Carbon-modified tungsten-copper composite powder and preparation method thereof

Abstract

The application discloses carbon modified tungsten copper composite powder and a preparation method thereof, and the method comprises the following steps: tungsten powder and copper powder are proportioned according to a certain mass, a small amount of anhydrous ethanol is added, and a mixed suspension liquid is obtained; the suspension liquid is proportioned with tungsten steel balls, high-energy ball milling is carried out, and tungsten copper composite powder is obtained after drying; in a nitrogen protection atmosphere, high-temperature cracking gas of a small molecule alcohol is used as a carbon source to perform in-situ carburizing and carbon deposition on the surface of the tungsten copper composite powder, so that carbon modified tungsten copper composite powder with a small amount of tungsten carbide reinforcing phase is obtained. In summary, the method has the economic benefit advantages of short process, low energy consumption and environmental protection, and greatly simplifies the preparation process of the carbon modified tungsten copper composite powder. The prepared tungsten copper composite powder contains an ultrathin carbon layer on the surface and a small amount of tungsten carbide reinforcing phase, and has certain guiding significance for the practical application of the tungsten copper composite powder in the field of electric contact alloys.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, specifically relating to a carbon-modified tungsten-copper composite powder and its preparation method. Background Technology

[0002] Copper-tungsten alloys are widely used in the electrical contacts of ultra-high voltage circuit breakers due to their excellent resistance to high-temperature corrosion, friction and wear, and high hardness. The key to producing high-performance tungsten-copper alloys lies in the preparation of high-performance tungsten-copper composite materials. Therefore, the performance requirements for tungsten-copper composite powder are increasing as its application in ultra-high voltage circuit breaker contacts grows.

[0003] Tungsten carbide can be used as a reinforcement to improve the hardness of tungsten-copper alloys. Chinese invention patent application number 202410017299.5 discloses a WC-reinforced modified tungsten-copper composite material and its preparation method. The method involves ball milling and dispersing tungsten powder, followed by acid washing to form tungsten oxide on the surface of the tungsten powder; then, the tungsten powder is thoroughly mixed with a binder solution and dried to obtain a mixed powder; then, it is pre-calcined under a reducing atmosphere to obtain a tungsten skeleton and reduce and carburize the tungsten oxide to form WC; finally, the tungsten skeleton is infiltrated with copper and pressure sintered to obtain the WC-reinforced modified tungsten-copper composite material.

[0004] Furthermore, the electrical conductivity and heat dissipation of tungsten-copper composites with added carbon materials remain almost unchanged. Simultaneously, carbon materials possess self-lubricating properties, effectively reducing the coefficient of friction of the alloy and improving its friction resistance. Its low work function may also enhance the material's resistance to ablation. Therefore, carbon can serve as a reinforcing agent for metal-based composites. Chinese invention patent application number 202210611479.7 discloses a tungsten-copper alloy and its preparation method, including (1) the preparation of porous hollow tungsten oxide nanospheres; (2) the preparation of tungsten-copper nanospheres; (3) the preparation of composite activating elements; (4) the modification of carbon nanotubes; and (5) molding and sintering. By adding composite activating elements and modified carbon nanotubes, an alloy material with high density and uniform tungsten-copper phase distribution is obtained.

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

[0006] The purpose of this invention is to provide a carbon-modified tungsten-copper composite powder that overcomes the problems 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 objective of this invention is to provide a method for preparing carbon-modified tungsten-copper composite powder.

[0008] The objective of this invention is achieved through the following technical solutions.

[0009] This invention provides a carbon-modified tungsten-copper composite powder, which is prepared sequentially by the following method:

[0010] (1) Mix tungsten powder and copper powder with anhydrous ethanol with a certain particle size distribution and mass ratio to obtain a mixed suspension;

[0011] (2) The above mixed suspension is mixed with tungsten steel balls and placed in a ball mill jar for high-energy ball milling dispersion, followed by vacuum drying to obtain tungsten copper mixed powder;

[0012] (3) The obtained tungsten-copper mixed powder is placed in a high-temperature furnace, and a small molecule alcohol is introduced under nitrogen protection. The high-temperature cracking gas of the small molecule alcohol is used as a carbon source to perform surface carburizing and carbon deposition on the above tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder.

[0013] This invention involves mixing tungsten powder, copper powder, and anhydrous ethanol to obtain a mixed suspension. This ensures the uniformity of the microstructure and improves the dispersion and distribution uniformity of copper within the hard tungsten framework, thereby preventing the self-aggregation of copper particles. The resulting tungsten-copper mixed suspension is then mixed with tungsten steel balls and subjected to high-energy ball milling dispersion in a ball mill. After vacuum drying, a tungsten-copper composite powder is obtained. Compared to other mixing methods such as mixers, using a ball mill can transform soft copper particles into flakes, partially encapsulating tungsten particles. Finally, under a nitrogen protective atmosphere, a small-molecule alcohol cracking gas is introduced at high temperature as a reducing and carbonizing atmosphere, directly reducing some tungsten oxide to tungsten carbide, and carburizing the exposed tungsten surface to generate partial tungsten carbide, while simultaneously depositing an ultrathin carbon layer on the copper surface. Therefore, by using the method of the present invention, carbon-modified tungsten copper composite powder containing a small amount of tungsten carbide reinforcing phase can be synthesized in two steps, thereby greatly reducing the production cycle of carbon-modified tungsten copper composite powder, saving production costs, and thus obtaining carbon-modified tungsten copper composite powder with stable performance.

[0014] In addition, the carbon-modified tungsten-copper composite powder of the present invention may also have the following additional technical features:

[0015] In step (1), the tungsten powder particles have a size of 2~10μm, and the copper powder particles have a size of 10~25μm. Thus, the tungsten powder and copper powder particles are mixed with a certain particle size distribution, which makes the contact between the tungsten powder and copper powder more sufficient.

[0016] In step (1), the mass ratio of tungsten powder to copper powder is 8:2 to 6:4.

[0017] 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, helps reduce the viscosity of the tungsten powder and copper powder mixture, improving the efficiency of ball milling dispersion.

[0018] In step (2), the mass ratio of tungsten powder, copper powder, and tungsten steel balls in the ball mill jar is 1:3 to 1:10. The purpose of this material-to-ball ratio is to reduce the particle size of tungsten powder and copper powder, while pressing the granular copper powder into flake copper powder, making it easier for the flake copper to coat some of the tungsten particles.

[0019] In step (2), the high-energy ball milling is performed in an intermittent forward and reverse rotation, with an interval of 0.1 to 0.5 hours. This improves the ball milling efficiency and saves production costs.

[0020] In step (2), the ball milling speed for high-energy ball milling dispersion is 300-500 rpm, and the ball milling time is 4-10h.

[0021] In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4-12 hours. This avoids particle agglomeration due to the Ostwald ripening effect.

[0022] In step (3), the small molecule alcohol is one or both of methanol and ethanol.

[0023] The flow rate of the small molecule alcohol is 0.1~0.5 mL / min. -1 Therefore, controlling the flow rate of small molecule alcohols to a lower level is more conducive to the full utilization of the high-temperature cracking gas of small molecule alcohols by the tungsten-copper mixed powder.

[0024] In step (3), the heating rate of the high-temperature furnace is 8~10℃ min. -1 .

[0025] In step (3), the temperature at which the carbon source is introduced is 700~900℃. 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 ultrathin carbon layer deposited in situ on the powder surface is beneficial to improving the interfacial bonding between tungsten powder, copper powder and carbon layer. At the same time, a small amount of tungsten carbide can be generated at higher temperatures, which can serve as a reinforcement to improve the hardness of the alloy.

[0026] In step (3), the carbon source is passed through for 0.1 to 2 hours.

[0027] A method for preparing carbon-modified tungsten-copper composite powder, comprising the following steps:

[0028] (1) Mix tungsten powder and copper powder with anhydrous ethanol with a certain particle size distribution and mass ratio to obtain a mixed suspension;

[0029] (2) The above mixed suspension is mixed with tungsten steel balls and placed in a ball mill jar for high-energy ball milling dispersion, followed by vacuum drying to obtain tungsten copper mixed powder;

[0030] (3) The obtained tungsten-copper mixed powder is placed in a high-temperature furnace, and a small molecule alcohol is introduced under nitrogen protection. The high-temperature cracking gas of the small molecule alcohol is used as a carbon source to perform surface carburizing and carbon deposition on the above tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder.

[0031] In step (1), the tungsten powder particles have a size of 2~10μm, and the copper powder particles have a size of 10~25μm. Thus, the tungsten powder and copper powder particles are mixed with a certain particle size distribution, which makes the contact between the tungsten powder and copper powder more sufficient.

[0032] In step (1), the mass ratio of tungsten powder to copper powder is 8:2 to 6:4.

[0033] 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, helps reduce the viscosity of the tungsten powder and copper powder mixture, improving the efficiency of ball milling dispersion.

[0034] In step (2), the mass ratio of tungsten powder, copper powder, and tungsten steel balls in the ball mill jar is 1:3 to 1:10. The purpose of this material-to-ball ratio is to reduce the particle size of tungsten powder and copper powder, while pressing the granular copper powder into flake copper powder, making it easier for the flake copper to coat some of the tungsten particles.

[0035] In step (2), the high-energy ball milling is performed in an intermittent forward and reverse rotation, with an interval of 0.1 to 0.5 hours. This improves the ball milling efficiency and saves production costs.

[0036] In step (2), the ball milling speed for high-energy ball milling dispersion is 300-500 rpm, and the ball milling time is 4-10h.

[0037] In step (2), the ball-milled tungsten-copper mixed powder is dried in a vacuum drying oven for 4-12 hours. This avoids particle agglomeration due to the Ostwald ripening effect.

[0038] In step (3), the small molecule alcohol is one or both of methanol and ethanol.

[0039] The flow rate of the small molecule alcohol is 0.1~0.5 mL / min. -1 Therefore, controlling the flow rate of small molecule alcohols to a lower level is more conducive to the full utilization of the high-temperature cracking gas of small molecule alcohols by the tungsten-copper mixed powder.

[0040] In step (3), the heating rate of the high-temperature furnace is 8~10℃ min. -1 .

[0041] In step (3), the temperature at which the carbon source is introduced is 700~900℃. 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 ultrathin carbon layer deposited in situ on the powder surface is beneficial to improving the interfacial bonding between tungsten powder, copper powder and carbon layer. At the same time, a small amount of tungsten carbide can be generated at higher temperatures, which can serve as a reinforcement to improve the hardness of the alloy.

[0042] In step (3), the carbon source is passed through for 0.1 to 2 hours.

[0043] This invention provides a method for preparing carbon-modified tungsten-copper composite powder. This method has the advantages of short process, low energy consumption, economy and environmental protection, and the carbon-modified tungsten-copper composite powder prepared has stable performance. This method has certain guiding significance for simplifying the preparation process of carbon-modified tungsten-copper composite powder and improving the practical application of carbon-modified tungsten-copper composite powder in the field of electrical contact alloys.

[0044] The carbon-modified tungsten-copper composite powder obtained by the method described in this invention has an ultra-thin carbon layer on its surface and contains a small amount of tungsten carbide reinforcement. This composite powder can be used to prepare electrical contact alloys for ultra-high voltage circuit breakers that are resistant to high-temperature corrosion, friction and wear, and have high hardness, meeting the needs of industrial fields such as ultra-high voltage circuit breakers.

[0045] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0046] The embodiments of the present invention are described in detail below, and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0047] In one aspect of the present invention, a method for preparing carbon-modified tungsten-copper composite powder is provided. According to an embodiment of the present invention, the method includes:

[0048] 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.

[0049] It should be noted that the particle size of tungsten powder and copper powder in this invention is not particularly limited, and those skilled in the art can select them based on particle size distribution. For example, the particle size of tungsten powder is 2~10μm, and the particle size of copper powder is 10~25μm. The inventors have found that when the particle size difference between tungsten powder and copper powder is too large, the contact between them is insufficient, and local agglomeration is likely to occur, resulting in uneven dispersion of tungsten powder and copper powder. Conversely, when the particle size difference between tungsten powder and copper powder is too small, the contact between the particles is insufficient, and subsequent ball milling will cause the copper powder particles to transform from spherical to flake-like, while also reducing the size of the copper powder, resulting in uneven distribution of tungsten powder and copper powder particles, which is not conducive to close contact between the flake-like copper and the tungsten powder. Therefore, by using tungsten powder and copper powder with a certain particle size distribution according to this invention, sufficient contact between tungsten powder and copper powder can be ensured, and the interfacial contact area between tungsten powder and copper powder can be increased.

[0050] Furthermore, the mass ratio of the aforementioned tungsten powder to copper powder is 8:2 to 6:4.

[0051] S200: The mixed suspension is subjected to high-energy ball milling and vacuum drying.

[0052] In this step, the above-mentioned mixed suspension is subjected to high-energy ball milling, and after complete cooling, it is vacuum dried to obtain tungsten-copper mixed powder, wherein the vacuum drying time is 4-12 hours. The inventors have found that, compared with other drying methods such as heating drying, the vacuum drying method used in this invention can avoid partial agglomeration of particles caused by heat transfer.

[0053] It should be noted that the vacuum drying in the above steps and other conditions are conventional operations in the field. Those skilled in the art can choose according to actual needs, and will not be elaborated here.

[0054] S300: High-temperature cracking gas of small molecule alcohols is used as a carbon source for surface carburizing and carbon deposition of the tungsten-copper composite powder.

[0055] 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 a nitrogen atmosphere to synthesize tungsten-copper composite powder containing a small amount of tungsten carbide phase in situ. At the same time, an ultrathin 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 in traditional methods.

[0056] Furthermore, the reduction carbonization temperature is 700~900℃, and the carbonization time is 0.1~2h. Specifically, in this invention, tungsten powder is fully dispersed and mixed with copper powder, while a small amount of copper flakes coat the surface of the tungsten powder. In a gaseous carbon source atmosphere, the copper surface is easily catalytically grown into an ultrathin carbon layer; a carburizing reaction occurs on the surface of some exposed tungsten particles, generating a partial tungsten carbide phase at a relatively low temperature, and an ultrathin carbon layer precipitates on the tungsten carbide surface. Thus, this invention uses a lower reduction carbonization temperature and a shorter carbonization time, which not only saves production costs but also inhibits the abnormal growth of tungsten carbide grains.

[0057] Furthermore, the aforementioned small molecule alcohol can be selected from one or both of methanol and ethanol. Simultaneously, the carbon source flow rate is 0.1~0.5 mL / min. -1 The inventors discovered 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 subsequent pressing of the green body and the sintering products; when the flow rate of the small molecule alcohol cracking gas is too low, the small amount of gaseous carbon source, apart from reduction carburization on the tungsten oxide surface, cannot uniformly catalytically grow an ultrathin carbon layer on the copper surface. The tungsten carbide grain size in the carbon-modified tungsten-copper composite powder obtained by this invention is 100~400 nm, thus it can be used to prepare tungsten-copper alloys with high hardness and high temperature resistance.

[0058] The method for preparing carbon-modified tungsten-copper composite powder according to embodiments of the present invention involves mixing tungsten powder, copper powder, and anhydrous ethanol with a certain particle size distribution, followed by high-energy ball milling to transform spherical copper particles into a plate-like structure. This ensures sufficient contact between the tungsten and copper powders, with some copper coating the tungsten powder. The resulting tungsten-copper powder suspension is then vacuum-dried to prepare the tungsten-copper composite powder. Compared to other drying methods such as heating, vacuum drying avoids particle agglomeration caused by heat transfer. Finally, under a nitrogen protective atmosphere, a small-molecule alcohol cracking gas is introduced to perform carburizing and surface carbon growth on the tungsten-copper composite powder. The small-molecule alcohol cracking gas serves as a reducing and carbonizing atmosphere, resulting in the in-situ synthesis of a small amount of tungsten carbide phase on the surface of the composite powder, and the growth of an ultrathin carbon layer. Therefore, the method of the present invention, through a two-step synthesis process, can synthesize tungsten-copper composite powder containing an ultrathin carbon layer and a tungsten carbide reinforcing phase, thereby saving production costs and producing a carbon-modified tungsten-copper composite powder with stable properties.

[0059] The carbon-modified tungsten-copper composite powder prepared by the method described in this invention has an ultra-thin carbon layer attached to its surface and contains a small amount of tungsten carbide reinforcing particles. It can be used to prepare electrical contact alloys with high-temperature corrosion resistance, friction and wear resistance, and high hardness. It should be noted that the features and advantages described above for the method of preparing carbon-modified tungsten-copper composite powder also apply to this carbon-modified tungsten-copper composite powder, and will not be repeated here.

[0060] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way. Example 1

[0061] (1) Prepare tungsten powder with an average particle size of 2 μm and copper powder with an average particle size of 10 μm at a mass ratio of 80:20, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0062] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:5. High-energy ball milling was performed with a forward and reverse rotation interval of 0.5 h, a ball milling speed of 300 rpm and a ball milling time of 4 h. Then, vacuum drying was performed for 6 h to obtain tungsten-copper mixed powder.

[0063] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.1 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 800°C. o C, maintain the carbon source for 0.5 h. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 2

[0064] (1) Prepare tungsten powder with an average particle size of 5 μm and copper powder with an average particle size of 20 μm at a mass ratio of 70:30, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0065] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:7. High-energy ball milling was performed with a forward and reverse rotation interval of 0.4 h, a ball milling speed of 400 rpm and a ball milling time of 6 h. Then, vacuum drying was performed for 8 h to obtain tungsten-copper mixed powder.

[0066] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.3 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 900°C. o C, maintain the carbon source for 1 hour. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 3

[0067] (1) Prepare tungsten powder with an average particle size of 10 μm and copper powder with an average particle size of 25 μm at a mass ratio of 60:40, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0068] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:10. High-energy ball milling was performed with a forward and reverse rotation interval of 0.2 h, a ball milling speed of 400 rpm and a ball milling time of 10 h. Then, vacuum drying was performed for 12 h to obtain tungsten-copper mixed powder.

[0069] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.2 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 700°C. o C. Maintain the carbon source flow time for 2 hours. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 4

[0070] (1) Prepare tungsten powder with an average particle size of 2 μm and copper powder with an average particle size of 10 μm at a mass ratio of 80:20, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0071] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:5. High-energy ball milling was performed with a forward and reverse rotation interval of 0.1 h, a ball milling speed of 400 rpm and a ball milling time of 6 h. Then, vacuum drying was performed for 6 h to obtain tungsten-copper mixed powder.

[0072] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.5 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 850°C. o C, maintain the carbon source for 0.5 h. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 5

[0073] (1) Prepare tungsten powder with an average particle size of 10 μm and copper powder with an average particle size of 25 μm at a mass ratio of 80:20, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0074] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:7. High-energy ball milling was performed with a forward and reverse rotation interval of 0.5 h, a ball milling speed of 400 rpm and a ball milling time of 6 h. Then, vacuum drying was performed for 6 h to obtain tungsten-copper mixed powder.

[0075] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.2 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 850°C. o C, maintain the carbon source for 0.5 h. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 6

[0076] (1) Prepare tungsten powder with an average particle size of 5 μm and copper powder with an average particle size of 20 μm at a mass ratio of 80:20, and then mix with anhydrous ethanol to obtain a mixed suspension;

[0077] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:7. High-energy ball milling was performed with a forward and reverse rotation interval of 0.5 h, a ball milling speed of 500 rpm and a ball milling time of 4 h. Then, vacuum drying was performed for 6 h to obtain tungsten-copper mixed powder.

[0078] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.2 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 800°C. o C, maintain the carbon source for 0.5 h. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder. Example 7

[0079] (1) Prepare tungsten powder with an average particle size of 5 μm and copper powder with an average particle size of 15 μm at a mass ratio of 80:20, and then mix them with anhydrous ethanol to obtain a mixed suspension;

[0080] (2) The mixed suspension was placed in a ball mill jar, and tungsten steel balls were added. The mass ratio of tungsten powder, copper powder and tungsten steel balls in the ball mill jar was 1:5. High-energy ball milling was performed with a forward and reverse rotation interval of 0.5 h, a ball milling speed of 400 rpm and a ball milling time of 4 h. Then, vacuum drying was performed for 6 h to obtain tungsten-copper mixed powder.

[0081] (3) A small molecule alcohol is introduced under nitrogen protection, using the high-temperature cracking gas of the small molecule alcohol as a carbon source. The flow rate of the small molecule alcohol cracking gas is set to 0.1 mL / min. -1 The heating rate of the high-temperature furnace is 8~10℃ / min. -1 The temperature at which the carbon source is introduced is 800°C. o C, maintain the carbon source for 1 hour. Surface carburizing and carbon deposition are performed on the tungsten-copper mixed powder to obtain carbon-modified tungsten-copper composite powder.

[0082] Although embodiments of the present invention have been described above, these embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to 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 following these steps in sequence: (1) Mix tungsten powder and copper powder with anhydrous ethanol with a certain particle size distribution and mass ratio to obtain a mixed suspension; (2) The above mixed suspension is mixed with tungsten steel balls and placed in a ball mill jar for high-energy ball milling dispersion, followed by vacuum drying to obtain tungsten copper mixed powder; (3) The obtained tungsten copper mixed powder is placed in a high-temperature furnace, and a high-temperature cracking gas of a small molecule alcohol is introduced under nitrogen protection. The high-temperature cracking gas of the small molecule alcohol is used as a carbon source to perform surface carburizing and carbon deposition on the above tungsten copper mixed powder to obtain carbon-modified tungsten copper composite powder. In step (1), the tungsten powder particle size is 2~10μm, and the copper powder particle size is 10~25μm; the mass ratio of the tungsten powder to the copper powder is 8:2~6:

4. In step (2), the total amount of tungsten powder and copper powder in the ball mill jar and the mass ratio of tungsten steel balls are 1:3 to 1:10; the high-energy ball milling dispersion is intermittent forward and reverse rotation, and the intermittent time is 0.1 to 0.5 h; the ball milling speed of the high-energy ball milling dispersion is 300 to 500 rpm, and the ball milling time is 4 to 10 h; In step (3), the small molecule alcohol is one or both of methanol and ethanol; In step (3), the flow rate of the high-temperature cracking gas of the small molecule alcohol is 0.1~0.5 mL / min. -1 The heating rate of the high-temperature furnace is 8~10°C / min. -1 The temperature when introducing the carbon source is 700~900°C; the carbon source introduction time is 0.1~2 h.

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

3. A method for preparing carbon-modified tungsten-copper composite powder, characterized in that: Follow these steps in sequence: (1) Mix tungsten powder and copper powder with anhydrous ethanol with a certain particle size distribution and mass ratio to obtain a mixed suspension; (2) The above mixed suspension is mixed with tungsten steel balls and placed in a ball mill jar for high-energy ball milling dispersion, followed by vacuum drying to obtain tungsten copper mixed powder; (3) The obtained tungsten copper mixed powder is placed in a high-temperature furnace, and a high-temperature cracking gas of a small molecule alcohol is introduced under nitrogen protection. The high-temperature cracking gas of the small molecule alcohol is used as a carbon source to perform surface carburizing and carbon deposition on the above tungsten copper mixed powder to obtain carbon-modified tungsten copper composite powder. In step (1), the tungsten powder particle size is 2~10μm, and the copper powder particle size is 10~25μm; the mass ratio of the tungsten powder to the copper powder is 8:2~6:

4. In step (2), the total amount of tungsten powder and copper powder in the ball mill jar and the mass ratio of tungsten steel balls are 1:3 to 1:10; the high-energy ball milling dispersion is intermittent forward and reverse rotation, and the intermittent time is 0.1 to 0.5 h; the ball milling speed of the high-energy ball milling dispersion is 300 to 500 rpm, and the ball milling time is 4 to 10 h; In step (3), the small molecule alcohol is one or both of methanol and ethanol; In step (3), the flow rate of the high-temperature cracking gas of the small molecule alcohol is 0.1~0.5 mL / min. -1 The heating rate of the high-temperature furnace is 8~10°C / min. -1 The temperature when introducing the carbon source is 700~900°C; the carbon source introduction time is 0.1~2 h.

4. The method for preparing carbon-modified tungsten-copper composite powder according to claim 3, characterized in that: In step (2), the powder dispersed by high-energy ball milling is dried in a vacuum drying oven for 4 to 12 hours.