core wire (2) includes an aluminum alloy shell (201). The aluminum alloy shell (201) contains a mixture of reinforcing body and aluminum alloy powder (202).

2. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 1, characterized in that: The inner surface of the stationary shoulder (302) and the outer surface of the screw part (30103) are both provided with wear-resistant coatings.

3. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 2, characterized in that: The wear-resistant coating includes, but is not limited to, a Ni-Cr-B-Si based composite material reinforced with WC particles. The composite material uses a Ni-Cr-B-Si alloy as the matrix and WC particles as the reinforcing phase. The composition, by weight percentage, is Cr 5-15%, Co 5-10%, Si 2-5%, W 3-6%, Pd 1-4%, with the balance being Ni. The WC particles account for 10-20% of the total weight.

4. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 3, characterized in that: The thickness of the wear-resistant coating is 0.1-1.0 mm.

5. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 4, characterized in that: The wear-resistant coating also includes 0.5 to 2.0% of rare earth oxides by weight of the total coating, wherein the rare earth oxides are selected from at least one of CeO2, Y2O3, and La2O3.

6. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 5, characterized in that: The device also includes a water-cooling component (4) and a laser-assisted heat source component (5). The water-cooling component is sleeved on the lower part of the shoulder body (30203), and the laser-assisted heat source component (5) is located in front of the shoulder body (30203) in the direction of travel.

7. The solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 6, characterized in that: The water-cooling assembly includes a flow channel (401) and a housing (402). The housing 402 is fitted onto the lower part of the outer wall of the shoulder body (30203), and the flow channel (401) is provided inside the housing.

8. A method for preparing a triboelectric additive manufacturing process using a solid-phase additive manufacturing device for a medium-to-high volume fraction aluminum-based composite material as described in any one of claims 1 to 7, characterized in that: The method is performed according to the following steps: Step 1: Preparation of metal matrix composite powder: Take metal powder and reinforcing powder, with a mass ratio of metal powder to reinforcing powder of 0 or 1:4, and mix them by ball milling to prepare a uniformly dispersed mixed powder; Step 2: Preparation of metal matrix composite powder core wire (2); The mixed powder prepared in S1 is poured into the same aluminum alloy shell (201). The mass ratio of the mixed powder to the aluminum alloy shell (201) is 1~4:

4. The powder is evenly distributed in the shell to form a powder core wire. By controlling the mixing ratio of the powder in step one and the mass ratio of the powder to the aluminum alloy shell, the reinforcement accounts for 0-50% of the total volume. Step 3, Additive Deposition Molding: Start the friction stir additive manufacturing tool and laser-assisted heat source, and feed the powder core wire obtained in S2 into the wire feeding hole along the side wall of the stationary shoulder for additive manufacturing. Under the extrusion of the screw part (30103), the material moves downward to the vicinity of the stirring needle part (30104), deposits at the bottom of the stationary shoulder and moves along the designated path for deposition. The material at the bottom of the stationary shoulder (302) is preheated by the laser heating component. The temperature of the material at the bottom of the stationary shoulder (302) is monitored in real time by the infrared temperature measuring structure and fed back to the computer control system (6). The computer control system (6) adjusts the laser power in real time through the PID algorithm, and at the same time dynamically adjusts the coolant flow rate of the water cooling component (4) according to the temperature deviation, so that the temperature of the material at the bottom of the stationary shoulder (302) is always controlled within the preset range. The preset temperature is selected according to different types of aluminum alloys. Step 4, heat treatment of composite materials: The composite material is subjected to solution aging treatment, followed by water quenching after solution treatment.

9. The method for preparing triboelectric additive manufacturing according to claim 8, characterized in that: The reinforcing powders used in step 1 to prepare the metal matrix composite material include, but are not limited to, SiC, TiC, TiB2, Al2O3, and CNT.

10. A solid-phase additive manufacturing device for medium-high volume fraction aluminum-based composite materials according to claim 9, characterized in that: In step 3, the temperature control accuracy of the laser-assisted heat source component (5) is ±5 ℃.

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