A tungsten copper composite material, its preparation method and application

Abstract

The present invention belongs to the field of conductive materials, and specifically relates to a tungsten-copper composite material, a preparation method thereof, and an application thereof. The present invention provides a tungsten-copper composite material, the tungsten-copper composite material comprising 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 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 excellent electrical conductivity and corrosion resistance.

Description

Technical Field

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

[0002] An anodic oxidation clamp needs to have good electrical conductivity and corrosion resistance. The existing tungsten copper materials commonly used as anodic oxidation clamps are mainly prepared by infiltration method. First, tungsten powder is pressed and sintered to form a tungsten skeleton, and then copper powder or copper sheet is infiltrated into the tungsten skeleton by capillary force at a temperature higher than the melting point of copper to obtain tungsten copper materials. The existing methods for preparing tungsten copper materials not only have high energy consumption but also poor electrical conductivity. If the copper content is increased to improve the conductivity, the obtained tungsten copper materials do not have the advantage of high corrosion resistance and cannot balance 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 that the existing tungsten copper materials cannot simultaneously have excellent corrosion resistance and electrical conductivity, and thus provide a tungsten copper composite material, a preparation method thereof, and an application thereof.

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

[0005] For this purpose, the present invention provides the following technical solutions.

[0006] The present invention provides a tungsten copper composite material, which 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 a plurality of through structures, and the plurality of through structures penetrate the copper plate along the thickness direction of the copper plate. The components of the through structures include tungsten and copper.

[0007] In an optional embodiment, the components of the through structures further include additives;

[0008] In an optional embodiment, the additives include at least one of aluminum oxide, yttrium oxide, zirconium oxide, and lanthanum oxide;

[0009] In an optional embodiment, the tungsten copper layer includes tungsten and copper;

[0010] In an optional embodiment, the copper layer includes copper;

[0011] In an optional embodiment, the plurality of through structures are regularly arranged on the surface of the copper plate; and / or,

[0012] In an optional embodiment, the thickness of the copper plate ≥ 0.2 mm;

[0013] In an alternative embodiment, a plurality of micro-groove structures are arranged at equal intervals and symmetrically in the circumferential direction of the outer edge of the copper plate; the micro-groove structures are symmetric structures;

[0014] In an alternative embodiment, the circumferential arc length of a single micro-groove structure along the outer edge of the copper plate is less than the maximum length of a single micro-groove structure, and the maximum length refers to the maximum distance between two edge points of the micro-groove structure and passing through the center point;

[0015] In an alternative embodiment, the micro-groove structure is arc-shaped or rectangular; the shape of the arc-shaped one refers to Figure 4 ;

[0016] In an alternative embodiment, the micro-groove structure is provided with a first region, the first region is trapezoidal, and the opening of the first region gradually becomes larger from outside to inside;

[0017] Preferably, the micro-groove structure is provided with a second region and a first region from outside to inside along the copper plate, the second region is rectangular, and the structure refers to Figure 2 。

[0018] The present invention also provides a method for preparing a tungsten-copper composite material, comprising the following steps:

[0019] (1) Prepare tungsten-copper mixed powder;

[0020] (2) A plurality of through holes are provided in the copper plate; the copper powder and the tungsten-copper mixed powder are sequentially located on two surfaces of the copper plate, first pressing, first sintering, second pressing, and second sintering are performed to obtain a tungsten-copper composite material; the through holes form a through structure in the tungsten-copper composite material.

[0021] In an alternative embodiment, the particle size of the copper powder is 1-63 μm;

[0022] In an alternative embodiment, the copper powder includes electrolytic copper powder;

[0023] In an alternative embodiment, the aperture of the through hole is 0.2-0.6 mm;

[0024] In an alternative embodiment, the shortest distance between the edge points of two adjacent through holes is greater than twice the aperture of the through hole;

[0025] In an alternative embodiment, 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 area of the upper surface of the copper plate is 1:(100-1000);

[0026] The arrangement mode of the through holes in the present invention is set by using conventional methods in the art, specifically as follows:

[0027] In an alternative embodiment, the through holes are arranged on the copper plate along a first central axis and a second central axis perpendicular to each other; referring to Figure 2 , this arrangement is a "cross" distribution;

[0028] In an alternative embodiment, 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 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, perpendicular to each other, and this arrangement is a "well" character distribution;

[0029] The shape of the through hole is a conventional shape in the art such as a circle or a pentagram, and 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; referring to Figure 3 ;

[0030] 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°;

[0031] 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.;

[0032] When the included angle is 45°, it is denoted as a "rice" character distribution, referring to Figure 4 ; when the included angle is 72°, it is denoted as a "big" character distribution, referring to Figure 5 ;

[0033] 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;

[0034] Preferably, the masses of the tungsten - copper mixed powder placed on the two surfaces of the copper plate are equal or not equal; the purpose is to make the thickness of the tungsten - copper layer more uniform on the upper and lower surfaces of the copper plate, and further improve the performance of the tungsten - copper composite material.

[0035] In an alternative embodiment, step (1) includes: ball - milling and mixing tungsten powder and copper powder;

[0036] In an alternative embodiment, in step (1), the particle size of the tungsten powder is 1 - 45 μm;

[0037] In an alternative embodiment, in step (1), the particle size of the copper powder is 1 - 63 μm;

[0038] In an alternative embodiment, in step (1), the copper powder includes electrolytic copper powder;

[0039] In an alternative embodiment, in step (1), the mass ratio of the tungsten powder to the copper powder is (57.3 - 62):(38 - 42);

[0040] In an alternative embodiment, in step (1), the ball milling and mixing further includes adding an additive;

[0041] In an alternative embodiment, in step (1), the additive includes at least one of alumina, yttria, zirconia, and lanthanum oxide;

[0042] In an alternative 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);

[0043] In an alternative embodiment, in step (1), the time of the ball milling and mixing is 12 - 24 h;

[0044] In an alternative embodiment, in step (1), the rotation speed of the ball milling and mixing is 200 - 500 r / min;

[0045] Preferably, in step (1), the ball - to - material ratio of the ball milling and mixing is (3 - 8):1;

[0046] Preferably, in step (1), the procedure of the ball milling and mixing is ball milling for 25 min, stopping for 5 min, and repeating this procedure until the ball milling time is 12 - 24 h;

[0047] In an alternative embodiment, in step (1), the ball milling and mixing further includes adding ethanol;

[0048] Preferably, the ethanol is anhydrous ethanol;

[0049] The purpose of adding ethanol is to reduce oxidation and overheating during the mixing process;

[0050] In an alternative embodiment, the ratio of the sum of the masses of the tungsten powder and the copper powder to the mass of the ethanol is 5:(1 - 2);

[0051] In an alternative embodiment, in step (1), after the ball milling and mixing, it further includes drying;

[0052] In an alternative embodiment, the drying temperature is 70 - 80 °C and the time is 12 - 24 h.

[0053] In an alternative embodiment, the copper plate is subjected to an activation treatment.

[0054] In an alternative embodiment, the activation solution includes a sulfuric acid solution;

[0055] In an alternative embodiment, the mass concentration of the sulfuric acid solution is 10 - 20%;

[0056] In an alternative embodiment, the activation time is 20 - 40 min.

[0057] In an alternative embodiment, after activation, it further includes cleaning with at least one of deionized water and ethanol; the purpose of cleaning is for activation and facilitating drying;

[0058] Preferably, after activation, it further includes cleaning with deionized water and ethanol;

[0059] In an alternative embodiment, the pressure of the first pressing is 500 - 700 MPa;

[0060] In an alternative embodiment, the time of the first pressing is 1 - 5 min;

[0061] In an alternative embodiment, the first pressing includes hot pressing, cold pressing or hot isostatic pressing;

[0062] Preferably, the first pressing is cold pressing. Selecting cold pressing in actual production can be quickly pressed with a compression testing machine, with low equipment requirements, fast sample preparation, low cost, and is easy for industrial production;

[0063] In an alternative embodiment, the second pressing includes hot pressing, cold pressing or hot isostatic pressing;

[0064] Preferably, the second pressing is cold pressing;

[0065] In an alternative embodiment, the pressure of the second pressing is 60 - 150 MPa;

[0066] In an alternative embodiment, the time of the second pressing is 2 - 5 min.

[0067] In an alternative embodiment, it is heated from room temperature to 300 - 500 °C at a rate not higher than 5 °C / min, held for 1 h, then heated to 800 °C at a rate not higher than 5 °C / min, and then heated to the temperature of the first sintering at a rate not higher than 3 °C / min for the first sintering; if the temperature of the first sintering is 800 °C, then directly carry out the heat preservation procedure of the first sintering after heating to 800 °C;

[0068] First, heating to 300 - 500 °C and holding for 1 h can effectively remove copper oxide and organic pollutants, avoiding the generation of unnecessary impurities;

[0069] In an alternative embodiment, the time of the first sintering is 1 - 3 h;

[0070] In an alternative embodiment, the temperature of the first sintering is 800 - 950 °C;

[0071] In an alternative embodiment, the first sintering is carried out in a reducing atmosphere;

[0072] Preferably, the reducing atmosphere includes at least one of hydrogen, carbon monoxide, and ammonia decomposition gas;

[0073] In an alternative embodiment, the second sintering is carried out by heating to the temperature of the second sintering at a rate not higher than 3 °C / min;

[0074] In an alternative embodiment, the time of the second sintering is 1 - 3 h;

[0075] In an alternative embodiment, the temperature of the second sintering is 1000 - 1050 °C;

[0076] In an alternative embodiment, the second sintering is carried out in a reducing atmosphere;

[0077] Preferably, the reducing atmosphere includes at least one of hydrogen, carbon monoxide, and ammonia decomposition gas;

[0078] In an alternative embodiment, after the first sintering, it further includes cooling to 200 - 350 °C at a cooling rate not higher than 5 °C / min, and then naturally cooling to room temperature before the second pressing.

[0079] The present invention also provides an application of the above tungsten - copper composite material or the tungsten - copper composite material prepared by the above preparation method in conductive materials.

[0080] The technical solution of the present invention has the following advantages:

[0081] 1. The tungsten - copper composite material provided by the present invention, the tungsten - copper composite material 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 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 components of the through - structures include tungsten and copper. The tungsten - copper composite material provided by the present invention has good conductivity and corrosion resistance. The copper plate, the copper layer, the tungsten - copper layer, and the tungsten and copper in the through - structures form a riveting structure, which tightly combines the copper plate, the copper layer, and the tungsten - copper layer, improving the corrosion resistance and conductivity of the tungsten - copper composite material.

[0082] 2. The preparation method of the tungsten-copper composite material provided by the present invention includes the following steps: (1) preparing tungsten-copper mixed powder; (2) a copper plate is provided with a plurality of through holes; the copper powder and the tungsten-copper mixed powder are sequentially located on two surfaces of the copper plate, first pressing, first sintering, second pressing, and second sintering to obtain the 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 a good conductivity. Laying copper powder first and then tungsten-copper mixed powder on the upper and lower surfaces of the copper plate can effectively improve the bonding force between layers, making the tungsten-copper composite material have good corrosion resistance and conductivity; the present invention adopts two-stage sintering. The first sintering combines each layer into a block, and copper forms a skeleton; the second sintering makes each layer more closely combined, further promoting the diffusion of tungsten and copper, and improving the corrosion resistance and conductivity of the tungsten-copper material. The tungsten-copper composite material provided by the present invention forms a tungsten-copper alloy layer, has a relatively high surface hardness, strong resistance to deformation, and high density.

[0083] 3. In the preparation method of the tungsten-copper composite material provided by the present invention, adding an additive during 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 form better, 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 uses a sintering temperature lower than the melting point of copper, which is different from the commonly used infiltration method for preparing tungsten-copper materials on the market. While having a different structure, it can also save energy and reduce carbon emissions;

[0084] Both the first pressing and the second pressing are carried out under normal pressure, which is convenient for industrial use, and the second pressing can further reduce voids and microcracks. The present invention uses ball milling to mix and prepare the tungsten-copper mixed powder to alloyize the 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 a buffer for the thermal expansion of the tungsten-copper composite material, further reducing the occurrence of the bad 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.

[0085] The present invention uses different heating rates for heating to avoid the delamination phenomenon of the prepared tungsten-copper material caused by thermal shock; after the first sintering, it is cooled 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 bad phenomenon of interface peeling due to the difference in the thermal expansion coefficients of tungsten and copper.

[0086] The present invention optimizes the arrangement of the through holes to make the force distribution of the through structure more balanced, further improving the performance and service life of the tungsten-copper composite material. Description of the Drawings

[0087] 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 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 work, other drawings can also be obtained based on these drawings.

[0088] Figure 1 It is a structural diagram of a tungsten copper composite material provided by the present invention;

[0089] Figure 2 It is a reference diagram of the "cross" distribution of the through holes on the copper plate of the present invention;

[0090] Figure 3 It is a reference diagram of the "well" distribution of the through holes on the copper plate of the present invention;

[0091] Figure 4 It is a reference diagram of the "rice" distribution of the through holes on the copper plate of the present invention;

[0092] Figure 5 It is a reference diagram of the "big" distribution of the through holes on the copper plate of the present invention;

[0093] Reference numerals:

[0094] 1 - tungsten copper layer; 2 - copper layer; 3 - copper plate; 4 - through structure; 5 - microgroove structure. Specific embodiments

[0095] The following embodiments are provided to better further understand the present invention, which is not limited to the described best embodiment, and does not 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 those of other prior arts falls within the protection scope of the present invention.

[0096] For those not specifying specific experimental steps or conditions in the embodiments, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments not specifying the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0097] Example 1

[0098] This example 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, and the tungsten copper layer 1 covers the copper layer 2; the copper plate 3 has a through structure 4 (the arrangement mode refers to Figure 2 ) and a microgroove structure 5 (the arrangement mode and shape refer to Figure 2 ).

[0099] This embodiment also provides a method for preparing a tungsten-copper composite material, which includes the following steps:

[0100] (1) Mix 2μm tungsten powder and 45μm electrolytic copper powder, add absolute ethanol, mix at 320 r / min for 18 h, add ball-milling balls according to a ball-to-material ratio of 5:1, the ball-milling procedure is to ball-mill for 25 min, stop for 5 min, the total ball-milling procedure time is 18 h, dry at 70 °C for 24 h to obtain tungsten-copper mixed powder; the mass ratio of tungsten powder to electrolytic copper powder is 60:40; the ratio of the sum of the masses of tungsten powder and electrolytic copper powder to the mass of ethanol is 5:1;

[0101] (2) Select a copper plate with a thickness of 1.5 mm. The copper plate is circular and is straightened. Prepare symmetric through-holes on the copper plate according to the "cross" arrangement pattern (the arrangement pattern refers to Figure 2 ). The aperture of the through-hole is 0.3 mm; along the arrangement direction, the shortest distance between the edge points of two adjacent through-holes is 0.6 mm; the ratio of the total area of the projections of a number of through-holes on the upper surface of the copper plate to the area of the upper surface of the copper plate is 1:300; 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; the micro-groove structure has a second region and a first region from the outside to the inside of the copper plate. The second region is rectangular and the first region is trapezoidal. Along the direction from the outside to the inside of the copper plate, the opening of the first region becomes larger (the size of the micro-groove structure is not limited, and the arrangement pattern and shape refer to Figure 2 ); Activate the treated copper plate in sulfuric acid with a mass concentration of 18% for 30 min; wash with deionized water, wash with absolute ethanol, and dry with cold air for standby;

[0102] (3) In the powder press mold, lay flat tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder in a mass ratio of 32:1:100:1:38 in sequence, so that both surfaces of the copper plate are successively placed with copper powder and tungsten-copper mixed powder, and cold-press at 600 MPa for 3 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 after pressing, the through-holes will form a through structure; heat up to 500 °C at a heating rate of 5 °C / min, keep the temperature at 500 °C for 1 h, heat up to 800 °C at a heating rate of 3 °C / min, then heat up to 950 °C at 3 °C / min, sinter at 950 °C for 3 h, cool down to 300 °C at a cooling rate of 5 °C / min and then naturally cool to room temperature; then cold-press at 100 MPa for 3 min, heat up to 1050 °C at a heating rate of 3 °C / min, sinter at 1050 °C for 2 h, and cool down to 300 °C at a cooling rate of 5 °C / min and then naturally cool; obtain the tungsten-copper composite material.

[0103] Example 2

[0104] This embodiment provides a method for preparing a tungsten-copper composite material, comprising the following steps:

[0105] (1) Mix 1μm tungsten powder, 63μm electrolytic copper powder and alumina, add absolute ethanol, mix at 320 r / min for 12 h, add ball-milling balls according to a ball-to-material ratio of 4:1, the ball-milling program is ball-milling for 25 min, stopping for 5 min, the total ball-milling program time is 18 h, dry at 75 °C for 12 h to obtain tungsten-copper mixed powder; the mass ratio of tungsten powder, electrolytic copper powder and alumina is 57.8:42:0.2; the ratio of the sum of the masses of tungsten powder, electrolytic copper powder and alumina to the mass of ethanol is 5:1;

[0106] (2) Select a copper plate with a thickness of 1.8 mm, the copper plate is circular, straighten it, and prepare symmetric through holes on the copper plate according to the "well" - shaped arrangement (the arrangement method refers to Figure 3 ). The aperture of the through hole is 0.6 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 several through holes on the upper surface of the copper plate to the area of the upper surface of the copper plate is 1:100; on the circumference of the outer edge of the copper plate, 4 micro-groove structures are symmetrically arranged at equal intervals; the micro-groove structure is a symmetric structure; the circumferential arc length of a single micro-groove structure along the outer edge of the copper plate is less than the maximum length of a single micro-groove structure, and the maximum length refers to the maximum distance between two edge points of the micro-groove structure connected by a line passing through the center point (the size of the micro-groove structure is not limited, the arrangement method and shape refer to Figure 3 ); Activate the treated copper plate in sulfuric acid with a mass concentration of 20% for 30 min; wash with deionized water, wash with absolute ethanol, and dry with cold air for standby;

[0107] (3) In the powder press mold, lay flat tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder in sequence with a mass ratio of 36:1:120:1:44, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold-press at 650 MPa for 2 min; when laying flat copper powder and tungsten-copper mixed powder, some 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, hold 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 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 to 300 °C at a cooling rate of 4 °C / min and then naturally cool; obtain the tungsten-copper composite material.

[0108] Example 3

[0109] This example provides a method for preparing a tungsten-copper composite material, comprising the following steps:

[0110] (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 milling balls at a ball-to-material ratio of 7:1, and the milling program is milling for 25 min and stopping for 5 min. The total milling program time 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;

[0111] (2) Select a copper plate with a thickness of 1.0 mm. The copper plate is circular and straightened. Prepare symmetric through holes on the copper plate in a "meter" - shaped arrangement (the arrangement method refers to Figure 4 ) with a hole diameter of 0.3 mm for the through holes; 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;

[0112] (3) In the powder press mold, lay flat tungsten - copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten - copper mixed powder in a mass ratio of 36:1:150:1:40 in sequence, so that copper powder and tungsten - copper mixed powder are placed on both surfaces of the copper plate in turn, and cold - press at 700 MPa for 3 min; when laying flat copper powder and tungsten - copper mixed powder, some 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 will form a through - structure; heat up to 500 °C at a heating rate of 4 °C / min, hold 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 to 300 °C at a cooling rate of 4 °C / min and then naturally cool to room temperature; then cold - press at 120 MPa for 3 min, heat up to 1020 °C at a heating rate of 2 °C / min, sinter at 1020 °C for 2 h, and cool to 300 °C at a cooling rate of 4 °C / min and then naturally cool; obtain the tungsten - copper composite material.

[0113] Example 4

[0114] This embodiment provides a method for preparing a tungsten - copper composite material, comprising the following steps:

[0115] (1) Mix 1 - μm tungsten powder, 45 - μm electrolytic copper powder and zirconia, add absolute ethanol, mix at 500 r / min for 12 h, add milling balls according to a ball - to - material ratio of 3:1, with a milling program of milling for 25 min, a milling program time of 18 h, stop for 5 min, and dry at 75 °C for 16 h to obtain tungsten - copper mixed powder; the mass ratio of tungsten powder, electrolytic copper powder and zirconia is 58.9:41:0.1; the ratio of the sum of the masses of tungsten powder, electrolytic copper powder and zirconia to the mass of ethanol is 5:1;

[0116] (2) Select a copper plate with a thickness of 1.5 mm. The copper plate is circular, straightened, and symmetric through - holes are prepared on the copper plate in a "big" - character arrangement (the arrangement method refers to Figure 5 ) with a through - hole diameter of 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 projected area of several through - holes on the upper surface of the copper plate to the upper - surface area of the copper plate is 1:300; on the circumference of the outer edge of the copper plate, 4 micro - groove structures are symmetrically arranged at equal intervals; the micro - groove structure is a symmetric structure and is rectangular (the size of the micro - groove structure is not limited, and the arrangement method and shape refer to Figure 5 ); 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;

[0117] (3) In a powder press mold, lay flat tungsten - copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten - copper mixed powder in a mass ratio of 27:1:100:1:33 in sequence, so that copper powder and tungsten - copper mixed powder are placed on both surfaces of the copper plate in turn, and cold - press at 600 MPa for 3 min; when laying flat the copper powder and tungsten - copper mixed powder, some 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, hold at 500 °C for 1 h, heat up to 800 °C at a heating rate of 2 °C / min, then heat up to 950 °C at 2 °C / min, sinter at 950 °C for 2 h, cool to 300 °C at a cooling rate of 3 °C / min and then naturally cool to room temperature; then cold - press at 130 MPa for 2 min, heat up to 1020 °C at a heating rate of 2 °C / min, sinter at 1020 °C for 2 h, and cool to 300 °C at a cooling rate of 3 °C / min and then naturally cool; obtain the tungsten - copper composite material.

[0118] Example 5

[0119] This embodiment provides a method for preparing a tungsten - copper composite material, comprising the following steps:

[0120] (1) Mix 1 μm tungsten powder, 45 μm electrolytic copper powder and lanthanum oxide, add absolute ethanol, mix at 300 r / min for 12 h, add milling balls according to a ball-to-material ratio of 5:1, the ball milling process is to mill for 25 min, the ball milling process time is 18 h, stop for 5 min, and dry at 75 °C for 12 h to obtain tungsten-copper mixed powder; the mass ratio of tungsten powder, electrolytic copper powder and lanthanum oxide is 61.3:38:0.7; the ratio of the sum of the masses of tungsten powder, electrolytic copper powder and lanthanum oxide to the mass of ethanol is 5:1;

[0121] (2) Select a copper plate with a thickness of 0.5 mm, the copper plate is circular, straighten it, and prepare symmetric through holes on the copper plate according to the "cross" arrangement (the arrangement is referred to Figure 2 ), the aperture of the through hole is 0.2 mm; along the arrangement direction, the shortest distance between the edge points of two adjacent through holes is 0.4 mm; the ratio of the total area of the projections of several through holes on the upper surface of the copper plate to the area of the upper surface of the copper plate is 1:1000; on the circumference of the outer edge of the copper plate, 8 microgroove structures are symmetrically arranged at equal intervals; the microgroove structure is a symmetric structure; the microgroove structure is provided with a second area and a first area from the outside to the inside of the copper plate, and the second area is rectangular (the size of the microgroove structure is not limited, the arrangement and shape are referred to Figure 2 ); Activate the drilled copper plate in sulfuric acid with a mass concentration of 15% for 20 min; wash with deionized water, wash with absolute ethanol, and dry with cold air for standby;

[0122] (3) In the powder press mold, lay tungsten-copper mixed powder, electrolytic copper powder, copper plate, electrolytic copper powder, and tungsten-copper mixed powder in sequence according to a mass ratio of 36:1:130:1:38, so that copper powder and tungsten-copper mixed powder are placed on both surfaces of the copper plate in sequence, and cold press at 500 MPa for 5 min; when laying 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 300 °C at a heating rate of 5 °C / min, keep the temperature at 300 °C for 1 h, heat up to 800 °C at a heating rate of 3 °C / min, then heat up to 900 °C at a heating rate of 2 °C / min, sinter at 900 °C for 2 h, cool to 300 °C at a cooling rate of 3 °C / min and then naturally cool to room temperature; then cold press at 90 MPa for 5 min, heat up to 1050 °C at a heating rate of 3 °C / min, sinter at 1050 °C for 2 h, and cool to 300 °C at a cooling rate of 4 °C / min and then naturally cool; obtain tungsten-copper composite material.

[0123] Comparative Example 1

[0124] This comparative example provides a method for preparing a tungsten-copper material, including the following steps:

[0125] (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.

[0126] (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.

[0127] Comparative Example 2

[0128] This comparative example provides a method for preparing a tungsten copper material, comprising the following steps:

[0129] (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.

[0130] (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.

[0131] Comparative Example 3

[0132] This comparative example provides a method for preparing a tungsten copper material, comprising the following steps:

[0133] (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;

[0134] (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.

[0135] Comparative Example 4

[0136] This comparative example provides a method for preparing a tungsten copper material, comprising the following steps:

[0137] (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.

[0138] (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.

[0139] Comparative Example 5

[0140] This comparative example provides a method for preparing a tungsten copper material, comprising the following steps:

[0141] (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.

[0142] (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;

[0143] (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.

[0144] Test Case

[0145] The performance of the tungsten copper materials prepared in Examples 1-5 and Comparative Examples 1-5 was tested as follows:

[0146] (1) The conductivity was tested according to GB / T 32791-2016 "Eddy Current Testing Method for Electrical Conductivity of Copper and Copper Alloys", and the average value of five test points was taken as the final result. The results are shown in Table 1.

[0147] (2) The corrosion resistance was tested according to GB / T 10125—2021 "Artificial Atmosphere Corrosion Tests Salt Spray Tests", and the time when corrosion began to appear was recorded, and the results were rounded to an integer. The results are shown in Table 1.

[0148] (3) The thermal conductivity was tested according to GB / T 22588—-2008 "Flash Method for Measuring Thermal Diffusivity or Thermal Conductivity". The results are shown in Table 1.

[0149] (4) The Vickers hardness was tested according to GB / T 9097-2016 "Determination of Apparent Hardness and Microhardness of Sintered Metal Materials (Excluding Cemented Carbides)", and the average value of ten test points was taken as the final result. The results are shown in Table 1.

[0150] Table 1 Performance Test Results of Each Example and Comparative Example

[0151]

[0152] As can be seen from Table 1, the tungsten copper material prepared by the present invention has high conductivity and thermal conductivity, good corrosion resistance, and high hardness. By comparing the examples and comparative examples, it can be seen that 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 a number of through structures, and the number of the through structures penetrate the copper plate along the thickness direction of the copper plate, and the components of the through structures include tungsten copper mixed powder and copper powder, which can effectively improve the conductivity, thermal conductivity, corrosion resistance and hardness of the tungsten copper material; compared with the prior art infiltration method for preparing tungsten copper materials, on the premise of good corrosion resistance, the conductivity and thermal conductivity are significantly superior; compared with the tungsten copper materials prepared by simply increasing the copper content, the tungsten copper composite material with a special structure provided by the present invention has better 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 performance of the tungsten copper composite material.

[0153] Obviously, the above examples are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A tungsten-copper composite material, characterized in that, The tungsten copper composite material 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 a number of through structures that penetrate the copper plate along the thickness direction of the copper plate, and the components of the through structures include tungsten and copper. A number of the through structures are regularly arranged on the surface of the copper plate. On the circumference of the outer edge of the copper plate, a number of microgroove structures are arranged at equal intervals and symmetrically. The microgroove structure is a symmetric structure.

2. The tungsten copper composite material according to claim 1, wherein The components of the through structure further include additives; and / or The tungsten copper layer includes tungsten and copper; and / or The copper layer includes copper; 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 additives include 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. The maximum length refers to the maximum distance between 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 gradually becomes larger from the outside to the inside.

4. The preparation method of the tungsten-copper composite material according to any one of claims 1 to 3, characterized in that, It includes the following steps: (1) Prepare tungsten copper mixed powder. (2) A number of through holes are provided in the copper plate. The copper powder and the tungsten copper mixed powder are sequentially located on two surfaces of the copper plate, first pressing, first sintering, second pressing, and second sintering to obtain a tungsten copper composite material. The through holes form through structures in the tungsten copper composite material.

5. The preparation method according to claim 4, wherein The aperture of the through hole is 0.2 - 0.6 mm; and / or The ratio of the total projected area of a number of the through holes on the upper surface of the copper plate to the area of the upper surface of the copper plate is 1:(100 - 1000); and / or The through holes are arranged along a first central axis and a second central axis perpendicular to each other on the copper plate; and / or The through holes are arranged along a first direction and a second direction perpendicular to each other on the copper plate. 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 / or The through holes are distributed along the radial lines of the copper plate, and the included angle between adjacent two 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 includes 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) includes: ball milling and mixing tungsten powder and copper powder; and / or The copper plate is subjected to activation treatment.

6. The preparation method according to claim 5, characterized in that, Along the arrangement direction of the through holes, the shortest distance between the edge points of adjacent two through holes is greater than 2 times the aperture of the through holes; and / or In the 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 step (1), the copper powder includes electrolytic copper powder; and / or, In step (1), the ball milling and mixing further includes adding an additive; and / or, In 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 time of the ball milling and mixing is 12 - 24 h; and / or, In step (1), the rotation speed of the ball milling and mixing is 200 - 500 r / min; and / or, In step (1), the ball milling and mixing further includes adding ethanol; and / or, In step (1), after the ball milling and mixing, drying is further included; and / or, The activating solution includes a sulfuric acid solution; and / or, The activating time is 20 - 40 min.

7. The preparation method according to claim 6, characterized in that In step (1), the additive includes at least one of alumina, yttrium oxide, zirconium oxide, and lanthanum oxide; and / or, 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); and / or, The ratio of the sum of the masses 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 time is 12 - 24 h; and / or, The mass concentration of the sulfuric acid solution is 10 - 20%.

8. The preparation method according to claim 4, wherein The pressure of the first pressing is 500 - 700 MPa; and / or, The time of the first pressing is 1 - 5 min; and / or, The first pressing includes hot pressing, cold pressing, or hot isostatic pressing; and / or, The second pressing includes hot pressing, cold pressing, or hot isostatic pressing; and / or, The pressure of the second pressing is 60 - 150 MPa; and / or, The time of the second pressing is 2 - 5 min.

9. The preparation method according to claim 4, characterized in that, Heat up from room temperature to 300 - 500 °C at a rate not higher than 5 °C / min, hold for 1 h, then heat up to 800 °C at a rate not higher than 5 °C / min, and then heat up to the first sintering temperature at a rate not higher than 3 °C / min for the first sintering; and / or, The time of the first sintering is 1 - 3 h; and / or, The temperature of the first sintering is 800 - 950 °C; and / or, The first sintering is carried out in a reducing atmosphere; and / or, Heat up to the second sintering temperature at a rate not higher than 3 °C / min for the second sintering; and / or, The time of the second sintering is 1 - 3 h; and / or, The temperature of the second sintering is 1000 - 1050 °C; and / or, The second sintering is carried out in a reducing atmosphere; and / or, After the first sintering, it further includes cooling to 200 - 350 °C at a cooling rate not higher than 5 °C / min, and then naturally cooling to room temperature before the second pressing.

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

Images