A high thermal conductivity aluminum profile for 5G base station radiators and its preparation process

Abstract

The present invention relates to the field of aluminum alloy materials, and provides a high thermal conductivity aluminum profile for 5G base station radiators and a preparation process thereof, which is composed of a magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder. The diamond dual-scale reinforcement is composed of micron-sized and nano-sized diamond particles, and the mass ratio is (5.0~8.0):1. The surface of the diamond dual-scale reinforcement is coated with a 15~30nm magnesium boride layer. The magnesium boride coating layer is prepared by electroless plating, and an Al3BC transition layer is formed in-situ in the aluminum alloy matrix through vacuum sintering to optimize the interfacial bonding. The third-order cold pressing forming, hot isostatic pressing sintering and two-pass hot extrusion processes are adopted to ensure the high density and excellent thermal conductivity of the material. The present invention effectively improves the thermal conductivity and mechanical properties of the aluminum profile, and is applicable to 5G base station radiators and high-efficiency heat dissipation fields.

Description

Technical Field

[0001] The present invention relates to the field of aluminum alloy materials, and particularly to a high thermal conductivity aluminum profile for a 5G base station radiator and a preparation process thereof. Background Art

[0002] Under the background of the rapid development of 5G communication technology, the power consumption of base station equipment has increased significantly, resulting in heat dissipation problems becoming a key factor restricting its performance and stability. 5G base stations usually adopt high-density integrated circuits and high-power radio frequency devices. These core components will generate a large amount of heat during operation. If the heat cannot be effectively dissipated, the operating temperature of the equipment will increase, affecting the signal transmission stability, reducing the service life of the components, and even causing system failures. Therefore, as the core component of the base station thermal management system, the radiator must have high thermal conductivity to quickly transfer heat from the heat source to the heat dissipation medium, and at the same time ensure good mechanical strength to support the structural stability and adapt to complex environments. Specifically, an ideal 5G base station radiator material should have high thermal conductivity to reduce the thermal resistance and improve the heat dissipation efficiency, and at the same time have high strength and a low coefficient of thermal expansion to avoid deformation or cracking caused by thermal cycling. In addition, the material should have good corrosion resistance and processability to meet the long-term use requirements of the outdoor environment. Therefore, developing radiator materials with both high thermal conductivity and excellent mechanical properties is of great significance for improving the stability of 5G base station equipment, extending its service life, and reducing maintenance costs.

[0003] At present, aluminum matrix composites have become one of the main candidate materials for 5G base station radiators due to their excellent thermal conductivity, lightweight, and good processability. However, existing aluminum matrix composites still have the problem of being difficult to balance thermal conductivity and mechanical properties. For example, the Chinese patent with the publication number CN110117731B discloses a preparation method of an ultra-high thermal conductivity diamond particle-reinforced aluminum matrix composite, but its interfacial bonding force is weak, resulting in a decline in the mechanical properties of the composite and restricting its practical application. In addition, the reinforcing phases of traditional aluminum matrix composites are unevenly distributed, and the interfacial thermal resistance is large, making the overall thermal conductivity not reach the ideal level. Some studies have tried to improve the thermal conductivity of the material by adding thermal conductivity enhancers (such as SiC, AlN, etc.), but due to the poor interfacial matching between the reinforcing phase and the aluminum matrix, the brittleness of the material often increases, reducing the mechanical properties. On the other hand, some studies use powder metallurgy or melting casting processes to prepare high thermal conductivity aluminum matrix materials, but due to the difficulty in controlling the reaction between the reinforcing body and the matrix, brittle phases are easily formed at the interface, resulting in a decline in the toughness of the material. Therefore, how to improve the thermal conductivity of aluminum matrix composites while optimizing the interfacial bonding force, uniformly distributing the reinforcing phase, and improving the overall mechanical properties is still a key challenge in current research. Summary of the Invention

[0004] To solve the technical problems in the prior art, the purpose of the present invention is to provide a high thermal conductivity aluminum profile for a 5G base station radiator and its preparation process.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A high thermal conductivity aluminum profile for a 5G base station radiator, comprising the following raw materials in parts by weight: 45 - 60 parts of magnesium boride-coated diamond dual-scale reinforcement and 35 - 55 parts of aluminum alloy powder;

[0007] The magnesium boride-coated diamond dual-scale reinforcement consists of a diamond dual-scale reinforcement and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcement;

[0008] The diamond dual-scale reinforcement consists of micron-scale diamond particles and nano-scale diamond particles;

[0009] The mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is (5.0 - 8.0):1;

[0010] The high thermal conductivity aluminum profile for a 5G base station radiator includes a diamond dual-scale reinforcement, an aluminum alloy matrix, and a transition layer therebetween; the thickness of the transition layer is 30 - 42 nm.

[0011] The transition layer contains an Al3BC phase, and the Al3BC phase is in-situ generated at high temperature from the magnesium boride coating layer, the diamond dual-scale reinforcement, and the aluminum alloy powder.

[0012] Furthermore, the average particle size of the micron-scale diamond particles is 5.0 - 10.0 μm; the average particle size of the nano-scale diamond particles is 450.0 - 950.0 nm;

[0013] Furthermore, the thickness of the magnesium boride coating layer is 15 - 30 nm;

[0014] Furthermore, the aluminum alloy powder is an Al-Si-Mg alloy powder, the Si content is 5.0 - 8.0 wt.%, the Mg content is 0.5 - 1.2 wt.%, and the balance is Al;

[0015] The present invention adopts the design of compounding magnesium boride-coated diamond dual-scale reinforcements with an aluminum alloy matrix, which is mainly used to enhance the thermal conductivity and mechanical properties of the material to meet the requirements of high-efficiency thermal management and structural stability for 5G base station radiators. Diamond is an ideal reinforcement due to its excellent thermal conductivity, but the interfacial bonding force between it and the aluminum matrix is weak, which easily leads to an increase in interfacial thermal resistance and affects the overall performance of the composite material. The present invention optimizes the filling effect of the reinforcements by introducing a dual-scale combination of micron-scale and nano-scale diamond particles, enabling them to form a uniformly distributed high-thermal-conductivity network in the aluminum matrix. Among them, the micron-scale diamond particles provide the dominant heat conduction path, and the nano-scale diamond particles fill the micro-gaps, improving the compactness and uniformity of the interfacial bonding, thereby effectively reducing the interfacial thermal resistance of the composite material. To further enhance the interfacial compatibility between diamond and the aluminum matrix, the present invention uses a magnesium boride coating layer with a thickness controlled within 15 - 30 nm. An Al3BC transition layer is formed through a high-temperature in-situ reaction, and the thickness of this transition layer is 30 - 42 nm. It can effectively improve the bonding strength between diamond and the aluminum matrix, reduce interfacial defects, avoid interfacial heat loss caused by direct contact, and at the same time improve the mechanical properties of the material. The aluminum alloy matrix uses Al-Si-Mg alloy powder. The addition of Si helps to improve the fluidity and creep resistance of the aluminum matrix, while the addition of Mg can promote the precipitation of strengthening phases, further enhancing the mechanical strength and heat resistance stability of the material. Each component shows a high degree of synergy during the compounding process. The diamond dual-scale reinforcements provide an efficient heat conduction path, the magnesium boride coating layer and the Al3BC transition layer optimize the interfacial bonding, and the aluminum alloy matrix ensures good processability and structural strength, making the final material possess excellent thermal conductivity and mechanical properties, meeting the application requirements of 5G base station radiators in a high heat flux environment.

[0016] Further, the preparation method of the magnesium boride-coated diamond dual-scale reinforcement is as follows: Immerse the diamond dual-scale reinforcement in the electroless plating solution, and the mass ratio of the diamond dual-scale reinforcement to the electroless plating solution is (25-45):(80-120); The plating solution contains, by weight, 12-15 parts of nano magnesium boride, 20-22 parts of sodium hypophosphite, 4.5-5.5 parts of sodium succinate, 23-25 parts of sodium acetate, and 7-9 parts of dimethyl sulfoxide; Adjust the pH of the plating solution to 5.5-6.5 with 0.1-0.5 mol / L sodium hydroxide or hydrochloric acid solution, and disperse it at a mechanical stirring rate of 300-500 rpm for 10-30 min to form a uniform suspension; Transfer the suspension to a reaction kettle, heat it to 90-100 °C at a heating rate of 3-5 °C / min, and deposit at a constant temperature for 50-70 min; After the deposition is completed, cool it to room temperature at 2-4 °C / min, filter and separate the solid product, and wash the solid product with deionized water 3-5 times, with the water consumption per time being 5-10 times the mass of the solid product; Place the washed solid product in a vacuum drying oven, dry it at 60-80 °C for 2-4 h, and then heat it to 280-320 °C at a heating rate of 10-15 °C / min in a tubular furnace under an argon atmosphere, and keep it warm for 50-70 min to complete the annealing treatment. After cooling to room temperature, the magnesium boride-coated diamond dual-scale reinforcement is obtained.

[0017] Further, the preparation method of the surface-activated diamond dual-scale reinforcement is as follows: Place the diamond dual-scale reinforcement raw material in a plasma etching reaction chamber, evacuate to a base pressure ≤ 1×10 -3 Pa, introduce a mixed gas of argon and hydrogen, with an argon flow rate of 50-100 sccm and a hydrogen flow rate of 5-15 sccm, and maintain the chamber pressure at 10-50 Pa; Excite the plasma with a radio frequency power source, with a power density of 0.5-2.0 W / cm², control the substrate temperature at 300-500 °C, and the treatment time is 20-40 min; During the treatment, rotate the substrate holder at 5-15 rpm to ensure uniform irradiation of the plasma; After the reaction is completed, stop supplying gas, and cool it to room temperature at a cooling rate of 5-10 °C / min under argon protection to obtain the surface-activated diamond dual-scale reinforcement.

[0018] The present invention adopts the design of surface-activated diamond dual-scale reinforcements and magnesium boride coating, mainly used to enhance the thermal conductivity and interfacial bonding performance of the composite material. An amorphous carbon layer is obtained on the surface of the surface-activated diamond dual-scale reinforcements, which is beneficial to the formation of a transition layer from a thermodynamic perspective. To optimize the interfacial compatibility between the reinforcements and the aluminum matrix, the present invention conducts surface activation treatment on the diamond dual-scale reinforcements through a plasma etching process. In a mixed atmosphere of argon and hydrogen, the high-energy effect of radio-frequency plasma is used to remove surface impurities and induce the formation of an amorphous carbon layer. This amorphous carbon layer can reduce the interfacial energy, improve the interfacial reaction activity, and provide a uniform and stable deposition basis for the subsequent magnesium boride coating. Subsequently, a magnesium boride layer is deposited on the surface of the diamond dual-scale reinforcements through an electroless plating process. The synergistic effect of nanoscale magnesium boride, sodium hypophosphite, sodium succinate, sodium acetate, and dimethyl sulfoxide in the electroless plating solution enables the magnesium boride coating layer to adhere uniformly to the diamond surface, and the deposition quality is optimized by controlling the pH value and temperature. The deposited reinforcements are annealed in a tubular furnace under an argon atmosphere to further densify the magnesium boride layer, improve its structural stability, and promote chemical reactions with the aluminum matrix during the subsequent high-temperature composite process, in-situ generating a transition layer containing Al3BC phase. The formation of this transition layer not only enhances the bonding strength between the diamond and the aluminum matrix, effectively reduces the interfacial thermal resistance, but also avoids problems such as interfacial debonding or thermal expansion mismatch that may be caused by direct contact, thus ensuring the overall structural stability and long-term service performance of the composite material. Each component shows a high degree of synergy during the entire preparation process. Plasma etching provides an activated surface, the amorphous carbon layer optimizes the interfacial reaction thermodynamics, the magnesium boride coating layer improves the interfacial bonding ability, and finally, heat treatment promotes the formation of the Al3BC transition layer, realizing a firm combination between the reinforcements and the matrix, enabling the composite material to have excellent thermal conductivity and mechanical properties, and meeting the requirements of high-efficiency thermal management and structural stability for 5G base station radiators.

[0019] Furthermore, the interface between the Al3BC phase and the aluminum alloy matrix is a semi-coherent interface.

[0020] The semi-coherent interface can effectively relieve interfacial stress, reduce interfacial defects, enhance the interfacial bonding strength, and lower the interfacial thermal resistance, thereby optimizing the heat conduction efficiency. At the same time, it helps to reduce phonon scattering losses, improve the overall thermal conductivity of the material, enhance the structural stability and durability of the composite material, and ensure its long-term service in a high heat flux environment.

[0021] The present invention also discloses a preparation method for an aluminum profile of a high-thermal-conductivity 5G base station radiator, including the following steps:

[0022] S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder separately. The drying temperature is 80-100°C, and the drying time is 2-4h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, with an addition amount of 0.1-0.5wt.% of the system. Fill the ball mill tank with argon for protection. The ball-to-powder ratio is (10-15):1, the ball mill rotation speed is 100-150rpm, and the ball milling time is 60-90min;

[0023] S2. Load the mixed powder into the cavity of a cold pressing mold, and perform three-stage pressing at room temperature to obtain a green body preform;

[0024] S3. Place the green body preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened body;

[0025] S4. After preheating the strengthened body to 420-430°C, perform two-stage extrusion on a four-column hydraulic press: The first pass is completed with a rate of 1-2mm / s and an extrusion ratio of (10-12):1 to form the basic cavity. The second pass is adjusted to a rate of 3-5mm / s and an extrusion ratio of (8-12):1 to finally obtain a high thermal conductivity 5G base station radiator aluminum profile.

[0026] Further, the three-stage pressing is as follows: In the pre-pressing stage, maintain the pressure at 50-80MPa for 5-10min to eliminate particle gaps. In the main pressing stage, pressurize at a rate of 10-15MPa / s to 300-350MPa and maintain the pressure for 10-15min. In the final pressing stage, apply a pressure of 350-400MPa to break through the frictional locking between particles to obtain a green body preform;

[0027] Further, the isostatic pressing sintering process includes implementing staged loading: After an axial preload of 100-120MPa, heat up to 540-560°C at a rate of 5-8°C / min, and simultaneously apply a radial pressure of 150-180MPa and keep it warm for 60-90min.

[0028] The present invention adopts the design of compounding magnesium boride-coated diamond dual-scale reinforcement with an aluminum alloy matrix, mainly used to enhance the thermal conductivity and structural stability of aluminum profiles for high thermal conductivity 5G base station radiators. By optimizing the interfacial bonding of the reinforcement and the preparation process of the composite material, efficient heat conduction and excellent mechanical properties are achieved. First, the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder are dried to ensure their stable dispersion during the subsequent ball milling process. By adding zinc stearate as a process control agent, agglomeration of powder particles during high-energy ball milling is prevented, and the mixing uniformity is improved. The ball milling process is carried out under argon protection, controlling the ball-to-powder ratio, ball milling speed and time to uniformly disperse magnesium boride-coated diamond in the aluminum alloy matrix and form a good contact interface between the particles. Subsequently, a three-stage pressing process is used to prepare a green preform. The particle gaps are eliminated in the pre-pressing stage, a high pressure is applied in the main pressing stage to ensure dense packing of the particles, and the friction lock between the particles is broken through in the final pressing stage, so that the green preform has a uniform internal structure, providing a basis for subsequent densification treatment. The green preform is sintered by biaxial hot isostatic pressing. By loading in stages, after axial preloading, the temperature is slowly increased, and a radial pressure is applied synchronously to uniformly densify the material, reduce the porosity, improve the interfacial bonding strength, and ensure effective bonding between the reinforcement and the aluminum alloy matrix. In the final extrusion forming process, a two-stage extrusion process is adopted. First, the basic cavity is formed at a lower rate and a larger extrusion ratio, and then the extrusion rate and extrusion ratio are adjusted to further optimize the internal tissue structure while the material undergoes controlled plastic deformation, reduce defects, and improve the mechanical properties and thermal conductivity of the final aluminum profile. Each process link cooperates with each other. The drying treatment ensures the stability of the powder, the ball milling process realizes uniform dispersion, the three-stage pressing improves the green density, the hot isostatic pressing sintering optimizes the interfacial bonding, and the two-stage extrusion improves the tissue structure, thus ensuring the high-efficiency heat dissipation capacity, excellent mechanical properties and long-term stability of the material in the application of 5G base station radiators.

[0029] Compared with the prior art, the advantages of this solution are as follows:

[0030] 1. Through the compounding of magnesium boride-coated diamond dual-scale reinforcement with an aluminum alloy matrix, the present invention optimizes the interfacial bonding, reduces the thermal resistance, improves the thermal conductivity and mechanical strength, and meets the heat dissipation requirements of 5G base stations. The dual-scale diamond constructs an efficient heat conduction network, the magnesium boride coating and the Al3BC transition layer enhance the interfacial bonding, and the aluminum alloy matrix improves the structural stability. The synergy of each component ensures that the material has both high thermal conductivity, excellent mechanical properties and long-term service stability.

[0031] 2. The present invention optimizes the interfacial bonding by using a surface-activated diamond dual-scale reinforcement and magnesium boride coating, reduces the thermal resistance, and improves the thermal conductivity and structural stability. The synergistic effects of plasma etching, amorphous carbon layer, magnesium boride coating, and Al3BC transition layer enhance the interfacial compatibility, reduce defects, and improve the long-term service performance of the composite material in the 5G base station radiator.

[0032] 3. The present invention composites a magnesium boride-coated diamond dual-scale reinforcement with an aluminum alloy matrix, optimizes the interfacial bonding, reduces the thermal resistance, improves the thermal conductivity and mechanical strength, and enhances the thermal management efficiency of the 5G base station radiator. The synergistic effects of drying, ball milling, three-stage pressing, hot isostatic pressing, and two-stage extrusion processes ensure the material is uniform, dense, and has a stable interface, with both high thermal conductivity, excellent mechanical properties, and long-term service stability. Brief Description of the Drawings

[0033] Figure 1 It is the microscopic structure morphology of the high-thermal-conductivity 5G base station radiator aluminum profile prepared in Example 1 of the present invention.

[0034] Figure 2 It is the microstructure morphology characteristics of the surface-activated diamond prepared in Example 1 of the present invention.

[0035] Figure 3 It is the macroscopic morphology of magnesium boride on the surface of the magnesium boride-coated diamond dual-scale reinforcement prepared in Example 1 of the present invention.

[0036] Figure 4 It is the microscopic morphology of magnesium boride on the surface of the magnesium boride-coated diamond dual-scale reinforcement prepared in Example 1 of the present invention.

[0037] Figure 5 It is the cross-sectional morphology of the diamond dual-scale reinforcement, aluminum alloy matrix, and the transition layer between them in the aluminum profile prepared in Example 1 of the present invention.

[0038] Figure 6 It is the interface between the Al3BC phase and the aluminum alloy matrix prepared in Example 1 of the present invention.

[0039] Figure 7 It is the microscopic structure morphology of the high-thermal-conductivity 5G base station radiator aluminum profile prepared in Comparative Example 3 of the present invention. Detailed Description of the Embodiments

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0041] Example 1

[0042] A high thermal conductivity aluminum profile for 5G base station radiators, comprising the following raw materials in parts by weight: 45 parts of magnesium boride-coated diamond dual-scale reinforcement and 35 parts of aluminum alloy powder;

[0043] The magnesium boride-coated diamond dual-scale reinforcement consists of a diamond dual-scale reinforcement and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcement; the diamond dual-scale reinforcement consists of micron-scale diamond particles and nano-scale diamond particles; the mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is 5.0:1;

[0044] The high thermal conductivity aluminum profile for 5G base station radiators includes a diamond dual-scale reinforcement, an aluminum alloy matrix, and a transition layer therebetween; the thickness of the transition layer is 30 nm. The transition layer contains Al3BC phase, and the Al3BC phase is in-situ generated at high temperature from the magnesium boride coating layer, the diamond dual-scale reinforcement, and the aluminum alloy powder. The interface between the Al3BC phase and the aluminum alloy matrix is a semi-coherent interface.

[0045] In this embodiment, the average particle size of the micron-scale diamond particles is 5.0 μm; the average particle size of the nano-scale diamond particles is 450 nm; the thickness of the magnesium boride coating layer is 15 nm; the aluminum alloy powder is Al-Si-Mg alloy powder, the Si content is 5.0 wt.%, the Mg content is 0.5 wt.%, and the balance is Al.

[0046] The preparation method of the magnesium boride-coated diamond dual-scale reinforcement in this embodiment is as follows: Immerse the diamond dual-scale reinforcement in the electroless plating solution, and the mass ratio of the diamond dual-scale reinforcement to the electroless plating solution is 25:80; the plating solution contains, by weight, 12 parts of nano magnesium boride, 20 parts of sodium hypophosphite, 4.5 parts of sodium succinate, 23 parts of sodium acetate, and 7 parts of dimethyl sulfoxide; adjust the pH of the plating solution to 5.5 with 0.1 mol / L sodium hydroxide or hydrochloric acid solution, and disperse it at a mechanical stirring rate of 300 rpm for 10 min to form a uniform suspension; transfer the suspension to a reaction kettle, heat it to 90 °C at a heating rate of 3 °C / min, and keep it at a constant temperature for 50 min; after the deposition is completed, cool it to room temperature at a rate of 2 °C / min, filter and separate the solid product, and wash the solid product 3 times with deionized water, with the amount of water used each time being 5 times the mass of the solid product; place the washed solid product in a vacuum drying oven, dry it at 60 °C for 2 h, and then heat it to 280 °C at a heating rate of 10 °C / min in a tubular furnace under an argon atmosphere, keep it at a constant temperature for 50 min to complete the annealing treatment, and obtain the magnesium boride-coated diamond dual-scale reinforcement after cooling to room temperature. The preparation method of the surface-activated diamond dual-scale reinforcement is as follows: Place the diamond dual-scale reinforcement raw material in a plasma etching reaction chamber, evacuate to a base pressure ≤ 1×10 -3Pa, introduce a mixed gas of argon and hydrogen. The argon flow rate is 50 sccm, the hydrogen flow rate is 5 sccm, and the chamber pressure is maintained at 10 Pa. Excite the plasma with a radio frequency power source, with a power density of 0.5 W / cm², control the substrate temperature at 300 °C, and the treatment time is 20 min. During the treatment process, rotate the substrate holder at 5 rpm to ensure uniform irradiation of the plasma. After the reaction, stop the gas supply and cool it to room temperature at a cooling rate of 5 °C / min under argon protection to obtain a surface-activated diamond dual-scale reinforcement.

[0047] A preparation method of a high thermal conductivity aluminum profile for a 5G base station radiator in this embodiment includes the following steps:

[0048] S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and the aluminum alloy powder separately. The drying temperature is 80 °C and the drying time is 2 h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and the aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, and the addition amount is 0.1 wt.% of the system. Fill the ball mill tank with argon for protection. The ball-to-powder ratio is 10:1, the ball mill rotation speed is 100 rpm, and the ball milling time is 60 min.

[0049] S2. Load the mixed powder into the cavity of a cold pressing mold, and perform three-stage pressing at room temperature to obtain a green billet preform. The three-stage pressing is that in the pre-pressing stage, keep the pressure at 50 MPa for 5 min to eliminate particle gaps. In the main pressing stage, pressurize at a rate of 10 MPa / s to 300 MPa and keep the pressure for 10 min. In the final pressing stage, apply a pressure of 350 MPa to break through the friction locking between particles to obtain a green billet preform.

[0050] S3. Place the green billet preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened billet. The isostatic pressing sintering process includes implementing staged loading: after an axial preload of 100 MPa, heat up to 540 °C at a rate of 5 °C / min, and simultaneously apply a radial pressure of 150 MPa and keep it warm for 60 min.

[0051] S4. After preheating the strengthened billet to 420 °C, perform two-stage extrusion on a four-column hydraulic press: the first pass is completed with a forming rate of 1 mm / s and an extrusion ratio of 10:1 for the basic cavity. The second pass is adjusted to a rate of 3 mm / s and an extrusion ratio of 8:1, and finally obtain a high thermal conductivity aluminum profile for a 5G base station radiator.

[0052] As can be seen from Figure 1, in the high thermal conductivity aluminum profile for 5G base station radiators prepared in the first embodiment of the present invention, the diamond dual-scale reinforcements are uniformly dispersed in the aluminum alloy matrix, demonstrating that the optimized ball milling and powder metallurgy processes can effectively prevent the agglomeration of reinforcements and improve the isotropic thermal conductivity of the material. Figure 2 shows the microscopic morphological characteristics of the surface-activated diamond prepared in the first embodiment. A continuous and uniform amorphous carbon layer is observed on the surface of the reinforcement, indicating that the plasma activation process has successfully improved the wettability of the diamond surface, which is conducive to the full occurrence of subsequent interfacial reactions. Figures 3 and 4 respectively show the macroscopic and microscopic morphologies of the magnesium boride-coated diamond dual-scale reinforcements, both indicating that the magnesium boride coating layer is uniform and complete, demonstrating that the optimized electroless plating process can stably form a high-quality coating layer and enhance the interfacial bonding force between the reinforcement and the aluminum matrix. Figure 5 further reveals the cross-sectional morphology of the reinforcement, matrix, and the transition layer between the two in the aluminum profile. It is observed that the interface is tightly bonded and the transition layer is uniform, confirming the formation of the Al3BC transition layer and verifying its semi-coherent interface structure with the aluminum alloy matrix, indicating that this interface has good stability and thermal conductivity. Figure 6 shows the interfacial morphology between the Al3BC phase and the aluminum alloy matrix, further confirming the existence of this phase and its role in interfacial bonding. In summary, these experimental results fully demonstrate the significant advantages of the key process optimization of the present invention in terms of reinforcement dispersion, interfacial bonding strength, transition layer uniformity, and interface stability, providing a theoretical and experimental basis for the preparation of high thermal conductivity aluminum profiles for 5G base station radiators.

[0053] Example 2

[0054] A high thermal conductivity aluminum profile for 5G base station radiators, comprising the following raw materials in parts by weight: 50 parts of magnesium boride-coated diamond dual-scale reinforcements and 41 parts of aluminum alloy powder;

[0055] The magnesium boride-coated diamond dual-scale reinforcements are composed of diamond dual-scale reinforcements and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcements; the diamond dual-scale reinforcements are composed of micron-scale diamond particles and nano-scale diamond particles; the mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is 5.9:1;

[0056] The high thermal conductivity aluminum profile for 5G base station radiators includes diamond dual-scale reinforcements, an aluminum alloy matrix, and a transition layer between the two; the thickness of the transition layer is 34 nm. The transition layer contains the Al3BC phase, and the Al3BC phase is in-situ generated at high temperature from the magnesium boride coating layer, diamond dual-scale reinforcements, and aluminum alloy powder. The interface between the Al3BC phase and the aluminum alloy matrix is a semi-coherent interface.

[0057] The average particle size of the micron-scale diamond particles in this embodiment is 6.5 μm; the average particle size of the nano-scale diamond particles is 550.0 nm; the thickness of the magnesium boride coating layer is 20 nm; the aluminum alloy powder is Al-Si-Mg alloy powder, the Si content is 5.9 wt.%, the Mg content is 0.7 wt.%, and the balance is Al.

[0058] The preparation method of the magnesium boride-coated diamond dual-scale reinforcement in this embodiment is as follows: Immerse the diamond dual-scale reinforcement in the electroless plating solution, and the mass ratio of the diamond dual-scale reinforcement to the electroless plating solution is 31:92; The plating solution contains, by weight: 13 parts of nano magnesium boride, 21 parts of sodium hypophosphite, 4.8 parts of sodium succinate, 24 parts of sodium acetate, and 7.6 parts of dimethyl sulfoxide; Adjust the pH of the plating solution to 5.8 with 0.2 mol / L sodium hydroxide or hydrochloric acid solution, and disperse for 16 min at a mechanical stirring rate of 360 rpm to form a uniform suspension; Transfer the suspension to a reaction kettle, heat it to 93 °C at a heating rate of 3.6 °C / min, and keep it at a constant temperature for 56 min; After the deposition is completed, cool it to room temperature at a rate of 2.6 °C / min, filter and separate the solid product, and wash the solid product 4 times with deionized water, with the water consumption per time being 6.5 times the mass of the solid product; Place the washed solid product in a vacuum drying oven, dry it at 66 °C for 2.6 h, and then heat it to 292 °C at a heating rate of 11.5 °C / min in a tubular furnace under an argon atmosphere, keep it at a constant temperature for 56 min to complete the annealing treatment, and cool it to room temperature to obtain the magnesium boride-coated diamond dual-scale reinforcement. The preparation method of the surface-activated diamond dual-scale reinforcement is as follows: Place the diamond dual-scale reinforcement raw material in the plasma etching reaction chamber, evacuate to a base pressure ≤ 1×10 -3 Pa, introduce a mixed gas of argon and hydrogen, the argon flow rate is 65 sccm, the hydrogen flow rate is 8 sccm, and maintain the chamber pressure at 22 Pa; Excite the plasma with a radio frequency power source, the power density is 0.95 W / cm², the substrate temperature is controlled at 360 °C, and the treatment time is 26 min; During the treatment, rotate the substrate support at 8 rpm to ensure uniform irradiation of the plasma; After the reaction is completed, stop supplying gas, and cool it to room temperature at a cooling rate of 6.5 °C / min under argon protection to obtain the surface-activated diamond dual-scale reinforcement.

[0059] The preparation method of a high thermal conductivity 5G base station radiator aluminum profile in this embodiment includes the following steps:

[0060] S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder separately. The drying temperature is 86 °C and the drying time is 3 h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, with an addition amount of 0.2 wt.% of the system, and fill the ball mill tank with argon for protection. The ball-to-powder ratio is 12:1, the ball milling speed is 115 rpm, and the ball milling time is 69 min.

[0061] S2. Load the mixed powder into the cavity of a cold pressing mold and perform three-stage pressing at room temperature to obtain a green body preform. The three-stage pressing is as follows: in the pre-pressing stage, keep the pressure at 59 MPa for 7 min to eliminate particle gaps; in the main pressing stage, pressurize at a rate of 12 MPa / s to 315 MPa and keep the pressure for 12 min; in the final pressing stage, apply a pressure of 365 MPa to break through the frictional locking between particles to obtain a green body preform.

[0062] S3. Place the green body preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened blank. The isostatic pressing sintering process includes implementing staged loading: after an axial preload of 106 MPa, heat up to 546 °C at a rate of 6 °C / min, and simultaneously apply a radial pressure of 159 MPa and keep the temperature for 69 min.

[0063] S4. After preheating the strengthened blank to 423 °C, perform two-stage extrusion on a four-column hydraulic press: in the first pass, complete the forming of the basic cavity at a rate of 1.3 mm / s and an extrusion ratio of 11:1; in the second pass, adjust to a rate of 3.6 mm / s and an extrusion ratio of 9:1 to finally obtain a high thermal conductivity aluminum profile for 5G base station radiators.

[0064] Example 3

[0065] A high thermal conductivity aluminum profile for 5G base station radiators includes the following raw materials in parts by weight: 60 parts of magnesium boride-coated diamond dual-scale reinforcement and 55 parts of aluminum alloy powder.

[0066] The magnesium boride-coated diamond dual-scale reinforcement is composed of a diamond dual-scale reinforcement and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcement; the diamond dual-scale reinforcement is composed of micron-scale diamond particles and nano-scale diamond particles; the mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is 8.0:1.

[0067] The high thermal conductivity aluminum profile for 5G base station radiators includes a diamond dual-scale reinforcement, an aluminum alloy matrix, and a transition layer therebetween; the thickness of the transition layer is 42 nm. The transition layer contains an Al3BC phase, and the Al3BC phase is in-situ generated from the magnesium boride coating layer, the diamond dual-scale reinforcement, and the aluminum alloy powder at high temperature. The interface between the Al3BC phase and the aluminum alloy matrix is a semi-coherent interface.

[0068] The average particle size of the micron-scale diamond particles in this embodiment is 10.0 μm; the average particle size of the nano-scale diamond particles is 850.0 nm; the thickness of the magnesium boride coating is 30 nm; the aluminum alloy powder is Al-Si-Mg alloy powder, the Si content is 8.0 wt.%, the Mg content is 1.2 wt.%, and the balance is Al.

[0069] The preparation method of the magnesium boride-coated diamond dual-scale reinforcement of this embodiment is as follows: immersing the diamond dual-scale reinforcement in a chemical plating solution, wherein the mass ratio of the diamond dual-scale reinforcement to the chemical plating solution is 45:120; the plating solution comprises, by weight, 15 parts of nano-magnesium boride, 22 parts of sodium hypophosphite, 5.5 parts of sodium succinate, 25 parts of sodium acetate, and 9 parts of dimethyl sulfoxide; adjusting the pH of the plating solution to 6.5 with 0.5 mol / L sodium hydroxide or hydrochloric acid solution, and dispersing the solution at a mechanical stirring rate of 500 rpm for 30 minutes to form a uniform suspension; and transferring the suspension to a slurry container. The product was transferred to a reactor and heated to 100°C at a heating rate of 5°C / min, and deposited at a constant temperature for 70 minutes. After the deposition was completed, the product was cooled to room temperature at a rate of 4°C / min, the solid product was separated by filtration, and the solid product was washed with deionized water 5 times, with the amount of water each time being 10 times the mass of the solid product. The washed solid product was placed in a vacuum drying oven and dried at 80°C for 4 hours. Subsequently, the product was heated to 320°C in an argon atmosphere tube furnace at a heating rate of 15°C / min and kept at this temperature for 70 minutes to complete the annealing treatment. After cooling to room temperature, the magnesium boride-coated diamond dual-scale reinforcement was obtained. The preparation method of the surface-activated diamond dual-scale reinforcement is as follows: the diamond dual-scale reinforcement raw material is placed in a plasma etching reaction chamber, and the vacuum is evacuated to a base pressure of ≤1×10 -3 Pa, a mixed gas of argon and hydrogen was introduced with an argon flow rate of 100 sccm and a hydrogen flow rate of 15 sccm, maintaining a chamber pressure of 50 Pa; the plasma was excited by a radio frequency power source with a power density of 2.0 W / cm², the substrate temperature was controlled at 500°C, and the treatment time was 40 minutes; during the treatment, the substrate holder was rotated at 15 rpm to ensure uniform plasma irradiation; after the reaction was completed, the gas supply was stopped and the chamber was cooled to room temperature at a cooling rate of 10°C / min under argon protection to obtain a surface-activated diamond dual-scale reinforcement.

[0070] A method for preparing a high thermal conductivity 5G base station radiator aluminum profile in this embodiment includes the following steps:

[0071] S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder separately. The drying temperature is 100 °C and the drying time is 4 h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, and the addition amount is 0.5 wt.% of the system. Fill the ball mill with argon for protection; the ball-to-powder ratio is 15:1, the ball milling speed is 150 rpm, and the ball milling time is 90 min;

[0072] S2. Load the mixed powder into the cavity of a cold pressing mold, and perform three-stage pressing at room temperature to obtain a green body preform; the three-stage pressing is that in the pre-pressing stage, keep the pressure at 80 MPa for 10 min to eliminate particle gaps, in the main pressing stage, pressurize at a rate of 15 MPa / s to 350 MPa and keep the pressure for 15 min, and in the final pressing stage, apply a pressure of 400 MPa to break through the friction locking between particles to obtain a green body preform;

[0073] S3. Place the green body preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened blank; the isostatic pressing sintering process includes implementing staged loading: after an axial preload of 120 MPa, heat up to 560 °C at a rate of 8 °C / min, synchronously apply a radial pressure of 180 MPa and keep it warm for 90 min.

[0074] S4. After preheating the strengthened blank to 430 °C, perform two-stage extrusion on a four-column hydraulic press: in the first pass, complete the forming of the basic cavity at a rate of 2 mm / s and an extrusion ratio of 12:1; in the second pass, adjust to a rate of 5 mm / s and an extrusion ratio of 12:1 to finally obtain a high thermal conductivity aluminum profile for 5G base station radiators.

[0075] Example 4

[0076] A high thermal conductivity aluminum profile for 5G base station radiators comprises the following raw materials in parts by weight: 54 parts of magnesium boride-coated diamond dual-scale reinforcement and 47 parts of aluminum alloy powder;

[0077] The magnesium boride-coated diamond dual-scale reinforcement consists of a diamond dual-scale reinforcement and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcement; the diamond dual-scale reinforcement consists of micron-scale diamond particles and nano-scale diamond particles; the mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is 6.8:1;

[0078] The high thermal conductivity aluminum profile for 5G base station radiators includes a diamond dual-scale reinforcement, an aluminum alloy matrix, and a transition layer therebetween; the thickness of the transition layer is 37 nm. The transition layer contains Al3BC phase, and the Al3BC phase is in-situ generated from the magnesium boride coating layer, the diamond dual-scale reinforcement, and the aluminum alloy powder at high temperature. The interface between the Al3BC phase and the aluminum alloy matrix is a semi-coherent interface.

[0079] In this embodiment, the average particle size of the micron-scale diamond particles is 8.0 μm; the average particle size of the nano-scale diamond particles is 950.0 nm; the thickness of the magnesium boride coating layer is 24 nm; the aluminum alloy powder is Al-Si-Mg alloy powder, the Si content is 6.8 wt.%, the Mg content is 0.9 wt.%, and the balance is Al.

[0080] The preparation method of the magnesium boride-coated diamond dual-scale reinforcement in this embodiment is as follows: Immerse the diamond dual-scale reinforcement in the electroless plating solution, and the mass ratio of the diamond dual-scale reinforcement to the electroless plating solution is 37:104; The plating solution contains, by weight: 14 parts of nano magnesium boride, 21 parts of sodium hypophosphite, 5.1 parts of sodium succinate, 24 parts of sodium acetate, and 8.2 parts of dimethyl sulfoxide; Adjust the pH of the plating solution to 6.1 with 0.3 mol / L sodium hydroxide or hydrochloric acid solution, and disperse it at a mechanical stirring rate of 420 rpm for 22 min to form a uniform suspension; Transfer the suspension to a reaction kettle, heat it to 96 °C at a heating rate of 4.2 °C / min, and keep it at a constant temperature for 62 min; After the deposition is completed, cool it to room temperature at a rate of 3.2 °C / min, filter and separate the solid product, and wash the solid product 4 times with deionized water, with the water consumption per time being 8 times the mass of the solid product; Place the washed solid product in a vacuum drying oven, dry it at 72 °C for 3.2 h, and then heat it to 304 °C at a heating rate of 13 °C / min in a tubular furnace under an argon atmosphere, keep it at a constant temperature for 62 min to complete the annealing treatment, and obtain the magnesium boride-coated diamond dual-scale reinforcement after cooling to room temperature. The preparation method of the surface-activated diamond dual-scale reinforcement is as follows: Place the diamond dual-scale reinforcement raw material in the plasma etching reaction chamber, evacuate to a base pressure ≤ 1×10 -3 Pa, introduce a mixed gas of argon and hydrogen, with an argon flow rate of 80 sccm and a hydrogen flow rate of 11 sccm, and maintain the chamber pressure at 34 Pa; Excite the plasma with a radio frequency power source, with a power density of 1.4 W / cm², control the substrate temperature at 420 °C, and the treatment time is 32 min; During the treatment, rotate the substrate holder at 11 rpm to ensure uniform irradiation of the plasma; After the reaction is completed, stop the gas supply, and cool it to room temperature at a cooling rate of 8 °C / min under argon protection to obtain the surface-activated diamond dual-scale reinforcement.

[0081] The preparation method of a high thermal conductivity 5G base station radiator aluminum profile in this embodiment includes the following steps:

[0082] S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder separately. The drying temperature is 92 °C and the drying time is 3 h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, and the addition amount is 0.3 wt.% of the system. Fill the ball mill tank with argon for protection; the ball-to-powder ratio is 13:1, the ball mill rotation speed is 130 rpm, and the ball milling time is 78 min;

[0083] S2. Load the mixed powder into the cavity of a cold pressing mold, and perform three-stage pressing at room temperature to obtain a green billet preform; the three-stage pressing is that in the pre-pressing stage, keep the pressure at 68 MPa for 8 min to eliminate particle gaps, in the main pressing stage, pressurize at a rate of 13 MPa / s to 330 MPa and keep the pressure for 13 min, and in the final pressing stage, apply a pressure of 380 MPa to break through the frictional locking between particles to obtain a green billet preform;

[0084] S3. Place the green billet preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened billet; the isostatic pressing sintering process includes implementing staged loading: after an axial preload of 112 MPa, heat up to 552 °C at a rate of 7 °C / min, synchronously apply a radial pressure of 168 MPa and keep it warm for 78 min.

[0085] S4. After preheating the strengthened billet to 426 °C, perform two-stage extrusion on a four-column hydraulic press: in the first pass, complete the forming of the basic cavity at a rate of 1.6 mm / s and an extrusion ratio of 11:1; in the second pass, adjust to a rate of 4.2 mm / s and an extrusion ratio of 10:1, and finally obtain a high thermal conductivity aluminum profile for 5G base station radiators.

[0086] Comparative Example 1

[0087] The difference from Example 1 is that the weight fraction of the magnesium boride-coated diamond dual-scale reinforcement is adjusted to 30 parts, and the weight fraction of the aluminum alloy powder is adjusted to 60 parts. Due to the decrease in the content of the reinforcement, the thermal conductivity of the material decreases, the mechanical strength decreases, and the interfacial bonding performance is poor. <0,

[0088] Comparative Example 2

[0089] The difference from Example 1 is that the mass ratio of the micron-scale diamond particles to the nano-scale diamond particles is adjusted to 3:1. This change leads to an imbalance in the size grading of the reinforcement, an unstable interfacial transition layer, ultimately resulting in a decrease in the thermal conductivity of the material and a reduction in the uniform distribution of the reinforcement in the matrix.

[0090] Comparative Example 3

[0091] The difference from Example 1 is that the thickness of the magnesium boride coating layer is adjusted to 3 nm. The thin coating leads to a decrease in the chemical stability of the reinforcement interface, and interface peeling is likely to occur during the sintering process, resulting in insufficient formation of the Al3BC transition layer, a decrease in the interface bonding force, and ultimately a reduction in the overall stability and thermal conductivity of the material. Figure 7 shows the microstructural characteristics of the aluminum profiles prepared in Comparative Example 3. Interface debonding is clearly observed, indicating that when the thickness of the magnesium boride layer is too thin, the interface bonding force between the reinforcement and the matrix decreases significantly, severely affecting the overall stability and thermal conductivity of the material.

[0092] Comparative Example 4

[0093] The difference from Example 1 is that the pH value of the electroless plating solution is adjusted to 4.0. The too low pH reduces the stability of the plating solution, resulting in uneven deposition of the coating, ultimately affecting the interface bonding quality of the reinforcement and reducing the formation efficiency of the Al3BC phase in the transition layer.

[0094] Comparative Example 5

[0095] The difference from Example 1 is that the content of sodium hypophosphite in the electroless plating solution is adjusted to 10 parts. Insufficient sodium hypophosphite leads to incomplete reduction reactions, uneven coatings, and incomplete formation of the magnesium boride coating layer on the surface of some reinforcements, affecting subsequent sintering and interface bonding performance.

[0096] Comparative Example 6

[0097] The difference from Example 1 is that the pressure in the final stage of cold pressing is adjusted to 200 MPa. Insufficient final pressure results in a lower initial density of the green compact, affecting the densification degree of subsequent sintering, ultimately leading to a decrease in the mechanical strength of the material and an increase in internal porosity.

[0098] Comparative Example 7

[0099] The difference from Example 1 is that the temperature of hot isostatic pressing (HIP) treatment is adjusted to 400 °C. Too low HIP treatment temperature results in insufficient sintering densification and insufficient interface bonding between the reinforcement and the matrix, ultimately affecting the thermal conductivity and mechanical strength of the material.

[0100] Comparative Example 8

[0101] The difference from Example 1 is that the pressure of hot isostatic pressing (HIP) treatment is adjusted to 50 MPa. Insufficient HIP pressure results in insufficient elimination of pores in the material and loose interface bonding, ultimately affecting the thermal conductivity and fatigue resistance of the material.

[0102] Comparative Example 9

[0103] The difference from Example 1 is that the diamond dual-scale reinforcement is not treated with magnesium boride coating.

[0104] Comparative Example Ten

[0105] The difference from Example 1 is that a single micron-scale diamond is used to replace the diamond dual-scale reinforcement of equal mass.

[0106] Comparative Example Eleven

[0107] The difference from Example 1 is that a single micron-scale diamond is used to replace the diamond dual-scale reinforcement of equal mass.

[0108] Comparative Example Twelve

[0109] The difference from Example 1 is that the diamond dual-scale reinforcement is not subjected to surface activation treatment, resulting in the absence of an amorphous carbon layer on the surface, which in turn affects the formation of the transition layer.

[0110] Performance Test:

[0111] Thermal Conductivity Test: The thermal diffusivity (α) of the aluminum profile was measured by the Laser Flash Analysis (LFA), and the thermal conductivity (κ) of the material was calculated by combining the density (ρ) and specific heat capacity (Cp). During the experiment, the sample was processed into a disc with a diameter of 1012 mm and a thickness of 23 mm. One side of the sample was heated by a laser pulse, and the temperature response curve on the other side was recorded by an infrared detector. The test temperature range was set from room temperature to 300 °C, and the change trend of the thermal conductivity with temperature was monitored to evaluate the thermal conduction performance of the material in the heat dissipation application of 5G base stations. This test method complies with the ASTM E1461-13 standard.

[0112] Mechanical Property Test: An electronic universal testing machine was used to measure the ultimate tensile strength (UTS), yield strength (YS), and elongation (ε) of the aluminum profile to evaluate the effect of the reinforcement on the mechanical properties of the aluminum alloy matrix. According to the ASTM E8 / E8M-16a standard, the sample was prepared into a dumbbell-shaped tensile specimen (25 mm gauge length), with a thickness of 2 - 3 mm and a width of 5 - 10 mm. During the test, the loading rate was set at 1 mm / min, the test temperature was room temperature (25 °C), the stress-strain curve was recorded, and the deformation behavior of the material was analyzed. In addition, a Vickers hardness tester (HV0.5) was used to conduct hardness tests in the matrix region, reinforcement region, and interface region. The loading pressure was set at 500 g, the loading time was 10 s, and 10 different regions were tested and the average value was statistically analyzed.

[0113] The performances of the aluminum profiles of Examples 1 to 4 and Comparative Examples 1 to 12 are summarized in Table 1.

[0114] Table 1 Performances of the Aluminum Profiles of Examples 1 to 4 and Comparative Examples 1 to 12

[0115]

[0116] As can be seen from Table 1, the key factors affecting the performance of the aluminum profile for the high thermal conductivity 5G base station radiator include the content of the reinforcement, the size grading of the reinforcement, the thickness of the coating layer, the pH value of the electroless plating solution, the content of sodium hypophosphite, the cold pressing pressure, the temperature and pressure of hot isostatic pressing (HIP) treatment, the surface coating treatment of the diamond reinforcement, the activation treatment of the reinforcement, and the uniformity of the microstructure. The reduction of the reinforcement content will decrease the thermal conductivity and mechanical properties of the material, while the imbalance of the size grading of the reinforcement will affect the interfacial bonding force and heat conduction efficiency; if the coating layer is too thin, the interfacial bonding force will decrease, affecting the formation of the Al3BC transition layer, thus reducing the thermal conductivity and mechanical strength; if the pH of the electroless plating solution is too low, it will affect the stability of the coating, resulting in uneven deposition of the coating layer on the surface of the reinforcement and a decrease in the interfacial bonding quality; insufficient content of sodium hypophosphite will make the electroless plating reaction incomplete, affecting the integrity of the coating layer, and further affecting the subsequent sintering and interfacial bonding performance; insufficient cold pressing pressure will lead to a low initial density of the material, affecting the densification degree of the subsequent sintering, increasing the porosity, and reducing the mechanical strength and thermal conductivity; too low HIP treatment temperature will lead to insufficient sintering densification, insufficient interfacial bonding between the reinforcement and the matrix, affecting the heat conduction efficiency and mechanical strength, while insufficient HIP pressure will lead to insufficient elimination of pores, a decrease in the interfacial bonding force, and affecting the fatigue resistance of the material; if the diamond reinforcement is not coated with magnesium boride, the interfacial reaction is insufficient, and the Al3BC transition layer cannot be effectively formed, resulting in a decrease in the thermal conductivity and mechanical properties; if the surface activation treatment is not carried out and the amorphous carbon layer is not formed on the surface of the reinforcement, it will affect the formation of the transition layer, reduce the interfacial bonding quality, and further affect the overall material performance; in addition, using a single micron-scale diamond to replace the dual-scale reinforcement will lead to uneven distribution of the reinforcement, weaken the interfacial bonding force, and reduce the thermal conductivity and mechanical strength of the material, ultimately affecting the overall performance of the radiator. Generally speaking, these factors have a significant impact on the thermal conductivity, tensile strength, yield strength, elongation, and hardness of the material. Optimizing these process parameters and the reinforcement structure is the key to improving the comprehensive performance of the material.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that all equivalent structural transformations made under the concept of the present invention by using the content of the specification and drawings of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A high thermal conductivity aluminum profile for 5G base station radiator, characterized in that, It includes the following raw materials in parts by weight: 45 - 60 parts of magnesium boride - coated diamond dual - scale reinforcement and 35 - 55 parts of aluminum alloy powder; The magnesium boride-coated diamond dual-scale reinforcement consists of a diamond dual-scale reinforcement and a magnesium boride coating layer on the surface of the diamond dual-scale reinforcement; the diamond dual-scale reinforcement is a surface-activated diamond dual-scale reinforcement, and the surface-activated diamond dual-scale reinforcement is prepared by the following method: placing the diamond dual-scale reinforcement raw material in a plasma etching reaction chamber, evacuating to a base pressure ≤ 1×10 -3 Pa, introducing a mixed gas of argon and hydrogen, with an argon flow rate of 50 - 100 sccm and a hydrogen flow rate of 5 - 15 sccm, maintaining the chamber pressure at 10 - 50 Pa; exciting the plasma with a radio frequency power source, with a power density of 0.5 - 2.0 W / cm 2 , controlling the substrate temperature at 300 - 500 °C, and the treatment time at 20 - 40 min; rotating the substrate holder at 5 - 15 rpm during the treatment to ensure uniform plasma irradiation; after the reaction ends, stop supplying gas, and cool to room temperature at a cooling rate of 5 - 10 °C / min under argon protection to obtain the surface-activated diamond dual-scale reinforcement; The diamond dual - scale reinforcement is composed of micron - scale diamond particles and nano - scale diamond particles; The mass ratio of the micron - scale diamond particles to the nano - scale diamond particles is (5.0 - 8.0):1; The thickness of the magnesium boride coating layer is 15 - 30 nm; The magnesium boride coating layer is prepared by electroless plating. The pH value of the electroless plating solution is controlled at 5.5 - 6.

5. The electroless plating solution contains, by weight: 12 - 15 parts of nano - magnesium boride, 20 - 22 parts of sodium hypophosphite, 4.5 - 5.5 parts of sodium succinate, 23 - 25 parts of sodium acetate, and 7 - 9 parts of dimethyl sulfoxide; The high - thermal - conductivity aluminum profile for 5G base station radiators includes diamond dual - scale reinforcement, aluminum alloy matrix, and a transition layer therebetween; the thickness of the transition layer is 30 - 42 nm; The transition layer contains Al3BC phase, and the Al3BC phase is in - situ generated from the magnesium boride coating layer, diamond dual - scale reinforcement, and aluminum alloy powder at high temperature; 2. The aluminum profile of a high thermal conductivity 5G base station radiator according to claim 1, wherein, The average particle size of the micron - scale diamond particles is 5.0 - 10.0 μm; the average particle size of the nano - scale diamond particles is 450.0 - 950.0 nm; 3. The aluminum profile of a high thermal conductivity 5G base station radiator according to claim 1, characterized in that, The aluminum alloy powder is Al - Si - Mg alloy powder, where the Si content is 5.0 - 8.0 wt.%, the Mg content is 0.5 - 1.2 wt.%, and the balance is Al; 4. The aluminum profile of a high thermal conductivity 5G base station radiator according to claim 1, characterized in that, The preparation method of the magnesium boride - coated diamond dual - scale reinforcement is as follows: Immerse the diamond dual - scale reinforcement in the electroless plating solution, and the mass ratio of the diamond dual - scale reinforcement to the electroless plating solution is (25 - 45):(80 - 120); Adjust the pH of the plating solution to 5.5 - 6.5 with 0.1 - 0.5 mol / L sodium hydroxide or hydrochloric acid solution, and disperse for 10 - 30 min at a mechanical stirring rate of 300 - 500 rpm to form a uniform suspension; Transfer the suspension to a reaction kettle, heat it to 90 - 100 °C at a heating rate of 3 - 5 °C / min, and keep it at a constant temperature for deposition for 50 - 70 min; After deposition, cool it to room temperature at a rate of 2 - 4 °C / min, filter and separate the solid product, and wash the solid product 3 - 5 times with deionized water, with the water consumption each time being 5 - 10 times the mass of the solid product; Place the washed solid product in a vacuum drying oven, dry it at 60 - 80 °C for 2 - 4 h, and then heat it to 280 - 320 °C at a heating rate of 10 - 15 °C / min in a tubular furnace under an argon atmosphere, keep it at a constant temperature for 50 - 70 min to complete the annealing treatment, and obtain the magnesium boride - coated diamond dual - scale reinforcement after cooling to room temperature; 5. The aluminum profile of a high thermal conductivity 5G base station radiator according to claim 1, characterized in that, The interface between the Al3BC phase and the aluminum alloy matrix is a semi - coherent interface; 6. The preparation method of an aluminum profile for a high thermal conductivity 5G base station radiator according to claim 1, characterized in that, It includes the following steps: S1. Dry the magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder separately. The drying temperature is 80-100 °C, and the drying time is 2-4 h. Place the dried magnesium boride-coated diamond dual-scale reinforcement and aluminum alloy powder in a high-energy planetary ball mill, add zinc stearate as a process control agent, and the addition amount is 0.1-0.5 wt.% of the system. Fill the ball mill tank with argon for protection; the ball-to-material ratio is (10-15):1, the ball mill rotation speed is 100-150 rpm, and the ball milling time is 60-90 min; S2. Load the mixed powder into the cavity of a cold pressing mold, and perform three-stage pressing at room temperature to obtain a green billet preform; the three-stage pressing is that in the pre-pressing stage, keep the pressure at 50-80 MPa for 5-10 min to eliminate particle gaps, in the main pressing stage, pressurize at a rate of 10-15 MPa / s to 300-350 MPa and keep the pressure for 10-15 min, and in the final pressing stage, apply a pressure of 350-400 MPa to break through the frictional locking between particles; S3. Place the green billet preform in a biaxial hot isostatic pressing equipment for hot isostatic pressing sintering to obtain a strengthened billet; the isostatic pressing sintering process includes implementing staged loading: after an axial preload of 100-120 MPa, heat up to 540-560 °C at a rate of 5-8 °C / min, and simultaneously apply a radial pressure of 150-180 MPa and keep it warm for 60-90 min; S4. After preheating the strengthened billet to 420-430 °C, perform two-stage extrusion on a four-column hydraulic press: in the first pass, complete the forming of the basic cavity at a rate of 1-2 mm / s and an extrusion ratio of (10-12):1; in the second pass, adjust to a rate of 3-5 mm / s and an extrusion ratio of (8-12):1 to finally obtain a high thermal conductivity aluminum profile for 5G base station radiators.

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