A carbide-reinforced copper-tungsten alloy material and its preparation method and application

Abstract

The present invention discloses a method for preparing a carbide-reinforced copper-tungsten alloy material, comprising: pre-treating tungsten powder with a silane coupling agent to obtain a tungsten powder suspension with a positive surface charge; filtering and washing the tungsten powder to obtain a tungsten powder suspension with a positive surface charge; pre-treating carbide with an anionic surfactant to obtain a carbide suspension with a negative surface charge; dispersing the tungsten powder with a positive surface charge in deionized water to obtain a tungsten powder suspension; slowly adding the carbide suspension with a negative surface charge to the tungsten powder suspension, and after the reaction is complete, obtaining a composite powder with carbides uniformly distributed on the surface of the tungsten powder; coating the composite powder with pure copper skin, and continuously reducing and drawing the composite powder using a flux-cored wire manufacturing process to obtain a carbide-reinforced copper-tungsten alloy wire; and performing arc additive manufacturing on the wire using arc additive manufacturing equipment to obtain a carbide-reinforced copper-tungsten alloy material. The carbide increases the interfacial bonding strength of the copper-tungsten alloy, improving its hardness, wear resistance, and high-temperature wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of tungsten-based composite materials, and in particular relates to a carbide-reinforced copper-tungsten alloy material and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Copper-tungsten alloys combine the excellent properties of copper (high electrical conductivity, high thermal conductivity, and good ductility) with the wear resistance and high hardness of tungsten. By adjusting the tungsten and copper content, the desired performance can be achieved, perfectly combining the excellent properties of copper and tungsten. However, the physical properties of copper and tungsten differ significantly, and they do not dissolve or react chemically with each other, posing a significant challenge to the preparation of tungsten-copper alloys. Traditionally, powder metallurgy techniques, including infiltration, liquid phase sintering (LPS), and hot pressing sintering (HPS), are commonly used to prepare copper-tungsten alloys.

[0004] Conventional preparation methods are currently limited by the high-temperature, high-pressure equipment required, resulting in a lack of flexibility in sample shape and size. Furthermore, because copper and tungsten do not dissolve in each other, the interfacial bonding strength is low. This is particularly true for copper-rich copper-tungsten alloys with low tungsten content. This low interfacial bonding strength results in poor wear resistance, making tungsten particles prone to flaking during wear. Summary of the Invention

[0005] To overcome the above-mentioned problems, the present invention provides a carbide-reinforced copper-tungsten alloy material, its preparation method, and its application. The present invention utilizes arc additive manufacturing (WAAM) technology to prepare the copper-tungsten alloy. Compared to traditional copper-tungsten alloy preparation methods, this method not only requires lower equipment costs and has higher manufacturing efficiency, but also allows the production of samples that are not restricted by the size and shape of hot pressing dies, greatly improving manufacturing flexibility. Furthermore, the use of carbides to modify the copper-tungsten alloy not only increases interfacial bonding strength, but also significantly improves the copper-tungsten alloy's hardness, wear resistance, and high-temperature wear resistance without significantly reducing its electrical conductivity.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a method for preparing a carbide-reinforced copper-tungsten alloy material, the method comprising:

[0008] S1. Pretreating tungsten powder with a silane coupling agent in a mixed solution of water and ethanol to prepare a tungsten powder suspension with a positive charge on the surface; filtering and washing to obtain tungsten powder with a positive charge on the surface;

[0009] S2. Pretreating the carbide with an anionic surfactant in deionized water to prepare a carbide suspension with a negative charge on the surface;

[0010] S3. The tungsten powder with a positive surface charge prepared in S1 is dispersed in deionized water to prepare a tungsten powder suspension. The carbide suspension with a negative surface charge prepared in S2 is slowly added to the tungsten powder suspension while continuously stirring. After the reaction is completed, the mixture is filtered, washed, and dried to obtain a composite powder with carbides evenly distributed on the surface of the tungsten powder.

[0011] S4, coating the composite powder prepared in S3 with pure copper, and continuously reducing and drawing the composite powder using a flux-cored wire manufacturing process to produce a carbide-reinforced copper-tungsten alloy wire;

[0012] S5. Using arc additive manufacturing equipment, the carbide-reinforced copper-tungsten alloy wire prepared in S4 is subjected to arc additive manufacturing to obtain a carbide-reinforced copper-tungsten alloy material.

[0013] A second aspect of the present invention provides a carbide-reinforced copper-tungsten alloy material prepared by the above preparation method.

[0014] A third aspect of the present invention provides the use of the carbide-reinforced copper-tungsten alloy material in electrical contacts.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention adds a certain amount of carbide during the preparation process of the copper-tungsten alloy, and pre-distributes these carbides evenly around the tungsten powder. During the arc additive manufacturing process, the low-melting-point copper melts to form a molten pool. Due to the high melting point characteristics of tungsten and carbides, most of them directly transition into the molten pool in the form of solid particles and solidify to form the copper-tungsten alloy. The carbides pre-coated around the tungsten powder are mostly retained and located at the copper-tungsten interface. Since the carbides have a certain solid solubility with copper and tungsten respectively, their interfacial bonding strength is increased. At the same time, the addition of a small amount of carbide can significantly improve the hardness, wear resistance, and high-temperature wear resistance of the copper-tungsten alloy without significantly reducing the conductivity.

[0017] (2) Arc additive manufacturing can produce samples that are not restricted by the size and shape of hot pressing molds, greatly improving manufacturing flexibility.

[0018] (3) By wrapping the alloy powder with copper foil, the ratio of copper, tungsten and other added elements can be adjusted within a certain range, providing a certain degree of flexibility in material selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 This is an SEM image of the carbide-reinforced copper-tungsten alloy material prepared in an embodiment of the present invention;

[0021] Figure 2 The electrical conductivity images of the carbide-reinforced copper-tungsten alloy material with different carbide (TiC) addition amounts in Example 1 of the present invention are shown;

[0022] Figure 3 The average hardness image of the carbide-reinforced copper-tungsten alloy material with different carbide (TiC) addition amounts in Example 1 of the present invention;

[0023] Figure 4 This is a graph showing the average friction coefficient of carbide-reinforced copper-tungsten alloy materials at 25°C and 400°C with different carbide (TiC) addition amounts in Example 1 of the present invention;

[0024] Figure 5 Surface roughness diagram of carbide-reinforced copper-tungsten alloy materials with different carbide (TiC) addition amounts after wear at 25°C and 400°C for one hour in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] A first typical embodiment of the present invention provides a method for preparing a carbide-reinforced copper-tungsten alloy material, the method comprising:

[0028] S1. Pretreating tungsten powder with a silane coupling agent in a mixed solution of water and ethanol to prepare a tungsten powder suspension with a positive charge on the surface; filtering and washing to obtain tungsten powder with a positive charge on the surface;

[0029] S2. Pretreating the carbide with an anionic surfactant in deionized water to prepare a carbide suspension with a negative charge on the surface;

[0030] S3. The tungsten powder with a positive surface charge prepared in S1 is dispersed in deionized water to prepare a tungsten powder suspension. The carbide suspension with a negative surface charge prepared in S2 is slowly added to the tungsten powder suspension while continuously stirring. After the reaction is completed, the mixture is filtered, washed, and dried to obtain a composite powder with carbides evenly distributed on the surface of the tungsten powder.

[0031] S4, coating the composite powder prepared in S3 with pure copper, and continuously reducing and drawing the composite powder using a flux-cored wire manufacturing process to produce a carbide-reinforced copper-tungsten alloy wire;

[0032] S5. Using arc additive manufacturing equipment, the carbide-reinforced copper-tungsten alloy wire prepared in S4 is subjected to arc additive manufacturing to obtain a carbide-reinforced copper-tungsten alloy material.

[0033] In one or more embodiments, the pretreatment process in step S1 is as follows: dispersing tungsten powder in a mixed solution of water and ethanol, stirring the mixture thoroughly, adding a silane coupling agent, and continuously stirring the mixture. After sufficient reaction, a tungsten powder suspension with a positive charge on the surface is obtained.

[0034] Preferably, the tungsten powder is dispersed in a mixed solution of water and ethanol, and the stirring time is 8 to 12 minutes, more preferably 10 minutes.

[0035] Preferably, after adding the silane coupling agent, the mixed solution is heated to 55-55° C., preferably 50° C.; the time for full reaction is 4-5 hours, preferably 5 hours.

[0036] In one or more embodiments, in step S1, the volume ratio of water to ethanol in the mixed solution of water and ethanol is 0.8 to 1.2:1, preferably 1:1.

[0037] In one or more embodiments, in step S1, the particle size of the tungsten powder is 80-200 mesh.

[0038] In one or more embodiments, in step S1, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0039] In one or more embodiments, in step S1, the volume ratio of the silane coupling agent to the mixed solution of water and ethanol is 0.9-1.1:100, preferably 1:100.

[0040] In one or more embodiments, in step S1, the volume ratio of the mass of the tungsten powder to the mixed solution of water and ethanol is 0.9-1.1 g:100 ml, preferably 1 g:100 ml.

[0041] In one or more embodiments, in step S1, the washing method is: washing with ethanol and deionized water. The purpose of washing is to remove unreacted silane coupling agent.

[0042] In one or more embodiments, the pretreatment process in step S2 is: adding anionic surfactant to deionized water, stirring evenly and then adding carbide, and then ultrasonically dispersing at room temperature to obtain a carbide suspension with a negative charge on the surface; preferably, the power of ultrasonic dispersion is 450 to 550 W, preferably 500 W; the time of ultrasonic dispersion is 25 to 35 minutes, more preferably 30 minutes.

[0043] In one or more embodiments, in step S2, the anionic surfactant includes but is not limited to: sodium stearate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate; preferably sodium lauryl sulfate.

[0044] In one or more embodiments, in step S2, the mass fraction of the anionic surfactant in the aqueous solution is 1.5-2.5%, preferably 2%.

[0045] In one or more embodiments, in step S2, the carbide is one or more of TiC, NbC and VC having a cubic structure.

[0046] In one or more embodiments, in step S2, the ratio of the mass of the carbide to the volume of deionized water is 0.9-1.1 g:1000 ml, preferably 1 g:1000 ml.

[0047] In one or more embodiments, the mass ratio of the carbide in step S2 to the tungsten powder in step S1 is (1-10):100, preferably 3:100.

[0048] In one or more embodiments, in step S3, the tungsten powder with positive surface charge prepared in S1 is dispersed in deionized water by ultrasonic dispersion. Preferably, the power of ultrasonic dispersion is 450 to 550 W, preferably 500 W; and the time is 25 to 35 min, preferably 30 min.

[0049] In one or more embodiments, in step S3, the stirring time is 0.5 to 1.5 hours, preferably 1 hour.

[0050] In one or more embodiments, in step S3, the cleaning method is: cleaning with ethanol.

[0051] In one or more embodiments, in step S3, the drying method is vacuum filtration followed by drying in a freeze dryer.

[0052] In one or more embodiments, in step S4, the thickness of the pure copper sheet is 0.2-0.4 mm, preferably 0.3 mm.

[0053] In one or more embodiments, in step S4, the diameter of the carbide-reinforced copper-tungsten alloy wire is 1.0 mm to 1.5 mm, preferably 1.2 mm.

[0054] In one or more embodiments, in step S5, the arc additive manufacturing equipment includes but is not limited to CMT arc additive manufacturing equipment and plasma arc additive manufacturing equipment.

[0055] Preferably, when the carbide is TiC, a CMT arc additive manufacturing device is used, with a peak current of 200 A, a shielding gas of 99.99% purity Ar gas, a shielding gas flow rate of 15 L / min, and a dry extension length of 15 mm.

[0056] Preferably, when the carbide is NbC, the plasma arc additive manufacturing technology is used to manufacture the equipment; the shielding gas is Ar gas with a purity of 99.99%, the shielding gas flow rate is 15 L / min, and the wire feeding speed is 2.8 m.min -1 , voltage 23V, first layer current 220A, subsequent layer current 210A, overlap rate 47%.

[0057] A second typical embodiment of the present invention provides a carbide-reinforced copper-tungsten alloy material prepared by the above preparation method.

[0058] A third typical embodiment of the present invention provides application of the carbide-reinforced copper-tungsten alloy material in an electrical contact.

[0059] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0060] Example 1

[0061] S1. Disperse 10g of 80-200 mesh tungsten powder in 1000mL of a mixed solution of deionized water and ethanol (volume ratio of 1:1). Stir the mixed solution thoroughly for 10 minutes, then add 10mL of 3-aminopropyltriethoxysilane. Heat the mixture to 50°C and stir thoroughly. After stirring for 5 hours, a tungsten powder suspension with a positive surface charge is obtained. The suspension is filtered and washed thoroughly with ethanol and deionized water to remove unreacted 3-aminopropyltriethoxysilane, thereby obtaining a tungsten powder with a positive surface charge.

[0062] S2. Add 20 g of sodium dodecyl sulfate to 1000 mL of deionized water to prepare a 2% sodium dodecyl sulfate solution, add 1 g of TiC powder to the sodium dodecyl sulfate solution, and ultrasonically disperse for 30 minutes at room temperature to obtain a carbide suspension with a negative charge on the surface.

[0063] S3. Disperse the positively charged tungsten powder prepared in S1 in 1000 mL of deionized water. Add the negatively charged carbide suspension prepared in step S2 according to the mass ratio of carbide to tungsten powder (1% to 10%). For example, if the mass of carbide and tungsten powder is 1 g, add 100 mL of the negatively charged carbide suspension prepared in step S2, and so on. Stir continuously during the addition process. After stirring at room temperature for 1 hour, filter, wash with anhydrous ethanol, and dry to obtain a composite powder with carbides evenly distributed on the tungsten powder surface.

[0064] S4: The composite powder prepared in S3 is coated with pure copper and continuously reduced in diameter by using the currently mature flux-cored welding wire manufacturing process to produce a carbide-reinforced copper-tungsten alloy wire with a diameter of 1.2 mm.

[0065] S5. Copper-tungsten alloy was manufactured using CMT additive manufacturing technology. An Austrian Fronius TPS 5000CMT welding machine was used in conjunction with a KUKA robot to perform arc additive manufacturing on the above-mentioned wire. The peak current was 200A, the shielding gas was 99.99% pure Ar gas, the gas flow rate was 15L / min, and the dry extension length was 15mm.

[0066] The copper-tungsten alloy prepared in this example was characterized. Figure 1 When the mass ratio of carbide to tungsten is 3%, the SEM electron microscope picture shows Figure 1 It can be seen that TiC is well distributed around the W particles.

[0067] Figure 2 The electrical conductivity images of carbide-reinforced copper-tungsten alloy materials prepared with different carbide addition amounts are shown in Figure 2. Figure 2It can be seen that with the increase of TiC, the electrical conductivity of copper-tungsten alloy material decreases slightly.

[0068] Figure 3 The average microhardness images of carbide-reinforced copper-tungsten alloy materials prepared with different carbide addition amounts are shown in Figure 2. Figure 3 It can be seen that when the ratio of TiC to tungsten is 3%, the average microhardness of the copper-tungsten alloy material is the largest.

[0069] Figure 4 and Figure 5 The average friction coefficient and surface roughness of carbide-reinforced copper-tungsten alloy materials at 25°C and 400°C are obtained with different carbide addition amounts. Figure 4 and Figure 5 It can be seen that the addition of TiC can improve the wear resistance of copper-tungsten alloy materials at room temperature and high temperature conditions.

[0070] Example 2 (Added carbide is replaced by NbC)

[0071] S1. Disperse 10g of 80-200 mesh tungsten powder in 1000mL of a mixed solution of deionized water and ethanol (volume ratio of 1:1). Stir the mixed solution thoroughly for 10 minutes, then add 10mL of 3-aminopropyltriethoxysilane. Heat the mixture to 50°C and stir thoroughly. After stirring for 5 hours, a tungsten powder suspension with a positive surface charge is obtained. The suspension is filtered and washed thoroughly with ethanol and deionized water to remove unreacted 3-aminopropyltriethoxysilane, thereby obtaining a tungsten powder with a positive surface charge.

[0072] S2. Add 20 g of sodium dodecyl sulfate to 1000 mL of deionized water to prepare a 2% sodium dodecyl sulfate solution, add 1 g of NbC to the sodium dodecyl sulfate solution, and ultrasonically disperse for 30 minutes at room temperature to obtain a carbide suspension with a negative charge on the surface.

[0073] S3. Disperse the positively charged tungsten powder prepared in S1 in 1000 mL of deionized water. Add the negatively charged carbide suspension prepared in step S2 according to the mass ratio of carbide to tungsten powder (1% to 10%). For example, if the mass ratio of carbide to tungsten powder is 1%:1, add 100 mL of the negatively charged carbide suspension prepared in step S2, and so on. Stir continuously during the addition process. After stirring at room temperature for 1 hour, filter, wash with anhydrous ethanol, and dry to obtain a composite powder with carbides uniformly distributed on the tungsten powder surface.

[0074] S4. The composite powder prepared in S3 is coated with pure copper and continuously reduced in diameter by a flux-cored wire manufacturing process to produce a carbide-reinforced copper-tungsten alloy wire with a diameter of 1.2 mm.

[0075] S5, using plasma arc additive manufacturing technology to manufacture copper tungsten alloy equipment, with a wire feeding speed of 2.8m.min -1 , voltage 23V, first layer current 220A, subsequent layer current 200A, overlap rate 40%.

[0076] The performance of the carbide-reinforced copper-tungsten alloy sample prepared in this example is similar to that of the carbide-reinforced copper-tungsten alloy prepared in Example 1, but the average microhardness is slightly reduced.

[0077] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a carbide-reinforced copper-tungsten alloy material, characterized in that: The method comprises: S1. Pretreating tungsten powder with a silane coupling agent in a mixed solution of water and ethanol to prepare a tungsten powder suspension with a positive charge on the surface; filtering and washing to obtain tungsten powder with a positive charge on the surface; S2. Pretreating the carbide with an anionic surfactant in deionized water to prepare a carbide suspension with a negative charge on the surface; S3. The tungsten powder with a positive surface charge prepared in S1 is dispersed in deionized water to prepare a tungsten powder suspension. The carbide suspension with a negative surface charge prepared in S2 is slowly added to the tungsten powder suspension while continuously stirring. After the reaction is completed, the mixture is filtered, washed, and dried to obtain a composite powder with carbides evenly distributed on the surface of the tungsten powder. S4, coating the composite powder prepared in S3 with pure copper, and continuously reducing and drawing the composite powder using a process for manufacturing flux-cored welding wire to produce a carbide-reinforced copper-tungsten alloy wire; S5. Using an arc additive manufacturing device to perform arc additive manufacturing on the carbide-reinforced copper-tungsten alloy wire prepared in S4 to obtain a carbide-reinforced copper-tungsten alloy material; In step S1, the pretreatment process is as follows: tungsten powder is dispersed in a mixed solution of water and ethanol, and after being fully stirred, a silane coupling agent is added and continuously stirred. After sufficient reaction, a tungsten powder suspension with a positive charge on the surface is obtained; The tungsten powder is dispersed in a mixed solution of water and ethanol and stirred for 8 to 12 minutes. The volume ratio of water to ethanol in the mixed solution of water and ethanol is (0.8 to 1.2):

1. After adding the silane coupling agent, the mixed solution is heated to 55-65°C, and the reaction time is 4-6 hours; the silane coupling agent is 3-aminopropyltriethoxysilane; The particle size of the tungsten powder is 80-200 mesh; The volume ratio of the silane coupling agent to the mixed solution of water and ethanol is 0.9-1.1:100; The mass of tungsten powder and the volume ratio of the mixed solution of water and ethanol is (0.9~1.1) g:100 ml; In step S2, the pretreatment process is as follows: adding anionic surfactant to deionized water, stirring evenly, adding carbide, and then ultrasonically dispersing at room temperature to obtain a carbide suspension with a negative charge on the surface; The power of ultrasonic dispersion is 450~550W; the time of ultrasonic dispersion is 25~35min; The anionic surfactant is: sodium stearate or sodium dodecylbenzenesulfonate, sodium lauryl sulfate; The mass fraction of the anionic surfactant in the aqueous solution is 1.5-2.5%; The carbide is one or more of TiC, NbC and VC having a cubic structure; the mass of the carbide to the volume of deionized water is (0.9-1.1) g:1000 ml; In step S2, the mass ratio of carbide to tungsten powder in step S1 is (1-10):100; In step S4, the thickness of the pure copper sheet is 0.2-0.4 mm; The diameter of the carbide-reinforced copper-tungsten alloy wire is 1.0 mm to 1.6 mm.

2. The preparation method according to claim 1, wherein In step S1, the washing method is: washing with ethanol and deionized water; the purpose of washing is to remove unreacted silane coupling agent.

3. The preparation method according to claim 1, wherein In step S3, the tungsten powder with positive surface charge prepared in step S1 is dispersed in deionized water by ultrasonic dispersion.

4. The preparation method according to claim 3, wherein The power of ultrasonic dispersion is 450~550W; the time is 25~35min.

5. The preparation method according to claim 1, wherein In step S3, it is characterized in that the stirring time is 0.5~1.5h.

6. The preparation method according to claim 1, wherein In step S3, the cleaning method is: cleaning with ethanol.

7. The preparation method according to claim 1, wherein In step S3, the drying method is to place the product in a freeze dryer for drying after vacuum filtration.

8. The preparation method according to claim 1, wherein In step S5, the arc additive manufacturing equipment includes CMT arc additive manufacturing equipment and plasma arc additive manufacturing equipment.

9. The preparation method according to claim 7, wherein When the carbide is TiC, CMT arc additive manufacturing equipment is used with a peak current of 200 A, a shielding gas of 99.99% purity Ar gas, a shielding gas flow rate of 15 L / min, and a dry extension length of 15 mm.

10. The preparation method according to claim 7, wherein When the carbide is NbC, plasma arc additive manufacturing technology can be used to manufacture the equipment; the shielding gas is Ar gas with a purity of 99.99%, the shielding gas flow rate is 15 L / min, the wire feeding speed is 2.8 m.min-1, the voltage is 23 V, the first layer current is 220 A, the subsequent layer current is 210 A, and the overlap rate is 47%.

11. A carbide-reinforced copper-tungsten alloy material prepared by the preparation method according to any one of claims 1 to 10.

12. Use of the carbide-reinforced copper-tungsten alloy material according to claim 11 in electrical contacts.

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