A copper-based composite material containing aluminum carbon nanotubes and preparation method thereof

Abstract

The invention relates to the technical field of metal material processing, and discloses a copper-based composite material containing aluminum carbon nanotubes and a preparation method thereof, wherein the raw materials are CNTs, Al powder and Cu powder, and the composite material is composed of copper powder with a metal purity of 99.9%, aluminum powder with a purity of 99.9% preserved by wet method and carbon nanotubes, wherein the carbon nanotubes are attached to the aluminum powder, and copper is added to make them grow on the carbon nanotubes, so as to prepare a copper-based composite material containing aluminum carbon nanotubes, and Al powder is introduced and fully mixed for connection, and CNTs are uniformly dispersed on Al, thereby improving the electrical conductivity of the material. The metallurgical bonding surface of Al-C (CNTs) is well bonded, and Cu powder is added to the Al-C (CNTs) mixed powder, thereby overcoming the problem of poor interface bonding between aluminum and copper matrix, and by fully introducing and mixing CNTs, uniform dispersion of Al and Cu is ensured, thereby effectively improving the high temperature stability of the material.

Description

Technical Field

[0001] The invention relates to the technical field of metal material processing, in particular to a copper-based composite material containing aluminum carbon nanotubes and a preparation method thereof. Background Art

[0002] For welding conductive nozzle materials, high conductivity, high hardness and high temperature resistance are required. In the past, chromium-zirconium-copper was widely used in automotive welding conductive nozzles. Its conductivity and hardness made it an ideal choice. However, chromium-zirconium-copper easily reacts with the zinc coating on the surface of the automotive plate, resulting in reduced conductivity on the surface of the welded joint, so it is necessary to find a more superior alternative material. In this context, alumina-dispersed copper has become a candidate material that has attracted much attention. However, the wettability between alumina and the copper matrix is ​​very poor, resulting in a weak bond between the metal film and the matrix, resulting in insufficient plasticity and easy fracture during the molding process. In order to solve this problem, Al-C (CNTs) was introduced to improve plasticity through nano-fiber reinforcement. Carbon nanotubes (CNTs) are considered to be one of the ideal reinforcing phases for metal matrix composites due to their special nanostructure and excellent physical, chemical and mechanical properties.

[0003] There are the following problems in the prior art:

[0004] (1) Difficulty in dispersion: Due to their nanostructure, CNTs are often difficult to disperse evenly in a metal matrix.

[0005] (2) The interface bonding between CNTs and Cu is usually not ideal, and the interface bonding between aluminum and copper matrix is ​​poor, which leads to the degradation of the performance of the composite material. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a copper-based composite material containing aluminum carbon nanotubes and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a copper-based composite material containing aluminum carbon nanotubes, whose raw materials are CNTs, Al powder and Cu powder. The components of the composite material are copper powder with a metal purity of 99.9%, aluminum powder with a purity of 99.9% preserved by wet method and carbon nanotubes. The carbon nanotubes are attached to the aluminum powder, and copper is added to make it grow on the carbon nanotubes to prepare a copper-based composite material containing aluminum carbon nanotubes.

[0008] Preferably, the material is prepared by selecting aluminum powder and CNTs as raw materials, with the mass percentage of aluminum powder and CNTs being 2:1 to 4:1, and mixing and ball milling to obtain Al-C (CNTs) mixed powder, and then mixing Al-C (CNTs) with Cu powder and ball milling to obtain the final Cu-Al-CNTs composite material.

[0009] Preferably, a method for preparing a copper-based composite material containing aluminum carbon nanotubes comprises the following steps:

[0010] (1) Mixing and ball milling of CNTs and Al powder;

[0011] (2) Vacuum heat treatment;

[0012] (3) Ball milling;

[0013] (4) Al-C (CNTs) mixed with Cu powder and ball milling;

[0014] (5) Extrusion molding;

[0015] (6) Pulling.

[0016] Preferably, in the step of mixing and ball milling the CNTs and Al powder, aluminum powder and CNTs are selected as raw materials, the mass percentage of aluminum powder and CNTs is 2:1~4:1, placed in a ball milling jar, sealed after adding anhydrous ethanol and passed into a low-pressure argon ball mill, the ball milling speed is 80~500r / min, the ball milling time is 3~6h, the argon pressure is 0.1~0.9MPa, and the ball milling is dried.

[0017] Preferably, the CNTs are uniformly dispersed on the surface of the aluminum powder with a mesh size of -500 through continuous impact and collision between the powder, the grinding balls and the container wall to form an Al-C (CNTs) mixed powder.

[0018] Preferably, in the vacuum heat treatment step, -1 ~10 -3 Under the condition of Pa vacuum, heat treatment was performed at 450℃ for 3h to fully react and form a composite material powder with a metallurgical bonding interface.

[0019] Preferably, in the ball milling step, CNTs tend to aggregate locally to form clusters, and argon-protected ball milling is required again for 0.1 to 1 h, with a ball milling speed of 80 to 500 r / min and an argon pressure of 1 to 2 MPa, so that the CNTs are uniformly dispersed on the Al powder.

[0020] Preferably, in the Al-C (CNTs) mixed Cu powder and ball milling step, minus 500 mesh Cu powder is added to the Al-C (CNTs) mixed powder, the mass percentage of the Al-C (CNTs) mixed powder to the Cu powder is 3:97~6:94, and argon-protected ball milling is performed for 0.1~1h, the ball milling speed is 80~500r / min, and the argon pressure is 0.1~0.2Mpa.

[0021] Preferably, in the extrusion molding step, the powder is fed into a continuous extruder for molding through a powder feeding mechanism, the extrusion wheel speed is 5-15 r / min, the extrusion temperature is 760-830°C, and the Cu-Al-CNTs composite rod with a metallurgical bonding surface has a diameter of 20-40 mm.

[0022] Preferably, in the drawing step, the drawing is performed at room temperature, the deformation is about 30%-60%, and the rod diameter is 8-28 mm.

[0023] Compared with the prior art, the present invention provides a copper-based composite material containing aluminum carbon nanotubes and a preparation method thereof, which has the following beneficial effects:

[0024] 1. The copper-based composite material containing aluminum carbon nanotubes and its preparation method have good electrical conductivity, strong interface bonding, higher density than general dispersed copper, and good high-temperature stability. CNTs themselves have good thermal stability, which improves their high-temperature stability. Since the interface bonding between CNTs and Cu is usually not ideal, which will lead to the decline of the performance of the composite material, Al powder is introduced and fully mixed for connection, and CNTs are uniformly dispersed on Al, which improves the electrical conductivity of the material. The metallurgical bonding surface of Al-C (CNTs) is well bonded. Adding Cu powder to the Al-C (CNTs) mixed powder overcomes the problem of poor interface bonding between aluminum and copper matrix. By fully introducing CNTs and mixing, the uniform dispersion of Al and Cu is ensured, thereby effectively improving the high-temperature stability of the material.

[0025] 2. The copper-based composite material containing aluminum carbon nanotubes and its preparation method, uniformly dispersed CNTs, ensure that the CNTs are uniformly dispersed on the surface of Al powder during the ball milling process, and obtain Al-C (CNTs) mixed powder with good dispersibility. This helps to improve the uniformity and density of the final material.

[0026] 3. The copper-based composite material containing aluminum carbon nanotubes and its preparation method strengthen the metallurgical bonding interface. By heat treatment at 450°C, CNTs and Al powder are fully reacted to form a composite material with a metallurgical bonding interface. The poor interface bonding between aluminum and copper matrix is ​​overcome by adding intermediate material CNTs. This can improve the strength and wear resistance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0028] Figure 2 This is a schematic diagram of the performance of the alloy strip according to the first embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the performance of the alloy strip according to Example 2 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] For example, see Figure 1-2 ,

[0032] (1) Mixing and ball milling of CNTs and Al powder

[0033] Aluminum powder and CNTs with a mass percentage of 3:1 were selected as raw materials, placed in a ball mill, sealed after adding anhydrous ethanol and passed into a low-pressure argon ball mill, the ball milling speed was 100r / min, the ball milling time was 5h, the argon gas pressure was 0.2MPa, and the ball milling was dried. Through the continuous impact and collision between the powder, the grinding ball and the container wall, the CNTs were evenly dispersed on the surface of the aluminum powder with a mesh size of minus 500, forming an Al-C (CNTs) mixed powder.

[0034] (2) Vacuum heat treatment

[0035] Under the condition of 10-2Pa vacuum, heat treatment was performed at 450℃ for 3h to fully react and form a composite material powder with a metallurgical bonding interface.

[0036] (3) Ball milling

[0037] CNTs tend to aggregate locally to form clusters, which require another 0.5 h of argon-protected ball milling at a ball milling speed of 100 r / min and an argon pressure of 1.5 MPa to make the CNTs evenly dispersed on the Al powder.

[0038] (4) Al-C (CNTs) mixed with Cu powder, ball milling

[0039] 4wt.% Al-C (CNTs) mixed powder was selected, and the rest was minus 500 mesh Cu powder, and argon protection ball milling was carried out for 0.5h. The ball milling speed was 100r / min and the argon pressure was 0.1MPa.

[0040] (5) Extrusion molding

[0041] The powder is fed into a continuous extruder through a powder feeding mechanism for forming, the extrusion wheel speed is 6r / min, the extrusion temperature is 760~830℃, and the Cu-Al-CNTs composite rod with a metallurgical bonding surface is produced.

[0042] (6) Drawing

[0043] Drawing is performed at room temperature with a deformation of about 40% to obtain a rod with a diameter of 15 mm. The properties of the obtained rod are as follows Figure 2 shown.

[0044] For example 2, please refer to Figure 3 ,

[0045] (1) Mixing and ball milling of CNTs and Al powder

[0046] Aluminum powder and CNTs with a mass percentage of 4:1 were selected as raw materials, placed in a ball mill, sealed after adding anhydrous ethanol and passed into a low-pressure argon ball mill, the ball milling speed was 100r / min, the ball milling time was 5h, the argon gas pressure was 0.2MPa, and the ball milling was dried. Through the continuous impact and collision between the powder, the grinding ball and the container wall, the CNTs were evenly dispersed on the surface of the aluminum powder with a mesh size of minus 500, forming an Al-C (CNTs) mixed powder.

[0047] (2) Vacuum heat treatment

[0048] Under the condition of 10-2Pa vacuum, heat treatment was performed at 450℃ for 3h to fully react and form a composite material powder with a metallurgical bonding interface.

[0049] (3) Ball milling

[0050] CNTs tend to aggregate locally to form clusters, which require another 0.5 h of argon-protected ball milling at a ball milling speed of 100 r / min and an argon pressure of 1.5 MPa to make the CNTs evenly dispersed on the Al powder.

[0051] (4) Al-C (CNTs) mixed with Cu powder, ball milling

[0052] 4wt.% Al-C (CNTs) mixed powder was selected, and the rest was minus 500 mesh Cu powder, and argon protection ball milling was carried out for 0.5h. The ball milling speed was 100r / min and the argon pressure was 0.1MPa.

[0053] (5) Extrusion molding

[0054] The powder is fed into a continuous extruder through a powder feeding mechanism for forming, the extrusion wheel speed is 6 r / min, the extrusion temperature is 800°C, and a Cu-Al-CNTs composite rod with a metallurgical bonding surface is produced.

[0055] (6) Drawing

[0056] Drawing is performed at room temperature with a deformation of about 40% to obtain a rod with a diameter of 15 mm. The properties of the obtained rod are as follows Figure 3 shown.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A copper-based composite material containing aluminum carbon nanotubes, characterized in that: The raw materials are CNTs, Al powder and Cu powder. The composite material is composed of copper powder with a metal purity of 99.9%, aluminum powder with a purity of 99.9% preserved by wet method and carbon nanotubes. The carbon nanotubes are attached to the aluminum powder, and copper is added to grow on the carbon nanotubes to prepare a copper-based composite material containing aluminum carbon nanotubes. The preparation method comprises the following steps: (1) CNTs and Al powder are mixed and ball-milled, and the mass percentage of Al powder and CNTs is 2:1~4:1; In the step of mixing and ball milling the CNTs and Al powder, aluminum powder and CNTs are selected as raw materials, placed in a ball milling jar, sealed after adding anhydrous ethanol and passed into a low-pressure argon ball mill, the ball milling speed is 80-500 r / min, the ball milling time is 3-6 h, the argon pressure is 0.1-0.9 MPa, and the ball milling is dried; Through the continuous impact and collision between the powder, the grinding balls and the container wall, the CNTs are evenly dispersed on the surface of the aluminum powder with a mesh size of -500, forming an Al-C (CNTs) mixed powder. (2) Vacuum heat treatment, at 10 -1 ~10 -3 Under the condition of vacuum degree Pa, heat treatment was performed at 450℃ for 3h to fully react and form composite material powder with metallurgical bonding interface; (3) Ball milling: perform argon-protected ball milling again for 0.1-1 h, with a ball milling speed of 80-500 r / min and an argon pressure of 1-2 MPa, so that the CNTs are evenly dispersed on the Al powder; (4) Al-C (CNTs) mixed with Cu powder, ball milling, the mass percentage of Al-C (CNTs) mixed powder to Cu powder is 3:97~6:94, minus 500 mesh Cu powder is added to the Al-C (CNTs) mixed powder, and argon protection ball milling is performed for 0.1~1h, the ball milling speed is 80~500r / min, and the argon pressure is 0.1~0.2Mpa; (5) Extrusion molding; (6) Pulling.

2. The copper-based composite material containing aluminum carbon nanotubes according to claim 1, characterized in that: In the extrusion molding step, the powder is fed into a continuous extruder for molding through a powder feeding mechanism, the extrusion wheel speed is 5-15 r / min, the extrusion temperature is 760-830° C., and the Cu-Al-CNTs composite rod with a metallurgical bonding surface has a diameter of 20-40 mm.

3. The copper-based composite material containing aluminum carbon nanotubes according to claim 1, characterized in that: In the drawing step, the drawing is performed at room temperature, the deformation is 30%-60%, and the rod diameter is 8-28 mm.

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