Carbon modified tungsten copper composite powder and preparation method thereof

Abstract

The invention discloses carbon modified tungsten-copper composite powder and a preparation method thereof.The method comprises the steps that tungsten powder and copper powder are matched according to a certain mass, a small amount of absolute ethyl alcohol is added, and mixed turbid liquid is obtained; the turbid liquid and tungsten steel balls are matched, then high-energy ball milling mixing is conducted, and tungsten-copper composite powder is obtained after drying; and in the nitrogen protective atmosphere, high-temperature pyrolysis gas of small molecule alcohol serves as a carbon source, in-situ carburization and carbon deposition are conducted on the surface of the tungsten-copper composite powder, and therefore the carbon modified tungsten-copper composite powder with a small amount of tungsten carbide reinforced phase is obtained. In conclusion, the method has the economic benefits and advantages of being short in process, low in energy consumption, environmentally friendly and the like, and the preparation technology of the carbon modified tungsten-copper composite powder is greatly simplified. The surface of the prepared tungsten-copper composite powder contains an ultrathin carbon layer and contains a small amount of tungsten carbide reinforced phase, and the tungsten-copper composite powder has certain guiding significance in practical application of the tungsten-copper composite powder in the field of electrical contact alloys.

Description

Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a carbon-modified tungsten-copper composite powder and a preparation method thereof. Background Art

[0002] Copper-tungsten alloy is widely used in the electrical contacts of UHV circuit breakers due to its excellent properties such as high temperature corrosion resistance, friction and wear resistance, and high hardness. The key to producing high-performance tungsten-copper alloy is to prepare high-performance tungsten-copper composite materials. Therefore, the requirements for the performance of tungsten-copper composite powder are also increasing as it is widely used in the electrical contacts of UHV circuit breakers.

[0003] Tungsten carbide can be used as a reinforcement to improve the hardness of tungsten-copper alloys. The Chinese invention patent with patent application number 202410017299.5 discloses a WC-reinforced modified tungsten-copper composite material and its preparation method, which disperses tungsten powder by ball milling, forms tungsten oxide on the surface of tungsten powder after acid washing; then fully mixes tungsten powder with binder solution and dries to obtain a mixed powder; then pre-sinters in a reducing atmosphere to obtain a tungsten skeleton and reduce and carbonize tungsten oxide to form WC; finally, copper is infiltrated into the tungsten skeleton and pressure sintered to obtain a WC-reinforced modified tungsten-copper composite material.

[0004] In addition, the conductivity and heat dissipation of the tungsten-copper composite material with the addition of carbon material remain almost unchanged. At the same time, the carbon material has self-lubricating properties, which can effectively reduce the friction coefficient of the alloy and improve its friction resistance; its low work function may also improve the material's anti-ablation performance. Therefore, carbon can be used as a reinforcement for metal-based composite materials. The Chinese invention patent with patent application number 202210611479.7 discloses a tungsten-copper alloy and a preparation method thereof, including (1) preparation of porous hollow tungsten oxide nanospheres; (2) preparation of tungsten-copper nanospheres; (3) preparation of composite activation elements; (4) modification of carbon nanotubes; (5) molding and sintering. By adding composite activation elements and modified carbon nanotubes, an alloy material with high density and uniform distribution of tungsten-copper phases is obtained.

[0005] However, in the above methods, adding carbon materials such as graphene or carbon nanotubes to the tungsten-copper composite material will lead to uneven material distribution and easy agglomeration, making it difficult to fully utilize the advantages of the graphene material. Summary of the invention

[0006] The purpose of the present invention is to provide a carbon-modified tungsten-copper composite powder, which overcomes the problem of uneven distribution and easy agglomeration of tungsten-copper composite materials after adding carbon materials in the prior art, and obtains a carbon-modified tungsten-copper composite powder with more stable performance.

[0007] Another object of the present invention is to provide a method for preparing carbon-modified tungsten-copper composite powder.

[0008] The purpose of the present invention is achieved through the following technical solutions.

[0009] The present invention provides a carbon-modified tungsten-copper composite powder, which is prepared by the following methods in sequence: (1) Mixing tungsten powder and copper powder with a certain particle size distribution and mass ratio with anhydrous ethanol to obtain a mixed suspension; (2) Mixing the above mixed suspension with tungsten steel balls, placing it in a ball mill for high-energy ball milling dispersion, and then vacuum drying to obtain tungsten-copper mixed powder; (3) placing the obtained tungsten-copper mixed powder in a high-temperature furnace, introducing small-molecule alcohol under nitrogen protection, using the high-temperature cracking gas of the small-molecule alcohol as a carbon source, and performing surface carburization and carbon deposition on the above-mentioned tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder.

[0010] The present invention mixes tungsten powder, copper powder and anhydrous ethanol to obtain a mixed suspension. The uniformity of the microstructure can be ensured, and the dispersibility and distribution uniformity of copper in the tungsten hard skeleton are improved, thereby avoiding the self-aggregation of copper particles. Then, the obtained mixed suspension containing tungsten and copper is mixed with tungsten steel balls, placed in a ball mill for high-energy ball milling dispersion, and vacuum dried to obtain tungsten-copper composite powder. Compared with other mixing methods such as mixers, the use of a ball mill can turn soft copper particles into flakes and wrap part of the tungsten particles. Finally, under a nitrogen protective atmosphere, a small molecule alcohol cracking gas is introduced at high temperature as a reducing and carburizing atmosphere to directly reduce part of the tungsten oxide to tungsten carbide, and the exposed tungsten surface is carburized to generate part of the tungsten carbide, and an ultra-thin carbon layer is deposited on the copper surface. Therefore, the carbon-modified tungsten-copper composite powder containing a small amount of tungsten carbide reinforcement phase can be synthesized by the method of the present invention through a two-step synthesis process, thereby greatly shortening the production cycle of the carbon-modified tungsten-copper composite powder, saving production costs, and obtaining a carbon-modified tungsten-copper composite powder with stable performance.

[0011] In addition, the carbon-modified tungsten-copper composite powder of the present invention may also have the following additional technical features: In step (1), the particle size of the tungsten powder is 2-10 μm, and the particle size of the copper powder is 10-25 μm. Thus, the tungsten powder and the copper powder particles are mixed with a certain particle size distribution, so that the contact between the tungsten powder and the copper powder is more complete.

[0012] In step (1), the mass ratio of the tungsten powder to the copper powder is 8:2-6:4.

[0013] In step (1), the amount of anhydrous ethanol used is preferably sufficient to submerge the surface of the composite powder. Thus, ethanol, as a co-solvent, can help reduce the viscosity of the tungsten powder and copper powder when they are mixed, thereby improving the efficiency of ball milling dispersion.

[0014] In step (2), the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:3 to 1:10. The purpose of this material-ball ratio is to reduce the particle size of tungsten powder and copper powder, and at the same time press the granular copper powder into flaky copper powder, so that the flaky copper can more easily cover part of the tungsten particles.

[0015] In step (2), the high-energy ball milling dispersion is intermittent forward and reverse, and the intermittent time is 0.1 to 0.5 hours. Thus, the ball milling efficiency is improved and the production cost is saved.

[0016] In step (2), the ball milling speed of the high-energy ball milling dispersion is 300-500 rpm, and the ball milling time is 4-10 hours.

[0017] In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4 to 12 hours, thereby preventing the particles from agglomerating due to the Ostwald ripening effect.

[0018] In step (3), the small molecule alcohol is one or both of methanol and ethanol.

[0019] The flow rate of the small molecule alcohol is 0.1-0.5 mL min -1 Therefore, controlling the small molecule alcohol to be introduced at a lower flow rate is more conducive to the high temperature cracking gas of the small molecule alcohol being fully utilized by the tungsten copper mixed powder.

[0020] In step (3), the heating rate of the high temperature furnace is 8~10℃ min -1 .

[0021] In step (3), the temperature when the carbon source is introduced is 700-900°C. This temperature is more conducive to the carburization and carbon deposition of the carbon source cracking gas on the surface of the tungsten-copper composite powder. The ultra-thin carbon layer deposited in situ on the powder surface is conducive to improving the interface bonding between the tungsten powder, copper powder and the carbon layer. At the same time, a small amount of tungsten carbide can be generated at a higher temperature, which can be used as a reinforcement to improve the hardness of the alloy.

[0022] In step (3), the carbon source is passed for 0.1 to 2 h.

[0023] A method for preparing carbon-modified tungsten-copper composite powder, comprising the following steps: (1) Mixing tungsten powder and copper powder with a certain particle size distribution and mass ratio with anhydrous ethanol to obtain a mixed suspension; (2) Mixing the above mixed suspension with tungsten steel balls, placing it in a ball mill for high-energy ball milling dispersion, and then vacuum drying to obtain tungsten-copper mixed powder; (3) placing the obtained tungsten-copper mixed powder in a high-temperature furnace, introducing small-molecule alcohol under nitrogen protection, using the high-temperature cracking gas of the small-molecule alcohol as a carbon source, and performing surface carburization and carbon deposition on the above-mentioned tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder.

[0024] In step (1), the particle size of the tungsten powder is 2-10 μm, and the particle size of the copper powder is 10-25 μm. Thus, the tungsten powder and the copper powder particles are mixed with a certain particle size distribution, so that the contact between the tungsten powder and the copper powder is more complete.

[0025] In step (1), the mass ratio of the tungsten powder to the copper powder is 8:2-6:4.

[0026] In step (1), the amount of anhydrous ethanol used is preferably sufficient to submerge the surface of the composite powder. Thus, ethanol, as a co-solvent, can help reduce the viscosity of the tungsten powder and copper powder when they are mixed, thereby improving the efficiency of ball milling dispersion.

[0027] In step (2), the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:3 to 1:10. The purpose of this material-ball ratio is to reduce the particle size of tungsten powder and copper powder, and at the same time press the granular copper powder into flaky copper powder, so that the flaky copper can more easily cover part of the tungsten particles.

[0028] In step (2), the high-energy ball milling dispersion is intermittent forward and reverse, and the intermittent time is 0.1 to 0.5 hours. Thus, the ball milling efficiency is improved and the production cost is saved.

[0029] In step (2), the ball milling speed of the high-energy ball milling dispersion is 300-500 rpm, and the ball milling time is 4-10 hours.

[0030] In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4 to 12 hours, thereby preventing the particles from agglomerating due to the Ostwald ripening effect.

[0031] In step (3), the small molecule alcohol is one or both of methanol and ethanol.

[0032] The flow rate of the small molecule alcohol is 0.1-0.5 mL min -1 Therefore, controlling the small molecule alcohol to be introduced at a lower flow rate is more conducive to the high temperature cracking gas of the small molecule alcohol being fully utilized by the tungsten copper mixed powder.

[0033] In step (3), the heating rate of the high temperature furnace is 8~10℃ min -1 .

[0034] In step (3), the temperature when the carbon source is introduced is 700-900°C. This temperature is more conducive to the carburization and carbon deposition of the carbon source cracking gas on the surface of the tungsten-copper composite powder. The ultra-thin carbon layer deposited in situ on the powder surface is conducive to improving the interface bonding between the tungsten powder, copper powder and the carbon layer. At the same time, a small amount of tungsten carbide can be generated at a higher temperature, which can be used as a reinforcement to improve the hardness of the alloy.

[0035] In step (3), the carbon source is passed for 0.1 to 2 h.

[0036] The present invention provides a method for preparing a carbon-modified tungsten-copper composite powder. The method has the advantages of short process, low energy consumption, economy and environmental protection, and the prepared carbon-modified tungsten-copper composite powder has stable performance. The method has certain guiding significance for simplifying the preparation process of the carbon-modified tungsten-copper composite powder and improving the practical application of the carbon-modified tungsten-copper composite powder in the field of electrical contact alloys.

[0037] The carbon-modified tungsten-copper composite powder obtained by the method of the present invention has an ultra-thin carbon layer attached to its surface and a small amount of tungsten carbide reinforcement. The composite powder can be used to prepare an electrical contact alloy for ultra-high voltage circuit breakers that is resistant to high temperature corrosion, friction and wear, and has high hardness, meeting the needs of ultra-high voltage circuit breakers and other industrial fields.

[0038] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, which are intended to explain the present invention but should not be construed as limiting the present invention.

[0040] In one aspect of the present invention, the present invention provides a method for preparing a carbon-modified tungsten-copper composite powder and a method for preparing the same. According to an embodiment of the present invention, the method comprises: S100: Tungsten powder and copper powder with a certain particle size distribution and mass ratio are mixed with anhydrous ethanol to obtain a mixed suspension.

[0041] It should be noted that the particle size of tungsten powder and copper powder in the present invention is not particularly limited, and those skilled in the art can select it according to the particle grading. For example, the particle size of tungsten powder is 2~10μm, and the particle size of copper powder is 10~25μm. The inventors found that when the particle size difference between tungsten powder and copper powder is too large, the contact between tungsten powder and copper powder is insufficient, local agglomeration is prone to occur, resulting in uneven dispersion of tungsten powder and copper powder; and when the particle size difference between tungsten powder and copper powder is too small, the contact between particles is insufficient, and the later ball milling will cause the copper powder particles to change from spherical to lamellar, and at the same time reduce the size of copper powder, resulting in uneven distribution of tungsten powder and copper powder particles, which is not conducive to the close contact between lamellar copper and tungsten powder. Therefore, the use of tungsten powder and copper powder with a certain particle size distribution of the present invention can ensure sufficient contact between tungsten powder and copper powder, and increase the interface contact area between tungsten powder and copper powder.

[0042] Furthermore, the mass ratio of the tungsten powder to the copper powder is 8:2-6:4.

[0043] S200: subjecting the mixed suspension to high-energy ball milling and vacuum drying.

[0044] In this step, the mixed suspension is subjected to high-energy ball milling, and after being completely cooled, it is vacuum dried to obtain a tungsten-copper mixed powder, wherein the vacuum drying time is 4 to 12 hours. The inventors have found that compared with other drying methods such as heating drying, the vacuum drying of the present invention can avoid partial agglomeration of particles caused by heat transfer.

[0045] It should be noted that the vacuum drying in the above steps and other conditions are conventional operations in the art, and those skilled in the art can select them according to actual needs, which will not be described in detail here.

[0046] S300: using the high temperature cracking gas of small molecule alcohol as a carbon source to perform surface carburization and carbon deposition on the tungsten-copper composite powder.

[0047] In this step, the tungsten-copper mixed powder obtained above is placed in a high-temperature furnace, and small molecule cracking gas is introduced under the protection of nitrogen atmosphere to synthesize tungsten-copper composite powder containing a small amount of tungsten carbide phase in situ, and an ultra-thin carbon layer is deposited in situ on the surface of the composite powder. This avoids the uneven dispersion phenomenon caused by adding carbon materials to tungsten-copper composite powder by the traditional method.

[0048] Furthermore, the above-mentioned reduction carbonization temperature is 700-900°C, and the carbonization time is 0.1-2h. Specifically, in the present invention, tungsten powder is fully dispersed and mixed with copper powder, and a small amount of copper flakes are wrapped on the surface of tungsten powder. In the gaseous carbon source atmosphere, the copper surface is easily catalytically grown with an ultra-thin carbon layer; a carburizing reaction occurs on the surface of partially exposed tungsten particles, and a partial tungsten carbide phase is generated at a relatively low temperature, and an ultra-thin carbon layer is precipitated on the surface of tungsten carbide. Therefore, the present invention adopts a lower reduction carbonization temperature and a shorter carbonization time, which not only saves production costs, but also suppresses the abnormal growth of tungsten carbide grains.

[0049] Furthermore, the above-mentioned small molecule alcohol can be selected from one or both of methanol and ethanol. Meanwhile, the above-mentioned carbon source flow rate is 0.1-0.5 mL min -1 . The inventors found that when the flow rate of the small molecule alcohol cracking gas is too high, the gaseous carbon source will deposit a thick amorphous carbon layer on the surface of the prepared tungsten-copper composite powder, affecting the performance of the later green body pressing and sintering products; when the flow rate of the small molecule alcohol cracking gas is too low, a small amount of gaseous carbon source can only reduce carburization on the surface of tungsten oxide, but cannot evenly catalyze the growth of an ultra-thin carbon layer on the copper surface. The grain size of tungsten carbide in the carbon-modified tungsten-copper composite powder obtained by the present invention is 100~400 nm, so it can be used to prepare high-hardness, high-temperature resistant tungsten-copper alloy.

[0050] According to the method for preparing carbon-modified tungsten-copper composite powder of an embodiment of the present invention, tungsten powder, copper powder and anhydrous ethanol of a certain particle gradation are mixed, and then high-energy ball milling is performed to change the spherical copper particles into a flaky structure, which can ensure sufficient contact between tungsten powder and copper powder, and part of the copper wraps the tungsten powder. Then the mixed suspension of tungsten-copper powder obtained is vacuum dried to prepare tungsten-copper composite powder. Compared with other drying methods such as heating drying, vacuum drying can avoid particle agglomeration caused by heat transfer. Finally, small molecule alcohol cracking gas is introduced under nitrogen protective atmosphere to carburize and grow surface carbon on the tungsten-copper composite powder. Small molecule alcohol cracking gas is used as a reducing and carbonizing atmosphere to synthesize a small amount of tungsten carbide phase on the surface of the composite powder in situ, and grow an ultra-thin carbon layer. Thus, the method of the present invention can synthesize a tungsten-copper composite powder containing an ultra-thin carbon layer through a two-step synthesis process, and there is a tungsten carbide reinforcement phase, thereby saving production costs, and the obtained carbon-modified tungsten-copper composite powder has stable performance.

[0051] The carbon-modified tungsten-copper composite powder prepared by the method for preparing a carbon-modified tungsten-copper composite powder according to the present invention has an ultra-thin carbon layer attached to the surface and a small amount of tungsten carbide reinforcement particles, which can be used to prepare an electrical contact alloy with high temperature corrosion resistance, friction and wear resistance and hardness. It should be noted that the characteristics and advantages described above for the method for preparing the carbon-modified tungsten-copper composite powder are also applicable to the carbon-modified tungsten-copper composite powder, and will not be repeated here.

[0052] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way. Example 1

[0053] (1) preparing tungsten powder with an average particle size of 2 μm and copper powder with an average particle size of 10 μm in a mass ratio of 80:20, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) Place the mixed suspension in a ball mill, add tungsten steel balls, the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:5, perform high-energy ball milling, set the forward and reverse interval time to 0.5 h, the ball milling speed to 300 rpm, and the ball milling time to 4 h. Then vacuum dry for 6 h to obtain a tungsten-copper mixed powder; (3) Small molecule alcohol was introduced under nitrogen protection, and the high temperature cracking gas of small molecule alcohol was used as the carbon source. The flow rate of the cracking gas of small molecule alcohol was set to 0.1 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 800 o C, and the carbon source is passed for 0.5 h. Surface carburization and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 2

[0054] (1) preparing tungsten powder with an average particle size of 5 μm and copper powder with an average particle size of 20 μm in a mass ratio of 70:30, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) The mixed suspension is placed in a ball mill, and tungsten steel balls are added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:7. High-energy ball milling is performed, and the forward and reverse interval time is set to 0.4 h, the ball milling speed is 400 rpm, and the ball milling time is 6 h. Then vacuum drying is performed for 8 h to obtain a tungsten-copper mixed powder; (3) Introduce small molecule alcohol under nitrogen protection and use the high temperature cracking gas of small molecule alcohol as the carbon source. Set the flow rate of small molecule alcohol cracking gas to 0.3 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 900 o C, and the carbon source is passed for 1 h. Carburizing and carbon deposition are performed on the surface of the tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder. Example 3

[0055] (1) preparing tungsten powder with an average particle size of 10 μm and copper powder with an average particle size of 25 μm in a mass ratio of 60:40, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) Place the mixed suspension in a ball mill, add tungsten steel balls, the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:10, perform high-energy ball milling, set the forward and reverse interval time to 0.2 h, the ball milling speed to 400 rpm, and the ball milling time to 10 h. Then vacuum dry for 12 h to obtain a tungsten-copper mixed powder; (3) Small molecule alcohol was introduced under nitrogen protection, and the high temperature cracking gas of small molecule alcohol was used as the carbon source. The flow rate of the cracking gas of small molecule alcohol was set to 0.2 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 700 o C, and the carbon source is passed for 2 h. Surface carburization and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 4

[0056] (1) preparing tungsten powder with an average particle size of 2 μm and copper powder with an average particle size of 10 μm in a mass ratio of 80:20, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) Place the mixed suspension in a ball mill, add tungsten steel balls, the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:5, perform high-energy ball milling, set the forward and reverse interval time to 0.1 h, the ball milling speed to 400 rpm, and the ball milling time to 6 h. Then vacuum dry for 6 h to obtain tungsten-copper mixed powder; (3) Introduce small molecule alcohol under nitrogen protection and use the high temperature cracking gas of small molecule alcohol as the carbon source. Set the flow rate of small molecule alcohol cracking gas to 0.5 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 850 o C, and the carbon source is passed for 0.5 h. Surface carburization and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 5

[0057] (1) preparing tungsten powder with an average particle size of 10 μm and copper powder with an average particle size of 25 μm in a mass ratio of 80:20, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) Place the mixed suspension in a ball mill, add tungsten steel balls, the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:7, perform high-energy ball milling, set the forward and reverse interval time to 0.5 h, the ball milling speed to 400 rpm, and the ball milling time to 6 h. Then vacuum dry for 6 h to obtain a tungsten-copper mixed powder; (3) Small molecule alcohol was introduced under nitrogen protection, and the high temperature cracking gas of small molecule alcohol was used as the carbon source. The flow rate of the cracking gas of small molecule alcohol was set to 0.2 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 850 o C, and the carbon source is passed for 0.5 h. Surface carburization and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 6

[0058] (1) preparing tungsten powder with an average particle size of 5 μm and copper powder with an average particle size of 20 μm in a mass ratio of 80:20, and then mixing with anhydrous ethanol to obtain a mixed suspension; (2) The mixed suspension is placed in a ball mill, and tungsten steel balls are added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:7. High-energy ball milling is performed, and the forward and reverse interval time is set to 0.5 h, the ball milling speed is 500 rpm, and the ball milling time is 4 h. Then vacuum drying is performed for 6 h to obtain a tungsten-copper mixed powder; (3) Small molecule alcohol was introduced under nitrogen protection, and the high temperature cracking gas of small molecule alcohol was used as the carbon source. The flow rate of the cracking gas of small molecule alcohol was set to 0.2 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 800 o C, and the carbon source is passed for 0.5 h. Surface carburization and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 7

[0059] (1) 5 μm tungsten powder and 15 μm copper powder were prepared in a mass ratio of 80:20, and then mixed with anhydrous ethanol to obtain a mixed suspension; (2) Place the mixed suspension in a ball mill, add tungsten steel balls, the mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill is 1:5, perform high-energy ball milling, set the forward and reverse interval time to 0.5 h, the ball milling speed to 400 rpm, and the ball milling time to 4 h. Then vacuum dry for 6 h to obtain tungsten-copper mixed powder; (3) Small molecule alcohol was introduced under nitrogen protection, and the high temperature cracking gas of small molecule alcohol was used as the carbon source. The flow rate of the cracking gas of small molecule alcohol was set to 0.1 mL min -1 The heating rate of the high temperature furnace is 8~10℃ min -1 The temperature when the carbon source is introduced is 800 o C, and the carbon source is passed for 1 h. Carburizing and carbon deposition are performed on the surface of the tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder.

[0060] Although the embodiments of the present invention have been described above, the above embodiments are exemplary and should not be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A carbon-modified tungsten-copper composite powder, characterized in that: It is prepared by the following methods: (1) Mixing tungsten powder and copper powder with a certain particle size distribution and mass ratio with anhydrous ethanol to obtain a mixed suspension; (2) Mixing the above mixed suspension with tungsten steel balls, placing it in a ball mill for high-energy ball milling dispersion, and then vacuum drying to obtain tungsten-copper mixed powder; (3) placing the obtained tungsten-copper mixed powder in a high-temperature furnace, introducing small-molecule alcohol under nitrogen protection, using the high-temperature cracking gas of the small-molecule alcohol as a carbon source, and performing surface carburization and carbon deposition on the above-mentioned tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder; In step (1), the particle size of the tungsten powder is 2-10 μm, and the particle size of the copper powder is 10-25 μm; the mass ratio of the tungsten powder to the copper powder is 8:2-6:

4.

2. The carbon-modified tungsten-copper composite powder according to claim 1, characterized in that: In step (2), the mass ratio of tungsten powder, copper powder and tungsten steel ball in the ball mill is 1:3~1:10; the high-energy ball milling dispersion is intermittent forward and reverse rotation, and the intermittent time is 0.1~0.5 h; the ball milling speed of the high-energy ball milling dispersion is 300~500 rpm, and the ball milling time is 4~10 h.

3. The carbon-modified tungsten-copper composite powder according to claim 1, characterized in that: In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4 to 12 hours.

4. The carbon-modified tungsten-copper composite powder according to claim 1, characterized in that: In step (3), the small molecule alcohol is one or both of methanol and ethanol.

5. The carbon-modified tungsten-copper composite powder according to claim 1, characterized in that: In step (3), the flow rate of the small molecule alcohol is 0.1-0.5 mL min -1 ; The heating rate of the high temperature furnace is 8~10℃ min -1 ; The temperature when the carbon source is introduced is 700~900℃; The time for passing the carbon source is 0.1~2 h.

6. A method for preparing carbon-modified tungsten-copper composite powder, characterized in that: Follow these steps: (1) Mixing tungsten powder and copper powder with a certain particle size distribution and mass ratio with anhydrous ethanol to obtain a mixed suspension; (2) Mixing the above mixed suspension with tungsten steel balls, placing it in a ball mill for high-energy ball milling dispersion, and then vacuum drying to obtain tungsten-copper mixed powder; (3) placing the obtained tungsten-copper mixed powder in a high-temperature furnace, introducing small-molecule alcohol under nitrogen protection, using the high-temperature cracking gas of the small-molecule alcohol as a carbon source, and performing surface carburization and carbon deposition on the above-mentioned tungsten-copper mixed powder to obtain a carbon-modified tungsten-copper composite powder; In step (1), the particle size of the tungsten powder is 2-10 μm, and the particle size of the copper powder is 10-25 μm; the mass ratio of the tungsten powder to the copper powder is 8:2-6:

4.

7. The method for preparing a carbon-modified tungsten-copper composite powder according to claim 6, characterized in that: In step (2), the mass ratio of tungsten powder, copper powder and tungsten steel ball in the ball mill is 1:3~1:10; the high-energy ball milling dispersion is intermittent forward and reverse rotation, and the intermittent time is 0.1~0.5 h; the ball milling speed of the high-energy ball milling dispersion is 300~500 rpm, and the ball milling time is 4~10 h.

8. The method for preparing a carbon-modified tungsten-copper composite powder according to claim 6, characterized in that: In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4 to 12 hours.

9. The method for preparing a carbon-modified tungsten-copper composite powder according to claim 6, characterized in that: In step (3), the small molecule alcohol is one or both of methanol and ethanol.

10. The method for preparing a carbon-modified tungsten-copper composite powder according to claim 6, characterized in that: In step (3), the flow rate of the small molecule alcohol is 0.1-0.5 mL min -1 ; The heating rate of the high temperature furnace is 8~10℃ min -1 ; The temperature when the carbon source is introduced is 700~900℃; The time for passing the carbon source is 0.1~2 h.