Tungsten-copper composite material and preparation method and application thereof

Abstract

The invention belongs to the field of conductive materials, and particularly relates to a tungsten-copper composite material and a preparation method and application thereof. The invention provides a tungsten-copper composite material which comprises a copper plate, a copper layer and a tungsten-copper layer, the copper plate is coated with the copper layer, and the copper layer is coated with the tungsten-copper layer; the copper plate is provided with a plurality of penetrating structures, the penetrating structures penetrate through the copper plate in the thickness direction of the copper plate, and the penetrating structures comprise tungsten and copper. The tungsten-copper composite material provided by the invention has excellent electric conductivity and corrosion resistance.

Description

Technical Field

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

[0002] Anodized clips need to have good electrical conductivity and corrosion resistance. The existing tungsten copper materials commonly used for anodized clips are mainly prepared by the melt infiltration method, which is to first press and sinter tungsten powder to form a tungsten skeleton, and then use capillary force to infiltrate copper powder or copper sheet into the tungsten skeleton at a temperature higher than the melting point of copper to obtain tungsten copper materials. The existing method of preparing tungsten copper materials not only has high energy consumption, but also has poor electrical conductivity. If the copper content is increased to improve the conductivity, the tungsten copper material obtained does not have the advantage of high corrosion resistance, and cannot take into account both corrosion resistance and electrical conductivity. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the tungsten-copper material in the prior art that it cannot simultaneously have excellent corrosion resistance and electrical conductivity, thereby providing a tungsten-copper composite material and a preparation method and application thereof.

[0004] The tungsten-copper composite material of the present invention has good thermal conductivity and electrical conductivity, and overcomes the defect that the prior art can only improve thermal conductivity but cannot improve electrical conductivity by increasing density.

[0005] To this end, the present invention provides the following technical solutions.

[0006] The present invention provides a tungsten-copper composite material, which comprises a copper plate, a copper layer and a tungsten-copper layer, wherein the copper layer covers the copper plate, and the tungsten-copper layer covers the copper layer; the copper plate has a plurality of penetrating structures, and the plurality of penetrating structures penetrate the copper plate along the thickness direction of the copper plate, and the penetrating structure components include tungsten and copper. In an optional embodiment, the through-structure component further comprises an additive; In an optional embodiment, the additive includes at least one of aluminum oxide, yttrium oxide, zirconium oxide and lanthanum oxide; In an optional embodiment, the tungsten-copper layer includes tungsten and copper; In an optional embodiment, the copper layer comprises copper; In an optional embodiment, a plurality of the through structures are regularly arranged on the surface of the copper plate; and / or, In an optional embodiment, the thickness of the copper plate is ≥0.2 mm; In an optional embodiment, a plurality of microgroove structures are symmetrically arranged at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structures are symmetrical structures; In an optional embodiment, the circumferential arc length of a single microgroove structure along the outer edge of the copper plate is less than the maximum length of a single microgroove structure, and the maximum length refers to the maximum distance between two edge points of the microgroove structure and passing through the center point; In an optional embodiment, the microgroove structure is arc-shaped or rectangular; the shape of the arc-shaped structure is as shown in FIG. Figure 4 ; In an optional embodiment, the microgroove structure is provided with a first region, the first region is trapezoidal, and the opening of the first region gradually increases from the outside to the inside; Preferably, the microgroove structure is provided with a second region and a first region from the outside to the inside along the copper plate, the second region is rectangular, and the structure is as shown in FIG. Figure 2 .

[0007] The present invention also provides a method for preparing a tungsten-copper composite material, comprising the following steps: (1) Preparation of tungsten-copper mixed powder; (2) The copper plate is provided with a plurality of through holes; copper powder and tungsten-copper mixed powder are sequentially placed on two surfaces of the copper plate, first pressed, first sintered, second pressed, and second sintered to obtain a tungsten-copper composite material; the through holes form a penetrating structure in the tungsten-copper composite material.

[0008] In an optional embodiment, the particle size of the copper powder is 1-63 μm; In an optional embodiment, the copper powder includes electrolytic copper powder; In an optional embodiment, the through hole has a diameter of 0.2-0.6 mm; In an optional embodiment, the shortest distance between two adjacent edge points of the through hole is greater than twice the aperture of the through hole; In an optional embodiment, the ratio of the total area of ​​the projections of the plurality of through holes onto the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:(100-1000); The arrangement of the through holes of the present invention is set by conventional methods in the art, which are as follows: In an optional embodiment, the through holes are arranged on the copper plate along a first central axis and a second central axis that are perpendicular to each other; Figure 2 , the arrangement is a "cross" distribution; In an alternative embodiment, the through holes are arranged on the copper plate in a first direction and a second direction that are perpendicular to each other; the first direction is parallel to the first central axis of the copper plate, and the through holes are symmetrically distributed on both sides of the first central axis; the second direction is parallel to the second central axis of the copper plate, and the through holes are symmetrically distributed on both sides of the second central axis; the first central axis and the second central axis are the symmetry axes of the copper plate and are perpendicular to each other, and this arrangement is a "grid" distribution; The shape of the through hole is a conventional shape in the art such as a circle or a pentagram. Preferably, the shape of the through hole is a circle, which is easy to prepare and convenient for industrialization; here, the symmetry axis is the center line passing through the center of the through hole; refer to Figure 3 ; In an alternative embodiment, the through holes are distributed along the radial lines of the copper plate, and the included angle between two adjacent radial lines is 40°-90°; Preferably, the through holes are distributed along the radial lines of the copper plate, and the included angle between two adjacent radial lines is 45°-72°; Exemplarily, the included angles are 45°, 60°, 72°, etc.; When the included angle is 45°, it is recorded as a "star" distribution, refer to Figure 4 ; when the included angle is 72°, it is recorded as a "big" character distribution, refer to Figure 5 ; In an alternative embodiment, the mass ratio of the copper plate, the copper powder, and the tungsten-copper mixed powder is (100-150):(1-2):(60-80); here, the masses of the copper powder and the tungsten-copper mixed powder refer to the total amounts added to the two surfaces of the copper plate; Preferably, the masses of the tungsten-copper mixed powder placed on the two surfaces of the copper plate are equal or unequal; the purpose is to make the thickness of the tungsten-copper layer more uniform on the upper and lower surfaces of the copper plate, further improving the performance of the tungsten-copper composite material.

[0009] In an alternative embodiment, step (1) includes: ball-milling and mixing tungsten powder and copper powder; In an alternative embodiment, in step (1), the particle size of the tungsten powder is 1-45 μm; In an alternative embodiment, in step (1), the particle size of the copper powder is 1-63 μm; In an alternative embodiment, in step (1), the copper powder includes electrolytic copper powder; In an alternative embodiment, in step (1), the mass ratio of the tungsten powder and the copper powder is (57.3-62):(38-42); In an alternative embodiment, in step (1), the ball-milling and mixing further includes adding an additive; In an optional embodiment, in step (1), the additive includes at least one of aluminum oxide, yttrium oxide, zirconium oxide and lanthanum oxide; In an optional embodiment, in step (1), the mass ratio of the tungsten powder, the copper powder and the additive is (57.3-62):(38-42):(0.1-0.7); In an optional embodiment, in step (1), the ball milling mixing time is 12-24 hours; In an optional embodiment, in step (1), the rotation speed of the ball milling mixing is 200-500 r / min; Preferably, in step (1), the ball-to-material ratio of the ball-milling mixture is (3-8):1; Preferably, in step (1), the ball milling mixing procedure is ball milling for 25 minutes, stopping for 5 minutes, and repeating the procedure until the ball milling time is 12-24 hours; In an optional embodiment, the ball milling mixing in step (1) further comprises adding ethanol; Preferably, the ethanol is anhydrous ethanol; The purpose of adding ethanol is to reduce oxidation and overheating during mixing; In an optional embodiment, the ratio of the mass of the tungsten powder, the copper powder and the mass of the ethanol is 5:(1-2); In an optional embodiment, the step (1), after the ball milling mixing, further comprises drying; In an optional embodiment, the drying temperature is 70-80°C and the drying time is 12-24 hours.

[0010] In an optional embodiment, the copper plate is activated.

[0011] In an optional embodiment, the activated solution includes a sulfuric acid solution; In an optional embodiment, the mass concentration of the sulfuric acid solution is 10-20%; In an optional embodiment, the activation time is 20-40 minutes.

[0012] In an optional embodiment, the activation further comprises washing with at least one of deionized water and ethanol; the purpose of washing is activation and facilitating drying; Preferably, the activation further comprises washing with deionized water and ethanol; In an optional embodiment, the first pressing pressure is 500-700 MPa; In an optional embodiment, the first pressing time is 1-5 min; In an optional embodiment, the first pressing comprises hot pressing, cold pressing or hot isostatic pressing; Preferably, the first pressing is cold pressing. Cold pressing can be used in actual production to quickly press with a compression testing machine, which has low equipment requirements, fast sample preparation, low cost, and is easy for industrial production. In an optional embodiment, the second pressing comprises hot pressing, cold pressing or hot isostatic pressing; Preferably, the second pressing is cold pressing; In an optional embodiment, the second pressing pressure is 60-150 MPa; In an optional embodiment, the second pressing time is 2-5 minutes.

[0013] In an optional embodiment, the temperature is raised from room temperature to 300-500°C at a rate not higher than 5°C / min, kept at that temperature for 1 hour, then raised to 800°C at a rate not higher than 5°C / min, and then raised to the first sintering temperature at a rate not higher than 3°C / min for the first sintering; if the first sintering temperature is 800°C, the first sintering heat preservation procedure can be directly carried out after the temperature is raised to 800°C; Heating to 300-500℃ and keeping it for 1 hour can effectively remove copper oxide and organic pollutants and avoid the generation of excess impurities; In an optional embodiment, the first sintering time is 1-3h; In an optional embodiment, the first sintering temperature is 800-950°C; In an optional embodiment, the first sintering is performed under a reducing atmosphere; Preferably, the reducing atmosphere comprises at least one of hydrogen, carbon monoxide, and ammonia decomposition gas; In an optional embodiment, the second sintering is performed at a temperature not higher than 3°C / min. In an optional embodiment, the second sintering time is 1-3h; In an optional embodiment, the second sintering temperature is 1000-1050°C; In an optional embodiment, the second sintering is performed under a reducing atmosphere; Preferably, the reducing atmosphere comprises at least one of hydrogen, carbon monoxide, and ammonia decomposition gas; In an optional embodiment, after the first sintering, the second pressing is performed after cooling to 200-350° C. at a cooling rate not higher than 5° C. / min, and then naturally cooling to room temperature.

[0014] The present invention also provides an application of the tungsten-copper composite material or the tungsten-copper composite material prepared by the above preparation method in conductive materials.

[0015] The technical solution of the present invention has the following advantages: 1. The tungsten-copper composite material provided by the present invention comprises a copper plate, a copper layer and a tungsten-copper layer, wherein the copper layer covers the copper plate, and the tungsten-copper layer covers the copper layer; the copper plate has a plurality of through structures, and the plurality of through structures penetrate the copper plate along the thickness direction of the copper plate, and the through structure components include tungsten and copper. The tungsten-copper composite material provided by the present invention has good electrical conductivity and corrosion resistance. The copper plate, the copper layer, the tungsten-copper layer and the tungsten and copper in the through structure form a nailing structure, so that the copper plate, the copper layer and the tungsten-copper layer are tightly combined, thereby improving the corrosion resistance and electrical conductivity of the tungsten-copper composite material.

[0016] 2. The preparation method of the tungsten-copper composite material provided by the present invention comprises the following steps: (1) preparing tungsten-copper mixed powder; (2) a copper plate is provided with a plurality of through holes; copper powder and tungsten-copper mixed powder are sequentially arranged on the two surfaces of the copper plate, first pressing, first sintering, second pressing, second sintering, to obtain a tungsten-copper composite material; the through holes form a through structure in the tungsten-copper composite material. The tungsten-copper composite material provided by the present invention has good electrical conductivity. The copper powder is first laid on the upper and lower surfaces of the copper plate, and then the tungsten-copper mixed powder is laid, which can effectively improve the bonding force between the layers, so that the tungsten-copper composite material has good corrosion resistance and electrical conductivity; the present invention adopts two-stage sintering, the first sintering combines the layers into a block, and copper forms a skeleton; the second sintering makes the layers more closely combined, further promotes the diffusion of tungsten and copper, and improves the corrosion resistance and electrical conductivity of the tungsten-copper material. The tungsten-copper composite material provided by the present invention forms a tungsten-copper alloy layer, has a high surface hardness, strong resistance to deformation, and high density.

[0017] 3. The preparation method of the tungsten-copper composite material provided by the present invention, by adding additives in the preparation of the tungsten-copper mixed powder, can effectively improve the wettability of tungsten powder and copper powder, reduce the sintering activation energy of the system, make the sintering neck better formed, improve the hardness, strength and density of the tungsten-copper composite material, reduce the cracking phenomenon caused by thermal expansion, and refine the grains; the present invention adopts sintering at a temperature lower than the melting point of copper, which is different from the commonly used melt infiltration method on the market to prepare tungsten-copper materials. The structure is different and it can also save energy and reduce carbon; Both the first pressing and the second pressing are carried out under normal pressure, which is convenient for industrial use. The second pressing can further reduce voids and microcracks. In the present invention, ball milling is used to mix and prepare tungsten-copper mixed powder to alloy tungsten powder and copper powder; a microgroove structure is arranged at the edge position of the copper plate, which can improve the mechanical bite force and provide buffering for the thermal expansion of the tungsten-copper composite material, further reducing the occurrence of the adverse phenomenon of cracking of the tungsten-copper material; activating with sulfuric acid solution can not only form slight roughening on the surface of the copper plate, but also remove the oxides on the surface of the copper plate, improving the bonding force between the copper plate and other layers.

[0018] In the present invention, different heating rates are used for heating, which can avoid the delamination phenomenon of the prepared tungsten-copper material caused by thermal shock; after the first sintering, the temperature is reduced to 300 °C at a cooling rate not higher than 5 °C / min, and then naturally cooled to room temperature before the second pressing, which can avoid the adverse phenomenon of interface peeling due to the difference in the thermal expansion coefficients of tungsten and copper.

[0019] The present invention preferably arranges the through holes, making the force distribution of the through structure more balanced, and further improving the performance and service life of the tungsten-copper composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a structural diagram of a tungsten-copper composite material provided by the present invention; Figure 2 It is a reference diagram of the "cross" distribution of the through holes on the copper plate of the present invention; Figure 3 It is a reference diagram of the "well" distribution of the through holes on the copper plate of the present invention; Figure 4 It is a reference diagram of the "rice" distribution of the through holes on the copper plate of the present invention; Figure 5 It is a reference diagram of the "big" distribution of the through holes on the copper plate of the present invention; REFERENCE SIGNS: 1 - tungsten-copper layer; 2 - copper layer; 3 - copper plate; 4 - through structure; 5 - microgroove structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0023] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0024] Example 1 This embodiment provides a tungsten-copper composite material, the structure of which is shown in Figure 1 , including a tungsten copper layer 1, a copper layer 2, a copper plate 3, a through structure 4 and a microgroove structure 5; the copper layer 2 covers the copper plate 3, the tungsten copper layer 1 covers the copper layer 2; the copper plate 3 has a through structure 4 (arrangement method refers to Figure 2 ) and microgroove structure 5 (arrangement and shape refer to Figure 2 ).

[0025] This embodiment also provides a method for preparing a tungsten-copper composite material, comprising the following steps: (1) 2μm tungsten powder and 45μm electrolytic copper powder were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 18h. Ball milling balls were added at a ball-to-material ratio of 5:1. The ball milling procedure was 25min, 5min rest, 18h, and dried at 70℃ for 24h to obtain tungsten-copper mixed powder. The mass ratio of tungsten powder to electrolytic copper powder was 60:40. The mass ratio of tungsten powder to electrolytic copper powder to ethanol was 5:1. (2) Select a 1.5 mm thick copper plate that is round and straightened. Arrange it in a "cross" shape (see the arrangement method). Figure 2 ) Symmetrical through holes are prepared on the copper plate, and the aperture of the through holes is 0.3 mm; along the arrangement direction, the shortest spacing between two adjacent edge points of the through holes is 0.6 mm; the ratio of the total area of ​​the projections of a plurality of through holes on the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:300; 8 microgroove structures are arranged symmetrically and at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structure is a symmetrical structure; the microgroove structure is provided with a second area and a first area from the outside to the inside of the copper plate, the second area is rectangular, and the first area is trapezoidal, and the opening of the first area becomes larger from the outside to the inside of the copper plate (the size of the microgroove structure is not limited, and the arrangement method and shape refer to Figure 2 ); Activate the treated copper plate in 18% sulfuric acid for 30 minutes; wash with deionized water, wash with anhydrous ethanol, dry with cold air, and set aside; (3) In the powder tablet press mold, tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder with a mass ratio of 32:1:100:1:38 are laid flat in sequence, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold pressed at 600 MPa for 3 minutes; when the copper powder and tungsten-copper mixed powder are laid flat, some of the copper powder and tungsten-copper mixed powder will enter the through holes of the copper plate. During the cold pressing process, the copper powder and tungsten-copper mixed powder on both surfaces of the copper plate will enter the through holes, and after pressing, the through holes form a through structure; the heating rate is 5°C. / min to 500℃, keep at 500℃ for 1h, heat to 800℃ at a heating rate of 3℃ / min, then heat to 950℃ at 3℃ / min, sinter at 950℃ for 3h, cool to 300℃ at a cooling rate of 5℃ / min, and naturally cool to room temperature; then cold press at 100MPa for 3min, heat to 1050℃ at a heating rate of 3℃ / min, sinter at 1050℃ for 2h, cool to 300℃ at a cooling rate of 5℃ / min, and naturally cool to obtain a tungsten-copper composite material.

[0026] Example 2 This embodiment provides a method for preparing a tungsten-copper composite material, comprising the following steps: (1) 1μm tungsten powder, 63μm electrolytic copper powder and alumina were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 12h. Ball milling balls were added at a ball-to-material ratio of 4:1. The ball milling procedure was 25min, 5min rest, 18h of ball milling procedure, and dried at 75℃ for 12h to obtain tungsten-copper mixed powder. The mass ratio of tungsten powder, electrolytic copper powder and alumina was 57.8:42:0.2. The ratio of the mass of tungsten powder, electrolytic copper powder and alumina to the mass of ethanol was 5:1. (2) Select a copper plate with a thickness of 1.8 mm. The copper plate is round and straightened. Arrange it in a "well" shape (see the arrangement method). Figure 3 ) Symmetrical through holes are prepared on the copper plate, and the aperture of the through holes is 0.6 mm; along the arrangement direction, the shortest distance between two adjacent edge points of the through holes is 2 mm; the ratio of the total area of ​​the projections of a plurality of the through holes on the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:100; 4 microgroove structures are symmetrically arranged at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structure is a symmetrical structure; the circumferential arc length of a single microgroove structure along the outer edge of the copper plate is less than the maximum length of a single microgroove structure, and the maximum length refers to the maximum distance between the line connecting the two edge points of the microgroove structure and passing through the center point (the size of the microgroove structure is not limited, and the arrangement method and shape refer to Figure 3 ); Activate the treated copper plate in 20% sulfuric acid for 30 minutes; wash with deionized water, wash with anhydrous ethanol, dry with cold air, and set aside; (3) In the powder press mold, tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder with a mass ratio of 36:1:120:1:44 are laid flat in sequence, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold pressed at 650 MPa for 2 min; when laying flat the copper powder and tungsten-copper mixed powder, part of the copper powder and tungsten-copper mixed powder will enter the through holes of the copper plate. During the cold pressing process, the copper powder and tungsten-copper mixed powder on both surfaces of the copper plate will enter the through holes, and a through structure will be formed in the through holes after pressing; heat up to 500 °C at a heating rate of 4 °C / min, keep it at 500 °C for 1 h, heat up to 800 °C at a heating rate of 2 °C / min, then heat up to 900 °C at 2 °C / min, sinter at 900 °C for 3 h, cool down to 300 °C at a cooling rate of 4 °C / min and then naturally cool to room temperature; then cold press at 150 MPa for 3 min, heat up to 1050 °C at a heating rate of 2 °C / min, sinter at 1050 °C for 2 h, and cool down to 300 °C at a cooling rate of 4 °C / min and then naturally cool; obtain tungsten-copper composite material.

[0027] Example 3 This example provides a preparation method of tungsten-copper composite material, including the following steps: (1) Mix 45 μm tungsten powder, 45 μm electrolytic copper powder and yttrium oxide, add absolute ethanol, mix at 400 r / min for 24 h, add ball milling balls according to a ball-to-material ratio of 7:1, and the ball milling program is ball milling for 25 min, stopping for 5 min, the total time of the ball milling program is 18 h, and dry at 80 °C for 12 h to obtain tungsten-copper mixed powder; the mass ratio of tungsten powder, electrolytic copper powder and yttrium oxide is 60.5:39:0.5; the ratio of the sum of the masses of tungsten powder, electrolytic copper powder and yttrium oxide to the mass of ethanol is 5:2; (2) Select a copper plate with a thickness of 1.0 mm. The copper plate is circular, straightened, and symmetric through holes are prepared on the copper plate according to the "meter" - shaped arrangement (the arrangement method refers to Figure 4 ). The aperture of the through holes is 0.3 mm; along the arrangement direction, the shortest distance between the edge points of two adjacent through holes is 2 mm; the ratio of the total projected area of several through holes on the upper surface of the copper plate to the area of the upper surface of the copper plate is 1:400; on the circumference of the outer edge of the copper plate, 8 micro - groove structures are symmetrically arranged at equal intervals; the micro - groove structure is a symmetric structure and is arc - shaped (the size of the micro - groove structure is not limited, and the arrangement method and shape refer to Figure 4 ); activate the treated copper plate in sulfuric acid with a mass concentration of 15% for 30 min; wash with deionized water, wash with absolute ethanol, and dry with cold air for standby; (3) In the powder tablet press mold, tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder with a mass ratio of 36:1:150:1:40 are laid out in sequence, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold pressed at 700 MPa for 3 minutes; when the copper powder and tungsten-copper mixed powder are laid out, some of the copper powder and tungsten-copper mixed powder will enter the through holes of the copper plate. During the cold pressing process, the copper powder and tungsten-copper mixed powder on both surfaces of the copper plate will enter the through holes, and after pressing, the through holes form a through structure; the heating rate is 4 °C. / min to 500℃, keep at 500℃ for 1h, heat to 800℃ at a heating rate of 2℃ / min, then heat to 900℃ at 2℃ / min, sinter at 900℃ for 3h, cool to 300℃ at a cooling rate of 4℃ / min, and naturally cool to room temperature; then cold press at 120MPa for 3min, heat to 1020℃ at a heating rate of 2℃ / min, sinter at 1020℃ for 2h, cool to 300℃ at a cooling rate of 4℃ / min, and naturally cool; obtain tungsten-copper composite material.

[0028] Example 4 This embodiment provides a method for preparing a tungsten-copper composite material, comprising the following steps: (1) 1 μm tungsten powder, 45 μm electrolytic copper powder and zirconium oxide were mixed, anhydrous ethanol was added, and the mixture was mixed at 500 r / min for 12 h. Ball milling balls were added at a ball-to-material ratio of 3:1. The ball milling procedure was 25 min, the ball milling procedure time was 18 h, and the ball milling was stopped for 5 min. The mixture was dried at 75 °C for 16 h to obtain a tungsten-copper mixed powder. The mass ratio of tungsten powder, electrolytic copper powder and zirconium oxide was 58.9:41:0.1. The ratio of the mass of tungsten powder, electrolytic copper powder and zirconium oxide to the mass of ethanol was 5:1. (2) Select a copper plate with a thickness of 1.5 mm. The copper plate is round and straightened. Arrange it in the shape of a "big" character (refer to the arrangement method). Figure 5 ) A symmetrical through hole is prepared on the copper plate, and the aperture of the through hole is 0.5 mm; along the arrangement direction, the shortest distance between the edge points of two adjacent through holes is 2 mm; the ratio of the total area of ​​the projections of a plurality of through holes on the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:300; 4 microgroove structures are arranged symmetrically and at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structure is a symmetrical structure, and the microgroove structure is rectangular (the size of the microgroove structure is not limited, and the arrangement and shape refer to Figure 5 ); Activate the treated copper plate in 15% sulfuric acid for 30 minutes; wash with deionized water, wash with anhydrous ethanol, dry with cold air, and set aside; (3) In the powder tablet press mold, tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder with a mass ratio of 27:1:100:1:33 are laid out in sequence, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold pressed at 600 MPa for 3 minutes; when the copper powder and tungsten-copper mixed powder are laid out, some of the copper powder and tungsten-copper mixed powder will enter the through holes of the copper plate. During the cold pressing process, the copper powder and tungsten-copper mixed powder on both surfaces of the copper plate will enter the through holes, and after pressing, the through holes form a through structure; the heating rate is 4 °C. / min to 500℃, keep at 500℃ for 1h, heat to 800℃ at a heating rate of 2℃ / min, then heat to 950℃ at 2℃ / min, sinter at 950℃ for 2h, cool to 300℃ at a cooling rate of 3℃ / min, and naturally cool to room temperature; then cold press at 130MPa for 2min, heat to 1020℃ at a heating rate of 2℃ / min, sinter at 1020℃ for 2h, cool to 300℃ at a cooling rate of 3℃ / min, and naturally cool; obtain tungsten-copper composite material.

[0029] Example 5 This embodiment provides a method for preparing a tungsten-copper composite material, comprising the following steps: (1) 1 μm tungsten powder, 45 μm electrolytic copper powder and lanthanum oxide were mixed, anhydrous ethanol was added, and the mixture was mixed at 300 r / min for 12 h. Ball milling balls were added at a ball-to-material ratio of 5:1. The ball milling procedure was 25 min, the ball milling time was 18 h, and the ball milling was stopped for 5 min. The mixture was dried at 75 °C for 12 h to obtain a tungsten-copper mixed powder. The mass ratio of tungsten powder, electrolytic copper powder and lanthanum oxide was 61.3:38:0.7. The ratio of the mass of tungsten powder, electrolytic copper powder and lanthanum oxide to the mass of ethanol was 5:1. (2) Select a copper plate with a thickness of 0.5 mm. The copper plate is round and straightened. Arrange it in a "cross" shape (refer to the arrangement method). Figure 2 ) A symmetrical through hole is prepared on the copper plate, and the aperture of the through hole is 0.2 mm; along the arrangement direction, the shortest spacing between two adjacent edge points of the through hole is 0.4 mm; the ratio of the total area of ​​the projections of a plurality of the through holes on the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:1000; 8 microgroove structures are arranged symmetrically and at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structure is a symmetrical structure; the microgroove structure is provided with a second area and a first area along the copper plate from the outside to the inside, and the second area is a rectangle (the size of the microgroove structure is not limited, and the arrangement and shape refer to Figure 2 ); Activate the drilled copper plate in 15% sulfuric acid for 20 minutes; wash with deionized water, wash with anhydrous ethanol, dry with cold air, and set aside; (3) In the powder tablet press mold, tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder with a mass ratio of 36:1:130:1:38 are laid out in sequence, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold pressed at 500 MPa for 5 minutes; when the copper powder and tungsten-copper mixed powder are laid out, some of the copper powder and tungsten-copper mixed powder will enter the through holes of the copper plate. During the cold pressing process, the copper powder and tungsten-copper mixed powder on both surfaces of the copper plate will enter the through holes, and after pressing, the through holes form a through structure; the heating rate is 5 °C. / min to 300℃, keep at 300℃ for 1h, heat to 800℃ at a heating rate of 3℃ / min, then heat to 900℃ at 2℃ / min, sinter at 900℃ for 2h, cool to 300℃ at a cooling rate of 3℃ / min, and naturally cool to room temperature; then cold press at 90MPa for 5min, heat to 1050℃ at a heating rate of 3℃ / min, sinter at 1050℃ for 2h, cool to 300℃ at a cooling rate of 4℃ / min, and naturally cool; obtain tungsten-copper composite material.

[0030] Comparative Example 1 This comparative example provides a method for preparing a tungsten copper material, comprising the following steps: (1) 2μm tungsten powder and 45μm electrolytic copper powder were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 18h. Ball milling balls were added at a ball-to-material ratio of 5:1. The ball milling procedure was 25min, the ball milling time was 18h, and the ball milling was stopped for 5min. The mixture was dried at 70℃ for 24h to obtain tungsten-copper mixed powder. The mass ratio of tungsten powder to electrolytic copper powder was 60:40. The mass ratio of tungsten powder to electrolytic copper powder to ethanol was 5:1. (2) In a powder tablet press mold, tungsten-copper mixed powder and electrolytic copper powder are added in sequence, and then electrolytic copper powder and tungsten-copper mixed powder are added in sequence, with a mass ratio of 32:1:1:38 to form a copper layer and a tungsten-copper layer, wherein the tungsten-copper layer covers the copper layer, and the material is cold pressed at 600 MPa for 3 min. The thickness of the material after cold pressing is substantially the same as that in Example 1. The material is heated to 500°C at a heating rate of 5°C / min, kept at 500°C for 1 h, heated to 800°C at a heating rate of 3°C / min, and then heated to 950°C at 3°C / min, sintered at 950°C for 3 h, cooled to 300°C at a cooling rate of 5°C / min, and then naturally cooled to room temperature. The material is cold pressed at 100 MPa for 3 min, heated to 1050°C at a heating rate of 3°C / min, sintered at 1050°C for 2 h, cooled to 300°C at a cooling rate of 5°C / min, and then naturally cooled. A tungsten-copper material is obtained.

[0031] Comparative Example 2 This comparative example provides a method for preparing a tungsten copper material, comprising the following steps: (1) 1μm tungsten powder, 63μm electrolytic copper powder and alumina were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 12h. Ball milling balls were added at a ball-to-material ratio of 4:1. The ball milling procedure was 25min, the ball milling time was 18h, and the ball milling was stopped for 5min. The mixture was dried at 75℃ for 12h to obtain a tungsten-copper mixed powder. The mass ratio of tungsten powder, electrolytic copper powder and alumina was 57.8:42:0.2. The ratio of the mass of tungsten powder, electrolytic copper powder and alumina to the mass of ethanol was 5:1. (2) In a powder tablet press mold, tungsten-copper mixed powder and electrolytic copper powder are added in sequence, and then electrolytic copper powder and tungsten-copper mixed powder are added in sequence, with a mass ratio of 36:1:1:44 to form a copper layer and a tungsten-copper layer, wherein the tungsten-copper layer covers the copper layer, and the material is cold pressed at 650 MPa for 2 min. The thickness of the material after cold pressing is basically the same as that in Example 2; the temperature is increased to 500°C at a heating rate of 4°C / min, kept at 500°C for 1 h, increased to 800°C at a heating rate of 2°C / min, and then increased to 900°C at 2°C / min, sintered at 900°C for 3 h, cooled to 300°C at a cooling rate of 4°C / min, and then naturally cooled to room temperature; cold pressed at 150 MPa for 3 min, increased to 1050°C at a heating rate of 2°C / min, sintered at 1050°C for 2 h, cooled to 300°C at a cooling rate of 4°C / min, and then naturally cooled; a tungsten-copper material is obtained.

[0032] Comparative Example 3 This comparative example provides a method for preparing a tungsten copper material, comprising the following steps: (1) 5 μm tungsten powder and 20 μm electrolytic copper powder were mixed in a V-type mixer for 2 h to obtain tungsten-copper mixed powder; the mass ratio of tungsten powder to electrolytic copper powder was 75:10; (2) Add tungsten-copper mixed powder into the powder tablet press mold, cold press at 300 MPa for 3 min, heat up to 900 °C at a heating rate of 5 °C / min, and keep at 900 °C for 1.5 h to obtain a pre-sintered green body; place a copper sheet on the pre-sintered green body, heat up to 1250 °C at a heating rate of 5 °C / min, sinter at 1250 °C for 2 h, cool to 300 °C at a cooling rate of 5 °C / min, and then naturally cool to room temperature to obtain tungsten-copper material.

[0033] Comparative Example 4 This comparative example provides a method for preparing a tungsten copper material, comprising the following steps: (1) 2μm tungsten powder and 45μm electrolytic copper powder were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 18h. Ball milling balls were added at a ball-to-material ratio of 5:1. The ball milling procedure was ball milling for 25min, stopping for 5min, and drying at 70℃ for 24h to obtain tungsten-copper mixed powder. The mass ratio of tungsten powder to electrolytic copper powder was 25:75; the mass ratio of tungsten powder to electrolytic copper powder to ethanol was 5:1. (2) In a powder tablet press mold, tungsten-copper mixed powder and electrolytic copper powder are added in sequence, and then electrolytic copper powder and tungsten-copper mixed powder are added in sequence, with a mass ratio of 32:1:1:38 to form a copper layer and a tungsten-copper layer, wherein the tungsten-copper layer covers the copper layer, and the material is cold pressed at 600 MPa for 3 min. The thickness of the material after cold pressing is substantially the same as that in Example 1. The material is heated to 500°C at a heating rate of 5°C / min, kept at 500°C for 1 h, heated to 800°C at a heating rate of 3°C / min, and then heated to 950°C at 3°C / min, sintered at 950°C for 3 h, cooled to 300°C at a cooling rate of 5°C / min, and then naturally cooled to room temperature. The material is cold pressed at 100 MPa for 3 min, heated to 1050°C at a heating rate of 3°C / min, sintered at 1050°C for 2 h, cooled to 300°C at a cooling rate of 5°C / min, and then naturally cooled. A tungsten-copper material is obtained.

[0034] Comparative Example 5 This comparative example provides a method for preparing a tungsten copper material, comprising the following steps: (1) 2μm tungsten powder and 45μm electrolytic copper powder were mixed, anhydrous ethanol was added, and the mixture was mixed at 320r / min for 18h. Ball milling balls were added at a ball-to-material ratio of 5:1. The ball milling procedure was 25min, 5min rest, 18h, and dried at 70℃ for 24h to obtain tungsten-copper mixed powder. The mass ratio of tungsten powder to electrolytic copper powder was 60:40. The mass ratio of tungsten powder to electrolytic copper powder to ethanol was 5:1. (2) Select a 1.5 mm thick copper plate, which is round and straightened; activate the copper plate in 18% sulfuric acid for 30 min; wash it with deionized water, wash it with anhydrous ethanol, blow it dry with cold air, and set it aside; (3) In the powder tablet press mold, tungsten copper mixed powder, electrolytic copper powder, and copper plate are added in sequence, and then electrolytic copper powder and tungsten copper mixed powder are added in sequence, with a mass ratio of 32:1:100:1:38 to form a copper plate, a copper layer, and a tungsten copper layer. The copper layer covers the copper plate, and the tungsten copper layer covers the copper layer. The mixture is cold pressed at 600 MPa for 3 min; the temperature is increased to 500°C at a heating rate of 5°C / min, and the temperature is kept at 500°C for 1 h. The temperature was raised to 800°C at a heating rate of 3°C / min, then raised to 950°C at a heating rate of 3°C / min, sintered at 950°C for 3h, cooled to 300°C at a cooling rate of 5°C / min, and naturally cooled to room temperature; then cold pressed at 100MPa for 3min, raised to 1050°C at a heating rate of 3°C / min, sintered at 1050°C for 2h, cooled to 300°C at a cooling rate of 5°C / min, and naturally cooled; tungsten copper material was obtained.

[0035] Test Case The performance tests of the tungsten copper materials obtained in Examples 1-5 and Comparative Examples 1-5 are as follows: (1) The electrical conductivity is tested according to GB / T32791-2016 Eddy Current Test Method for Electrical Conductivity of Copper and Copper Alloys, and the average of the five test points is taken as the final result. The results are shown in Table 1.

[0036] (2) Corrosion resistance was tested according to GB / T10125-2021 "Artificial atmosphere corrosion test salt spray test", and the time when corrosion began to occur was recorded, and the results were rounded to integers. The results are shown in Table 1.

[0037] (3) Thermal conductivity was tested according to GB / T22588-2008 "Flash method for measuring thermal diffusivity or thermal conductivity". The results are shown in Table 1.

[0038] (4) Vickers hardness was tested in accordance with GB / T9097-2016 "Determination of apparent hardness and microhardness of sintered metal materials (excluding cemented carbide)", and the average of ten test points was taken as the final result. The results are shown in Table 1.

[0039] Table 1 Performance test results of various embodiments and comparative examples

[0040] As can be seen from Table 1, the tungsten copper material prepared by the present invention has high electrical conductivity and thermal conductivity, good corrosion resistance and high hardness. As can be seen from the examples and comparative examples, the tungsten copper material provided by the present invention includes a copper plate, a copper layer and a tungsten copper layer, the copper layer covers the copper plate, and the tungsten copper layer covers the copper layer; the copper plate has several through structures, and several through structures penetrate the copper plate along the thickness direction of the copper plate, and the through structure components include tungsten copper mixed powder and copper powder, which can effectively improve the electrical conductivity, thermal conductivity, corrosion resistance and hardness of the tungsten copper material; compared with the tungsten copper material prepared by the infiltration method of the prior art, under the premise of good corrosion resistance, the electrical conductivity and thermal conductivity are significantly superior; compared with the tungsten copper material obtained by blindly increasing the copper content, the tungsten copper composite material with a special structure provided by the present invention has better electrical conductivity, thermal conductivity, Vickers hardness and corrosion resistance, and a longer service life; the copper plate of the present invention has a special structure, which can effectively improve the various properties of the tungsten copper composite material.

[0041] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A tungsten-copper composite material, characterized in that: The tungsten-copper composite material comprises a copper plate, a copper layer and a tungsten-copper layer, wherein the copper layer covers the copper plate, and the tungsten-copper layer covers the copper layer; the copper plate has a plurality of penetrating structures, and the plurality of penetrating structures penetrate the copper plate along the thickness direction of the copper plate, and the penetrating structure components include tungsten and copper.

2. The tungsten-copper composite material according to claim 1, characterized in that: The through-structure component further comprises an additive; and / or, The tungsten-copper layer comprises tungsten and copper; and / or, The copper layer comprises copper; and / or, A plurality of the through structures are regularly arranged on the surface of the copper plate; and / or, A plurality of microgroove structures are arranged symmetrically and at equal intervals on the circumference of the outer edge of the copper plate; the microgroove structures are symmetrical structures; and / or, The thickness of the copper plate is ≥0.2 mm.

3. The tungsten-copper composite material according to claim 2, characterized in that: The additive comprises at least one of aluminum oxide, yttrium oxide, zirconium oxide and lanthanum oxide; and / or, The circumferential arc length of a single microgroove structure along the outer edge of the copper plate is less than the maximum length of a single microgroove structure, wherein the maximum length refers to the maximum distance between the line connecting two edge points of the microgroove structure and passing through the center point; and / or, The microgroove structure is arc-shaped or rectangular; and / or, The microgroove structure is provided with a first region, the first region is trapezoidal, and the opening of the first region becomes larger from the outside to the inside.

4. A method for preparing a tungsten-copper composite material, characterized in that: The following steps are involved: (1) Preparation of tungsten-copper mixed powder; (2) The copper plate is provided with a plurality of through holes; copper powder and tungsten-copper mixed powder are sequentially placed on two surfaces of the copper plate, first pressed, first sintered, second pressed, and second sintered to obtain a tungsten-copper composite material; the through holes form a penetrating structure in the tungsten-copper composite material.

5. The preparation method according to claim 4, characterized in that: The through hole has a diameter of 0.2-0.6 mm; and / or, The ratio of the total area of ​​the projections of the plurality of through holes on the upper surface of the copper plate to the upper surface area of ​​the copper plate is 1:(100-1000); and / or, The through holes are arranged on the copper plate along a first central axis and a second central axis that are perpendicular to each other; and / or, The through holes are arranged on the copper plate along a first direction and a second direction perpendicular to each other; the first direction is parallel to a first central axis of the copper plate, and the through holes are symmetrically distributed on both sides of the first central axis; the second direction is parallel to a second central axis of the copper plate, and the through holes are symmetrically distributed on both sides of the second central axis; the first central axis and the second central axis are symmetry axes of the copper plate and are perpendicular to each other; and / or, The through holes are distributed along the radial lines of the copper plate, and the angle between two adjacent radial lines is 40°-90°; and / or, In the step (2), the particle size of the copper powder is 1-63 μm; and / or, In the step (2), the copper powder comprises electrolytic copper powder; and / or, The mass ratio of the copper plate, the copper powder and the tungsten-copper mixed powder is (100-150):(1-2):(60-80); and / or, The step (1) comprises: mixing tungsten powder and copper powder by ball milling; and / or, The copper plate is activated.

6. The preparation method according to claim 5, characterized in that: Along the arrangement direction of the through holes, the shortest distance between two adjacent edge points of the through holes is greater than twice the aperture of the through holes; and / or, In step (1), the particle size of the tungsten powder is 1-45 μm; and / or, In the step (1), the particle size of the copper powder is 1-63 μm; and / or, In the step (1), the copper powder comprises electrolytic copper powder; and / or, In step (1), the ball milling mixing further comprises adding additives; and / or, In the step (1), the mass ratio of the tungsten powder to the copper powder is (57.3-62):(38-42); and / or, In step (1), the ball milling mixing time is 12-24 hours; and / or, In step (1), the rotation speed of the ball milling is 200-500 r / min; and / or, In step (1), the ball milling mixing further comprises adding ethanol; and / or, The step (1), after the ball milling and mixing, further comprises drying; and / or, The activated solution comprises a sulfuric acid solution; and / or, The activation time is 20-40 min.

7. The preparation method according to claim 6, characterized in that: In step (1), the additive comprises at least one of aluminum oxide, yttrium oxide, zirconium oxide and lanthanum oxide; and / or, In the step (1), the mass ratio of the tungsten powder, the copper powder and the additive is (57.3-62):(38-42):(0.1-0.7); and / or, The ratio of the mass of the tungsten powder and the copper powder to the mass of the ethanol is 5:(1-2); and / or, The drying temperature is 70-80°C and the drying time is 12-24h; and / or, The mass concentration of the sulfuric acid solution is 10-20%.

8. The preparation method according to claim 4, characterized in that: The first pressing pressure is 500-700 MPa; and / or, The first pressing time is 1-5 min; and / or, The first pressing comprises hot pressing, cold pressing or hot isostatic pressing; and / or, The second pressing comprises hot pressing, cold pressing or hot isostatic pressing; and / or, The second pressing pressure is 60-150 MPa; and / or, The second pressing time is 2-5 min.

9. The preparation method according to claim 4, characterized in that: Heating from room temperature to 300-500°C at a rate not higher than 5°C / min, keeping the temperature for 1 hour, then heating to 800°C at a rate not higher than 5°C / min, and then heating to the first sintering temperature at a rate not higher than 3°C / min for the first sintering; and / or, The first sintering time is 1-3h; and / or, The first sintering temperature is 800-950° C.; and / or, The first sintering is performed in a reducing atmosphere; and / or, The second sintering is performed by heating the temperature to the second sintering temperature at a rate not higher than 3°C / min; and / or, The second sintering time is 1-3h; and / or, The second sintering temperature is 1000-1050° C.; and / or, The second sintering is performed in a reducing atmosphere; and / or, After the first sintering, the process further includes cooling to 200-350° C. at a cooling rate of no more than 5° C. / min, and then naturally cooling to room temperature before performing a second pressing.

10. Use of the tungsten-copper composite material according to any one of claims 1 to 3 or the tungsten-copper composite material prepared by the preparation method according to any one of claims 4 to 9 in conductive materials.

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