Preparation method of copper-tungsten composite powder with high-mass-fraction nano tungsten particles dispersed and distributed
By using citric acid complexation and multi-stage heat treatment technology, the problems of unstable complexation and agglomeration in the preparation of high tungsten content Cu-W composite powder were solved, and the uniform distribution of high-quality fractional tungsten nanoparticles in the copper matrix was achieved, thereby improving the microstructure and performance of the material.
Patent Information
- Application Number
- CN202511840003.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-03-03
AI Technical Summary
Existing technologies for preparing high-tungsten-content Cu-W composite powders suffer from problems such as unstable complexation, decreased gel quality, high carbon residue, and easy agglomeration of tungsten particles, resulting in uneven powder distribution and affecting the subsequent material properties.
High-quality copper-tungsten composite powder with dispersed fractional nano-sized tungsten particles was prepared by using citric acid complexation regulation, drying behavior optimization, and multi-stage heat treatment technology, including two-stage air calcination and three-stage hydrogen reduction, to control the particle size and distribution of tungsten particles.
It achieves uniform dispersion of tungsten particles in a copper matrix with a particle size of 7-50 nm and a carbon residue of less than 0.01%, making it suitable for the industrial production of high-performance Cu-W materials.
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Figure CN121592897A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of materials science and powder metallurgy, and more particularly to a method for preparing high-quality copper-tungsten composite powder with dispersed fractional nano-sized tungsten particles. Background Technology
[0002] Copper-tungsten (Cu-W) composites combine the high electrical conductivity of copper with the high melting point, high strength, and excellent heat and ablation resistance of tungsten. They maintain good electrothermal stability and structural integrity under extreme service conditions such as high temperature, strong electricity, strong magnetism, high pressure, and severe friction, and are widely used in high-tech fields such as electrical contact materials, vacuum appliances, electrode materials, and electromagnetic emission. In such composite applications, Cu-W materials exhibit comprehensive performance advantages that are difficult for single-component metals to match.
[0003] However, due to the significant differences in physical properties between copper and tungsten, such as their large differences in melting points (copper 1083°C, tungsten 3422°C), they almost never form solid solutions with each other and are difficult to alloy using traditional metallurgical methods. Therefore, powder metallurgy technology is currently the primary method for preparing Cu-W composite materials. Among these methods, preparing uniformly dispersed Cu-W composite powder is one of the key prerequisites for achieving ideal microstructure and properties.
[0004] Currently, mechanical alloying high-energy ball milling is commonly used in the preparation of Cu-W composite powders. However, with the increase of tungsten content, this method has gradually revealed a series of process limitations. For example, during high-energy ball milling, phenomena such as copper powder flakes, cold welding adhesion, difficulty in controlling particle size, and severe powder agglomeration are prone to occur, resulting in uneven particle distribution, high impurity content, and severe fluctuations in microstructure and properties of the composite powder, which adversely affect the subsequent pressing, densification, and sintering processes.
[0005] In comparison, the sol-gel method, with its significant advantages such as molecular-level mixing, uniform elemental distribution, and easy particle size control, has gradually become an important direction for the preparation of high-quality Cu-W composite powders. Existing research shows that Cu-W powders can be stabilized with complexing agents such as citric acid to transition metal ions, and combined with subsequent dry gel pyrolysis and reduction processes to obtain nanoscale dispersed metal composite powders. This is mostly concentrated under conditions of low tungsten content. However, for Cu-W composite powders with high tungsten content (e.g., W ≥ 20 wt.%), existing technologies still face significant technical obstacles in terms of complexation stability, gel quality, powder morphology, and subsequent heat treatment, including but not limited to the following: 1) Commonly used tungsten precursors (such as ammonium paratungstate and ammonium metatungstate) readily form complex polymer structures in aqueous solutions (such as [H2W...). 12 O 42 ]¹ 0-This leads to an unstable interaction with citric acid ligands, affecting the uniformity of the complexation system. In citric acid-dominated complexation systems, high tungsten content often induces precipitation and crystallization in the gel system, resulting in a significant decrease in gel stability and ultimately affecting the quality of the dry gel. 2) If the carbon source is not completely removed during the dry gel calcination stage, the residual organic carbon may form a carbon coating layer during the reduction process, preventing the sintering connection between particles, and ultimately causing a separation effect between composite powders, interfering with the bonding of components. 3) The large difference in reduction temperature range between copper and tungsten oxide components makes the reduction process prone to the phenomenon of "local premature reduction - agglomeration - local sintering". Especially under high tungsten content conditions, tungsten particles are more likely to agglomerate and coarsen, and the microstructure is not easy to control.
[0006] Therefore, in the face of the above-mentioned technical bottlenecks in the preparation of Cu-W composite powder with high tungsten content, it is urgent to develop a novel sol-gel synergistic method that can achieve a stable complex structure system with a wide range of copper / tungsten ratios (especially when W≥20wt.%), improve gel quality, optimize the removal efficiency of organic residues, and control the powder particle size and distribution to achieve uniform dispersion of nano-sized tungsten particles on the copper matrix, thereby providing a basic powder guarantee for high-performance Cu-W composite materials. Summary of the Invention
[0007] To address the common technical challenges in the existing sol-gel method for preparing high-tungsten-content (tungsten mass fraction ≥20%) Cu-W composite powders, such as unstable hydrolysis reaction, uneven distribution of metal elements, excessive carbon residue, easy agglomeration of tungsten particles, and difficulty in dispersing tungsten, this invention provides a method for preparing high-quality copper-tungsten composite powders with dispersed tungsten particles of high fraction. Based on complexation control, drying behavior optimization, and multi-stage heat treatment technology, this invention can obtain composite powders with fine tungsten particle size (7-50nm), low carbon residue, uniform distribution, and stable composition under high tungsten content conditions, providing high-quality raw materials for the subsequent synthesis of high-performance Cu-W materials.
[0008] The technical means employed in this invention are as follows: A method for preparing high-quality copper-tungsten composite powder with dispersed tungsten nanoparticles, used to prepare copper-tungsten composite powder with a tungsten mass fraction not exceeding 50%, the copper-tungsten composite powder being composed of copper and tungsten, specifically including the following steps: (1) Preparation of tungsten salt solution The amounts of ammonium paratungstate and copper nitrate are determined based on the mass fraction of tungsten in the copper-tungsten composite powder to be prepared. Simultaneously, the amount of citric acid required for preparing the tungsten salt solution is determined: when the mass fraction of tungsten is less than or equal to 20%, the ratio of the moles of citric acid to the total moles of metal ions is 1:1; when the mass fraction of tungsten is in the range of 20%-50%, for every 10% increase in the mass fraction of tungsten, the ratio of the moles of citric acid to the total moles of metal ions doubles; the metal ions in the copper-tungsten composite powder include copper ions and tungsten ions. Ammonium paratungstate was dissolved in deionized water, and citric acid was added to carry out a complexation reaction to prepare a tungsten salt solution. (2) Preparation of copper-tungsten mixed salt solution The tungsten salt solution is heated to 120-140℃ and stirred until dissolved to form a transparent complex solution. Then, an aqueous solution of copper nitrate is added dropwise to the complex solution to form a copper-tungsten mixed salt solution. (3) Synthesis of copper-tungsten colloid The temperature of the copper-tungsten mixed salt solution was lowered to 80°C and stirred continuously for 12 hours to form a uniformly mixed and stable copper-tungsten sol. (4) Preparation of copper-tungsten precursor The copper-tungsten sol was transferred to the drying process and dried at a temperature above 100°C to remove moisture, resulting in a fluffy and dry powdery dry gel. After grinding, copper-tungsten precursor powder was obtained. (5) Decarburization of copper-tungsten precursor by calcination The copper-tungsten precursor powder was decarburized by two-stage heating and calcination in air atmosphere: first calcination at 550℃, then calcination at 650℃; after calcination, copper-tungsten oxide powder was obtained. (6) Hydrogen reduction of copper-tungsten oxide powder Copper-tungsten oxide powder was reduced in a hydrogen environment in three stages: the temperature was kept at 400℃, 550℃ and 750℃ respectively; after reduction, copper-tungsten composite powder was obtained.
[0009] Further, in step (5), organic residual carbon in the copper-tungsten precursor is removed by two-stage heating and calcination to obtain copper-tungsten oxide powder composed of CuO, WO3 and CuWO4; in step (5), the calcination time of each stage does not exceed 1 hour.
[0010] Furthermore, in step (6), the thickness of the copper tungsten oxide powder does not exceed 2 mm during the three-stage reduction process; the three-stage reduction process in step (6) includes: holding at 400℃ for 0.5 h, holding at 550℃ for 0.5 h, and holding at 750℃ for no more than 70 min.
[0011] Furthermore, the tungsten particles in the prepared copper-tungsten composite powder have a particle size of 7-50 nm and are uniformly dispersed in the copper matrix.
[0012] Compared with the prior art, the present invention has the following advantages: (1) The average particle size of the tungsten component in the prepared composite metal powder can be controlled between 7-50 nm. The tungsten particles are uniformly dispersed in the copper matrix without obvious agglomeration. (2) It effectively solves the problem of excessive carbon residue caused by carbon residue in traditional gel structures, and the final carbon residue can be controlled below 0.01% (mass fraction); (3) The powder has a uniform particle size and no obvious secondary agglomeration, exhibiting good dispersibility and is suitable for subsequent pressing and sintering processes; (4) The raw materials used are widely available, the synthesis process is stable and the steps are clear, and the process is well controllable. It can be scaled up for production, providing a reliable solution for the industrial preparation of high tungsten content Cu-W materials.
[0013] In summary, this invention provides a method for preparing high-quality, highly uniform Cu-W composite nanopowders with low carbon residue, which significantly improves the microstructure of alloy powders and has important application value for the development of high-performance Cu-W materials under complex service conditions. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is a macroscopic image of the copper-tungsten precursor powder obtained after drying and grinding in Example 1.
[0016] Figure 2 This is a microscopic image of the oxide powder obtained after calcination in Example 1.
[0017] Figure 3 This is one of the microscopic images of the copper-tungsten composite powder obtained after hydrogen reduction in Example 1.
[0018] Figure 4 This is the second microscopic image of the copper-tungsten composite powder obtained after hydrogen reduction in Example 1.
[0019] Figure 5 The image shows a microscopic image of the copper-tungsten composite powder obtained after hydrogen reduction in Comparative Example 2.
[0020] Figure 6 The image shows a microscopic image of the copper-tungsten composite powder obtained after hydrogen reduction in Comparative Example 3. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] This invention provides a method for preparing high-quality copper-tungsten composite powder with dispersed tungsten nanoparticles. This method employs a non-traditional gelation path, eliminating the need for acid-base adjustment and isothermal aging. By controlling the citric acid complexation ratio, a precursor is formed under mild and dry conditions. Subsequently, a two-stage air calcination effectively removes residual organic carbon, followed by a three-stage hydrogen reduction to achieve synergistic reduction of multiple components, including oxides CuO, WO3, and CuWO4. This preparation method is used to prepare copper-tungsten composite powder with a tungsten mass fraction not exceeding 50%, particularly copper-tungsten composite powder with a tungsten mass fraction between 20% and 50%. The copper-tungsten composite powder is composed of copper and tungsten and specifically includes the following steps: (1) Preparation of tungsten salt solution The amounts of ammonium paratungstate and copper nitrate are determined based on the mass fraction of tungsten in the target copper-tungsten composite powder. Simultaneously, the amount of citric acid required for preparing the tungsten salt solution is determined: when the mass fraction of tungsten is less than or equal to 20%, the ratio of the moles of citric acid to the total moles of metal ions is 1:1; when the mass fraction of tungsten is in the range of 20%-50%, for every 10% increase in the mass fraction of tungsten, the ratio of the moles of citric acid to the total moles of metal ions doubles (for example, when the mass fraction of tungsten is 40%, the ratio of the moles of citric acid to the total moles of metal ions is 3:1); the metal ions in the copper-tungsten composite powder include copper ions and tungsten ions; the configuration strategy of increasing the ratio of the moles of citric acid to the total moles of metal ions with increasing tungsten mass fraction can be used to adjust suitable complexation behavior and stabilize the configuration; Ammonium paratungstate was dissolved in deionized water, and citric acid was added to carry out a complexation reaction to prepare a tungsten salt solution. (2) Preparation of copper-tungsten mixed salt solution The tungsten salt solution is heated to 120-140℃ and stirred until dissolved to form a transparent complex solution. Then, an aqueous copper nitrate solution is added dropwise to the complex solution to form a copper-tungsten mixed salt solution. The dropwise addition rate of the aqueous copper nitrate solution should not exceed 5 ml / min. Controlling the addition rate can avoid precipitation or crystallization caused by sudden changes in pH or concentration. (3) Synthesis of copper-tungsten colloid The temperature of the copper-tungsten mixed salt solution was lowered to 80°C and stirred continuously for 12 hours to form a uniformly mixed and stable copper-tungsten sol. (4) Preparation of copper-tungsten precursor This method avoids the pH adjustment and isothermal aging required by traditional gelation methods, and does not rely on low-flow gel formation. Instead, it directly dehydrates and dries to obtain a fluffy, dry precursor: the copper-tungsten sol is transferred to the drying process, and after being dried by forced air at above 100°C to remove moisture, a fluffy, dry powdery dry gel is obtained. This powder is then ground (mechanically crushed or ball-milled) to obtain the copper-tungsten precursor powder, achieving good metal ion mixing and structural stability during the drying process. The forced air drying time depends on the forced air drying equipment and heating volume used. (5) Decarburization of copper-tungsten precursor by calcination The copper-tungsten precursor powder was placed in a high-temperature furnace and subjected to two-stage heating and calcination decarburization in an air atmosphere: first, it was calcined at 550℃ to remove most of the nitrogen and carbon elements, and then the temperature was raised to 650℃ to completely complete the oxidation reaction of the organic carbon source; after calcination, copper-tungsten oxide powder was obtained, which was prepared for the reduction step. (6) Hydrogen reduction of copper-tungsten oxide powder Copper-tungsten oxide powder was subjected to a three-stage reduction in a hydrogen environment: sequentially heated to 400℃, 550℃, and 750℃; after reduction, copper-tungsten composite powder was obtained. The three-stage reduction method can achieve sequential reduction of Cu-W oxides, avoid local carbon reduction or tungsten particle agglomeration, and achieve synergistic reduction of metal components, ultimately obtaining copper-tungsten composite powder with tungsten particles dispersed in the copper matrix at the nanoscale.
[0023] The preparation method described in this invention does not rely on pH adjustment or isothermal aging in traditional gelation methods to obtain wet gels. Instead, it relies on the complexation reaction of citric acid with metal ions to obtain a very stable sol, which is then directly dried to obtain dry gel precursor powder. The pH adjustment and isothermal aging steps in traditional gelation methods reduce powder quality and are not suitable for industrial production. This invention bypasses pH adjustment and isothermal aging and adopts a new technical route, which enables the stable acquisition of tungsten particles with a particle size of 7-50 nanometers under high tungsten mass fraction (20%-50%), and achieves uniform distribution in a copper matrix.
[0024] Further, in step (5), organic residual carbon in the copper-tungsten precursor is removed by two-stage heating and calcination to obtain copper-tungsten oxide powder composed of CuO, WO3 and CuWO4; in step (5), the calcination time of each stage does not exceed 1 hour.
[0025] Furthermore, in step (6), the thickness of the copper tungsten oxide powder does not exceed 2 mm during the three-stage reduction process; the three-stage reduction process in step (6) includes: holding at 400℃ for 0.5 h, holding at 550℃ for 0.5 h, and holding at 750℃ for no more than 70 min.
[0026] Furthermore, the tungsten particles in the prepared copper-tungsten composite powder have a particle size of 7-50 nm and are uniformly dispersed in the copper matrix.
[0027] Traditional gelation methods can only prepare composite powders with a tungsten content of less than 20%, while the preparation method described in this invention is applicable to Cu-W composite systems with a tungsten mass fraction of 50% or less, and is especially suitable for the preparation of high-tungsten-content copper-tungsten composite powders with a tungsten content of 20%-50%. It can achieve nanoscale control of tungsten particles and uniform dispersion in the copper matrix, breaking through the technical bottleneck of traditional preparation methods in controlling high tungsten content and microstructure uniformity. This invention adopts a non-traditional gelation path and combines two-stage air atmosphere calcination and three-stage hydrogen segmented reduction treatment to achieve synergistic optimization of residual carbon control and particle size regulation.
[0028] This invention provides a method for preparing high-quality copper-tungsten composite powder with dispersed tungsten nanoparticles. It overcomes the limitations of traditional gel synthesis processes on tungsten content, achieving stable production of tungsten particles with a diameter of 7-50 nanometers even with high tungsten mass fraction (20%-50%), and ensuring uniform distribution within a copper matrix. The preparation process employs a non-traditional gel path, eliminating the need for acid-base adjustment and isothermal aging. Ideal precursor powders are obtained by controlling the citric acid complexation ratio. Furthermore, an innovative two-stage air calcination and three-stage hydrogen reduction method effectively removes carbon, hydrogen, and oxygen, successfully producing nanoscale pure tungsten particles uniformly distributed within a pure copper matrix. Compared to existing technologies, this invention significantly improves the particle fineness and dispersibility of the powder under high tungsten content conditions, solving the problems of tungsten particle agglomeration and uneven reduction. The technical solution of this invention is simple, efficient, and suitable for industrial production, and can be widely applied in advanced structural or functional materials such as high-temperature resistant materials and electromagnetic launch track materials.
[0029] Example 1 This embodiment uses a method for preparing copper-tungsten composite powder with a tungsten content of 30% by dispersing high-quality fractional nano-tungsten particles. The specific steps include: (1) Take a certain amount of ammonium paratungstate hydrate (3060.46 molecular weight) and mix it with citric acid hydrate (210.14 molecular weight) in a molar ratio of 2:1 (citric acid: total metal ions) to prepare a tungsten salt solution; (2) Heat the tungsten salt solution to 140°C and stir until completely dissolved to form a clear and transparent solution; slowly add the copper nitrate hydrate (241.6 molecular weight) solution to the above solution, controlling the addition rate to avoid sudden changes in pH or concentration that could cause crystallization or precipitation. (3) Reduce the temperature of the copper-tungsten mixed salt solution to 80°C and stir continuously for 12 hours to form a uniformly mixed and stable copper-tungsten sol; (4) The copper-tungsten sol is directly transferred to a drying oven and dried rapidly at 120°C for 2 hours. After drying, a fluffy dried copper-tungsten sol is obtained. The copper-tungsten precursor powder with good dispersion is obtained by manual grinding or ball milling (the color is usually blue-green, and brownish if the tungsten content is high). In this embodiment, the macroscopic image of the copper-tungsten precursor powder obtained after drying and grinding is as follows. Figure 1 As shown, the powder has a uniform color and fine texture, indicating that the sol-gel effect is very good and there are no adverse conditions such as crystallization segregation. (5) The copper-tungsten precursor powder is evenly spread into a quartz crucible and then placed in a high-temperature furnace. First, it is heated to 550°C for 1 hour in an air atmosphere; then it is heated to 650°C for 1 hour. During the calcination process, the oxygen supply is maintained at an air flow rate of 100 mL / min. After calcination, copper tungsten oxide powder composed of CuO, WO3, and CuWO4 was obtained, and its microscopic image is shown below. Figure 2 As shown, the copper-tungsten oxide powder is fine and uniform. (6) The sample was loaded into a tube furnace, and 99.99% pure hydrogen gas was introduced. The copper-tungsten oxide powder was reduced in a three-stage process in a hydrogen environment: successively held at 400℃ for 0.5h, at 550℃ for 0.5h, and at 750℃ for 1h. The heating rate of each stage was controlled within 10℃ / min to prevent local overheating of the powder. The final result was as follows: Figure 3 and Figure 4 The image shows a copper-tungsten composite powder with a copper matrix and finely dispersed tungsten particles (approximately 7-50 nm in diameter). Figure 3 and Figure 4 It can be seen that the composite powder contains only two single phases, copper and tungsten. The bright contrast in the figure represents nano-tungsten phase particles, while the darker contrast represents the micron-sized copper phase matrix.
[0030] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that in step (5), a one-stage calcination is used, that is, calcination is carried out only at 550°C for 2 hours, while the remaining steps and conditions are the same as in Example 1.
[0031] The carbon content of the copper-tungsten oxide powders obtained after calcination in Example 1 and Comparative Example 1 was tested using a sulfur-carbon analyzer. The experiment was repeated 5 times, and the test results are shown in Table 1.
[0032] Table 1. Test results of copper-tungsten oxide powder sulfur and carbon in Example 1 and Comparative Example 1 using an analyzer.
[0033] As can be seen from the test results in Table 1, the carbon residue in the oxide powder obtained by one-stage calcination in Comparative Example 1 is as high as 5% or more, while the carbon residue in the composite oxide powder obtained by two-stage calcination in Example 1 is only 0.0018-0.0066%, which proves that two-stage calcination is a necessary condition for obtaining oxide powder with low carbon residue.
[0034] Comparative Example 2 and Comparative Example 3 The only difference between Comparative Example 2 and Example 1 is that in step (5), a one-stage hydrogen reduction is used, that is, the temperature is kept at 750°C for 1 hour, and the remaining steps and conditions are the same as in Example 1.
[0035] The only difference between Comparative Example 3 and Example 1 is that a two-stage hydrogen reduction was used, i.e., the temperature was kept at 400°C for 1 hour, followed by a temperature of 750°C for 1 hour. The remaining steps and conditions were the same as in Example 1.
[0036] The SEM images of the copper-tungsten composite powders finally obtained in Comparative Examples 2 and 3 are as follows: Figure 5 and Figure 6 As shown, in the SEM image, the bright contrast represents tungsten phase particles, while the dark contrast represents a micron-sized copper phase matrix; (Comparison) Figure 4 and Figure 5 and Figure 6 As can be seen, the three-stage hydrogen reduction method used in Example 1 has a significant improvement effect on both the size of the copper substrate and the nano-sizing and dispersion distribution of tungsten particles, proving that the three-stage hydrogen reduction is a necessary condition for obtaining uniformly dispersed nano-tungsten particles.
[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing high-quality copper-tungsten composite powder with dispersed fractional nano-sized tungsten particles, characterized in that, The preparation of copper-tungsten composite powder with a tungsten mass fraction not exceeding 50%, wherein the copper-tungsten composite powder is composed of copper and tungsten, specifically includes the following steps: (1) Preparation of tungsten salt solution The amounts of ammonium paratungstate and copper nitrate are determined based on the mass fraction of tungsten in the copper-tungsten composite powder to be prepared. Simultaneously, the amount of citric acid required for preparing the tungsten salt solution is determined: when the mass fraction of tungsten is less than or equal to 20%, the ratio of the moles of citric acid to the total moles of metal ions is 1:1; when the mass fraction of tungsten is in the range of 20%-50%, for every 10% increase in the mass fraction of tungsten, the ratio of the moles of citric acid to the total moles of metal ions doubles; the metal ions in the copper-tungsten composite powder include copper ions and tungsten ions. Ammonium paratungstate was dissolved in deionized water, and citric acid was added to carry out a complexation reaction to prepare a tungsten salt solution. (2) Preparation of copper-tungsten mixed salt solution The tungsten salt solution is heated to 120-140℃ and stirred until dissolved to form a transparent complex solution. Then, an aqueous solution of copper nitrate is added dropwise to the complex solution to form a copper-tungsten mixed salt solution. (3) Synthesis of copper-tungsten colloid The temperature of the copper-tungsten mixed salt solution was lowered to 80°C and stirred continuously for 12 hours to form a uniformly mixed and stable copper-tungsten sol. (4) Preparation of copper-tungsten precursor The copper-tungsten sol was transferred to the drying process and dried at a temperature above 100°C to remove moisture, resulting in a fluffy and dry powdery dry gel. After grinding, copper-tungsten precursor powder was obtained. (5) Decarburization of copper-tungsten precursor by calcination The copper-tungsten precursor powder was decarburized by two-stage heating and calcination in air atmosphere: first calcination at 550℃, then calcination at 650℃; after calcination, copper-tungsten oxide powder was obtained. (6) Hydrogen reduction of copper-tungsten oxide powder Copper-tungsten oxide powder was reduced in a hydrogen environment in three stages: the temperature was kept at 400℃, 550℃ and 750℃ respectively; after reduction, copper-tungsten composite powder was obtained.
2. The method for preparing high-quality fractional nano-sized tungsten particle dispersed copper-tungsten composite powder according to claim 1, characterized in that, Step (5) removes organic residual carbon from the copper-tungsten precursor by two-stage heating and calcination to obtain copper-tungsten oxide powder composed of CuO, WO3 and CuWO4; in step (5), the calcination time of each stage does not exceed 1 hour.
3. The method for preparing high-quality fractional nano-sized tungsten particle dispersed copper-tungsten composite powder according to claim 1, characterized in that, When performing the three-stage reduction in step (6), the thickness of the copper tungsten oxide powder shall not exceed 2 mm; the three-stage reduction in step (6) includes: holding at 400℃ for 0.5 h, holding at 550℃ for 0.5 h, and holding at 750℃ for no more than 70 min.
4. The method for preparing high-quality fractional nano-sized tungsten particle dispersed copper-tungsten composite powder according to claim 1, characterized in that, The copper-tungsten composite powder obtained has a tungsten particle size of 7-50 nm, and the tungsten particles are uniformly dispersed in the copper matrix.