Manufacturing method of high-density tungsten-copper alloy
Through the high-density production method of tungsten copper alloy, the oxidation and reduction of copper elements are used to solve the problems of low density and poor sintering performance of tungsten copper alloy, and the performance improvement of high density and high thermal conductivity is achieved.
Patent Information
- Application Number
- CN202411594480.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-09
- Publication Date
- 2025-02-25
AI Technical Summary
In the existing tungsten copper alloy preparation process, due to the poor mutual insolubleness and wettability of tungsten and copper, the alloy density and sintering performance are low, resulting in poor performance such as density and thermal conductivity of the alloy.
A high-density tungsten copper alloy is used to make a tungsten copper powder mixture of a predetermined particle size and particle size, mix and binder, and make a blank raw material, which is subjected to blank molding, heating oxidation and sintering treatment under a reducing agent environment. Through the oxidation and reduction of copper elements, the activity of elemental copper is improved, sintering is promoted, and alloy density is improved.
The density and sintering performance of tungsten copper alloy are improved, the sintering temperature is reduced, and the density and thermal conductivity of the alloy are enhanced.
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Figure CN119501049A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of tungsten-copper alloys, and in particular to a method for manufacturing a high-density tungsten-copper alloy. Background Art
[0002] Tungsten copper alloy has both the high melting point and low expansion characteristics of tungsten and the high electrical conductivity and thermal conductivity of copper. It has a wide range of industrial applications and plays an important role in mobile communications, electrical contact materials, microelectronics and other fields. The alloy has a very similar thermal expansion coefficient to semiconductor silicon materials and is widely used in heat sink materials and packaging materials. It is also used in the armor-piercing field due to its high density, high sound velocity and high plasticity.
[0003] In the related technology, due to the large difference in density and melting point between tungsten and copper components, copper and tungsten are immiscible in the solid state. The density, hardness and other physical properties of tungsten and copper are very different and they are immiscible. If tungsten-copper alloy is prepared by melt infiltration, it is difficult to make all pores of the tungsten skeleton connected and of uniform size, and it is also difficult to ensure the uniformity of copper distribution in the product after melt infiltration, resulting in the alloy density not meeting the requirements.
[0004] If tungsten-copper alloy is prepared by the common "powder mixing + molding + liquid phase sintering" process, the sintering performance is poor due to the mutual insolubility and poor wettability of tungsten and copper. Even if ultrafine tungsten powder and copper powder are used to improve the sintering activity of the material, the sintering density is still low, so the density, thermal conductivity and other properties of the alloy are poor. Summary of the invention
[0005] In order to improve the density of the manufactured tungsten-copper alloy, the present application provides a method for manufacturing a high-density tungsten-copper alloy.
[0006] The present application provides a method for manufacturing a high-density tungsten-copper alloy using the following technical solutions: A method for making a high-density tungsten-copper alloy comprises the following steps: S1, preparing a tungsten-copper powder mixture with a predetermined particle size and particle size; S2, kneading the tungsten copper powder mixture with a binder to prepare a blank making raw material; S3, making the blanking raw material into the required blank; S4. Remove organic matter and other impurities in the blank; S5, heating and oxidizing the blank; S6. Sintering the blank in an environment with a reducing agent.
[0007] By adopting the above technical solution, the copper element is first oxidized and then reduced, so the newly generated single copper is more active, which is conducive to sintering, thereby increasing the density of the tungsten copper alloy and reducing the sintering temperature.
[0008] Preferably, the S1 further comprises the following steps: S11, ball-milling tungsten powder, copper powder and alcohol to form a primary mixed slurry; S12, removing alcohol from the primary mixed slurry to form a bulk tungsten-copper mixture; S13, crushing the tungsten-copper mixture to form a tungsten-copper powder mixture.
[0009] By adopting the above technical solution, while promoting the mixing of tungsten powder and copper powder, the particles can be crushed by means of balls and alcohol, so that a tungsten-copper powder mixture with a predetermined particle size and diameter can be prepared while reducing production costs.
[0010] Preferably, in S11, the initial particle size of the tungsten powder is less than 200 nm, and the initial particle size of the copper powder is less than 500 nm.
[0011] By adopting the above technical solution, the initial particle size is not too small, so the cost of the pulverization process will not be too high, the initial particle size is not too high, so the pulverization process cycle will not be too long, and the particle size produced will not be too large.
[0012] Preferably, in S13, the tungsten-copper mixture is passed through a 60-100 mesh sieve.
[0013] By adopting the above technical solution, since the strength of the blocky tungsten-copper mixture is not high, the tungsten-copper powder mixture with the required particle size and granularity can be more efficiently prepared by directly passing it through a sieve with a predetermined size requirement.
[0014] Preferably, if the parts to be manufactured have high requirements on dimensional accuracy and surface quality, then in S3, metal MIM molding is selected to achieve it; if the parts to be manufactured have high requirements on shape but low requirements on dimensional accuracy and surface quality, then in S3, binder jet metal 3D printing is selected to achieve it.
[0015] By adopting the above technical solution, the corresponding blank forming method can be selected according to actual needs, so that the performance of the manufactured tungsten copper alloy can be better.
[0016] Preferably, the S4 further comprises the following steps: S41, immersing the blank into an organic solvent and performing heating extraction; S42, drying the blank; S43, performing thermal degreasing treatment on the blank.
[0017] By adopting the above technical solution, compared with the method of removing organic matter and other impurities in the blank only by thermal degreasing treatment, this design method can remove more than 50% of organic matter through heating extraction with organic solvent, and the subsequent thermal degreasing time will not be too long, so the blank will not break.
[0018] Preferably, in S4, the blank is subjected to alternate thermal degreasing treatment and cooling treatment until organic matter and other impurities in the blank are removed.
[0019] By adopting the above technical solution, there is no need to add organic solvents or drying treatment in this process, so only a tunnel furnace can be used. Thermal degreasing is done in the heating zone of the tunnel furnace, and cooling is done in the cooling zone of the tunnel furnace, thereby saving consumable costs.
[0020] Preferably, in S5, the portion of the copper element in the blank that is oxidized is 10%-20%.
[0021] By adopting the above technical solution, the copper element that was originally oxidized can be fully reduced later, so that a higher density tungsten-copper alloy can be made at a lower production cost.
[0022] Preferably, in S6, the sintering temperature range has an oxidation zone and a sintering zone. When the temperature is in the oxidation zone and the sintering zone, the temperature changes slowly, and when the temperature is between the oxidation zone and the sintering zone, the temperature changes quickly.
[0023] By adopting the above technical solution, the production cycle can be shortened while copper oxide is fully reduced and copper and tungsten are fully combined.
[0024] Preferably, in S6, the reducing agent is hydrogen.
[0025] By adopting the above technical solution, firstly, compared with the method in which the reducing agent is carbon monoxide, in this design method, hydrogen can be continuously introduced into the sintering environment where the blank is located, so the implementation method is relatively simple; secondly, compared with the method in which the reducing agent is carbon, in this design method, more copper elements can be oxidized when the blank is heated and oxidized in the previous step, and the copper oxide can be fully reduced later, thereby improving the density of the tungsten copper alloy.
[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The copper element is first oxidized and then reduced, so the newly generated elemental copper is more active, which is conducive to sintering, thereby increasing the density of the tungsten copper alloy and reducing the sintering temperature; 2. If the parts to be manufactured have high requirements on dimensional accuracy and surface quality, then in S3, metal MIM molding is selected to achieve it; if the parts to be manufactured have high requirements on shape but low requirements on dimensional accuracy and surface quality, then in S3, binder jetting metal 3D printing is selected to achieve it; 3. The copper element that was originally oxidized can be fully reduced later, so that a higher density tungsten copper alloy can be made with lower production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a schematic diagram of a process for preparing a high-density tungsten-copper alloy disclosed in this embodiment.
[0028] Figure 2 It is a detailed flow chart of step S1 in a method for making a high-density tungsten-copper alloy disclosed in this embodiment.
[0029] Figure 3 It is a detailed flow chart of step S4 in a method for making a high-density tungsten-copper alloy disclosed in this embodiment. DETAILED DESCRIPTION
[0030] The following is combined with Figure 1-3 This application is described in further detail.
[0031] The embodiment of the present application discloses a method for manufacturing a high-density tungsten-copper alloy.
[0032] Reference Figure 1 The method for making high-density tungsten-copper alloy comprises the following steps: S1, preparing a tungsten-copper powder mixture with a predetermined particle size and particle size; S2, kneading the tungsten copper powder mixture with a binder to prepare a blank making raw material; S3, making the blanking raw material into the required blank; S4. Remove organic matter and other impurities in the blank; S5, heating and oxidizing the blank; S6. Sintering the blank in an environment with a reducing agent.
[0033] From the two steps of S5 and S6, the copper element will be oxidized first and then reduced, so the newly generated single copper is more active, which is conducive to sintering, thereby increasing the density of the tungsten copper alloy. In addition, the characteristics of the newly generated single copper are enhanced, so the sintering temperature can be lowered.
[0034] In this embodiment, in each step S1-S6, it is necessary to select a specific implementation method based on the actual working conditions, production costs, production cycles of each step, and the mutual influence between the steps, so there are the following settings.
[0035] In S1, in order to reduce production costs and production cycles, and to make the particle size and particle size of the tungsten copper powder mixture smaller, refer to Figure 2 , then S1 also includes the following steps: S11, ball milling tungsten powder, copper powder and alcohol to form a primary mixed slurry. In this step, the purpose is to crush the tungsten powder and copper powder of the initial particle size, and simultaneously mix the tungsten powder and copper powder, wherein the ball is used as a solid medium in the crushing process, and the alcohol is used as a liquid medium in the crushing process, and the alcohol can also enhance the fluidity of the powder, so as to accelerate the mixing efficiency between the tungsten powder and the copper powder. It should be noted that the initial particle size cannot be too large or too small. If it is too large, the crushing cycle will be too long, and even the particle size and particle size of the final tungsten-copper powder mixture will be too large. If it is too small, the production cost will be too high. Therefore, the initial particle size of the tungsten powder is less than 200nm, and the initial particle size of the copper powder is less than 500nm. S12, removing the alcohol in the primary mixed slurry to form a bulk tungsten copper mixture. In this step, the primary mixed slurry is first extracted from the ball mill mixing equipment, the alcohol is extracted after the settling time, and then the remaining slag is dried; S13, crushing the tungsten copper mixture to form a tungsten copper powder mixture. In this step, because the strength of the blocky tungsten copper mixture is not high, the tungsten copper mixture is directly passed through a 60-100 mesh sieve, so that a tungsten copper powder mixture with a desired particle size and particle size can be obtained under the synergistic effect of crushing and screening.
[0036] In S3, different methods will be selected to achieve the actual working conditions. For example, if the parts to be manufactured have high requirements on dimensional accuracy and surface quality, metal MIM molding will be selected to make the blank raw material. If the parts to be manufactured have high requirements on shape but low requirements on dimensional accuracy and surface quality, binder jet metal 3D printing will be selected to achieve it.
[0037] In S4, the main purpose is to remove organic matter and other impurities in the blank. The organic matter mainly comes from the binder in S2. If you want to reduce the working cycle of S4, refer to Figure 3, then S4 includes the following steps: S41, putting the blank into an organic solvent and performing heating extraction; S42, drying the blank; S43, performing thermal degreasing on the blank. In this way, the organic solvent heating extraction can remove more than 50% of the organic matter, and the subsequent thermal degreasing time will not be too long, so the blank will not break.
[0038] In order to reduce the consumables used in the S4 process, S4 will choose to alternately perform thermal degreasing and cooling treatments on the blanks until the organic matter and other impurities in the blanks are removed. In this working process, there is no need to add organic solvents or drying treatments, so only the tunnel furnace can be used. Thermal degreasing is performed in the heating zone of the tunnel furnace, and cooling is performed in the cooling zone of the tunnel furnace, thereby saving consumable costs.
[0039] Since S5 and S6 have opposite processing processes, they will affect each other. Specifically, the amount of newly generated copper in S6 will affect the density of the final tungsten-copper alloy. Therefore, it is hoped that more copper elements will be oxidized in S5. However, too much copper element oxidation may make it impossible to reduce all copper oxide in S6, which is not conducive to improving the density of tungsten-copper alloy. Therefore, in S5, the portion of copper element oxidized in the blank is 10%-20%.
[0040] In S6, taking into account factors such as production cycle and production cost, the following settings are made accordingly. First, during the sintering process, the sintering temperature range includes an oxidation zone and a sintering zone. The temperature of the oxidation zone is lower than that of the sintering zone. At the same time, when the temperature is in the oxidation zone and the sintering zone, the temperature changes slowly. When the temperature is between the oxidation zone and the sintering zone, the temperature changes rapidly. In this way, the production cycle can be shortened while copper oxide is fully reduced and copper and tungsten are fully combined. Second, hydrogen is selected as the reducing agent. Compared with carbon monoxide, hydrogen can be continuously introduced into the sintering environment where the blank is located, and the operation method is relatively simple. Compared with carbon, copper oxide can be more fully reduced, thereby increasing the density of the tungsten-copper alloy.
[0041] The implementation principle of the method for preparing a high-density tungsten-copper alloy in the embodiment of the present application is as follows: the copper element is first oxidized and then reduced, so that the newly generated elemental copper has higher activity, which is conducive to sintering, thereby increasing the density of the tungsten-copper alloy and also reducing the sintering temperature.
[0042] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A method for preparing a high-density tungsten-copper alloy, characterized in that: The following steps are involved: S1, preparing a tungsten-copper powder mixture with a predetermined particle size and particle size; S2, kneading the tungsten copper powder mixture with a binder to prepare a blank making raw material; S3, making the blanking raw material into the required blank; S4. Remove organic matter and other impurities in the blank; S5, heating and oxidizing the blank; S6. Sintering the blank in an environment with a reducing agent.
2. The method for making a high-density tungsten-copper alloy according to claim 1, characterized in that: The S1 further comprises the following steps: S11, ball-milling tungsten powder, copper powder and alcohol to form a primary mixed slurry; S12, removing alcohol from the primary mixed slurry to form a bulk tungsten-copper mixture; S13, crushing the tungsten-copper mixture to form a tungsten-copper powder mixture.
3. The method for making a high-density tungsten-copper alloy according to claim 2, characterized in that: In the above S11, the initial particle size of the tungsten powder is less than 200 nm, and the initial particle size of the copper powder is less than 500 nm.
4. The method for making a high-density tungsten-copper alloy according to claim 2, characterized in that: In S13, the tungsten-copper mixture is passed through a 60-100 mesh sieve.
5. The method for preparing a high-density tungsten-copper alloy according to claim 1, characterized in that: If the parts to be manufactured have high requirements on dimensional accuracy and surface quality, then in S3, metal MIM molding is selected to achieve it. If the parts to be manufactured have high requirements on shape but low requirements on dimensional accuracy and surface quality, then in S3, binder jet metal 3D printing is selected to achieve it.
6. The method for making a high-density tungsten-copper alloy according to claim 1, characterized in that: The S4 further comprises the following steps: S41, immersing the blank into an organic solvent and performing heating extraction; S42, drying the blank; S43, performing thermal degreasing treatment on the blank.
7. The method for making a high-density tungsten-copper alloy according to claim 1, characterized in that: In S4, the blank is subjected to thermal degreasing treatment and cooling treatment alternately until organic matter and other impurities in the blank are removed.
8. The method for making a high-density tungsten-copper alloy according to claim 1, characterized in that: In S5, the portion of the copper element in the blank that is oxidized is 10%-20%.
9. The method for making a high-density tungsten-copper alloy according to claim 1, characterized in that: In the above S6, the sintering temperature range includes an oxidation zone and a sintering zone. When the temperature is in the oxidation zone and the sintering zone, the temperature changes slowly. When the temperature is between the oxidation zone and the sintering zone, the temperature changes quickly.
10. The method for making a high-density tungsten-copper alloy according to claim 8, characterized in that: In the step S6, the reducing agent is hydrogen.