A cold spray additive manufacturing method for near-zero expansion metal matrix composites

Abstract

This invention discloses a cold-spray additive manufacturing method for near-zero expansion metal matrix composites, belonging to the technical field of metal matrix composites. The method comprises the following steps: selecting raw materials for preparing negative expansion materials; subjecting the selected raw materials to high-temperature solid-state sintering to obtain the negative expansion material; uniformly mixing the prepared negative expansion material with metal powder using a ball milling process to obtain a mixed powder; spraying the mixed powder into a near-zero expansion metal matrix composite through cold spray additive manufacturing to obtain the near-zero expansion metal matrix composite; and subjecting the obtained near-zero expansion metal matrix composite to heat treatment to improve the mechanical properties of the composite. This invention addresses the problem that when using traditional methods to prepare near-zero expansion metal matrix composites, the process often involves high temperatures, and many materials are sensitive to temperature changes, which may lead to problems such as oxidation, phase transformation, or grain coarsening.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, specifically relating to a cold spray additive manufacturing method for near-zero expansion metal matrix composites. Background Technology

[0002] Against the backdrop of rapid development in key industries such as aerospace, communications, and precision instruments, higher demands are placed on the dimensional stability of materials under extreme temperature variations to ensure that these components and structures maintain high precision, high reliability, and good service performance. For example, in the aerospace field, materials may experience temperature differences of up to 200°C in regions near and far from the sun. This can lead to significant internal stress at material joints (such as pins, keys, and holes) due to mismatched coefficients of thermal expansion, potentially causing microcracks, shortening service life, or even destroying the overall structure. In the communications field, especially optical communication systems, temperature changes are extremely sensitive, and it is essential to ensure precise focusing of the optical path under varying temperature conditions. High-performance fiber optic gyroscopes, as part of optical systems, are highly sensitive to temperature changes and require low environmental sensitivity and high stability. However, under temperature variations, fiber optic loops may be compressed due to thermal mismatch stress, leading to decreased accuracy. In electronic packaging and microelectronics, the functionality and shape accuracy of components are closely related to stress variations. High heat generation leads to significant temperature variations in the application environment. The mismatch in thermal expansion coefficients between components and packaging materials may generate huge thermal mismatch forces, severely affecting the size and function of components and causing failure.

[0003] In summary, structural changes and functional failures caused by thermal expansion and contraction are becoming increasingly prominent in the aerospace, communications, and microelectronics fields, limiting the development of these industries. Therefore, developing materials with excellent dimensional stability and low coefficients of thermal expansion is crucial for improving the technological level and reliability of these key industries. Based on this, existing technologies propose mixing negative expansion materials as thermal expansion inhibitors with positive thermal expansion materials (such as resins, ceramics, and metals) to form composite materials. Adding negative expansion materials to positive thermal expansion materials can give the material low or even near-zero thermal expansion characteristics, thus keeping the coefficient of thermal expansion of the composite material stable under varying external temperatures, significantly reducing residual stress problems in materials and components caused by thermal expansion and contraction. However, current traditional preparation methods often involve high-temperature treatments during material preparation, which may lead to oxidation, phase transformation, or grain coarsening, thus affecting the material's performance. Furthermore, traditional preparation methods may require more post-processing steps to improve the material's microstructure and mechanical properties. Summary of the Invention

[0004] The technical problem to be solved:

[0005] To avoid the shortcomings of the prior art, the present invention provides a cold spraying additive manufacturing method for near-zero expansion metal matrix composites. The near-zero expansion metal matrix composites are prepared by cold spraying additive manufacturing method. During the cold spraying forming process, the temperature is kept below the melting point of the material, which helps to reduce problems such as oxidation, phase transformation or grain coarsening.

[0006] Meanwhile, the cold spray additive manufacturing method, when preparing near-zero expansion metal matrix composites, can directly obtain better material properties by optimizing process parameters, offering advantages such as shorter R&D cycles, lower costs, wider material applicability, higher processing efficiency, and better material performance. This invention addresses the problem that when using traditional methods to prepare near-zero expansion metal matrix composites, which often involve high-temperature processes, many materials are sensitive to temperature changes, potentially leading to oxidation, phase transformation, or grain coarsening.

[0007] The technical solution of this invention is: a cold spray additive manufacturing method for near-zero expansion metal matrix composite materials, the specific steps of which are as follows:

[0008] Raw materials for preparing negative expansion materials are selected, and the selected raw materials are subjected to high-temperature solid-state sintering to obtain negative expansion materials;

[0009] The prepared negative expansion material was mixed with metal powder using a ball milling process to obtain a mixed powder.

[0010] The mixed powders were sprayed and formed by cold spray additive manufacturing to obtain a metal matrix composite material with near-zero expansion.

[0011] The obtained near-zero expansion metal matrix composite material was heat-treated to improve its mechanical properties.

[0012] A further technical solution of the present invention is: the process parameters for high-temperature solid-state sintering of the negative expansion material are: holding at 600-1400℃ for 12-36 hours.

[0013] A further technical solution of the present invention is: the raw material for preparing the negative expansion material is Sc2W3O. 12 Y2W3O 12 Er2W3O 12 Yb2W3O 12 Lu2W3O 12 Sc2Mo3O 12 Y2Mo3O 12 Er2Mo3O 12 Yb2Mo3O 12 Lu2Mo3O 12 One or more mixtures of ZrW2O8, HfW2O8, CaZrF6, and LiAlSiO4.

[0014] A further technical solution of the present invention is: the parameters of the ball milling process are: a transmission ratio of 1 to 2.25 and a ball milling rate of 100 to 500 r / min.

[0015] A further technical solution of the present invention is that the particle size of the metal powder is 15-53μm, 53-105μm or 105-150μm; the type of metal powder is aluminum powder, copper powder, nickel powder, titanium powder, alumina powder, nickel-titanium or copper-titanium powder.

[0016] A further technical solution of the present invention is: the volume ratio of negative expansion material powder to metal powder in the mixed powder is 20%:80%, 30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30%, or 80%:20%.

[0017] A further technical solution of the present invention is: the process parameters for the cold spray additive manufacturing spraying are: gas temperature of 200℃~600℃, carrier gas type of helium, nitrogen, oxygen, air or argon, and gas pressure of 1.5~3.5MPa.

[0018] A further technical solution of the present invention is: the process parameters for heat treatment of the near-zero expansion metal matrix composite material are: heat treatment at 300-450℃ for 3-6 hours.

[0019] A near-zero expansion metal-based composite material includes a negative expansion material powder and a metal powder, wherein the volume ratio of the negative expansion material powder to the metal powder is 20%:80%, 30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30%, or 80%:20%.

[0020] The negative expansion material powder is composed of Sc2W3O 12 Y2W3O 12 Er2W3O 12 Yb2W3O 12 Lu2W3O 12 Sc2Mo3O 12 Y2Mo3O 12 Er2Mo3O 12 Yb2Mo3O 12 Lu2Mo3O 12 One or more mixtures of ZrW2O8, HfW2O8, CaZrF6, and LiAlSiO4 are obtained by high-temperature sintering and ball milling;

[0021] The metal powder is aluminum powder, copper powder, nickel powder, titanium powder, alumina powder, nickel-titanium powder, or copper-titanium powder.

[0022] A further technical solution of the present invention is: the near-zero expansion metal matrix composite material is Y2W3O 12 / Al、Sc2W3O 12 / Al、Er2W3O 12 / Al、Sc2W3O 12 / Cu、Yb2Mo3O 12 / Cu、Sc2Mo3O 12 / Cu, ZrW₂O₈ / Ag, Lu₂Mo₃O 12 One or more combinations of / Ag.

[0023] Beneficial effects

[0024] The beneficial effects of this invention are as follows: the near-zero expansion metal matrix composite material prepared by the method of this invention can ensure the dimensional stability of components and precision structures, low environmental sensitivity, and structural and functional stability under thermal shock conditions, while greatly extending the service life of the material while ensuring high precision. Specific advantages are analyzed as follows:

[0025] 1. The near-zero expansion metal matrix composite material prepared by this invention, using negative expansion materials as raw materials, has the following advantages: ① Controlling the coefficient of thermal expansion: By combining negative expansion materials with positive expansion materials, the coefficient of thermal expansion can be precisely adjusted, solving problems such as thermal stress, fatigue fracture, and microcrack generation caused by mismatch in coefficients of thermal expansion; ② Maintaining dimensional stability: The addition of negative expansion materials can significantly reduce the coefficient of thermal expansion of metal matrix composite materials. Different coefficients of thermal expansion can be obtained by adjusting the content of reinforcement to meet the requirements of various working conditions and improve dimensional stability; ③ Enhancing material strength: In some composite materials, negative expansion materials can form a synergistic effect with ordinary metal materials, improving the overall strength and stiffness of the material. For example, adding negative expansion fibers or particles to a metal matrix can generate microscopic stress distribution changes when the temperature changes, hindering dislocation movement and crack propagation, thereby enhancing the mechanical properties of the composite material; ④ Improve material toughness: Some negative expansion materials themselves have good toughness. When combined with ordinary metal materials, they can improve the toughness and impact resistance of the metal materials, making the materials less prone to fracture when subjected to external impact, thus improving the safety and reliability of the materials; ⑤ Isotropic: Most negative expansion materials are isotropic, which can avoid the formation of microcracks during thermal cycling and improve the reliability of the materials.

[0026] 2. The near-zero expansion metal matrix composite material prepared by this invention, using a high-temperature solid-state sintering method to prepare negative expansion materials, has the following advantages compared to other methods: ① Simple process: Generally, it only requires mixing and grinding the raw material powders, followed by sintering at high temperature, without the need for complex chemical reaction equipment or special processing. Compared with wet chemical methods such as co-precipitation, hydrothermal methods, and sol-gel methods, it eliminates the need for cumbersome steps such as solution preparation, precipitation reaction, and gelation, reducing process steps and lowering operational difficulty and cost; ② Low equipment requirements: The main equipment is a high-temperature furnace, such as a tube furnace or box furnace, which is relatively common and easy to operate and maintain. In contrast, microwave sintering requires a specialized microwave sintering furnace, spark plasma sintering requires special molds and power supply equipment, and flash sintering requires platinum electrodes and complex current control equipment. The high-temperature solid-state sintering method has lower equipment costs and is easier to achieve large-scale production; ③ Good compositional uniformity: At high temperatures, the raw material powders can fully diffuse and react, which is beneficial for forming a negative expansion material with uniform composition. For some negative expansion materials with high requirements for compositional uniformity, such as rare earth tungstate negative thermal expansion materials, solid-state reaction processes can better ensure the material's performance stability and consistency; ④ Wide applicability: Applicable to the preparation of various negative expansion materials, including oxides, fluorides, perovskite-structured compounds, etc. For example, rare earth tungstate negative thermal expansion materials and copper pyrophosphate negative thermal expansion materials can be prepared by high-temperature solid-state sintering, while other methods may only be applicable to specific types of materials or have certain limitations; ⑤ Capable of preparing large-size materials: For some applications requiring large-size negative expansion materials, such as structural components in aerospace, precision instrument manufacturing, etc., high-temperature solid-state sintering can prepare large-size bulk materials by selecting appropriate molds and process parameters, while microwave sintering, spark plasma sintering, and other methods may be limited by equipment size and heating uniformity when preparing large-size materials. Therefore, this invention uses high-temperature sintering to prepare negative expansion materials.

[0027] 3. The near-zero expansion metal matrix composite material prepared by this invention, using a cold spray additive manufacturing method, has the following advantages compared to the commonly used hot pressing sintering method for preparing metal matrix composites: ① Reaction mechanism: The principle of cold spraying is based on the kinetic energy of high-speed solid particles. The mixed metal matrix composite powder (including metal matrix powder and reinforcing phase powder) is accelerated by a high-speed airflow. When these high-speed particles impact the matrix surface, the kinetic energy of the particles is converted into plastic deformation energy. For metal powder, this plastic deformation causes the particles to bond tightly together to form a metal matrix, while the reinforcing phase particles embed themselves into the metal matrix through high-speed impact. The entire process does not involve a traditional metallurgical reaction; it is mainly a physical embedding and deformation process. Hot pressing sintering, on the other hand, is mainly based on the principles of diffusion and sintering. Under the dual action of high temperature and pressure, the atoms on the surface of the metal powder particles gain sufficient energy and begin to diffuse between the particles, forming a necking phenomenon. As time progresses, the bonding between the particles gradually strengthens, eventually forming a dense metal matrix. Regarding the interaction between the reinforcing phase and the metal matrix, on the one hand, there is physical contact and bonding; on the other hand, if a chemical reaction can occur between them at high temperatures, new compounds will be generated. These compounds will fill the interface, thereby affecting the material's properties.

[0028] ② Microstructure: The microstructure of metal matrix composites prepared by cold spraying is quite unique. The bonding between the metal matrix and the reinforcing phase is mainly mechanical. At the microscopic level, the reinforcing phase particles are embedded into the metal matrix by high-speed impacts from the metal particles, forming a "mosaic" structure. This structure makes the distribution of the reinforcing phase in the matrix relatively uniform, and the content and distribution of the reinforcing phase can be controlled by adjusting the spraying parameters. For example, in the preparation of Al-SiC metal matrix composites, SiC particles can be relatively uniformly dispersed in the Al matrix. However, the metal matrix composites after hot pressing and sintering exhibit a relatively dense microstructure. Unlike the cold spraying method, some new phases may appear inside the material after hot pressing and sintering due to diffusion (if a chemical reaction occurs between the metal and the reinforcing phase).

[0029] ③ Material Properties: Because cold spraying is a low-temperature process (generally below the material's melting point), the material does not undergo melting and solidification, thus avoiding defects generated during hot processing, such as solidification cracks. The resulting composite material has high density and retains the properties of the original powder material, such as the good toughness of the original metal powder and the special properties of the reinforcing phase. Simultaneously, due to the bonding method between the reinforcing phase (such as a negative expansion material) and the matrix, it can effectively resist thermal expansion and contraction when the external temperature changes, improving the material's dimensional stability. In contrast, hot pressing sintering involves a high-temperature process, and the difference in thermal contraction between different phases during cooling leads to significant residual stress in the material. However, if a new phase with a large coefficient of thermal expansion is generated during sintering, it may negatively affect the composite material's thermal expansion properties. Furthermore, excessive chemical reactions or grain growth during sintering may adversely affect the material's toughness.

[0030] 4. The near-zero expansion metal matrix composite material prepared by this invention has controllable thermal expansion properties. By adjusting the ratio and distribution of negative expansion powder and metal powder, the thermal expansion properties of the metal matrix composite material can be controlled to a certain extent. The cold spraying process does not change the thermal expansion characteristics of the negative expansion powder. Therefore, the negative thermal expansion properties of the negative expansion powder can be used to "compensate" for the positive thermal expansion of the metal matrix, thereby preparing a metal matrix composite material with a specific coefficient of thermal expansion or even near-zero expansion, meeting the requirements for material dimensional stability under different temperature environments.

[0031] 5. The near-zero expansion metal matrix composite material prepared by the present invention enables a strong mechanical bond between the reinforcing phase and the matrix metal through the use of cold spray additive manufacturing, rather than relying on the formation of intermetallic compounds or excessive metallurgical bonding. This method helps to obtain a more uniform and stable interface bond, which is beneficial to improving the mechanical properties and wear resistance of the material.

[0032] 6. The near-zero expansion metal matrix composite material mentioned in this invention has a low-cost and simple preparation method, and does not require the addition of large amounts of chemical reagents or solvents during the spraying process, resulting in a lower overall environmental impact. Compared with traditional preparation methods, this method generates less waste gas, wastewater, and solid waste, which helps reduce environmental pollution and worker health risks. Attached Figure Description

[0033] Figure 1 X-ray diffraction image of the near-zero expansion metal matrix composite material prepared in Embodiment 1 of the present invention;

[0034] Figure 2 A scanning electron microscope image of the near-zero expansion metal matrix composite material prepared in Example 1 of this invention;

[0035] Figure 3 This is a scanning electron microscope (SEM) image of the interface structure between the negative expansion material (reinforcing phase) and the metal matrix in the near-zero expansion metal matrix composite material prepared in Example 1 of the present invention.

[0036] Figure 4 This is an EDS image of the near-zero expansion metal matrix composite material prepared in Example 1 of the present invention.

[0037] Figure 5 The image shows the coefficient of thermal expansion of the near-zero expansion metal matrix composite material prepared in Embodiment 1 of the present invention. Detailed Implementation

[0038] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0039] Traditional material preparation methods often involve high-temperature treatments, which can lead to oxidation, phase transformation, or grain coarsening. This invention uses a negative expansion material as a thermal expansion inhibitor, mixed with a positive thermal expansion material (metal) to form a composite material. Adding a negative expansion material to a positive thermal expansion material results in a low or even near-zero thermal expansion characteristic, thus ensuring the composite material's coefficient of thermal expansion remains stable under varying external temperatures. This significantly reduces residual stress caused by thermal expansion and contraction in materials and components. Furthermore, the near-zero expansion material ensures dimensional stability of components and precision structures, low environmental sensitivity, and structural and functional stability under thermal shock conditions. While maintaining high precision, it greatly extends the material's lifespan and reduces unnecessary wear (such as temperature compensators), demonstrating significant application potential.

[0040] In one embodiment, a cold spray additive manufacturing method for near-zero expansion metal matrix composites comprises the following steps:

[0041] Step 1: Select the raw materials for preparing negative expansion materials, and perform high-temperature solid-state sintering on the selected raw materials to obtain negative expansion materials; the process parameters for high-temperature solid-state sintering are: holding at 600~1400℃ for 12~36h;

[0042] For example, Sc2W3O is selected as the raw material for preparing negative expansion materials. 12 Y2W3O 12 Er2W3O 12 Yb2W3O 12 Lu2W3O 12 Sc2Mo3O 12 Y2Mo3O 12 Er2Mo3O 12 Yb2Mo3O12 Lu2Mo3O 12 One or more mixtures of ZrW2O8, HfW2O8, CaZrF6, and LiAlSiO4.

[0043] Step 2: The prepared negative expansion material is mixed with metal powder by ball milling to obtain a mixed powder; the parameters of the ball milling process are: transmission ratio of 1 to 2.25, and ball milling speed of 100 to 500 r / min.

[0044] For example, the particle size of the metal powder is 15–53 μm, 53–105 μm, or 105–150 μm;

[0045] For example, the types of metal powders include aluminum powder, copper powder, nickel powder, titanium powder, alumina powder, nickel-titanium powder, or copper-titanium powder.

[0046] For example, the volume ratio of negative expansion material powder to metal powder in the mixed powder is 20%:80%, 30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30%, or 80%:20%.

[0047] Step 3: The mixed powder is sprayed and formed by cold spray additive manufacturing to obtain a near-zero expansion metal matrix composite material; the process parameters for cold spray additive manufacturing are: gas temperature of 200℃~600℃, carrier gas type of helium, nitrogen, oxygen, air or argon, and gas pressure of 1.5~3.5MPa.

[0048] The obtained near-zero expansion metal matrix composite material was heat-treated at 300–450℃ for 3–6 hours to improve the mechanical properties of the composite material.

[0049] The above technical solution will be further explained below with reference to the accompanying drawings:

[0050] In one embodiment, a cold spray additive manufacturing method for near-zero expansion metal matrix composites is carried out according to the following steps:

[0051] I. Negative expansion materials were prepared by high-temperature solid-state sintering at 600–1400℃ for 12–36 h.

[0052] 2. The obtained negative expansion material is ball-milled at a transmission ratio (r) of 1 to 2.25 and a ball milling rate of 100 to 500 r / min and then mixed with metal powder until homogeneous.

[0053] Third, by spraying the uniformly mixed powder through cold spray additive manufacturing, a metal matrix composite material with near-zero expansion can be obtained.

[0054] Fourth, the obtained near-zero expansion metal matrix composite material is heat-treated at 300-450℃ for 3-6 hours to improve the mechanical properties of the composite material.

[0055] The method of this invention is to fully mix the synthesized negative expansion material with metal powder, and then prepare a near-zero expansion metal matrix composite material by cold spray additive manufacturing. This ensures that the coefficient of thermal expansion remains stable when external conditions (temperature, pressure) change drastically, which greatly reduces the residual stress problem caused by thermal expansion and contraction of materials and components.

[0056] In one embodiment, the negative expansion material is prepared at 1200°C for 12 hours.

[0057] In one embodiment, the negative expansion material is Sc2W3O. 12 Y2W3O 12 Er2W3O 12 Yb2W3O 12 Lu2W3O 12 Sc2Mo3O 12 Y2Mo3O 12 Er2Mo3O 12 Yb2Mo3O 12 Lu2Mo3O 12 One or more mixtures of ZrW2O8, HfW2O8, CaZrF6, and LiAlSiO4.

[0058] In one embodiment, the ball milling parameters are a transmission ratio (r) of 2 and a ball milling rate of 400 r / min.

[0059] In one embodiment, the particle size of the metal powder is 15–53 μm, 53–105 μm, 105–150 μm, etc.

[0060] In one embodiment, the metal particles are aluminum powder, copper powder, nickel powder, titanium powder, alumina powder, nickel-titanium powder, and copper-titanium powder, etc.

[0061] In one embodiment, the volume ratio of the mixed powder is negative expansion powder: metal powder = 20%:80%, 30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30%, 80%:20%, etc.

[0062] In one embodiment, the process parameters of the cold spraying equipment include a gas temperature of 200℃ to 600℃, a carrier gas of helium (He), nitrogen (N2), oxygen (O2), air, and argon (Ar), and a gas pressure of 1.5 to 3.5 MPa.

[0063] In one embodiment, the metal matrix composite material is Y2W3O 12 / Al、Sc2W3O 12 / Al、Er2W3O 12 / Al、Sc2W3O 12 / Cu、Yb2Mo3O 12 / Cu、Sc2Mo3O 12 / Cu, ZrW₂O₈ / Ag, Lu₂Mo₃O 12 / Ag and one or more combinations thereof proposed above.

[0064] In one embodiment, the heat treatment temperature is 400°C and the holding time is 4 hours.

[0065] In one embodiment, a cold spray additive manufacturing method for a near-zero expansion metal matrix composite material is carried out according to the following steps:

[0066] Step 1: This experiment uses a high-temperature solid-state sintering method to prepare negative expansion materials. Specifically, anhydrous ethanol is used as the ball milling medium. Stoichiometric amounts of Y₂O₃ (Aladdin, 99.99%) and WO₃ (Aladdin, 99.99%) powders are thoroughly mixed at a stoichiometric ratio of 1:3 and then ball-milled for 10 hours. After drying at 75°C for 48 hours, the mixed powder is poured into a platinum crucible using a solid-state sintering method. The platinum crucible is then placed in a muffle furnace and heated to 1100°C, held for 20 hours to obtain Y₂W₃O₃. 12 Powder, and the obtained Y2W3O 12 The powder undergoes a final ball milling process to obtain fine Y2W3O. 12 powder;

[0067] Step 2: Obtain Y2W3O 12 The powder was ball-milled and then mixed uniformly with metal powder to prepare mixed powders in different proportions.

[0068] Step 3: The uniformly mixed powder is sprayed and molded using cold spray additive manufacturing to obtain a metal matrix composite material with near-zero expansion.

[0069] Step 4: Heat-treat the obtained near-zero expansion metal matrix composite material at 300-450℃ for 3-6 hours to improve the mechanical properties of the composite material.

[0070] Preferably, the method for preparing the negative expansion material in step one is high-temperature solid-state sintering.

[0071] Preferably, the negative expansion material mentioned in step one is Y2W3O. 12 .

[0072] Preferably, the ball milling parameters in step one are a transmission ratio (r) of 2.25 and a ball milling rate of 300 r / min.

[0073] Preferably, the particle size of the metal powder in step two is 15–53 μm.

[0074] Preferably, the metal powder mentioned in step two is aluminum powder.

[0075] Preferably, the ratio of the mixed powder in step two is Y2W3O. 12 :Al=30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30%, 80%:20%, etc.

[0076] Preferably, the process parameters of the cold spraying equipment described in step three are: gas temperature 400℃, carrier gas type N2, and gas pressure 2.5MPa.

[0077] Preferably, the near-zero expansion metal matrix composite material mentioned in step three is Y2W3O. 12 / Al.

[0078] Preferably, the heat treatment temperature in step four is 300°C and the holding time is 3 hours.

[0079] To demonstrate the Y2W3O prepared in this invention 12 / Al composites exhibit near-zero expansion. First, Y₂O₃ powder and WO₃ powder are mixed in a stoichiometric ratio of 1:3 and ball-milled. The mixture is then poured into a platinum crucible, which is placed in a muffle furnace and heated to 1100℃. After holding at this temperature for 20 hours, Y₂W₃O₃ is obtained. 12 The powder, and its XRD pattern are shown below. Figure 1 As shown, the resulting Y2W3O 12 The powder undergoes a final ball milling process to obtain fine Y2W3O. 12 Y₂W₃O₃ powder was prepared by thoroughly mixing it with spherical Al powder with a particle size of 15–53 micrometers, and then the uniformly mixed powder was sprayed into shape by cold spray additive manufacturing to obtain Y₂W₃O₃ with near-zero expansion. 12 / Al composite material, its XRD image is as follows Figure 1 As shown, the near-zero expansion of Y2W3O 12 The deposition effect of Al mixed powder on the substrate is as follows: Figure 2 As shown, the near-zero expansion of Y2W3O 12 Scanning electron microscope images of the interface structure between the Al composite material and the substrate are shown below. Figure 3 As shown, near-zero expansion Y2W3O 12 EDS spectrum of Al composite material as shown in the image. Figure 4As shown, the near-zero expansion of Y2W3O 12 The coefficient of thermal expansion of Al composite materials is as follows: Figure 5 As shown.

[0080] Figure 1 The image shows the XRD pattern of the near-zero expansion metal matrix composite material in this embodiment. The image demonstrates that negative expansion Y₂W₃O₄ can be precisely prepared using solid-state sintering. 12 The material reacted completely without the appearance of other impurity phases (such as WO3, Y2O3, etc.). Y2W3O was prepared by cold spraying. 12 / Al composite materials only have Y2W3O 12 The peaks of Al did not introduce a new phase.

[0081] Figure 2 The near-zero expansion Y2W3O prepared by cold spray additive manufacturing method in this embodiment 12 Scanning electron microscope (SEM) images of Al composite materials, showing the negative expansion material (Y2W3O). 12 The material is uniformly and densely deposited on the substrate, and the deposition effect is relatively good, so that the coefficient of thermal expansion of the composite material remains stable when the external temperature changes.

[0082] Figure 3 To prepare near-zero expansion Y2W3O 12 Scanning electron microscope (SEM) image of the interface structure between the Al composite material and the substrate. As shown in the figure, the near-zero expansion Y₂W₃O₂... 12 The Al composite material has a close interface with the matrix, a low degree of interface reaction, a very thin interface reaction layer, and a high bonding strength that makes it difficult to break.

[0083] Figure 4 The near-zero expansion Y2W3O prepared for this embodiment 12 EDS energy dispersive spectroscopy image of the / Al composite material. As shown in the figure, the prepared Y2W3O 12 The bright white coating in the Al composite material is Y2W3O. 12 The black part is Al, and both are evenly distributed with little aggregation.

[0084] Figure 5 The near-zero expansion Y2W3O prepared for this embodiment 12 Image of the thermal expansion coefficient of Al composite material. The image shows the thermal expansion coefficient of Y2W3O prepared by the cold spray additive manufacturing method. 12 The coefficient of thermal expansion of the Al composite material was calculated to be infinitely close to 0, which indicates that doping Al (metal) with negative expansion materials can significantly reduce its coefficient of thermal expansion and give it better mechanical properties.

[0085] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A cold spray additive manufacturing method of near-zero expansion metal matrix composites, characterized by The specific steps are as follows: The raw materials for preparing the negative expansion material are selected, and the selected raw materials are prepared into the negative expansion material through high-temperature solid-phase sintering; the process parameters for the high-temperature solid-phase sintering of the negative expansion material are as follows: 600-1400 DEG C for 12-36 h; The prepared negative expansion material is mixed with metal powder uniformly through a ball milling process to obtain mixed powder; The mixed powder is sprayed and formed through cold spraying additive manufacturing to obtain a near-zero expansion metal matrix composite material; the process parameters for the cold spraying additive manufacturing spraying forming are as follows: the gas temperature is 200 DEG C-600 DEG C, the carrier gas type is helium, nitrogen, oxygen, air or argon, and the gas pressure is 1.5-3.5 MPa; The obtained near-zero expansion metal matrix composite material is heat treated to improve the mechanical properties of the composite material; the process parameters for the heat treatment of the near-zero expansion metal matrix composite material are as follows: 300-450 DEG C for 3-6 h.

2. A cold spray additive manufacturing method of near-zero expansion metal matrix composite according to claim 1, characterized in that: The raw materials for preparing the negative expansion material are selected from one or more mixtures of Sc2W3O 12 , Y2W3O 12 , Er2W3O 12 , Yb2W3O 12 , Lu2W3O 12 , Sc2Mo3O 12 , Y2Mo3O 12 , Er2Mo3O 12 , Yb2Mo3O 12 , Lu2Mo3O 12 , ZrW2O8, HfW2O8, CaZrF6, LiAlSiO4.

3. A cold spray additive manufacturing method of near-zero expansion metal matrix composite according to claim 2, characterized in that: The parameters of the ball milling process are as follows: the transmission ratio is 1-2.25, and the ball milling speed is 100-500 r / min.

4. A cold spray additive manufacturing method of near-zero expansion metal matrix composite according to claim 3, characterized in that: The particle size of the metal powder is 15-53 mu m, 53-105 mu m or 105-150 mu m; and the type of the metal powder is aluminum powder, copper powder, nickel powder, titanium powder, nickel-titanium powder or copper-titanium powder.

5. A cold spray additive manufacturing method of near-zero expansion metal matrix composite according to claim 4, characterized in that: The volume ratio of the negative expansion material powder to the metal powder in the mixed powder is as follows: negative expansion material powder: metal powder = 20%:80%, 30%:70%, 40%:60%, 50%:50%, 60%:40%, 70%:30% or 80%:20%.

6. A near-zero expansion metal matrix composite obtained by the cold spray additive manufacturing method of the near-zero expansion metal matrix composite according to any one of claims 1 to 5; characterized in that: The metal powder is aluminum powder, copper powder, nickel powder, titanium powder, nickel-titanium powder or copper-titanium powder. The negative expansion material powder is obtained by high-temperature sintering and ball milling of one or more mixtures of Sc2W3O 12 , Y2W3O 12 , Er2W3O 12 , Yb2W3O 12 , Lu2W3O 12 , Sc2Mo3O 12 , Y2Mo3O 12 , Er2Mo3O 12 , Yb2Mo3O 12 , Lu2Mo3O 12 , ZrW2O8, HfW2O8, CaZrF6, LiAlSiO4. The metal powder is aluminum powder, copper powder, nickel powder, titanium powder, nickel-titanium powder or copper-titanium powder.

7. A near-zero expansion metal matrix composite according to claim 6, wherein: The near-zero expansion metal matrix composite is one or more combinations of Y2W3O 12 / Al, Sc2W3O 12 / Al, Er2W3O 12 / Al, Sc2W3O 12 / Cu, Yb2Mo3O 12 / Cu, Sc2Mo3O 12 / Cu, ZrW2O8 / Ag, Lu2Mo3O 12 / Ag.

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