Ultrasonic consolidation graphite-reinforced copper-aluminum gradient composite functional structure

Abstract

This utility model discloses an ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, comprising a layered matrix formed by alternating consolidation of aluminum and copper layers, and a graphite rod embedded in the layered matrix. The layered matrix has a three-dimensional flow channel structure internally, and heat dissipation fins are disposed on its surface. The layered matrix is ​​fabricated using an ultrasonic consolidation device. By alternately consolidating copper and aluminum foil to form the layered matrix, and integrating internal cooling channels and external heat dissipation fins, it achieves coordinated heat dissipation through liquid and air cooling. This structure utilizes ultrasonic low-temperature solid-state bonding technology to avoid the formation of intermetallic compounds, and possesses high thermal conductivity, low density, and multifunctional heat dissipation characteristics. It is suitable for efficient thermal management in fields such as electronic equipment and new energy devices, and its manufacturing process is simple with significant engineering application value.

Description

Technical Field

[0001] This utility model relates to the field of metal matrix composite material manufacturing technology, and in particular to an ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure. Background Technology

[0002] In fields such as electronics, new energy vehicles, and aerospace, efficient thermal management and electrical conductivity are core requirements. Traditional heat dissipation structures often use single-metal materials (such as pure copper or pure aluminum), which have performance limitations: pure copper has excellent thermal conductivity but high density and cost; pure aluminum has low density but its thermal conductivity is only 60% of that of copper. Although copper-aluminum composite technologies (such as brazing and explosive welding) can combine the advantages of both, traditional welding processes suffer from the problem of intermetallic compounds (such as Cu9Al4 and CuAl2) forming at high temperatures, which seriously affects the interfacial bonding strength and thermal conductivity (interfacial thermal resistance can increase by 30%-50%). In addition, due to the inherent limits of electrical and thermal conductivity of aluminum and copper, traditional metal materials are gradually failing to meet the ever-increasing heat dissipation demands. To overcome performance bottlenecks, the addition of second phases with ultra-high electrical and thermal conductivity, such as graphite and diamond, has become an important approach. Additive manufacturing technology has made complex structural designs possible, but existing fusion forming processes such as laser cladding and arc welding are prone to defects such as porosity and cracks when copper and aluminum are composited, and the non-destructive embedding of the second phase cannot be achieved in high-temperature environments. Although ultrasonic solid-phase additive manufacturing (UAM) can achieve solid-phase bonding of metal foils at low temperatures (150-200℃), there is still a lack of systematic solutions for the design and functional expansion of second-phase reinforced copper-aluminum gradient structures (such as integrated flow channels and heat dissipation fins). Summary of the Invention

[0003] In order to overcome the above-mentioned problems in the existing technology, this utility model proposes an ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure.

[0004] The technical solution adopted by this utility model to solve its technical problem is: an ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, comprising a layered matrix formed by alternating consolidation of aluminum and copper layers, and a graphite rod, wherein the graphite rod is embedded in the layered matrix, the layered matrix has a three-dimensional flow channel structure inside, and heat dissipation fins are provided on the surface of the layered matrix, and the layered matrix is ​​prepared by an ultrasonic consolidation device.

[0005] The above-mentioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure has a rectangular cross-sectional shape for the three-dimensional flow channel structure, a width of 1-5 mm, and an inner wall roughness Ra≤1.6μm.

[0006] The above-mentioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure has a three-dimensional flow channel structure that is either linear or spiral.

[0007] The above-mentioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure has heat dissipation fins with a height of 5-20mm, a thickness of 0.5-2mm, and a spacing of 2-5mm.

[0008] In the aforementioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, the heat dissipation fins are oriented in the same direction as the airflow.

[0009] In the above-mentioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, the graphite rod is pre-placed on the aluminum and copper layers, and during ultrasonic consolidation of the layered matrix, the low-temperature solid phase characteristics of ultrasonic additive manufacturing are utilized to non-destructively embed the graphite rod into the layered matrix.

[0010] In the above-mentioned ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, the thickness of both the copper layer and the aluminum layer is 0.3-0.5 mm.

[0011] The beneficial effects of this invention are that by alternately solidifying copper and aluminum foils (with graphite rods pre-placed within) to form a layered matrix, and integrating built-in cooling channels and external heat dissipation fins, it achieves coordinated heat dissipation through liquid cooling and air cooling. This structure utilizes ultrasonic low-temperature solid-state bonding technology to avoid the formation of intermetallic compounds, and possesses high thermal conductivity (300W / (m・K)), low density (60% pure copper), and multifunctional heat dissipation characteristics. It is suitable for efficient thermal management in fields such as electronic equipment and new energy devices, and its manufacturing process is simple with significant engineering application value. Attached Figure Description

[0012] Figure 1 This is a cross-sectional schematic diagram of the present invention;

[0013] Figure 2 This is a schematic diagram of the preparation process of this utility model. Detailed Implementation

[0014] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] like Figure 1 As shown, this embodiment discloses an ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure, including a layered matrix formed by alternating consolidation of aluminum and copper layers (n≥2, where n is the number of copper-aluminum cycles), a graphite rod 4, the graphite rod 4 being embedded in the layered matrix, a three-dimensional flow channel structure 2 being provided inside the layered matrix, and heat dissipation fins 5 being provided on the surface of the layered matrix, the heat dissipation fins 5 being integrally formed with the layered matrix, and the layered matrix being prepared by an ultrasonic consolidation device.

[0016] In this embodiment, a graphite rod is pre-placed on aluminum layer 1 and copper layer 3. During ultrasonic consolidation of the layered matrix, the low-temperature solid-phase characteristics of ultrasonic additive manufacturing are utilized to non-destructively embed the graphite rod into the layered matrix. The diameter of the graphite rod 4 is 0.2-0.4 mm, and the thickness of aluminum layer 1 and copper layer 3 is 0.3-0.5 mm. A graphite rod with a diameter of 0.2-0.4 mm is pre-placed in an aluminum foil with a thickness of 0.3-0.5 mm. Then, copper foil with a thickness of 0.3-0.5 mm is alternately stacked and solidified with the aluminum foil. After the oxide film on the surface of the single-layer foil is removed by ultrasonic vibration, a metallurgical bonding interface is formed. The graphite is well encapsulated by the metal matrix without obvious defects. There is no continuous intermetallic compound layer at the interface, and the interlayer peel strength is ≥80 MPa.

[0017] A three-dimensional flow channel structure is formed within the layered matrix through machining (such as CNC milling or laser cutting). The three-dimensional flow channel structure is linear or spiral in shape, with a rectangular cross-section. The width of the three-dimensional flow channel structure is 1-5 mm, and the depth is the same as the thickness of the aluminum or copper layer. The roughness Ra of the inner wall of the three-dimensional flow channel structure is ≤1.6 μm. The inlet and outlet of the three-dimensional flow channel structure are respectively located at both ends of the composite functional structure, allowing water, coolant, or phase change material to be introduced for liquid cooling.

[0018] Fin-like structures are machined onto the surface of a layered substrate. The fins are 5-20 mm high, 0.5-2 mm thick, and spaced 2-5 mm apart. The fin direction is aligned with the airflow direction (angle ≤30°). The fin area can be combined with the air-cooling area to form a composite heat dissipation system of "liquid cooling channel + air-cooling fins". The heat dissipation fins are 5-20 mm high, 0.5-2 mm thick, and spaced 2-5 mm apart.

[0019] like Figure 1 As shown, in this embodiment, the first layer at the bottom is an aluminum layer, and above the aluminum layer is a copper layer, with the copper layer being larger than the aluminum layer. The copper layer extends to the outside of the aluminum layer on both sides, forming heat dissipation fins. A three-dimensional flow channel structure is fabricated in the middle of the copper layer. The aluminum and copper layers are stacked alternately to form a composite functional structure. Alternatively, the first layer at the bottom can be a copper layer, with a three-dimensional flow channel structure fabricated in the middle of the aluminum layer, and the aluminum layer extending to the outside of the copper layer on both sides. The copper and aluminum layers are stacked alternately. Furthermore, one or more single-layer three-dimensional flow channel structures can be provided; in this embodiment, one is provided.

[0020] The above-mentioned method for preparing ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structures, such as... Figure 2 As shown, Figure 2 for Figure 1 The preparation process of the view is as follows: Foil pretreatment: Cut copper foil (such as T2 copper) and aluminum foil (such as 6061 aluminum) with a purity of ≥99.9% to remove the surface oxide film with sandpaper (800-1200 mesh) and ultrasonically clean with anhydrous ethanol for 10-15 minutes.

[0021] Graphite rod pre-positioning: Use a milling cutter to cut a groove 0.2-0.4mm deep and wide on the surface of the bonded aluminum foil and copper foil, and pre-position a graphite rod of the corresponding size in it.

[0022] Layer-by-layer consolidation and milling: Using an ultrasonic consolidation device (such as a dual-transducer push-pull type, output power 6000-9000W, vibration frequency 20kHz), layers are stacked sequentially in the order of "copper foil → aluminum foil → copper foil →..." (or aluminum foil → copper foil → aluminum foil →...), with a consolidation pressure of 0.3-0.6MPa for each layer. After consolidating the first layer of foil and pre-positioning the graphite rod, the second fin layer is milled to create pre-set flow channels, while simultaneously pre-positioning the graphite rod. The next layer of foil is then consolidated to cover the flow channels. Preheating temperature is 50-150℃ to form the initial layered blank.

[0023] Surface treatment and encapsulation: The inner wall of the flow channel is anodized (aluminum layer) or electroless nickel-plated (copper layer) to improve corrosion resistance; a heat dissipation coating (such as graphene modified coating with thermal conductivity ≥50W / (m・K)) is sprayed on the outside of the composite functional structure, and the inlet and outlet joints of the flow channel are encapsulated.

[0024] The composite functional structure prepared by this method achieves an optimized balance between thermal conductivity and density through alternating copper and aluminum layers (such as Cu / Al / Cu / Al / Cu… multilayer structure). The measured thermal conductivity of the composite structure can reach 300 W / (m・K), and the density is only 60% of that of pure copper.

[0025] Integrated composite heat dissipation function: The built-in flow channel can withstand fluid pressure of 0.5-1MPa, and the temperature rise is ≤15℃ when the flow rate is 5-20L / min; the external fins can achieve a surface convective heat transfer coefficient of 50-80W / (m²・K) when the wind speed is 5-10m / s, forming a "liquid cooling + air cooling" synergistic heat dissipation system.

[0026] Advantages of low-temperature solid-state manufacturing: The solidification process temperature is ≤200℃, and thermocouples, micro sensors and other components can be pre-embedded between layers (such as embedding a K-type thermocouple in an aluminum layer with a temperature measurement accuracy of ±1℃) to achieve structural health monitoring functions.

[0027] The above embodiments are merely exemplary embodiments of this utility model and are not intended to limit this utility model. Those skilled in the art can make various modifications or equivalent substitutions to this utility model within its substance and protection scope, and such modifications or equivalent substitutions should also be considered to fall within the protection scope of this utility model.

Claims

1. An ultrasonic consolidated graphite-reinforced copper-aluminum gradient composite functional structure, characterized in that, The material comprises a layered matrix formed by alternating solidification of aluminum and copper layers, and a graphite rod. The graphite rod is embedded in the layered matrix. The layered matrix has a three-dimensional flow channel structure inside and heat dissipation fins on its surface. The layered matrix is ​​prepared by ultrasonic solidification equipment.

2. The ultrasonic consolidated graphite-reinforced copper-aluminum gradient composite functional structure according to claim 1, characterized in that, The cross-sectional shape of the three-dimensional flow channel structure is rectangular, the width of the three-dimensional flow channel structure is 1-5mm, and the roughness Ra of the inner wall of the three-dimensional flow channel structure is ≤1.6μm.

3. The ultrasonic consolidated graphite-reinforced copper-aluminum gradient composite functional structure of claim 1, wherein, The three-dimensional flow channel structure is either linear or spiral.

4. The ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure according to claim 1, characterized in that, The heat dissipation fins have a height of 5-20mm, a thickness of 0.5-2mm, and a spacing of 2-5mm.

5. The ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure according to claim 1, characterized in that, The heat dissipation fins are oriented in the same direction as the airflow.

6. The ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure according to claim 1, characterized in that, The graphite rod is pre-placed on the aluminum and copper layers, and during ultrasonic consolidation of the layered matrix, the low-temperature solid phase characteristics of ultrasonic additive manufacturing are used to embed the graphite rod into the layered matrix without damage.

7. The ultrasonically consolidated graphite-reinforced copper-aluminum gradient composite functional structure according to claim 1, characterized in that, The thickness of both the copper and aluminum layers is 0.3-0.5 mm.

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