CN117551909A - Three-dimensional high-heat-conductivity carbon fiber reinforced copper-based composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material and a preparation method thereof, which includes the following steps: A. Loading carbon fiber on the surface of copper foam to prepare a carbon fiber-copper foam composite skeleton; B. Composite carbon fiber-copper foam The skeleton is placed in the mold, and copper powder is filled into the holes in the carbon fiber-copper foam composite skeleton to obtain a rough body; C. Apply pressure to the mold and prepress the green body into a green body through cold pressing; D. The green body is sintered and densified to obtain. The present invention mainly loads carbon fiber onto the foamed copper skeleton through the electrodeposition method, and at the same time coats the surface of the carbon fiber with copper plating, thereby improving the interface bonding force and reducing the interface thermal resistance. The prepared composite material not only has good It has good heat dissipation performance and good mechanical properties, which solves the problem of poor thermal conductivity in the vertical plane of carbon fiber composite materials.

Description

A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material and its preparation method

Technical field

The invention relates to the field of metal matrix composite materials, and in particular to a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material and a preparation method thereof.

Background technique

In recent years, with the rapid development of microelectronics technology, electronic devices are developing in the direction of miniaturization, high power, and high integration. Therefore, higher and higher requirements are put forward for the heat dissipation of electronic packaging materials. Traditional metals and their alloys can no longer meet the heat dissipation needs of current electronic products due to factors such as low thermal conductivity, high thermal expansion coefficient, and heavy weight. Metal matrix composite materials combine the performance advantages of metal matrix and reinforcement, which not only ensures the mechanical properties of the composite material, but also improves the heat dissipation performance of the composite material. It is an ideal choice for advanced thermal management materials. In particular, carbon/copper composite materials prepared with copper as the matrix and carbon materials (carbon fiber, graphite sheets, graphene, diamond, etc.) as reinforcements exhibit high thermal conductivity, high strength, low density and adjustable thermal expansion coefficient. In recent years, it has developed into an advanced electronic packaging material with extremely competitive advantages due to its comprehensive performance.

Carbon fiber has the advantages of high thermal conductivity (up to 1100W/m·K along the axial direction), low thermal expansion coefficient, light weight and high strength. With the improvement of production technology, the cost continues to decrease, and it has become a very attractive composite material. Material reinforcement phase. Carbon fiber/copper composites have high thermal conductivity in theory. However, the thermal conductivity of carbon fiber/copper composites currently studied is far lower than expected. The main reason is that the interface wettability of copper and carbon fiber is poor, which leads to defects inside the composite material and poor interface bonding, which hinders the transfer of heat during the heat dissipation process. On the other hand, carbon fiber has high thermal conductivity along the axial direction, which gives it a better directional heat dissipation effect within the composite material. However, the thermal conductivity in the vertical plane is poor, thus controlling the space of the fibers in the composite material. Distribution is the key to improving the thermal conductivity of composite materials.

Contents of the invention

The object of the present invention is to: in view of the above existing problems, provide a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material and a preparation method thereof, so as to overcome the technical problems existing in the prior art and make the prepared composite material have good Thermal conductivity, low thermal expansion coefficient and good mechanical properties.

The technical solution adopted by the present invention is as follows: a preparation method of three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, including the following steps:

A. Load carbon fiber on the surface of copper foam to prepare a carbon fiber-copper foam composite skeleton;

B. Place the carbon fiber-copper foam composite skeleton in the mold, fill the holes in the carbon fiber-copper foam composite skeleton with copper powder, and obtain a preliminary blank;

C. Apply pressure to the mold and pre-press the blank into a green body through cold pressing;

D. Sinter and densify the green body to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material.

In the present invention, the purity of the copper foam is not less than 99.9%, its pore diameter is 20-60PPI (for example, it can be 20PPI, 30PPI, 40PPI, 60PPI, etc.), and its thickness is 2-8mm (for example, it can be 2mm, 3mm, 5mm) , 8mm, etc.); the purity of the copper powder is not less than 99.9% (for example, it can be aerosolized spherical pure copper powder), and its particle size is 5-50 μm (for example, it can be 5 μm, 10 μm, 20 μm, 40 μm, 50 μm, etc.) ; The diameter of the carbon fiber is 7-20 μm (for example, it can be 7 μm, 10 μm, 12 μm, 15 μm, 20 μm, etc.), the length is 100-300 μm (for example, it can be 100 μm, 200 μm, 250 μm, 300 μm, etc.), and the thermal conductivity is 600 -900W/m·K, for example, it can be 600W/m·K, 700W/m·K, 800W/m·K, 900W/m·K, etc. The carbon fiber can use high thermal conductivity carbon fiber powder.

Furthermore, the method of loading carbon fibers on the surface of the copper foam is an electrodeposition method, which includes the following steps:

(1) Pretreatment of copper foam and carbon fiber powder;

(2) Prepare the electroplating solution and pour it into the electroplating tank, and disperse the carbon fibers in the electroplating solution;

(3) Use foamed copper as the cathode and copper sheet as the anode, turn on the power and start deposition;

(4) After the deposition is completed, the skeleton is rinsed with deionized water and dried in vacuum to obtain the carbon fiber-copper foam composite skeleton.

Further, the pretreatment process of the copper foam skeleton is: ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 5-20 minutes (the specific ultrasonic cleaning time is selected according to the actual situation), then rinse it with deionized water, and then clean it for 50-20 minutes. Vacuum dry at 70℃ for 1-3h (select according to actual situation);

The pretreatment process of the carbon fiber includes the following steps: place the carbon fiber in acetone, soak it for 10-14 hours (the specific soaking time is selected according to the actual situation), then clean it with deionized water, vacuum filter it, and then put it in a blast oven Dry at 50-70℃ for 5-7h (select according to actual situation).

Further, the electroplating solution is composed of copper sulfate, potassium sodium tartrate, sodium citrate and potassium nitrate in a mass ratio of 18-22:3-5:30-40:4-5 (for example, it can be 18:3:30 :4, 20:4:36:4.8, 22:5:40:5, etc.), mixed and dissolved in deionized water.

Further, fix the foam copper cathode in the center area of the electroplating tank and connect it to the negative pole of the DC power supply. Place a phosphor copper plate on each side of the electroplating tank as an anode and connect it to the positive pole of the DC power supply. Then turn on the power and adjust the power supply voltage to 1-3V ( For example, it can be 1V, 1.5V, 3V, etc.), stirring while depositing, the rotation speed is 200-400rpm (for example, it can be 200rpm, 300rpm, 400rpm, etc.), the plating time is 2-12h, the plating time needs to be based on the plating voltage and The size of copper foam and carbon fiber is determined according to the specific situation, but it should not be too long or too short.

Further, in step B, vacuum filtration is used to fill the holes in the carbon fiber-copper foam composite skeleton with copper powder until the entire composite skeleton is filled, and then placed in a vacuum drying oven and dried at 50-70°C. 10-14h (select according to actual situation).

Further, in step C, the pressure of cold pressing is 10-20MPa (for example, it can be 10MPa, 15MPa, 20MPa, etc.), and the pressure holding time is 1-3 minutes.

Further, in step D, the process for sintering and densifying the green body is one of hot pressing sintering and discharge plasma sintering. The mold during the sintering process is a graphite mold. The sintering pressure of 30-50MPa can be, for example, 30MPa, 40MPa, 50MPa, etc.), the sintering temperature is 800-950°C (for example, it can be 800°C, 850°C, 950°C, etc.), and the holding time is 10-60min, for example, it can be 10min, 50min, 60min, etc.

Furthermore, the present invention also includes a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, which is prepared by the above preparation method.

In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

1. The present invention uses a copper foam skeleton as a template to prepare a copper foam-carbon fiber-copper composite heat dissipation material. The foamed copper skeleton provides a template for the carbon fiber to form a three-dimensional network structure inside the composite material, while retaining the complete copper heat transfer path and providing strength support for the subsequent filling of copper powder. The formed three-dimensional network skeleton improves the performance of the composite material. The thermal conductivity in the vertical in-plane direction also improves the mechanical properties of the composite heat dissipation material;

2. The through-hole structure of the copper foam-carbon fiber composite skeleton of the present invention enables the copper matrix to form a continuous structure inside the three-dimensional network, and forms a dual-connected structure of carbon fiber and copper inside the composite material. At the same time, compared with the random distribution of carbon fibers With directional arrangement, the three-dimensional carbon fiber network formed by the copper foam template in the present invention greatly improves the thermal conductivity of the composite material. Moreover, when preparing the composite material, the copper foam-carbon fiber composite skeleton obtained by the electrodeposition method not only enables the carbon fiber to be loaded On the foam copper skeleton, the surface of the carbon fiber is also plated with copper plating. The formation of the copper plating effectively improves the problem of poor wettability between the carbon fiber and the copper matrix, improves the interface bonding force, and reduces the interface thermal resistance. The preparation is The three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material not only has good heat dissipation performance, but also has good mechanical properties;

3. The present invention solves the problem of poor thermal conductivity in the vertical plane of the carbon fiber composite material, and at the same time improves the interface bonding force between the carbon fiber and the copper matrix, which not only improves the thermal conductivity of the composite material but also improves its mechanical properties; the preparation of the present invention The process is simple. Carbon fibers are loaded on the surface of copper foam through electrodeposition, which improves the wettability of the copper-carbon fiber interface. Through cold pressing molding and sintering, the density of the composite material is increased, and the bonding between the carbon fiber and the composite material is improved. The interface combination of copper improves the thermal conductivity of the composite heat dissipation material.

Description of the drawings

Figure 1 is a schematic diagram of the preparation process flow of three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite materials of the present invention;

Figure 2 is a microstructure diagram of the carbon fiber-copper foam composite skeleton prepared in Example 1 of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

Example 1

As shown in Figure 1, a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, its preparation method includes the following steps:

S1. Preparation materials: The pore diameter of the copper foam is 30PPI, the thickness is 5mm, and the diameter of the copper foam is 30mm; the diameter of the carbon fiber powder is 12μm, the length is 150μm, and the thermal conductivity is 600W/(m·K); the particles of pure copper powder Diameter is 6.5μm;

S2. Ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 10 minutes, then rinse it with deionized water, put it in a vacuum drying box, and dry it at 60°C for 2 hours to remove impurities and oxides on the surface of the copper foam; place the carbon fiber in Soak in acetone for 12 hours, then wash with deionized water, vacuum filter, and dry in a 60°C blast oven for 6 hours;

S3. Dissolve 20g copper sulfate pentahydrate, 4g potassium sodium tartrate, 36g sodium citrate, and 4.8g potassium nitrate in 400mL deionized water to obtain an electroplating solution. Pour the electroplating solution into the electroplating tank, stir with a magnetic stirrer, and set the electroplating tank Add carbon fiber to disperse it in the plating solution;

S4. Place a piece of phosphor copper sheet on the left and right sides of the electroplating tank as the anode, and place the foam copper in the middle as the cathode. Connect the circuit, adjust the DC regulated power supply, and stir while depositing. The stirring speed is 300 rpm, so that the voltage is 2V. , plating time is 10h;

S5. The carbon fiber-copper foam composite skeleton obtained after electrodeposition (as shown in Figure 2). It can be seen from Figure 2 that the carbon fiber is plated on the copper foam template. The carbon fiber is distributed along the copper foam skeleton and forms a carbon fiber with the copper foam. -Foam copper composite skeleton structure) is put into a stainless steel mold, and then the mold is placed in a suction filtration device. The copper powder is pumped into the holes of the skeleton until the entire skeleton is filled. A pressure of 10MPa is applied to the mold and the pressure is maintained for 2 minutes to obtain Composite material cold-pressed green body;

S6. Put the cold-pressed green body into a graphite mold for vacuum hot-pressing sintering, with a sintering pressure of 50MPa, a sintering temperature of 900°C, and heat preservation for 60 minutes. Then, cool to room temperature in the furnace to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material.

The volume fraction of carbon fiber in the three-dimensional highly thermally conductive carbon fiber reinforced copper-based composite material obtained in the above embodiment is 10.9%, the density of the composite material reaches 98.2%, the thermal conductivity in the in-plane direction is 425.8W/(m·K), and the tensile strength The strength reaches 327.5MPa.

Example 2

A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, its preparation method includes the following steps:

S1. Preparation materials: The pore diameter of the copper foam is 20PPI, the thickness is 5mm, and the diameter of the copper foam is 30mm; the diameter of the carbon fiber powder is 7μm, the length is 200μm, and the thermal conductivity is 600W/(m·K); the particles of pure copper powder The diameter is 20μm;

S2. Ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 10 minutes, then rinse it with deionized water, put it in a vacuum drying box, and dry it at 60°C for 2 hours to remove impurities and oxides on the surface of the copper foam; place the carbon fiber in Soak in acetone for 12 hours, then wash with deionized water, vacuum filter, and dry in a 60°C blast oven for 6 hours;

S3. Dissolve 20g copper sulfate pentahydrate, 4g potassium sodium tartrate, 36g sodium citrate, and 4.8g potassium nitrate in 400mL deionized water to obtain an electroplating solution. Pour the electroplating solution into the electroplating tank, stir with a magnetic stirrer, and set the electroplating tank Add carbon fiber to disperse it in the plating solution;

S4. Place a piece of phosphor copper sheet on the left and right sides of the electroplating tank as the anode, and place the foam copper in the middle as the cathode. Connect the circuit, adjust the DC regulated power supply so that the voltage is 3V, stir while depositing, and the stirring speed is 300 rpm. , plating time is 10h;

S5. Put the carbon fiber-copper foam composite skeleton obtained after electrodeposition (as shown in Figure 2) into a stainless steel mold, then place the mold in a suction filtration device, and pump the copper powder into the holes of the skeleton until the entire skeleton, apply a pressure of 20MPa to the mold, and maintain the pressure for 2 minutes to obtain a cold-pressed composite body;

S6. Put the cold-pressed green body into a graphite mold for vacuum hot-pressing sintering, with a sintering pressure of 40MPa, a sintering temperature of 900°C, and a heat preservation period of 10 minutes. The furnace is then cooled to room temperature to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material.

The volume fraction of carbon fiber in the three-dimensional highly thermally conductive carbon fiber reinforced copper-based composite material obtained in the above embodiment is 6.8%, the density of the composite material reaches 98.4%, the thermal conductivity in the in-plane direction is 407.9W/(m·K), and the tensile strength The strength reaches 298.2MPa.

Example 3

A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, its preparation method includes the following steps:

S1. Preparation materials: The pore diameter of the copper foam is 30PPI, the thickness is 3mm, and the diameter of the copper foam is 30mm; the diameter of the carbon fiber powder is 14μm, the length is 300μm, and the thermal conductivity is 600W/(m·K); the particles of pure copper powder Diameter is 6.5μm;

S2. Ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 10 minutes, then rinse it with deionized water, put it in a vacuum drying box, and dry it at 60°C for 2 hours to remove impurities and oxides on the surface of the copper foam; place the carbon fiber in Soak in acetone for 12 hours, then wash with deionized water, vacuum filter, and dry in a 60°C blast oven for 6 hours;

S3. Dissolve 20g copper sulfate pentahydrate, 4g potassium sodium tartrate, 36g sodium citrate, and 4.8g potassium nitrate in 400mL deionized water to obtain an electroplating solution. Pour the electroplating solution into the electroplating tank, stir with a magnetic stirrer, and set the electroplating tank Add carbon fiber to disperse it in the plating solution;

S4. Place a piece of phosphor copper sheet on the left and right sides of the electroplating tank as the anode, and place the foam copper in the middle as the cathode. Connect the circuit, adjust the DC regulated power supply so that the voltage is 1.5V, and stir while depositing. The stirring speed is 300rpm, plating time is 12h;

S5. Put the carbon fiber-copper foam composite skeleton obtained after electrodeposition (as shown in Figure 2) into a stainless steel mold, then place the mold in a suction filtration device, and pump the copper powder into the holes of the skeleton until the entire skeleton, apply a pressure of 12MPa to the mold, and hold the pressure for 1 minute to obtain a cold-pressed composite body;

S6. Put the cold-pressed green body into a graphite mold for vacuum hot-pressing sintering, with a sintering pressure of 50MPa, a sintering temperature of 850°C, and a heat preservation period of 45 minutes. The furnace is then cooled to room temperature to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material.

The volume fraction of carbon fiber in the three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material obtained in the above embodiment is 9.1%, the density of the composite material reaches 97.9%, the thermal conductivity in the in-plane direction is 413.7W/(m·K), and the tensile strength The strength reaches 298.9MPa.

Example 4

A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, its preparation method includes the following steps:

S1. Preparation materials: The pore diameter of the copper foam is 40PPI, the thickness is 3mm, and the diameter of the copper foam is 30mm; the diameter of the carbon fiber powder is 10μm, the length is 200μm, and the thermal conductivity is 600W/(m·K); the particles of pure copper powder The diameter is 10μm;

S2. Ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 10 minutes, then rinse it with deionized water, put it in a vacuum drying box, and dry it at 60°C for 2 hours to remove impurities and oxides on the surface of the copper foam; place the carbon fiber in Soak in acetone for 12 hours, then wash with deionized water, vacuum filter, and dry in a 60°C blast oven for 6 hours;

S3. Dissolve 20g copper sulfate pentahydrate, 4g potassium sodium tartrate, 36g sodium citrate, and 4.8g potassium nitrate in 400mL deionized water to obtain an electroplating solution. Pour the electroplating solution into the electroplating tank, stir with a magnetic stirrer, and set the electroplating tank Add carbon fiber to disperse it in the plating solution;

S4. Place a piece of phosphor copper sheet on the left and right sides of the electroplating tank as the anode, and place the foam copper in the middle as the cathode. Connect the circuit, adjust the DC regulated power supply so that the voltage is 2V, stir while depositing, and the stirring speed is 300rpm. , plating time is 6h;

S5. Put the carbon fiber-copper foam composite skeleton obtained after electrodeposition (as shown in Figure 2) into a stainless steel mold, then place the mold in a suction filtration device, and pump the copper powder into the holes of the skeleton until the entire skeleton, apply a pressure of 10MPa to the mold, and maintain the pressure for 2 minutes to obtain a cold-pressed composite body;

S6. Put the cold-pressed green body into a graphite mold for vacuum hot-pressing sintering, with a sintering pressure of 40MPa, a sintering temperature of 900°C, and a heat preservation period of 10 minutes. The furnace is then cooled to room temperature to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material.

The volume fraction of carbon fiber in the three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material obtained in the above embodiment is 6.4%, the density of the composite material reaches 98.5%, the thermal conductivity in the in-plane direction is 403.5W/(m·K), and the tensile strength The strength reaches 288.8MPa.

Example 5

A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, its preparation method includes the following steps:

S1. Preparation materials: The pore diameter of the copper foam is 30PPI, the thickness is 3mm, and the diameter of the copper foam is 30mm; the diameter of the carbon fiber powder is 12μm, the length is 250μm, and the thermal conductivity is 600W/(m·K); the particles of pure copper powder The diameter is 20μm;

S2. Ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 10 minutes, then rinse it with deionized water, put it in a vacuum drying box, and dry it at 60°C for 2 hours to remove impurities and oxides on the surface of the copper foam; place the carbon fiber in Soak in acetone for 12 hours, then wash with deionized water, vacuum filter, and dry in a 60°C blast oven for 6 hours;

S3. Dissolve 20g copper sulfate pentahydrate, 4g potassium sodium tartrate, 36g sodium citrate, and 4.8g potassium nitrate in 400mL deionized water to obtain an electroplating solution. Pour the electroplating solution into the electroplating tank, stir with a magnetic stirrer, and set the electroplating tank Add carbon fiber to disperse it in the plating solution;

S4. Place a piece of phosphor copper sheet on the left and right sides of the electroplating tank as the anode, and place the foam copper in the middle as the cathode. Connect the circuit, adjust the DC regulated power supply so that the voltage is 1.5V, and stir while depositing. The stirring speed is 300rpm, plating time is 8h;

S5. Put the carbon fiber-copper foam composite skeleton obtained after electrodeposition (as shown in Figure 2) into a stainless steel mold, then place the mold in a suction filtration device, and pump the copper powder into the holes of the skeleton until the entire skeleton, apply a pressure of 10MPa to the mold, and maintain the pressure for 2 minutes to obtain a cold-pressed composite body;

S6. Put the cold-pressed green body into a graphite mold for vacuum hot-pressing sintering, with a sintering pressure of 50MPa, a sintering temperature of 900°C, and a heat preservation period of 50 minutes. The furnace is then cooled to room temperature to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper-based composite material.

The volume fraction of carbon fiber in the three-dimensional highly thermally conductive carbon fiber reinforced copper-based composite material obtained in the above embodiment is 6.9%, the density of the composite material reaches 97.8%, the thermal conductivity in the in-plane direction is 405.1W/(m·K), and the tensile strength The strength reaches 303.2MPa.

Comparative example 1

Comparative Example 1 is the same as Example 1, except that in step S4, the plating time is 12 hours.

The volume fraction of carbon fiber in the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite obtained in Comparative Example 1 is 11.1%, the density of the composite material reaches 97.3%, the thermal conductivity in the in-plane direction is 410.6W/(m·K), and the tensile strength The strength reaches 302.8MPa.

Comparative example 2

Comparative Example 2 is the same as Example 1, except that in step S4, the plating time is 8 hours.

The volume fraction of carbon fiber in the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite obtained in Comparative Example 2 is 7.3%, the density of the composite material reaches 98.7%, the thermal conductivity in the in-plane direction is 403.1W/(m·K), and the tensile strength The strength reaches 301.4MPa.

It can be seen from Comparative Example 1 and Comparative Example 2 that when the plating time is too long or too short, the density, thermal conductivity and tensile strength of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material are reduced. It can be seen that if the plating time is too short or too long, it will have a negative impact on the performance of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material. Only within the appropriate plating time range of the present invention can the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite be made. The performance of composite materials is optimized.

Comparative example 3

Comparative Example 3 is the same as Example 1, except that no electrodeposition treatment was performed, but the foamed copper was put into the electroplating solution for 10 hours and then taken out.

Test results: Copper foam and carbon fiber did not combine to form a composite material.

Comparative example 4

Comparative Example 4 is the same as Example 1, except that step S5 is not performed.

Test results: The volume fraction of carbon fiber in the obtained three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material is 21.6%, the density of the composite material reaches 96.8%, the thermal conductivity in the in-plane direction is 395.7W/(m·K), and the tensile strength Reaching 279.8MPa.

It can be seen that when there is a lack of copper powder filling, the volume fraction of carbon fiber in the composite material increases, and the density, thermal conductivity and tensile strength of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material are reduced. Therefore, the lack of copper powder filling will have a negative impact on the performance of three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composites.

Comparative example 5

Comparative Example 5 is the same as Example 1, except that the diameter of the carbon fiber is 12 μm, the length is 500 μm, and the thermal conductivity is 600 W/(m·K).

Test results: The volume fraction of carbon fiber in the obtained three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material is 5.4%, the density of the composite material reaches 97.3%, the thermal conductivity in the in-plane direction is 398.7W/(m·K), and the tensile strength Reaching 293.6MPa.

It can be seen that when the length of carbon fiber is too long, the volume fraction of carbon fiber in the composite material decreases, and the density, thermal conductivity and tensile strength of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material are reduced. Therefore, an excessively long length of carbon fiber will have a negative impact on the performance of the three-dimensional highly thermally conductive carbon fiber reinforced copper matrix composite material. Only within the appropriate carbon fiber length range of the present invention can the performance of the three-dimensional highly thermally conductive carbon fiber reinforced copper matrix composite material be maximized. excellent.

Comparative example 6

Comparative Example 6 is the same as Example 1, except that the diameter of the carbon fiber is 30 μm, the length is 250 μm, and the thermal conductivity is 600 W/(m·K).

Test results: The volume fraction of carbon fiber in the obtained three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material is 6.5%, the density of the composite material reaches 97.1%, the thermal conductivity in the in-plane direction is 400.3W/(m·K), and the tensile strength Reaching 291.8MPa.

It can be seen that when the diameter of carbon fiber is too large, the volume fraction of carbon fiber in the composite material decreases, and the density, thermal conductivity and tensile strength of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material are reduced. Therefore, an excessive diameter of carbon fiber will have a negative impact on the performance of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material. Only within the appropriate carbon fiber diameter range of the present invention can the performance of the three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material be optimized. .

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. A method for preparing a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, which is characterized by comprising the following steps: A. Load carbon fiber on the surface of copper foam to prepare a carbon fiber-copper foam composite skeleton; B. Place the carbon fiber-copper foam composite skeleton in the mold, fill the holes in the carbon fiber-copper foam composite skeleton with copper powder, and obtain a preliminary blank; C. Apply pressure to the mold and pre-press the blank into a green body through cold pressing; D. Sinter and densify the green body to obtain a three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material. 2. The preparation method according to claim 1, wherein the purity of the copper foam is not less than 99.9%, the pore diameter is 20-60PPI, and the thickness is 2-8mm; the purity of the copper powder is not less than 99.9%. , its particle size is 5-50 μm; the diameter of the carbon fiber is 7-20 μm, the length is 100-300 μm, and the thermal conductivity is 600-900W/m·K. 3. The preparation method according to claim 1 or 2, characterized in that the method of loading carbon fibers on the surface of the copper foam is an electrodeposition method, which includes the following steps: (1) Pretreatment of copper foam and carbon fiber powder; (2) Prepare the electroplating solution and pour it into the electroplating tank, and disperse the carbon fibers in the electroplating solution; (3) Use foamed copper as the cathode and copper sheet as the anode, turn on the power and start deposition; (4) After the deposition is completed, the skeleton is rinsed with deionized water and dried in vacuum to obtain the carbon fiber-copper foam composite skeleton. 4. The preparation method according to claim 3, characterized in that the pretreatment process of the copper foam skeleton is: ultrasonically clean the copper foam through acetone and hydrochloric acid solutions for 5-20 minutes, and then rinse it with deionized water. Then vacuum dry at 50-70℃ for 1-3h; The pretreatment process of the carbon fiber includes the following steps: place the carbon fiber in acetone, soak it for 10-14 hours, then clean it with deionized water, vacuum filter it, and then put it into a blast oven and dry it at 50-70°C for 5- 7h. 5. The preparation method as claimed in claim 3, characterized in that the electroplating solution is made of copper sulfate, potassium sodium tartrate, sodium citrate and potassium nitrate in a mass ratio of 18-22:3-5:30-40: It is prepared by mixing and dissolving in deionized water at a ratio of 4-5. 6. The preparation method according to claim 5, characterized in that the foamed copper cathode is fixed in the central area of the electroplating tank and connected to the negative electrode of the DC power supply. A phosphor copper plate is placed on both sides of the electroplating tank as an anode and connected to the DC power supply. positive electrode, then turn on the power, adjust the power supply voltage to 1-3V, stir while depositing, the rotation speed is 200-400rpm, and the plating time is 2-12h. 7. The preparation method according to claim 5, characterized in that in step B, the holes in the carbon fiber-copper foam composite skeleton are filled with copper powder by vacuum filtration until the entire composite skeleton is filled, and then Put it in a vacuum drying box and dry it at 50-70℃ for 10-14h. 8. The preparation method according to claim 5, characterized in that in step C, the pressure of cold pressing is 10-20MPa, and the holding time is 1-3 minutes. 9. The preparation method according to claim 5, characterized in that, in step D, the process for sintering and densifying the green body is one of hot pressing sintering and discharge plasma sintering, and the mold during the sintering process is graphite. Mold, sintering pressure 30-50MPa, sintering temperature 800-950℃, holding time 10-60min. 10. A three-dimensional high thermal conductivity carbon fiber reinforced copper matrix composite material, characterized in that the composite material is prepared by the preparation method described in any one of the above claims 1-9.