A multiphase doped high-conductivity tungsten-copper composite material, a preparation method and application thereof

Abstract

A multiphase doped high-conductivity tungsten-copper composite material and a preparation method and application thereof. The present application belongs to the field of tungsten-copper composite materials. The purpose of the present application is to solve the technical problems of poor W and Cu wettability and difficult to balance mechanical properties and electrical properties of the existing tungsten-copper composite material. The method of the present application is: Co is deposited on the surface of graphene powder and Cu powder respectively by magnetron sputtering to obtain MLG@Co powder and Cu@Co powder respectively; then they are ball-milled with tungsten powder, and sintered by hot isostatic pressing to obtain a multiphase doped tungsten-copper composite material. In the present application, Co film is plated on the surface of graphene and Cu powder, which optimizes the wettability between tungsten and copper, significantly improves the density and mechanical properties of the W / Cu composite material, and at the same time, by adjusting the ratio of MLG@Co, Cu@Co powder and tungsten powder, the obtained W / Cu composite material has excellent electrical conductivity and mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of tungsten-copper composite materials, and particularly relates to a multiphase doped high-conductivity tungsten-copper composite material and a preparation method and application thereof. BACKGROUND

[0002] The tungsten-copper alloy is an alloy composed of tungsten (W) and copper (Cu), which combines the high melting point and high strength of tungsten and the electrical conductivity and thermal conductivity of copper, and is applied to electronic packaging, thermal deposition and high-voltage electrical contact materials. However, the properties of W and Cu are quite different, and it is difficult for them to be mutually soluble and have poor wettability, so it is difficult to obtain a tungsten-copper alloy with high density. To solve this problem, the prior art mainly improves the wettability between W and Cu by doping transition group elements (Pd, Ni, Co), rare earth metal elements (La, Ce) and ceramic phases (TiC, TiB, Al2O3) to improve the mechanical properties, but the electrical conductivity and thermal conductivity will decrease. Graphene has high Young's modulus (1100 GPa), strength (130 GPa), thermal conductivity (5000 W / mK) and carrier mobility (15000 cm 2 / (v·s)), and can be used as a reinforcing phase of a composite material to improve the thermal conductivity and electrical conductivity. However, on the one hand, graphene is easy to form WC with W under high-temperature sintering, and the heat may be scattered at the interface between WC and the copper-tungsten matrix during heat transfer, resulting in a decrease in the thermal conductivity. On the other hand, graphene has a small density and is easy to agglomerate, so it is difficult to uniformly disperse graphene into the tungsten-copper alloy by the traditional powder mixing method. Therefore, the tungsten-copper alloy with high thermal conductivity, electrical conductivity and density and excellent comprehensive performance is prepared by combining the advantages of graphene and cobalt. SUMMARY

[0003] The purpose of the present application is to solve the technical problems of poor wettability of W and Cu in the existing tungsten-copper composite material and the difficulty in balancing the mechanical properties and electrical properties, and to provide a multiphase doped high-conductivity tungsten-copper composite material and a preparation method and application thereof.

[0004] One of the purposes of the present application is to provide a preparation method of a multiphase doped high-conductivity tungsten-copper composite material, which is performed according to the following steps:

[0005] S1: Co is deposited on the surface of graphene powder and the surface of Cu powder by magnetron sputtering to obtain MLG@Co powder and Cu@Co powder, respectively;

[0006] S2: The MLG@Co powder, Cu@Co powder and tungsten powder are ball-milled and mixed, and sintered by hot isostatic pressing to obtain a multiphase doped tungsten-copper composite material.

[0007] Further limit, the graphene powder and Cu powder in S1 are cleaned by ultrasonic-assisted acetone and ethanol solution before use to remove grease and oxidation layer on the surface of the graphene powder and Cu powder.

[0008] Further limit, the parameters for plating Co on the surface of the graphene powder in S1 are as follows: working pressure 1-2 Pa, bias voltage -100 V to -200 V, Co target power 100-150 W, and time 1-3 h.

[0009] Further limit, the thickness of the Co film on the surface of the graphene powder in S1 is 50-100 nm.

[0010] Further limit, the parameters for plating Co on the surface of the Cu powder in S1 are as follows: working pressure 1-2 Pa, temperature 50-200℃, bias voltage -50 V to -100 V, Co target power 50-90 W, and time 1-3 h.

[0011] Further limit, the thickness of the Co film on the surface of the Cu powder in S1 is 50-100 nm.

[0012] Further limit, before the magnetron sputtering in S1, the vacuum is first extracted to 5*10 -4 Pa, then Ar gas is introduced, and the graphene powder and Cu powder are cleaned by using Ar gas at a vibration frequency of 5-10 Hz and a sputtering power of 10-20 W.

[0013] Further limit, the mass percentage of the MLG@Co powder, Cu@Co powder and tungsten powder in S2 is 2-4%, 10-30% and 70-90%, respectively.

[0014] Further limit, the ball-to-material ratio of the ball milling in S2 is 10:1, the rotation speed is 200-400 r / min, and the ball milling time is 6-8 h.

[0015] Further limit, the hot isostatic pressing pressure in S2 is 80-100 Mpa, the sintering temperature is 1000-1200℃, and the holding time is 1-3 h.

[0016] The second object of the present application is to provide a high-conductivity tungsten-copper composite material prepared by the above method, wherein the conductivity of the composite material is ≥ 35% IACS, and the density is ≥ 97%.

[0017] The third object of the present application is to provide an application of the high-conductivity tungsten-copper composite material prepared by the above method as an electric appliance contact material and an electronic component heat dissipation material.

[0018] The fourth object of the present application is to provide a plasma first wall made of the above high-conductivity tungsten-copper composite material.

[0019] A fifth object of the present invention is to provide an application of the above-mentioned plasma first wall in the field of thermonuclear fusion.

[0020] The advantages of the present invention compared to the prior art are:

[0021] The present invention coats Co films on the surfaces of graphene and Cu respectively, optimizes the wettability between tungsten and copper, and significantly improves the density and mechanical properties of the W / Cu composite material. At the same time, by regulating the ratio of MLG@Co, Cu@Co powder and tungsten powder, the obtained W / Cu composite material has both excellent conductivity and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the SEM image of the ball-milled mixed powder in Example 1;

[0023] Figure 2 This is the microstructure of the W / Cu composite material in Example 1. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods, and instruments used are conventional in the art and can be obtained commercially by those skilled in the art unless otherwise specified.

[0026] Example 1: The preparation method of the multi-phase doped high-conductivity W / Cu composite material of this embodiment includes the following steps:

[0027] (1) Ultrasonic cleaning of graphene powder and Cu powder

[0028] Graphene powder (10-20 μm) and Cu powder (58-75 μm) were respectively washed with acetone solution for 20 min, deionized water for 5 min, then washed with ethanol solution for 20 min, and deionized water for 5 min to remove grease and part of the oxide layer on the surface of graphene powder and Cu powder.

[0029] (2) MLG@Co obtained by magnetron sputtering

[0030] The graphene powder of step (1) was placed in a vibration tank of a powder PVD coating device and vacuumed to 5×10 -4 Pa, and then 40 sccm Ar gas was introduced, and the graphene powder was cleaned with Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0031] Co film was plated on the graphene powder, the working pressure was 1.5 Pa, the bias voltage was -100 V, the Co target power was 100 W, the time was 2 h, and the Co film thickness was 60 nm.

[0032] (3) Cu@Co powder obtained by magnetron sputtering

[0033] The copper powder of step (1) was placed in a vibrating tank of a powder PVD film plating device, vacuumized for 5x10 -4 Pa, and then 40 sccm of Ar gas was introduced, the copper powder was cleaned by Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0034] Co film was plated on the copper powder, the working pressure was 1.5 Pa, the temperature was 100℃, the bias voltage was -50 V, the Co target power was 60 W, the time was 1.5 h, and the Co film thickness was 50 nm.

[0035] (4) Ball milling of mixed powder

[0036] The MLG@Co powder, the Cu@Co powder and the tungsten powder (20-30 μm) were ball-mixed according to a mass percentage of 2%, 18% and 80%, the ball-to-powder ratio was 10:1, the rotation speed was 300 r / min, and the ball milling time was 8 h.

[0037] (5) Hot isostatic pressing

[0038] The powder obtained in (4) was sintered by hot isostatic pressing at a pressure of 100 MPa and a sintering temperature of 1100℃ for 2 h.

[0039] The W / Cu composite material of the embodiment avoids the generation of WC, improves the electrical conductivity, avoids the direct contact between Cu and W, and improves the wettability between tungsten and copper, thereby obtaining a W / Cu composite material with excellent performance. Figure 1 The SEM image after ball milling of mixed powder is shown in FIG. 2, Figure 2 The microstructure of the W / Cu composite material is shown in FIG. 3, and the grain size is relatively uniform and the structure is relatively dense.

[0040] Embodiment 2: The preparation method of the multiphase doped high-conductivity W / Cu composite material of the embodiment includes the following steps:

[0041] (1) Ultrasonic cleaning of graphene powder and Cu powder

[0042] The graphene powder (10-20 μm) and the Cu powder (58-75 μm) were cleaned with acetone solution for 20 min, deionized water for 5 min, ethanol solution for 20 min, and deionized water for 5 min, respectively, to remove the oil and part of the oxide layer on the surface of the graphene powder and the Cu powder.

[0043] (2) MLG@Co obtained by magnetron sputtering

[0044] The graphene powder of step (1) was placed in a vibrating groove of a powder PVD film coating device, vacuumed for 5x10 -4 Pa, and then 40 sccm Ar gas was introduced, and the graphene powder was cleaned by Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0045] The graphene powder was coated with a Co film, the working pressure was 1.5 Pa, the bias voltage was -100 V, the Co target power was 100 W, the time was 2 h, and the Co film thickness was 60 nm.

[0046] (3) Cu@Co powder obtained by magnetron sputtering

[0047] The copper powder of step (1) was placed in a vibrating groove of a powder PVD film coating device, vacuumed for 5x10 -4 Pa, and then 40 sccm Ar gas was introduced, and the copper powder was cleaned by Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0048] The copper powder was coated with a Co film, the working pressure was 1.5 Pa, the temperature was 100℃, the bias voltage was -50 V, the Co target power was 60 W, the time was 1.5 h, and the Co film thickness was 50 nm.

[0049] (4) Ball milling of powders

[0050] The MLG@Co powder, the Cu@Co powder, and the tungsten powder (20-30 μm) were ball-milled at a mass percentage of 3%, 17%, and 80%, respectively, the ball-to-powder ratio was 10:1, the rotation speed was 300 r / min, and the ball milling time was 8 h.

[0051] (5) Hot isostatic pressing

[0052] The powder obtained in (4) was sintered by hot isostatic pressing at a pressure of 100 MPa and a sintering temperature of 1100℃ for 2 h.

[0053] The W / Cu composite material of the embodiment, the introduction of Co improves the wettability between tungsten and copper, promotes the sintering densification of the alloy, and makes the structure uniform and fine. At the same time, by changing the graphene addition content to 2%, the influence of the content on the performance of the W / Cu composite material is explored.

[0054] Example 3: The preparation method of the multiphase doped high-conductivity W / Cu composite material of the embodiment includes the following steps:

[0055] (1) Ultrasonic cleaning of graphene powder and Cu powder

[0056] The graphene powder (10-20 μm) and Cu powder (58-75 μm) were cleaned with acetone solution for 20 min, deionized water for 5 min, and ethanol solution for 20 min, and then deionized water for 5 min, so as to remove the grease and part of the oxidation layer on the surface of the graphene powder and Cu powder.

[0057] (2) MLG@Co obtained by magnetron sputtering

[0058] The graphene powder of step (1) was placed in a vibrating tank of a powder PVD film coating device, vacuumed for 5*10 -4 Pa, and then 40 sccm Ar gas was introduced, and the graphene powder was cleaned by Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0059] The graphene powder was coated with a Co film, the working pressure was 1.5 Pa, the bias voltage was -100 V, the Co target power was 100 W, the time was 2 h, and the Co film thickness was 60 nm.

[0060] (3) Cu@Co powder obtained by magnetron sputtering

[0061] The copper powder of step (1) was placed in a vibrating tank of a powder PVD film coating device, vacuumed for 5*10 -4 Pa, and then 40 sccm Ar gas was introduced, and the copper powder was cleaned by Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0062] The copper powder was coated with a Co film, the working pressure was 1.5 Pa, the temperature was 100℃, the bias voltage was -50 V, the Co target power was 60 W, the time was 1.5 h, and the Co film thickness was 50 nm.

[0063] (4) Ball milling of mixed powder

[0064] The MLG@Co powder, Cu@Co powder and tungsten powder (20-30 μm) were ball-mixed according to the mass percentage of 4%, 16% and 80%, the ball-to-material ratio was 10:1, the rotation speed was 300 r / min, and the ball milling time was 8 h.

[0065] (5) Hot isostatic pressing

[0066] The powder obtained in (4) was sintered by hot isostatic pressing at a pressure of 100 MPa and a sintering temperature of 1100℃ for 2 h.

[0067] In the W / Cu composite material of the embodiment, the introduction of Co improves the wettability between tungsten and copper, promotes the sintering densification of the alloy, and makes the structure uniform and fine. At the same time, by changing the graphene content to 3%, the influence of the content on the performance of the W / Cu composite material is explored.

[0068] Comparative Example 1: The preparation method of the W / Cu composite material of the present example includes the following steps:

[0069] (1) Ultrasonic cleaning of Cu powder

[0070] The Cu powder (58-75 μm) was cleaned with an acetone solution for 20 min, deionized water for 5 min, an ethanol solution for 20 min, and deionized water for 5 min to remove grease and part of the oxide layer on the surface of the Cu powder.

[0071] (2) Obtaining Cu@Co powder by magnetron sputtering

[0072] The copper powder of step (1) was placed in a vibrating tank of a powder PVD film coating device, and the tank was first vacuumed for 5x10 -4 Pa, and then 40 sccm of Ar gas was introduced, and the copper powder was cleaned with Ar gas at a vibration frequency of 10 Hz and a sputtering power of 15 W.

[0073] Co film was coated on the copper powder at a working pressure of 1.5 Pa, a temperature of 100°C, a bias voltage of -50 V, a Co target power of 60 W, and a time of 1.5 h, and the thickness of the Co film was 50 nm.

[0074] (3) Ball milling of the powder

[0075] The Cu@Co powder and tungsten powder (20-30 μm) were ball milled at a mass percentage of 20%, 80%, a ball-to-material ratio of 10:1, a rotation speed of 300 r / min, and a ball milling time of 8 h.

[0076] (4) Hot isostatic pressing

[0077] The powder obtained in step (3) was sintered by hot isostatic pressing at a pressure of 100 MPa and a sintering temperature of 1100°C for 2 h.

[0078] In the W / Cu composite material of the present example, the introduction of Co improves the wettability between tungsten and copper, but reduces the electrical conductivity and thermal conductivity of the tungsten-copper alloy.

[0079] Comparative Example 2: The preparation method of the W / Cu composite material of the present example includes the following steps:

[0080] (1) Ball milling of the powder

[0081] The Cu powder (58-75 μm) and tungsten powder (20-30 μm) were ball milled at a mass percentage of 20%, 80%, a ball-to-material ratio of 10:1, a rotation speed of 300 r / min, and a ball milling time of 8 h.

[0082] (2) Hot isostatic pressing

[0083] The powder obtained in (1) is sintered by hot isostatic pressing, the pressure is 100 MPa, the sintering temperature is 1100℃, and the holding time is 2h.

[0084] The W / Cu composite materials obtained in Examples 1-3 and Comparative Examples 1-2 are detected for density, thermal conductivity and hardness, and the results are shown in Table 1.

[0085] Table 1 Properties of W / Cu composite materials

[0086]

[0087] The above descriptions are only preferred embodiments of the present application, which are different implementations based on the overall concept of the present application, and the protection scope of the present application is not limited to this. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a multiphase doped high-conductivity tungsten-copper composite material, characterized in that: The method: S1: Co was deposited on the surface of graphene powder and Cu powder by magnetron sputtering to obtain MLG@Co powder and Cu@Co powder, respectively. The parameters for the Co coating on the graphene powder surface were as follows: working pressure of 1~2Pa, bias voltage of -100V~-200V, Co target power of 100~150W, and time of 1~3h. The parameters for the Co coating on the Cu powder surface were as follows: working pressure of 1~2Pa, temperature of 50~200℃, bias voltage of -50V~-100V, Co target power of 50~90W, and time of 1~3h. S2: MLG@Co powder, Cu@Co powder and tungsten powder are ball-milled and sintered by hot isostatic pressing to obtain a multiphase doped tungsten-copper composite material, wherein the mass percentages of MLG@Co powder, Cu@Co powder and tungsten powder are 2-4%, 10-30% and 70-90%, respectively.

2. The method according to claim 1, characterized in that The thickness of the Co film on the surface of graphene powder in S1 is 50~100nm, and the thickness of the Co film on the surface of Cu powder is 50~100nm.

3. The method according to claim 1, characterized in that The hot isostatic pressing pressure of S2 is 80~100Mpa, the sintering temperature is 1000~1200℃, and the holding time is 1~3h.

4. The high-conductivity tungsten-copper composite material prepared by the method according to any one of claims 1 to 3, characterized in that: The composite material has an electrical conductivity of ≥35% IACS and a density of ≥97%.

5. Use of the highly conductive tungsten-copper composite material according to claim 4 as an electrical contact material and a heat dissipation material for electronic components.

6. A plasma first wall, characterized in that The plasma first wall is made of the high-conductivity tungsten-copper composite material according to claim 4.

7. Application of the plasma first wall according to claim 6 in the field of thermonuclear fusion.

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