A tungsten-molybdenum-copper composite material and a method for preparing the same

Abstract

This invention relates to a tungsten-molybdenum-copper composite material and its preparation method, belonging to the field of metal composite material technology. The preparation method of this invention employs a copper infiltration process. The activating element is soluble in W, Mo, and Cu, reducing the wetting angle between W and Cu, lowering the sintering kinetics of W particles, and reducing the sintering temperature. Simultaneously, it can form an intermediate phase during sintering, creating numerous highly diffusive interfaces or improving the wetting properties between phases, promoting the densification process. Furthermore, it facilitates the formation of a WMo solid solution between W and Mo, improving the strength and ablation resistance of the tungsten-molybdenum-copper composite material. In addition, molybdenum and tungsten belong to the same group, both having a body-centered cubic lattice and similar lattice parameters. Molybdenum can strengthen the tungsten matrix through solid solution, further improving the strength and ablation resistance of the composite material.

Description

Technical Field

[0001] This invention relates to a tungsten-molybdenum-copper composite material and its preparation method, belonging to the field of metal composite material technology. Background Technology

[0002] Tungsten-copper composites possess properties such as high-temperature resistance, ablation resistance, high strength, high hardness, and good electrical and thermal conductivity, and are commonly used in the manufacture of ablation-resistant components such as high-voltage contacts, gas turbine rotors, and throat liners. As the operating conditions of high-voltage electrical appliances, weaponry, and other equipment become increasingly demanding, higher requirements are being placed on the high-temperature resistance, ablation resistance, and strength of tungsten-copper composites. Currently, the main approaches to improving the performance of tungsten-copper composites include adopting new processes, refining tungsten particles, and strengthening the tungsten framework by adding a third phase or activating elements. However, these methods offer limited improvements in the performance of tungsten-copper composites and suffer from drawbacks such as complex operation and high cost.

[0003] Therefore, there is an urgent need to develop a method for preparing tungsten-molybdenum-copper composite materials that is simple to operate, low in cost, and can improve strength and ablation resistance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing tungsten-molybdenum-copper composite materials, which can solve the problem of poor strength and ablation resistance of currently prepared tungsten-molybdenum-copper composite materials.

[0005] Another objective of this invention is to provide a tungsten-molybdenum-copper composite material that can solve the problem of poor strength and ablation resistance of current tungsten-molybdenum-copper composite materials.

[0006] To achieve the above objectives, the technical solution adopted in the preparation method of the tungsten-molybdenum-copper composite material of the present invention is as follows:

[0007] A method for preparing a tungsten-molybdenum-copper composite material includes the following steps: pressing raw material powder into a blank, then stacking the blank and a copper infiltrated block together to form a composite, pre-sintering the composite, and finally performing infiltration sintering on the pre-sintered composite to allow copper to infiltrate into the pre-sintered blank, thereby obtaining the tungsten-molybdenum-copper composite material; the raw material powder includes tungsten, molybdenum, an activating element, and copper, wherein the mass ratio of tungsten, molybdenum, activating element, and copper is (60-85):(5-30):(0.2-1):(0.5-2), and the activating element is nickel and / or chromium.

[0008] The preparation method of the tungsten-molybdenum-copper composite material of the present invention employs a copper infiltration process. The activating element is soluble in W, Mo, and Cu, reducing the wetting angle between W and Cu, decreasing the sintering kinetics of W particles, and lowering the sintering temperature. Simultaneously, it can form an intermediate phase during sintering, creating numerous highly diffusive interfaces or improving the wetting properties between phases, thus promoting the densification process. Furthermore, it facilitates the formation of a WMo solid solution between W and Mo, improving the strength and ablation resistance of the tungsten-molybdenum-copper composite material. In addition, molybdenum and tungsten belong to the same group, both having a body-centered cubic lattice and similar lattice parameters. Molybdenum can strengthen the tungsten matrix through solid solution, further improving the strength and ablation resistance of the composite material. The copper element in the raw material powder promotes infiltration, improving the sintering performance, bonding properties, and electrical conductivity of the framework.

[0009] To reduce costs, preferably, the raw material powder includes tungsten powder, molybdenum powder, activating element powder, and copper powder, wherein the activating element powder is nickel powder and / or chromium powder.

[0010] Preferably, the raw material powder is prepared by mixing tungsten powder, molybdenum powder, activated element powder and copper powder, and the mixing is performed by ball milling for 4 to 30 hours.

[0011] Preferably, the tungsten powder is composed of fine-grained tungsten powder and medium-grained tungsten powder in a mass ratio of (1-3):(1-3); or the tungsten powder is composed of fine-grained tungsten powder, medium-grained tungsten powder and coarse-grained tungsten powder in a mass ratio of (1-3):(1-3):(1-3); the average particle size of the fine-grained tungsten powder is 1-6 μm, the average particle size of the medium-grained tungsten powder is 10-30 μm, and the average particle size of the coarse-grained tungsten powder is 70-100 μm. Excessively large particle size of the tungsten powder can lead to a decrease in the uniformity and strength of the material, because large-particle-size tungsten powder is unevenly distributed in the composite material, easily forming pores and cracks, thus reducing the overall performance of the material. Insufficiently small particle size of the tungsten powder can lead to difficulties in melting and infiltration, easily forming closed pores during the pre-sintering process, which is detrimental to melting and infiltration, resulting in a decrease in performance.

[0012] Preferably, the molybdenum powder has an average particle size of 0.005–10 μm. The activation element powder has an average particle size of 0.5–10 μm. If the molybdenum powder particle size is too large, it is difficult to diffuse with tungsten particles; conversely, if it is too small, it is prone to agglomeration, leading to a decrease in performance. If the activation element particle size is too large or too small, it is not conducive to uniform dispersion and affects the activation effect.

[0013] More preferably, the mass ratio of tungsten, molybdenum, activating element, and copper is (60-80):(5-25):(0.2-1):(0.5-2). Preferably, the thickness of the billet is no greater than 15 mm. For example, the thickness of the billet is 10-15 mm. The porosity of the billet can be controlled to be 15-18%.

[0014] Preferably, the pressing process uses a pressure of 200–300 MPa and a time of 0.5–3 min.

[0015] Preferably, the pre-sintering treatment is carried out in a vacuum environment or a hydrogen atmosphere, and the temperature of the pre-sintering treatment is 900-1200℃, and the time is 0.5-1.5h.

[0016] Preferably, the melting and infiltration sintering is carried out in a hydrogen atmosphere, and the melting and infiltration sintering temperature is 1300-1400℃ for 2-6 hours.

[0017] Preferably, in the tungsten-molybdenum-copper composite material, the mass ratio of tungsten, molybdenum, activating element, and copper is (60-85):(5-30):(0.2-1):(5-15). More preferably, the mass ratio of tungsten, molybdenum, activating element, and copper is (60-80):(5-25):(0.2-1):(5-15).

[0018] The technical solution adopted in the tungsten-molybdenum-copper composite material of the present invention is as follows:

[0019] A tungsten-molybdenum-copper composite material prepared by the method described above.

[0020] The tungsten-molybdenum-copper composite material of the present invention is prepared by the above method. Molybdenum can solid-solution strengthen the tungsten matrix, thus playing a solid-solution strengthening role, while the activating elements can improve the density of the material. The tungsten-molybdenum-copper composite material of the present invention exhibits high strength and ablation resistance. Attached Figure Description

[0021] Figure 1 The images are SEM images of the tungsten-molybdenum-copper composite materials prepared in Examples 1-4 of Experimental Example 1 of this invention. Figure 1 a is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 1. Figure 1 b is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 2. Figure 1 c is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 3. Figure 1 d is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 4;

[0022] Figure 2 The image shows the SEM image and corresponding elemental line scan results of the tungsten-molybdenum-copper composite material prepared in Example 3 of Experimental Example 1 of this invention. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0024] I. Specific embodiments of the preparation method of the tungsten-molybdenum-copper composite material of the present invention are as follows:

[0025] Example 1

[0026] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0027] (1) Tungsten powder, nickel powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1 and the ball milling time was 4 hours to obtain mixed powder. Among them, the tungsten powder consisted of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the nickel powder was 1 μm, the average particle size of the copper powder was 30 μm, and the mass ratio of tungsten powder, nickel powder and copper powder was 85:0.5:2.

[0028] (2) Press the mixed powder obtained in step (1) into a blank. The pressure used during pressing is 210 MPa and the holding time is 0.5 min. The blank is cylindrical with a diameter of 50 mm, a height of 11 mm, and a porosity of 15%.

[0029] (3) The billet is placed in a graphite boat, and then a pure copper block is placed on top of the billet. The billet and the pure copper block are stacked together to form a composite. The graphite boat is then placed in a heating box, and the composite in the heating box is pre-sintered. Finally, the pre-sintered composite is melt-infiltrated to allow copper to infiltrate into the pre-sintered billet, thus obtaining a tungsten-molybdenum-copper composite material. The pre-sintering treatment is carried out in a vacuum environment at a temperature of 900℃ for 1.5 hours. The melt-infiltration sintering is carried out in a hydrogen atmosphere at a temperature of 1350℃ for 4 hours.

[0030] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, nickel, and copper elements, with a mass ratio of 85:0.5:14.5.

[0031] Example 2

[0032] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0033] (1) Tungsten powder, molybdenum powder, nickel powder and copper powder were ball-milled and mixed. The ball-to-material ratio during ball milling was 5:1 and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder was composed of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the nickel powder was 1 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, nickel powder and copper powder was 80:5:0.5:2.

[0034] (2) Press the mixed powder obtained in step (1) into a blank. The pressure used during pressing is 210 MPa and the holding time is 0.5 min. The blank is cylindrical with a diameter of 50 mm, a height of 11 mm, and a porosity of 15%.

[0035] (3) The billet is placed in a graphite boat, and then a pure copper block is placed on top of the billet. The billet and the pure copper block are stacked together to form a composite. The graphite boat is then placed in a heating box, and the composite in the heating box is pre-sintered. Finally, the pre-sintered composite is melt-infiltrated to allow copper to infiltrate into the pre-sintered billet, thus obtaining a tungsten-molybdenum-copper composite material. The pre-sintering is carried out in a vacuum environment at a temperature of 900°C for 1.5 hours. The melt-infiltration is carried out in a hydrogen atmosphere at a temperature of 1350°C for 4 hours.

[0036] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel and copper elements, with a mass ratio of 80:5:0.5:14.5.

[0037] Example 3

[0038] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0039] (1) Tungsten powder, molybdenum powder, nickel powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1 and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder was composed of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the nickel powder was 1 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, nickel powder and copper powder was 70:15:0.5:2.

[0040] (2) Press the mixed powder obtained in step (1) into a blank. The pressure used during pressing is 210 MPa and the holding time is 0.5 min. The blank is cylindrical with a diameter of 50 mm, a height of 11 mm, and a porosity of 16%.

[0041] (3) The billet is placed in a graphite boat, and then a pure copper block is placed on top of the billet. The billet and the pure copper block are stacked together to form a composite. The graphite boat is then placed in a heating box, and the composite in the heating box is pre-sintered. Finally, the pre-sintered composite is melt-infiltrated to allow copper to infiltrate into the pre-sintered billet, thus obtaining a tungsten-molybdenum-copper composite material. The pre-sintering is carried out in a vacuum environment at a temperature of 900°C for 1.5 hours. The melt-infiltration is carried out in a hydrogen atmosphere at a temperature of 1350°C for 4 hours.

[0042] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel and copper elements, with a mass ratio of 70:15:0.5:14.5.

[0043] Example 4

[0044] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0045] (1) Tungsten powder, molybdenum powder, nickel powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1 and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder was composed of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the nickel powder was 1 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, nickel powder and copper powder was 60:25:0.5:2.

[0046] (2) Press the mixed powder obtained in step (1) into a blank. The pressure used during pressing is 210 MPa and the holding time is 0.5 min. The blank is cylindrical with a diameter of 50 mm, a height of 11 mm, and a porosity of 16%.

[0047] (3) The billet is placed in a graphite boat, and then a pure copper block is placed on top of the billet. The billet and the pure copper block are stacked together to form a composite. The graphite boat is then placed in a heating box, and the composite in the heating box is pre-sintered. Finally, the pre-sintered composite is melt-infiltrated to allow copper to infiltrate into the pre-sintered billet, thus obtaining a tungsten-molybdenum-copper composite material. The pre-sintering is carried out in a vacuum environment at a temperature of 900°C for 1.5 hours. The melt-infiltration is carried out in a hydrogen atmosphere at a temperature of 1350°C for 4 hours.

[0048] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel and copper elements, with a mass ratio of 60:25:0.5:14.5.

[0049] Example 5

[0050] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0051] (1) Tungsten powder, molybdenum powder and nickel powder are ball-milled and mixed. The ball-to-material ratio during ball milling is 5:1 and the ball milling time is 4 hours to obtain mixed powder. The tungsten powder is the same as the tungsten powder in step (1) of Example 4, the molybdenum powder is the same as the molybdenum powder in step (1) of Example 4, and the nickel powder is the same as the nickel powder in step (1) of Example 4. The mass ratio of tungsten powder, molybdenum powder and nickel powder is 60:25:0.5.

[0052] (2) This step is the same as step (2) in Example 4;

[0053] (3) This step is the same as step (3) in Example 4.

[0054] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel and copper elements, with a mass ratio of 60:25:0.5:14.5.

[0055] Example 6

[0056] The difference between the preparation method of the tungsten-molybdenum-copper composite material in this embodiment and the preparation method of the tungsten-molybdenum-copper composite material in Example 4 is that the pre-sintering treatment in step (3) of the preparation method of the tungsten-molybdenum-copper composite material in this embodiment is carried out in a hydrogen atmosphere.

[0057] Example 7

[0058] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0059] (1) Tungsten powder, molybdenum powder, chromium powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1 and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder consisted of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the chromium powder was 3 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, chromium powder and copper powder was 60:25:0.5:2.

[0060] (2) This step is the same as step (2) in Example 4;

[0061] (3) This step is the same as step (3) in Example 4.

[0062] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, chromium and copper elements, with a mass ratio of 60:25:0.5:14.5.

[0063] Example 8

[0064] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0065] (1) Tungsten powder, molybdenum powder, nickel powder, chromium powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1, and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder was composed of fine-grained tungsten powder and medium-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the mass ratio of fine-grained tungsten powder to medium-grained tungsten powder was 1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the nickel powder was 1 μm, the average particle size of the chromium powder was 3 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, nickel powder, chromium powder and copper powder was 60:25:0.25:0.25:2.

[0066] (2) This step is the same as step (2) in Example 4;

[0067] (3) This step is the same as step (3) in Example 4.

[0068] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel, chromium and copper, with a mass ratio of 60:25:0.25:0.25:14.5.

[0069] Example 9

[0070] The preparation method of the tungsten-molybdenum-copper composite material in this embodiment specifically includes the following steps:

[0071] (1) Tungsten powder, molybdenum powder, nickel powder and copper powder were ball-milled and mixed. The ball-to-powder ratio during ball milling was 5:1, and the ball milling time was 4 hours to obtain a mixed powder. Among them, the tungsten powder consisted of fine-grained tungsten powder, medium-grained tungsten powder and coarse-grained tungsten powder. The average particle size of the fine-grained tungsten powder was 6 μm, the average particle size of the medium-grained tungsten powder was 20 μm, and the average particle size of the coarse-grained tungsten powder was 70 μm. The mass ratio of fine-grained tungsten powder, medium-grained tungsten powder and coarse-grained tungsten powder was 1:1:1. The average particle size of the molybdenum powder was 2 μm, the average particle size of the nickel powder was 1 μm, and the average particle size of the copper powder was 30 μm. The mass ratio of tungsten powder, molybdenum powder, nickel powder and copper powder was 60:25:0.5:2.

[0072] (2) This step is the same as step (2) in Example 4;

[0073] (3) This step is the same as step (3) in Example 4.

[0074] The tungsten-molybdenum-copper composite material prepared in this embodiment is composed of tungsten, molybdenum, nickel and copper elements, with a mass ratio of 60:25:0.5:14.5.

[0075] Comparative Example 1

[0076] The only difference between the preparation method of the composite material in this comparative example and the preparation method of the tungsten-molybdenum-copper composite material in Example 4 is that the mass of nickel powder in step (1) of the preparation method of the composite material in this comparative example is 0, and the mass ratio of tungsten powder, molybdenum powder and copper powder is 60.3:25.2:2.

[0077] Comparative Example 2

[0078] The only difference between the preparation method of the composite material in this comparative example and the preparation method of the tungsten-molybdenum-copper composite material in Example 4 is that the mass of molybdenum powder in step (1) of the preparation method of the composite material in this comparative example is 0, and the mass ratio of tungsten powder, nickel powder and copper powder is 84.8:0.7:2.

[0079] Comparative Example 3

[0080] The only difference between the preparation method of the composite material in this comparative example and the preparation method of the tungsten-molybdenum-copper composite material in Example 4 is that the mass of tungsten powder in step (1) of the preparation method of the composite material in this comparative example is 0, and the mass ratio of molybdenum powder, nickel powder and copper powder is 83.8:1.7:2.

[0081] II. Specific embodiments of the tungsten-molybdenum-copper composite material of the present invention are as follows:

[0082] The tungsten-molybdenum-copper composite material of this embodiment was prepared by any of the preparation methods of the tungsten-molybdenum-copper composite materials in Examples 1-9.

[0083] Experimental Example 1

[0084] To examine the microstructure of the tungsten-molybdenum-copper composite materials prepared in each example and comparative example, SEM characterization and elemental line scanning analysis were performed on the tungsten-molybdenum-copper composite materials prepared in each example and comparative example. SEM images of the tungsten-molybdenum-copper composite materials prepared in Examples 1-4 are shown below. Figure 1 As shown (where, Figure 1 a is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 1. Figure 1 b is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 2. Figure 1 c is a SEM image of the tungsten-molybdenum-copper composite material prepared in Example 3. Figure 1 d is the SEM image of the tungsten-molybdenum-copper composite material prepared in Example 4. The SEM image and corresponding elemental line scan results of the tungsten-molybdenum-copper composite material prepared in Example 3 are shown below. Figure 2 As shown.

[0085] Depend on Figure 1-2 It can be seen that as the molybdenum content increases, the thickness of the tungsten-molybdenum solid solution formed around the tungsten particles in the tungsten-molybdenum-copper composite increases, the tungsten-molybdenum-copper particles exhibit an increasingly obvious core-shell structure, and the proportion of the tungsten-molybdenum solid solution gradually increases. From the mechanical properties of the composite material, it can be seen that the tensile strength of the composite material increases with the increase of molybdenum content.

[0086] Experiment Example 2

[0087] To evaluate the mechanical properties of the composite materials prepared in each embodiment and comparative example, the tensile strength of the composite materials prepared in each embodiment and comparative example was tested at room temperature and high temperature (test temperature 600℃). The test results are shown in Table 1.

[0088] Table 1. Tensile strength and density of the composite materials prepared in each example and comparative example at room temperature and high temperature.

[0089] Example 1 640 242 98.7 Example 2 657 299 98.7 Example 3 683 341 99.1 Example 4 698 380 99.5 Example 5 672 312 98.9 Example 6 670 310 98.9 Example 7 675 313 99 Example 8 730 390 99.5 Example 9 770 395 99.6 Comparative Example 1 635 240 98.6 Comparative Example 2 635 244 98.7 Comparative Example 3 605 233 98.5

[0090] To investigate the effects of particle size and mass ratio of fine, medium, and coarse tungsten powder, pre-sintering temperature and time, melt infiltration sintering temperature and time, and pressing pressure and time on the experimental results, tungsten-molybdenum-copper composite materials were prepared repeatedly according to the method in Example 9. The difference was that the average particle size of the fine tungsten powder was replaced from 6 μm to 1 μm or 3 μm, or the average particle size of the medium tungsten powder was replaced from 20 μm to 10 μm or... 30μm, or replace the average particle size of the coarse tungsten powder from 70μm to 90μm or 100μm, or replace the mass ratio of fine, medium and coarse tungsten powder from 1:1:1 to 3:1:1, 3:3:1 or 1:3:3, or adjust the pre-sintering temperature from 900℃ to 950℃ or 1200℃, or adjust the pre-sintering time from 1.5h to 0.5h or 1h, or change the melting infiltration sintering... The temperature was adjusted from 1350℃ to 1300℃ or 1400℃, or the melting and sintering time was adjusted from 4h to 2h or 6h, or the pressure during pressing was adjusted from 210MPa to 200MPa or 300MPa, or the pressing time was adjusted from 0.5min to 1min or 3min. Then, the strength and density of the tungsten-molybdenum-copper composite material prepared after adjusting the parameters were tested according to the above methods. The test results showed that the strength of the tungsten-molybdenum-copper composite material prepared after adjusting the parameters at room temperature was no more than 30% different from that of the tungsten-molybdenum-copper composite material prepared in Example 9 at room temperature. The strength of the tungsten-molybdenum-copper composite material prepared after adjusting the parameters at 600℃ was no more than 35% different from that of the tungsten-molybdenum-copper composite material prepared in Example 9 at 600℃. The density of the tungsten-molybdenum-copper composite material prepared after adjusting the parameters was no more than 1% different from that of the tungsten-molybdenum-copper composite material prepared in Example 9.

[0091] To investigate the effect of the average particle size of molybdenum powder or the average particle size of the activated element powder on the experimental results, the tungsten-molybdenum-copper composite material was prepared repeatedly according to the method of Example 9, except that the average particle size of molybdenum powder was replaced from 2 μm to 0.005 μm or 10 μm, or the average particle size of nickel powder was replaced from 1 μm to 0.5 μm or 10 μm. Then the strength and density of the prepared tungsten-molybdenum-copper composite material were tested according to the above method. The test results are shown in Table 2.

[0092] Table 2. Effects of the average particle size of molybdenum powder or the average particle size of the activated element powder on the experimental results.

[0093]

Claims

1. A method for producing a tungsten-molybdenum-copper composite material, characterized by, Includes the following steps: The raw material powder is pressed into shape to obtain a billet. Then, the billet and a copper infiltrated metal block are stacked together to form a composite. The composite is then pre-sintered. Finally, the pre-sintered composite is infiltrated and sintered to allow copper to infiltrate into the pre-sintered billet, thus obtaining a tungsten-molybdenum-copper composite material. The raw material powder includes tungsten, molybdenum, an activating element, and copper. The mass ratio of tungsten, molybdenum, activating element, and copper is (60~85):(5~30):(0.2~1):(0.5~2). The activating element is nickel and / or chromium. The tungsten element is composed of fine-grained tungsten powder, medium-grained tungsten powder and coarse-grained tungsten powder in a mass ratio of (1~3):(1~3):(1~3); the average particle size of the fine-grained tungsten powder is 1~6μm, the average particle size of the medium-grained tungsten powder is 10~30μm, and the average particle size of the coarse-grained tungsten powder is 70~100μm.

2. The preparation method of the tungsten-molybdenum-copper composite material as described in claim 1, characterized in that, The raw material powder includes tungsten powder, molybdenum powder, activated element powder, and copper powder, wherein the activated element powder is nickel powder and / or chromium powder.

3. The method for preparing the tungsten-molybdenum-copper composite material as described in claim 2, characterized in that, The porosity of the blank is 15-18%.

4. The preparation method of the tungsten-molybdenum-copper composite material as described in claim 2, characterized in that, The molybdenum powder has an average particle size of 0.005~10μm.

5. The method for preparing the tungsten-molybdenum-copper composite material as described in claim 2, characterized in that, The average particle size of the activated element powder is 0.5~10μm.

6. The method for preparing the tungsten-molybdenum-copper composite material according to any one of claims 1-5, characterized in that, The mass ratio of tungsten, molybdenum, activation element and copper is (60~80):(5~25):(0.2~1):(0.5~2).

7. The method for preparing the tungsten-molybdenum-copper composite material according to any one of claims 1-5, characterized in that, The pre-sintering process is carried out in a vacuum environment or a hydrogen atmosphere, with a temperature of 950~1200℃ and a time of 0.5~1.5h.

8. The method for preparing the tungsten-molybdenum-copper composite material according to any one of claims 1-5, characterized in that, The melting and infiltration sintering is carried out in a hydrogen atmosphere at a temperature of 1300-1400℃ for 2-6 hours.

9. The method for preparing the tungsten-molybdenum-copper composite material according to any one of claims 1-5, characterized in that, In the tungsten-molybdenum-copper composite material, the mass ratio of tungsten, molybdenum, activating element and copper is (60~85):(5~30):(0.2~1):(5~15).

10. A tungsten-molybdenum-copper composite material prepared by the method described in any one of claims 1-9.

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