High-thermal-conductivity carbon material reinforced metal-based composite and preparation method thereof

Abstract

The invention provides a high-thermal-conductivity carbon material reinforced metal-based complex and a preparation method thereof, and belongs to the technical field of high-thermal-conductivity carbon materials. The method comprises the following steps: firstly, processing a metal or composite hard substrate into a required shape, and removing dirt and an oxide layer on the surface; then selecting one or a plurality of high-thermal-conductivity carbon materials, cutting or cutting the high-thermal-conductivity carbon materials into proper sizes according to actual requirements, and carrying out surface metallization treatment on the high-thermal-conductivity carbon materials; and finally, the high-thermal-conductivity carbon material subjected to surface treatment and a substrate material are subjected to brazing compounding to prepare the high-thermal-conductivity carbon material composite. The high-thermal-conductivity carbon material plays a role in enhancing thermal conductivity in the composite, and the thermal conductivity of the composite can be remarkably improved. The method is simple, reliable, low in cost and high in operability, and the composite manufactured through the method is high in heat conductivity, high in strength and controllable in shape and size. The defects that a high-heat-conduction carbon material is prone to abrasion and slag falling, low in strength and the like are effectively overcome, and the high-heat-conduction carbon material can be applied to heat dissipation structures of various substrates, cold plates, case shells and the like.

Description

Technical Field

[0001] The invention relates to a high thermal conductivity carbon material reinforced metal matrix composite and a preparation method thereof, belonging to the technical field of high thermal conductivity carbon materials. Background Art

[0002] As electronic devices develop towards miniaturization, integration and high energy density, the heat dissipation problems in aerospace, communications and new energy vehicles are becoming increasingly prominent. High thermal conductivity materials can transfer heat in a timely manner to avoid heat accumulation, thereby affecting and reducing the stability, reliability and service life of the equipment. Therefore, the design and development of thermal management materials with high thermal conductivity and excellent mechanical properties has become a top priority in solving the problem of equipment heat dissipation. With the development of science and technology, many high thermal conductivity materials have emerged, including artificial graphite film, pyrolytic graphite, graphene film, graphene composites, etc. Most of these high thermal conductivity materials are carbon materials with a layered structure, whose planar thermal conductivity can reach 150-1800W / (m·K), and their density is low, which is a thermal conductive material with broad application prospects. The thermal conductivity of high thermal conductivity graphite film can reach up to 1800 W / (m·K). Although graphite film has excellent thermal conductivity, the thickness of a single graphite film is only at the micron level. At the same time, the interlayer bonding force is low, and it is easy to peel off and fall off. When used alone, it cannot meet the environmental requirements of many precision electronic equipment, limiting its application scope in thermal management. It is usually necessary to compound it with other reinforcements to meet more application requirements.

[0003] The invention patent CN109133965A (Patent Document 1, Preparation of a Two-Dimensional High Thermal Conductivity Graphite Film / Aluminum Composite Material) is to cross-layer aluminum foil and graphite film and prepare a high thermal conductivity composite material by plasma discharge sintering. This process has a weak bonding force between the aluminum foil and the graphite film. In addition, the high thermal conductivity composite material itself has no metal matrix wrapped on the side, is easy to wear, has low strength, and is not suitable for continuous work in harsh environments.

[0004] The invention patent CN216775353U (Patent Document 2, a thermal connection based on graphite / aluminum-based multi-component composite material) is to overlap a number of graphite papers and a number of aluminum foils, and connect the graphite papers and aluminum foils with a mixed emulsion of boron nitride / silicon nitride. The radiator is connected by welding. The method has high process conditions and a large workload, and the prepared composite is not resistant to high temperatures. There is also no metal shell protection on the side. Summary of the invention

[0005] The purpose of the present application is to provide a high thermal conductivity carbon material reinforced metal matrix composite and a preparation method thereof, to overcome the deficiency that high thermal conductivity carbon material cannot meet the use requirements, and to provide a simple and reliable method for preparing a high thermal conductivity composite.

[0006] The present invention provides a method for preparing a high thermal conductivity carbon material reinforced metal matrix composite, comprising the following steps: The steps include: Step 1: Processing a metal or metal composite hard substrate into a base shell having a cavity therein, and removing surface dirt and oxide layer; Step 2: drying the carbon material after surface treatment, and then cutting the carbon material into a structure corresponding to the cavity of the base shell to obtain a middle carbon material and a pre-treated surface carbon material; Step 3, plating a metal material on the surface of the pretreated surface carbon material obtained in step 2, and then washing and drying to obtain a treated surface carbon material; Step 4: After stacking the middle carbon material obtained in step 2, the treated surface carbon material obtained in step 3 is arranged on the top and bottom of the stacked middle carbon material, and the obtained carbon material stack is placed in the cavity of the base shell treated in step 1, solder is placed on the upper and lower surfaces of the carbon material stack, and then the ends are inserted into both sides of the base shell to form a composite material; Step 5: brazing the composite material obtained in step 4 under the protection of argon gas. After brazing, the surface of the composite material is milled and polished.

[0007] Preferably, the metal or metal composite hard substrate is one or more of aluminum, copper, silver, invar or a composite material, and the composite material includes an aluminum-based silicon carbide material.

[0008] Preferably, the carbon material includes one or more of pyrolytic graphite, graphite film, a composite material of graphite film and pyrolytic graphite, carbon nanotube film, carbon nanotube composite film, graphene film, graphene composite film, carbon fiber composite material, diamond, and diamond composite material; the horizontal or axial thermal conductivity of the carbon material is greater than 50 W / (m·K) and the thickness is 1 µm-10 mm.

[0009] Preferably, the solder includes one or more of silver-based solder, copper-based solder, aluminum-based solder, tin-based solder, manganese-based solder, nickel-based solder, zirconium-based solder, titanium-based solder, and palladium-based solder; the solder is in paste or foil form.

[0010] Preferably, in step three, the method of plating the metal or composite metal includes one of chemical plating, electroplating, vacuum evaporation, and magnetron sputtering, and the coating thickness is 5 nm-200 µm.

[0011] Preferably, in step five, brazing includes vacuum or inert atmosphere protection brazing, the welding process pressure is 0.1-300 MPa, the welding time is 0.001-24 h, and the temperature is 100-1000 °C.

[0012] Preferably, in step three, the metal material is one or more of nickel, copper, titanium, gold and silver.

[0013] Preferably, in step one, the base shell is subjected to alkali treatment and acid treatment to remove surface dirt and oxide layer.

[0014] The present application also provides a carbon material reinforced metal matrix composite obtained according to the preparation method of the above-mentioned high thermal conductivity carbon material reinforced metal matrix composite.

[0015] Therefore, the present invention provides a high thermal conductivity carbon material reinforced metal matrix composite and a preparation method thereof, which has the following beneficial effects: (1) The manufacturing method of the present invention is simple, reliable, and easy to operate. The thickness of the composite body can be changed according to the thickness of the carbon material and the metal or metal composite hard substrate, and has wider applicability. (2) The present invention adopts the measures of metallization of the carbon material surface, pretreatment of the metal substrate, and use of solder to improve the problem of poor interface wettability, so that the substrate and the carbon material are fully combined, achieving effective composite and improving the thermal conductivity of the composite; (3) In this method, the substrate shell can effectively enhance the strength of the high thermal conductivity material, and the substrate shell is also beneficial to protect the high thermal conductivity material. The metallization of the carbon material surface makes the bonding better and has excellent mechanical properties. It is suitable for heat dissipation in aerospace or precision high-power electronic devices; it can also be used in various heat dissipation structures such as substrates, cold plates and chassis shells.

[0016] (4) The present invention utilizes the ultra-high in-plane thermal conductivity of high thermal conductivity carbon materials to prepare a high thermal conductivity composite with low density and good in-plane heat dissipation performance. The in-plane thermal conductivity can exceed 900 W / (m·K). BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a side view schematic diagram of a substrate through hole; Figure 2 Schematic diagram of graphite film stacking; Figure 3 Schematic diagram of the preparation process of the composite material. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further illustrated by the following examples.

[0019] Example 1 (1) Preparation: A 6063 aluminum alloy substrate (250×110×8 mm) was processed by wire cutting into a shell with two through-hole structures (250×50×4 mm), and four rectangular end caps (50×4×2 mm) were processed at the same time. Then, it was placed in a 2.5 mol / L KOH solution for cleaning for 2 min and then rinsed with distilled water until neutral. It was then placed in a 1 mol / L HCl solution for stirring and cleaning for 5 min, and then rinsed with distilled water until neutral to remove surface dirt and oxide layer. (2) Cutting: several high thermal conductivity graphite films (thermal conductivity of 1500 W / (m·K)) were soaked in acetone to remove surface impurities, and then dried in an oven to obtain pretreated graphite films. The graphite films were then cut into sizes of 246×50 mm to obtain middle carbon materials and pretreated surface carbon materials; (3) Carbon material surface metallization: The pretreated surface carbon material high thermal conductivity graphite film obtained in (2) is placed in a container filled with nickel electroplating solution, and the electroplating is carried out using direct current with a current density of 2 A / dm 2 , temperature 60 ℃, time 30 min, after electroplating, rinse with distilled water and dry; (4) Assembly: After stacking the middle carbon material obtained in (2), the treated surface carbon material obtained in (3) is arranged on the top and bottom of the stacked middle carbon material, and then the nickel-based solder is evenly coated on the outer surface of the surface carbon material. Finally, the 3.9 mm thick high thermal conductivity graphite film stack is placed in the treated base shell, and the ends are plugged into the holes at both ends; (5) Welding: The assembled composite material was brazed at high temperature (500 °C, 50 MPa) under the protection of argon gas for 30 min; (6) Processing: After welding is completed, the composite material surface is milled, polished and other finishing processes are performed.

[0020] The planar thermal conductivity of the high thermal conductor prepared in this example is 808 W / (m·K). This example shows that the high thermal conductor prepared in the present invention has the advantages of low density, high temperature resistance, high thermal conductivity, etc.

[0021] Example 2 The 6063 aluminum alloy substrate in step (1) of Example 1 was replaced with an oxygen-free copper substrate, whose thermal conductivity was 400 W / (m·K), and the other conditions were the same as Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 923 W / (m·K).

[0022] Example 3 The high thermal conductivity graphite film in step (2) of Example 1 was replaced with a graphene film with a thickness of 0.2 mm and a thermal conductivity of 1000 W / (m·K), and the other conditions were the same as those of Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 790 W / (m·K).

[0023] Example 4 The method of metallizing the surface of the high thermal conductivity carbon material in step (3) of Example 1 was removed, and the remaining conditions were the same as those of Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 683 W / (m·K).

[0024] Example 5 The method of metallizing the surface of the high thermal conductivity carbon material in step (3) of Example 1 was changed to magnetron sputtering, and the other conditions were the same as those of Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 833 W / (m·K).

[0025] Example 6 The nickel-based solder in step (4) of Example 1 was replaced with aluminum-based solder, and the remaining conditions were the same as those of Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 856 W / (m·K).

[0026] Example 7 The welding conditions of 500°C, 50 MPa, 30 min in step (5) of Example 1 were changed to 550°C, 40 MPa, 30 min, and the other conditions were the same as those of Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 876 W / (m·K).

[0027] Example 8 The size of the aluminum alloy substrate in step (1) of Example 1 was changed to 250×300×8 mm, processed into a structure with eight through holes (300×25×4 mm), the size of the graphite film was 296×25 mm, and the other conditions were the same as in Example 1. The planar thermal conductivity of the high thermal conductor prepared in this example was 843 W / (m·K).

[0028] Therefore, the present application provides the above-mentioned high thermal conductivity carbon material reinforced metal matrix composite and its preparation method. In this method, the high thermal conductivity carbon material is used to quickly transfer the heat of the heat source in a directional manner by utilizing its ultra-high directional heat transfer ability, thereby preparing a high directional thermal conductivity composite material. The matrix acts as an outer shell to provide protection and mechanical properties. After the high thermal conductivity carbon material is metallized, it is composited with the metal substrate through brazing material to improve the interface bonding strength. The problems of easy wear, slag falling, and low strength of carbon-based thermal conductive materials are solved. At the same time, the prepared composite has high thermal conductivity, low density, and excellent mechanical properties. The overall preparation process is simple, reliable, and easy to operate. The high thermal conductivity carbon material plays a role in enhancing thermal conductivity in the composite. The composite made by this method has high thermal conductivity, high strength, and controllable shape and size.

[0029] In the description of this specification, the description with reference to the terms "an experimental example", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the experimental example or example are included in at least one experimental example or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0030] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a highly thermally conductive carbon material reinforced metal matrix composite, characterized in that: The steps include: Step 1: Processing a metal or metal composite hard substrate into a base shell having a cavity therein, and removing surface dirt and oxide layer; Step 2: drying the carbon material after surface treatment, and then cutting the carbon material into a structure corresponding to the cavity of the base shell to obtain a middle carbon material and a pre-treated surface carbon material; Step 3, plating a metal material on the surface of the pretreated surface carbon material obtained in step 2, and then washing and drying to obtain a treated surface carbon material; Step 4: After stacking the middle carbon material obtained in step 2, the treated surface carbon material obtained in step 3 is arranged on the top and bottom of the stacked middle carbon material, and the obtained carbon material stack is placed in the cavity of the base shell treated in step 1, solder is placed on the upper and lower surfaces of the carbon material stack, and then the ends are inserted into both sides of the base shell to form a composite material; Step 5: brazing the composite material obtained in step 4 under the protection of argon gas. After brazing, the surface of the composite material is milled and polished.

2. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 1, characterized in that: The metal or metal composite hard substrate is one or more of aluminum, copper, silver, invar or a composite material, and the composite material includes an aluminum-based silicon carbide material.

3. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 2, characterized in that: The carbon material includes one or more of pyrolytic graphite, graphite film, a composite material of graphite film and pyrolytic graphite, carbon nanotube film, carbon nanotube composite film, graphene film, graphene composite film, carbon fiber composite material, diamond, and diamond composite material; the horizontal or axial thermal conductivity of the carbon material is greater than 50 W / (m·K) and the thickness is 1 µm-10 mm.

4. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 3, characterized in that: The solder includes one or more of silver-based solder, copper-based solder, aluminum-based solder, tin-based solder, manganese-based solder, nickel-based solder, zirconium-based solder, titanium-based solder, and palladium-based solder; Solder comes in paste or foil form.

5. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 4, characterized in that: In step three, the method of plating metal or composite metal includes one of chemical plating, electroplating vacuum evaporation, and magnetron sputtering, and the coating thickness is 5 nm-200 µm.

6. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 1, characterized in that: In step 5, brazing includes vacuum or inert atmosphere protection brazing, the welding process pressure is 0.1-300 MPa, the welding time is 0.001-24 h, and the temperature is 100-1000 °C.

7. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 1, characterized in that: In step three, the metal material is one or more of nickel, copper, titanium, gold, and silver.

8. The method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to claim 1, characterized in that: In step one, the base shell is subjected to alkali treatment and acid treatment to remove surface dirt and oxide layer.

9. A carbon material reinforced metal matrix composite obtained according to the method for preparing a high thermal conductivity carbon material reinforced metal matrix composite according to any one of claims 1 to 8.

Images