A tungsten-copper liner and its preparation method

Abstract

The present invention discloses a tungsten-copper liner, and the raw materials thereof include the following components by mass parts: 70-90 parts of tungsten powder, 10-30 parts of copper powder, and 2-10 parts of energetic material; the preparation method of the tungsten-copper liner comprises: 1. Mixing the tungsten powder, copper powder, and energetic material to obtain a mixture, and dissolving the lubricant and modifier with a solvent to obtain a solution; 2. Adding the solution to the mixture, and carrying out modification by heat preservation and stirring, and obtaining a modified powder through drying and sieving; 3. Molding the modified powder to obtain a liner blank, and obtaining the tungsten-copper liner through degreasing and sintering. The tungsten-copper liner of the present invention optimizes the morphology and particle size distribution of the tungsten powder and copper powder, and adds energetic material and modifier to ensure that the modified powder has good uniformity and fluidity, thereby having excellent molding performance, and simultaneously improving the density and penetration depth of the tungsten-copper liner, and can meet the needs of oil well perforation.

Description

Technical Field

[0001] The present invention belongs to the technical field of tungsten - copper composite materials, and particularly relates to a tungsten - copper liner and a preparation method thereof. Background Art

[0002] The armor - piercing process of a shaped charge warhead is a precise and complex process. As one of the key components of a shaped charge warhead, the liner is the main component for forming the jet. The structure and material of the liner have a significant impact on the armor - piercing performance. Tungsten - copper liners have been widely used in the petroleum perforation industry because the jets formed have a high head velocity and good continuity. However, due to the large density difference between tungsten powder and copper powder, during the forming process, due to the action of gravity, it is easy to cause uneven density distribution. In addition, differences in particle size, microscopic shape, crystal structure, lattice defects, etc. between the two will also directly affect the compactness, particle size distribution, fluidity, compressibility, and formability of the liner during the preparation process, thereby affecting the jet performance of the liner. And the requirements for the depth of the shaped jet penetrating the target plate in petroleum perforation shaped charge warheads are getting higher and higher.

[0003] Currently, the particle size and morphology of existing tungsten powder and copper powder are usually separately concerned, and less attention is paid to their compounding. As a result, the fluidity and formability of the material formed after mixing and forming are poor, and the compactness of the formed liner is difficult to meet the expectations. At the same time, the armor - piercing power of common tungsten - copper liners is insufficient and cannot meet the requirements of perforation penetration depth. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a tungsten - copper liner aiming at the deficiencies of the above - mentioned existing technologies. The tungsten - copper liner of the present invention optimizes the morphology and particle size distribution of tungsten powder and copper powder, and adds a modifier to ensure that the modified powder has good uniformity and fluidity, thereby having excellent forming performance. By combining the addition of an energetic material to achieve secondary reaction enhancement, the penetration depth of the tungsten - copper liner is further increased, solving the problems of poor fluidity and formability of existing tungsten - copper modified powders and the insufficient perforation penetration depth of the liners prepared therefrom.

[0005] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is: a tungsten - copper liner, characterized in that it comprises raw materials of the following components by mass fraction: 70 - 90 parts of tungsten powder, 10 - 30 parts of copper powder, and 2 - 10 parts of energetic material; the energetic material is selected from at least one of Ni, Zr, and Ti, and the ratio of the loose bulk density of the tungsten powder to the copper powder is 7.8 - 8.5:1.8 - 1.95, and the tungsten powder is spherical - like particles and the copper powder is dendritic structure. By controlling the morphology of the tungsten powder, it has good fluidity and reduces forming defects.

[0006] The above - mentioned tungsten - copper liner is characterized in that the ratio of the particle size D50 of the tungsten powder to the copper powder is 38 - 55:38 - 48.

[0007] The above-mentioned tungsten-copper liner is characterized in that the mass purity of the tungsten powder is not less than 99.95%, and the particle size is: D10 = 20μm - 27μm, D50 = 38μm - 50μm, D90 = 51μm - 60μm, and the apparent density is 7.8g / cm 3 ~8.5g / cm 3 , and the Hall flow rate does not exceed 25s / 50g; the particle size of the copper powder is: D10 = 15μm - 22μm, D50 = 38μm - 48μm, D90 = 74μm - 81μm, and the apparent density is 1.8g / cm 3 ~1.95g / cm 3 .

[0008] By controlling the particle size and apparent density of the tungsten powder and copper powder, etc., the present invention avoids the agglomeration of the raw material powder being too fine or adhering to the surface of larger particles, which affects the dispersion effect, and at the same time avoids the poor fluidity caused by the raw material powder being too coarse.

[0009] The above-mentioned tungsten-copper liner is characterized in that the tungsten powder, copper powder, and energetic material are all modified with a modifier, and the modifier is selected from one or more of stearic acid, titanate coupling agent, silane coupling agent, sulfamic acid, ethylene-vinyl acetate copolymer, and PEG, and the added mass of the modifier is 1% - 2% of the total mass of the tungsten powder, copper powder, and energetic material.

[0010] The above-mentioned tungsten-copper liner is characterized in that the density of the tungsten-copper liner is not less than 95%, and the penetration depth for static armor piercing test is not less than 760mm.

[0011] At the same time, the present invention also discloses a preparation method of a tungsten-copper liner as described above, which is characterized in that the method includes the following steps:

[0012] Step 1: Mix the tungsten powder, copper powder, and energetic material to obtain a mixture, and dissolve the lubricant and modifier in a solvent to obtain a solution; the lubricant is paraffin wax, and the solvent is gasoline or / and absolute ethanol;

[0013] Step 2: Add the solution in Step 1 to the mixture, and carry out modification by heat preservation and stirring, and obtain modified powder through drying and sieving;

[0014] Step 3: Mould the modified powder obtained in Step 2 to obtain a liner blank, and obtain a tungsten-copper liner through degreasing and sintering.

[0015] The above-mentioned preparation method is characterized in that the particle size D50 of the modified powder in Step 2 is 40μm - 55μm, and the apparent density is 5g / cm 3 ~8g / cm 3, the water contact angle is greater than 120°.

[0016] The above preparation method is characterized in that in step two, the modification temperature is 60°C to 90°C, the modification time is 60 min to 120 min, and the stirring speed is 100 r / min to 200 r / min.

[0017] The above preparation method is characterized in that in step three, the forming process is spin forming, and the rotational speed of the female mold is 580 r / min to 620 r / min, the pressure is 15 MPa to 30 MPa, and the single feed amount requirement is 70 g ± 5 g to 90 g ± 5 g.

[0018] The above preparation method is characterized in that in step three, the modified powder is fed by automatic on-line weighing of metal powder and is formed by centrifugal strong pressure rotation.

[0019] The present invention has the following advantages compared with the prior art:

[0020] 1. The tungsten-copper liner of the present invention optimizes the morphology and particle size distribution of tungsten powder and copper powder, so that the blank prepared from the raw materials does not occupy a large space volume, ensuring that the automatic pressing loading requirement is met during the forming process. While improving the formability of tungsten powder, it is also beneficial to reduce the ultimate pressing pressure of the modified powder, solving the problem of limited quality fluctuation of the modified powder for the liner.

[0021] 2. By adding an energetic material in the tungsten-copper liner of the present invention, a large amount of heat is released in a very short time during the armor-piercing process, and high-pressure gas is generated, which has a self-cleaning effect on the perforation and is beneficial to improving the penetration depth of the tungsten-copper liner.

[0022] 3. The tungsten powder, copper powder, and energetic material in the tungsten-copper liner of the present invention are all modified with a modifier. The modifier generates hydroxyl groups on the surface of metal particles, making the fine powder not easy to agglomerate, ensuring that the modified powder has good uniformity and fluidity, and making the liner blank formed by the modified powder have no obvious defects. At the same time, by adding a lubricant such as paraffin, the lubricity of the modified powder is greatly improved, ensuring the smooth progress of the demolding process after forming and not sticking to the wall.

[0023] 4. The externally added modifier and lubricant are removed by the sintering process, and do not chemically react with tungsten during the sintering process. No free diffusion carbon impurities are generated during the removal stage, and the removal is relatively complete. The finally obtained tungsten-copper liner has excellent performance, the density reaches 92% to 99%, and the penetration depth of the static armor-piercing test reaches more than 760 mm, which can meet the needs of oil well perforation.

[0024] The technical solution of the present invention will be further described in detail below through examples. Specific Embodiments

[0025] In Examples 1 to 3 of the present invention, the tungsten powder used was purchased from Zigong Cemented Carbide Co., Ltd., with the model of CTP crystalline tungsten and a spherical shape; the copper powder used was purchased from Chongqing Institute of Nonferrous Metals New Materials Co., Ltd., with the model of FTD-200 and a dendritic structure; the titanium powder was purchased from Sichuan Henghui New Materials Technology Co., Ltd., with the model of TF-0; the nickel powder was purchased from Jinchuan Group Co., Ltd., with the model of FNiT04; the zirconium powder was purchased from Beijing Xingrongyuan Technology Co., Ltd., with the model of XH-Zr-01; the particle sizes of the three energetic materials of Ni, Zr, and Ti were in accordance with the requirements of the copper powder.

[0026] Example 1

[0027] The tungsten-copper liner of this example includes raw materials of the following components by mass fraction: 80 parts of tungsten powder, 18 parts of copper powder, and 2 parts of titanium powder; the mass purity of the tungsten powder is 99.96%, the particle sizes are D10 = 26.58μm, D50 = 45.62μm, D90 = 58.64μm, and the loose bulk density is 7.8g / cm 3 , and the Hall flow rate is 20s / 50g; the particle sizes of the copper powder are D10 = 19.01μm, D50 = 44.87μm, D90 = 77.90μm, and the loose bulk density is 1.95g / cm 3 .

[0028] The preparation method of the tungsten-copper liner of this example includes the following steps:

[0029] Step 1: Add 80g of tungsten powder, 18g of copper powder, and 2g of titanium powder into a mixer at room temperature and mechanically mix for 4h at a rotation speed of 50r / min to obtain a mixed material; add 1g of titanate coupling agent into 25mL of industrial gasoline, hydrolyze at 80°C for 60min, then add a paraffin solution accounting for 1% of the mass of the mixed material, stir for 60min to mix evenly, and then heat up to 80°C and keep warm for 60min to obtain a solution;

[0030] Step 2: Add the solution in Step 1 into the mixed material, carry out modification at a stirring speed of 100r / min, the modification temperature is 90°C, the modification time is 120min, keep warm continuously after the modification is completed, and dry at 60°C for 2h, and pass through an 80-mesh sieve to obtain a modified powder;

[0031] Step 3: Feed the modified powder obtained in Step 2 automatically and online by weighing metal powder, and obtain a liner blank by centrifugal strong pressure rotary forming, that is, rotary forming. The rotation speed of the female mold is 580r / min, the pressure is 20MPa, the single feed amount is 70g ± 5g, and then degrease at 600°C and sinter in hydrogen at 1200°C to obtain a tungsten-copper liner.

[0032] The modifier in this embodiment may also be one or more of stearic acid, titanate coupling agent, silane coupling agent, sulfamic acid, ethylene-vinyl acetate copolymer, and PEG in addition to the titanate coupling agent; the solvent of the modifier may also be absolute ethanol, or gasoline and absolute ethanol.

[0033] Example 2

[0034] The tungsten-copper liner of this embodiment includes raw materials of the following components by mass: 80 parts of tungsten powder, 16 parts of copper powder, and 4 parts of nickel powder; the mass purity of the tungsten powder is 99.96%, the particle size D10 = 21.65μm, D50 = 39.41μm, D90 = 52.31μm, and the loose bulk density is 8.5g / cm 3 , and the Hall flow rate is 23s / 50g; the particle size D10 = 16.98μm, D50 = 39.72μm, D90 = 75.54μm of the copper powder, and the loose bulk density is 1.82g / cm 3 .

[0035] The preparation method of the tungsten-copper liner of this embodiment includes the following steps:

[0036] Step 1: Add 80g of tungsten powder, 16g of copper powder, and 4g of nickel powder into a mixer at room temperature and mechanically mix for 4h at a rotation speed of 50r / min to obtain a mixed material; add 2g of titanate coupling agent into 25mL of industrial gasoline, hydrolyze at 80°C for 60min, then add a paraffin solution accounting for 1% of the mass of the mixed material, stir for 60min to mix evenly, and then heat up to 80°C and keep warm for 60min to obtain a solution;

[0037] Step 2: Add the solution in Step 1 into the mixed material, carry out modification at a stirring speed of 150r / min, the modification temperature is 80°C, the modification time is 80min, keep warm continuously after the modification is completed, and dry at 60°C for 2h, and pass through an 80-mesh sieve to obtain a modified powder;

[0038] Step 3: Feed the modified powder obtained in Step 2 by automatic on-line weighing of metal powder, and obtain a liner blank by centrifugal high-pressure rotary forming, that is, rotary forming, and the rotation speed of the female mold is 620r / min, the pressure is 15MPa, the single feed amount is 90g ± 5g, and then degrease at 600°C and sinter in hydrogen at 1350°C to obtain a tungsten-copper liner.

[0039] Example 3

[0040] The tungsten-copper liner of this embodiment comprises raw materials of the following components by mass parts: 80 parts of tungsten powder, 16 parts of copper powder, and 4 parts of zirconium powder; the mass purity of the tungsten powder is 99.95%, the particle sizes are D10 = 24.07μm, D50 = 40.87μm, D90 = 55.07μm, the loose bulk density is 8.2g / cm 3 , and the Hall flow rate is 24s / 50g; the particle sizes of the copper powder are D10 = 20.30μm, D50 = 46.72μm, D90 = 79.93μm, and the loose bulk density is 1.87g / cm 3 .

[0041] The preparation method of the tungsten-copper liner of this embodiment comprises the following steps:

[0042] Step 1: Add 80g of tungsten powder, 16g of copper powder, and 4g of zirconium powder into a mixer at room temperature for mechanical mixing for 4h, with a rotation speed of 50r / min to obtain a mixed material; add 1.5g of titanate coupling agent into 25mL of industrial gasoline, hydrolyze at 80°C for 60min, then add a paraffin solution accounting for 1% of the mass of the mixed material, stir for 60min to mix evenly, and then heat up to 80°C for insulation for 60min to obtain a solution;

[0043] Step 2: Add the solution in Step 1 into the mixed material, carry out modification at a stirring speed of 200r / min, with a modification temperature of 60°C and a modification time of 60min. After the modification is completed, keep the temperature constant, and dry at 60°C for 2h, and pass through an 80-mesh sieve to obtain a modified powder;

[0044] Step 3: Feed the modified powder obtained in Step 2 by automatic online weighing of metal powder, and obtain a liner blank by centrifugal strong pressure rotary forming, i.e., spinning forming. The rotation speed of the female mold is 600r / min, the pressure is 30MPa, the single feed amount is 90g ± 5g, and then degrease at 600°C and sinter in hydrogen at 1300°C to obtain the tungsten-copper liner.

[0045] Comparative Example 1

[0046] The difference between this comparative example and Example 1 is that no energetic material titanium powder is added.

[0047] Comparative Example 2

[0048] The difference between this comparative example and Example 1 is that the modification in Step 2 is not carried out, and the mixed material in Step 1 is directly subjected to the forming, degreasing, and sintering processes in Step 3.

[0049] Comparative Example 3

[0050] The difference between this comparative example and Example 1 is that the tungsten powder in Example 1 is replaced with reduced tungsten powder produced by Zigong Cemented Carbide Co., Ltd., with the grade FW-1, mass purity of 99.95%, particle size D10 = 3.34μm, D50 = 8.40μm, D90 = 19.16μm, Hall flow rate of 24 s / 50 g, and loose bulk density of 3.55 g / cm 3 .

[0051] The tungsten copper liner of Examples 1-3 and Comparative Examples 1-3 of the present invention was tested for properties such as density, loose bulk density, particle size, penetration depth, and water contact angle. The results are shown in Table 1.

[0052] 1. Density

[0053] The volume of the tungsten copper liner was measured by the Archimedes drainage method, and then the density and density of the liner were calculated; the electronic analytical balance used had an accuracy of 0.1 mg and a range of 200 g.

[0054] The calculation formula for density: R = ρ 实际 / ρ 理论 .

[0055] 2. Penetration depth

[0056] After pressing the tungsten copper liner, static armor piercing tests were carried out at the same explosive height; after the static armor piercing test, the 60# steel target plate was cut along the direction parallel to the jet inflow direction, and the penetration depth of the shaped charge jet in the steel target was measured with a measuring tool, and the macroscopic damage characteristics of the target plate were observed.

[0057] 3. Water contact angle

[0058] The test was carried out using a G-1 type goniometer contact angle measuring instrument produced by Kyowa Co., Ltd., Japan; the modified powder was prepared into a powder compact with a diameter × height of 30 mm × 10 mm by a die pressing method, and deionized water was dropped on the surface of the powder compact for 1 min and then tested. Three points with a spacing of 5 mm were measured for each sample, and a total of 6 readings were taken, and the average value was taken.

[0059] 4. Loose bulk density

[0060] According to GB / T1479.1-2011 "Metallic powders - Determination of loose bulk density - Part 1: Funnel method", the loose bulk density of tungsten powder and copper powder was measured, and the powder was allowed to flow naturally through a 2.5 mm standard funnel into a cylindrical standard metal measuring cup with a volume of 25 cm 3 The ratio of the mass of the powder to the volume of the measuring cup is the loose bulk density.

[0061] 5. Particle size and proportion of particles in particle size distribution

[0062] The particle size of the metal powder sample was characterized using a Bettersize 2000 laser particle size analyzer to obtain the particle size distribution characteristics of the metal powder. The dry method was selected for measurement, with air as the dispersion medium. Among them, D10, D50, and D90 are typical parameters for characterizing the cumulative particle size distribution of the powder. A laser particle size tester was used to measure the particle size of the powder by the dry method, and the specific gravity within the particle size range was calculated.

[0063] Table 1

[0064]

[0065] In Table 1: The value of A is the ratio of the apparent density of tungsten powder and copper powder; the value of B is the ratio of the particle size D50 of tungsten powder and copper powder; D50 改 is the D50 particle size of the modified powder; ρ is the apparent density of the modified powder, r is the water contact angle of the modified powder; R is the density of the sintered liner.

[0066] It can be seen from Table 1 that compared with Comparative Example 1, the penetration depth of the tungsten-copper liner after adding the energetic material in Example 1 increased; compared with Comparative Example 2, the apparent density of the sintered liner increased and the density of the liner increased after adding the modifier in Example 1; at the same time, the modified powder used in Comparative Example 3 had a small apparent density, and the wall thickness of the liner prepared with the same loading amount was too thick to meet the requirements of the liner outer dimension.

[0067] The above are only the preferred embodiments of the present invention and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent changes made to the above embodiments according to the technical essence of the invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A tungsten copper liner, characterized in that, Raw materials comprising the following components by mass parts: 70 - 90 parts of tungsten powder, 10 - 30 parts of copper powder, 2 - 10 parts of energetic material; the energetic material is selected from at least one of Ni, Zr, and Ti, the ratio of the loose bulk density of the tungsten powder to the copper powder is 7.8 - 8.5:1.8 - 1.95, and the tungsten powder is spherical-like particles and the copper powder is dendritic structure; the tungsten powder, copper powder, and energetic material are all modified with a modifier, and the modifier is selected from one or more of stearic acid, titanate coupling agent, silane coupling agent, sulfamic acid, ethylene-vinyl acetate copolymer, and PEG, and the added mass of the modifier is 1% - 2% of the total mass of the tungsten powder, copper powder, and energetic material; The preparation method of this tungsten-copper liner comprises the following steps: Step 1, mix the tungsten powder, copper powder, and energetic material to obtain a mixture, and dissolve the lubricant and modifier in a solvent to obtain a solution; the lubricant is paraffin wax, and the solvent is gasoline or / and absolute ethanol; Step 2, add the solution in Step 1 to the mixture, and keep warm and stir for modification, and obtain modified powder after drying and sieving; the modification temperature is 60°C - 90°C, the modification time is 60 min - 120 min, and the stirring speed is 100 r / min - 200 r / min; Step 3, shape the modified powder obtained in Step 2 to obtain a liner blank, and obtain the tungsten-copper liner after degreasing and sintering.

2. The tungsten-copper liner according to claim 1, wherein The ratio of the particle size D50 of the tungsten powder to the copper powder is 38 - 55:38 - 48.

3. The tungsten copper liner according to claim 1, wherein, The mass purity of the tungsten powder is not less than 99.95%, and the particle size is: D10 = 20μm to 27μm, D50 = 38μm to 50μm, D90 = 51μm to 60μm, and the apparent density is 7.8g / cm 3 ~8.5g / cm 3 , and the Hall flow rate does not exceed 25s / 50g; the particle size of the copper powder is: D10 = 15μm to 22μm, D50 = 38μm to 48μm, D90 = 74μm to 81μm, and the apparent density is 1.8g / cm 3 ~1.95g / cm 3 .

4. A tungsten copper liner according to claim 1, characterized in that, The density of the tungsten-copper liner is not less than 95%, and the penetration depth for static armor piercing test is not less than 760 mm.

5. The tungsten-copper liner according to claim 1, characterized in that, The particle size D50 of the modified powder described in Step 2 is 40 μm to 55 μm, and the tapped density is 5 g / cm 3 ~8 g / cm 3 , and the water contact angle is greater than 120°.

6. The tungsten copper liner according to claim 1, characterized in that, The shaping process in Step 3 is spin forming, and the rotation speed of the female die is 580 r / min - 620 r / min, the pressure is 15 MPa - 30 MPa, and the single feed amount requirement is 70 g - 90 g.

7. The tungsten copper liner according to claim 1, characterized in that, In Step 3, the modified powder is fed by automatic on-line weighing of metal powder and formed by centrifugal strong pressure rotation.

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