A method for manufacturing a shaped charge liner

Abstract

The present application relates to the field of powder metallurgy, and particularly relates to a preparation method of a perforating charge liner, which comprises the following steps: preparing iron-coated tungsten powder by using iron pentacarbonyl and tungsten powder, putting the iron-coated tungsten powder into a prepared copper salt reaction solution, obtaining copper-coated tungsten composite powder from the copper salt reaction solution with the iron-coated tungsten powder, reducing the copper-coated tungsten composite powder, mixing the reduced copper-coated tungsten composite powder with graphite and machine oil to obtain mixed materials, and spinning and pressing the mixed materials to form the liner. The technical scheme is based on the displacement principle of iron and copper, and the copper-coated tungsten powder is prepared on the basis of the iron-coated tungsten powder. After drying and reduction, the finally obtained copper-coated tungsten composite powder has excellent performance indexes, the particle size distribution of the copper-coated tungsten powder is reasonable, and the loose bulk density can reach 5.9 g / cm 3 The powder body has good flowability, good powder uniformity and good formability.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy, and more particularly to a method for preparing a perforated ammunition shroud. Background Technology

[0002] Perforation technology is the final step in oil and gas extraction, and the performance of perforating explosives is a key technology for improving oil production capacity. Oil perforating explosives are oil well productivity multipliers and are closely related to the quality of oil extraction operations. The shaped charge liner is the most critical component in the performance of oil perforating explosives. After the explosive detonates, a high-speed jet is formed, and the effective mass and velocity of the jet are the determining factors for the penetration depth of the perforating explosive. Tungsten's high density and sound velocity, along with copper's high sound velocity and excellent formability, are widely used in shaped charge liners. For high-tungsten powder shaped charge liners, their formability and compositional uniformity are the most critical factors affecting the performance of perforating explosives.

[0003] Existing shaped charge liner materials are traditionally formed using copper-clad tungsten (90% tungsten) material under high pressure. However, this traditional 90% tungsten copper-clad tungsten material is prepared through electroplating or chemical plating. Due to the rapid settling of tungsten, the copper cannot be uniformly coated on the tungsten, resulting in poor formability of the final copper-clad tungsten material, poor compositional uniformity of the liner, and consequently, poor perforation performance when pressed into a perforating projectile. Furthermore, the limited copper source required for chemical vapor deposition (CVD) makes the direct use of CVD-prepared 90% tungsten copper-clad tungsten material for shaped charge liner production extremely costly and impractical. Summary of the Invention

[0004] This invention addresses the problems of poor molding performance and poor compositional uniformity in the preparation of propellant liner using traditional copper-clad tungsten materials with 90% tungsten content. It provides a method for preparing a perforated ammunition liner that can improve the molding performance and compositional uniformity of the propellant liner.

[0005] To achieve the above objectives, the present invention proposes the following technical solution: A method for preparing a perforated ammunition cover includes the following steps: S1, Iron-coated tungsten powder is prepared using iron pentacarbonyl and tungsten powder; S2, prepare the copper salt reaction solution, and add the iron-coated tungsten powder into the copper salt reaction solution; S3, copper-coated tungsten composite powder is obtained from a copper salt reaction solution containing iron-coated tungsten powder; S4, to reduce copper-clad tungsten composite powder; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

[0006] Preferably, in step S1, the preparation of iron-clad tungsten powder includes the following steps: S11, Prepare tungsten powder and load it into the rotary reactor; S12, After assembling the sealing cover of the rotary reactor, the rotary reactor is evacuated; S13, heating tungsten powder using a rotary reactor; S14, preheating iron pentacarbonyl; S15, start the rotary reactor to rotate, and put the preheated iron pentacarbonyl into the rotary reactor to prepare iron-coated tungsten powder based on iron pentacarbonyl and tungsten powder using the rotary reactor.

[0007] Preferably, in step S11, the particle size of the tungsten powder is 20μm to 100μm.

[0008] Preferably, in step S13, the tungsten powder is heated to 100℃~200℃ and kept at that temperature for 1~3 hours.

[0009] Preferably, in step S2, preparing the copper salt reaction solution includes the following steps: S21, copper salt is placed into a reaction vessel containing water to obtain a reaction solution; S22, a chelating agent is added to the reaction solution; S23, add sodium hydroxide to the reaction solution to adjust the pH value, stir well and let stand.

[0010] Preferably, in step S22, the chelating agent is one or more of EDTA, HEDP, and sodium citrate.

[0011] Preferably, in step S21, the copper salt is one or more of copper chloride, copper sulfate, and copper nitrate.

[0012] Preferably, in step S3, obtaining the copper-clad tungsten composite powder includes the following steps: S31, add iron-coated tungsten powder to the reaction solution, stir evenly and let stand, wait for iron and copper to fully replace each other to generate copper-coated tungsten; S32, after filtering the excess aqueous solution in the reaction vessel, add carbon tetrachloride to the remaining aqueous solution to separate the copper-coated tungsten from the aqueous solution using carbon tetrachloride. S33, based on the stratification of carbon tetrachloride and aqueous solution, the aqueous solution is extracted, leaving carbon tetrachloride containing copper-coated tungsten; S34. The carbon tetrachloride containing copper-coated tungsten is vacuum-treated and the carbon tetrachloride is filtered out to initially obtain copper-coated tungsten composite powder.

[0013] Preferably, in step S4, the reduction of the copper-clad tungsten composite powder includes the following steps: S41, vacuum dry the copper-clad tungsten composite powder after filtration; S42, put the dried copper-clad tungsten composite powder into the reduction equipment; S43, introduce reducing gas into the reduction equipment and adjust the pressure inside the reduction equipment; S44, copper-clad tungsten composite powder is reduced by heating with a reduction device to remove residual chelating agent.

[0014] Preferably, in step S44, the reduction of copper-clad tungsten composite powder includes two stages; the first stage is reduction at a temperature of 300℃~400℃ for 4~5 hours, and the second stage is reduction at a temperature of 700℃ for 0.5~1.5 hours.

[0015] The beneficial technical effects of this invention are as follows: This technical solution is based on the principle of iron-copper substitution. First, iron-coated tungsten powder is prepared using iron pentacarbonyl and tungsten powder. Then, the iron-coated tungsten powder is placed in a copper salt solution to prepare copper-coated tungsten powder. After drying and reduction, the final copper-coated tungsten composite powder contains 90-92 wt% tungsten, a high tungsten content required for materials used in the slow preparation of shaped charges. Furthermore, the copper-coated tungsten composite powder prepared by this technical solution exhibits excellent performance indicators, a reasonable particle size distribution, and a loose packing density of up to 5.9 g / cm³. 3 In summary, the powder exhibits good flowability, uniformity, and formability.

[0016] This technical solution prepares copper-coated tungsten composite powder based on iron-coated tungsten powder. It only requires ordinary copper salts, and the supply of copper source is basically unrestricted. Therefore, the preparation of the shaped charge liner through this technical solution has a low production cost. Attached Figure Description

[0017] Figure 1 This is the basic implementation process of this technical solution; Figure 2 This is a high-speed X-ray image of the jet stream of the perforating projectile (perforating projectile) prepared using this technical solution. Detailed Implementation

[0018] To make the purpose, technical solution and advantages of the invention clearer, the technical solution of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the invention, but not all embodiments.

[0019] Therefore, the following detailed description of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] Example 1 This embodiment discloses a method for preparing a perforated ammunition cover. As a preferred embodiment of the present invention, it includes the following steps: S1, Iron-coated tungsten powder is prepared using iron pentacarbonyl and tungsten powder; S2, prepare the copper salt reaction solution, and add the iron-coated tungsten powder into the copper salt reaction solution; S3, copper-coated tungsten composite powder is obtained from a copper salt reaction solution containing iron-coated tungsten powder; S4, reduce the copper-clad tungsten composite powder to remove the oxygen contained in the copper-clad tungsten composite powder; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

[0021] The principle of this technical solution is as follows: taking advantage of the fact that the chemical potential of iron (-0.037V) is lower than that of copper (+0.337V), iron is used to replace copper ions in the copper salt reaction solution. After the iron-copper replacement reaction, the powder is dried and reduced after removing the aqueous solution, and finally copper-coated tungsten composite powder containing 90% tungsten is prepared.

[0022] Example 2 This embodiment discloses a method for preparing a perforated ammunition cover. As a preferred embodiment of the present invention, it includes the following steps: S1, preparing iron-coated tungsten powder using iron pentacarbonyl and tungsten powder, specifically includes the following steps: S11, Prepare tungsten powder and load it into the rotary reactor; S12, After assembling the sealing cover of the rotary reactor, the rotary reactor is evacuated; S13, heating tungsten powder using a rotary reactor; S14, preheating iron pentacarbonyl; S15, start the rotary reactor to rotate, put the preheated iron pentacarbonyl into the rotary reactor, and use the rotary reactor to prepare iron-coated tungsten powder based on iron pentacarbonyl and tungsten powder; S2, Prepare the copper salt reaction solution by adding iron-coated tungsten powder to the copper salt reaction solution; wherein, preparing the copper salt reaction solution includes the following steps: S21, copper salt is placed into a reaction vessel containing water to obtain a reaction solution; S22, a chelating agent is added to the reaction solution; S23, add sodium hydroxide to the reaction solution to adjust the pH value, stir well and let stand; S3, copper-coated tungsten composite powder is obtained from a copper salt reaction solution containing iron-coated tungsten powder; S4, to reduce copper-clad tungsten composite powder; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

[0023] Example 3 This embodiment discloses a method for preparing a perforated ammunition cover. As a preferred embodiment of the present invention, it includes the following steps: S1, Iron-coated tungsten powder is prepared using iron pentacarbonyl and tungsten powder; S2, prepare the copper salt reaction solution, and add the iron-coated tungsten powder into the copper salt reaction solution; S3, Obtaining copper-coated tungsten composite powder from a copper salt reaction solution containing iron-coated tungsten powder, specifically includes the following steps: S31, add iron-coated tungsten powder to the reaction solution, stir evenly and let stand, wait for iron and copper to fully replace each other to generate copper-coated tungsten; S32, after filtering the excess aqueous solution in the reaction vessel, add carbon tetrachloride to the remaining aqueous solution to separate the copper-coated tungsten from the aqueous solution using carbon tetrachloride. S34, based on the stratification of carbon tetrachloride and aqueous solution, the aqueous solution is extracted, leaving carbon tetrachloride containing copper-coated tungsten; S35, the carbon tetrachloride containing copper-coated tungsten is vacuum-treated and the carbon tetrachloride is filtered out to initially obtain copper-coated tungsten composite powder. S4, to reduce copper-clad tungsten composite powder; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

[0024] Example 4 This embodiment discloses a method for preparing a perforated ammunition cover. As a preferred embodiment of the present invention, it includes the following steps: S1, Iron-coated tungsten powder is prepared using iron pentacarbonyl and tungsten powder; S2, prepare the copper salt reaction solution, and add the iron-coated tungsten powder into the copper salt reaction solution; S3, copper-coated tungsten composite powder is obtained from a copper salt reaction solution containing iron-coated tungsten powder; S4, the reduction of copper-clad tungsten composite powder is carried out, specifically including the following steps: S41, vacuum dry the copper-clad tungsten composite powder after filtration; S42, put the dried copper-clad tungsten composite powder into the reduction equipment; S43, introduce reducing gas into the reduction equipment and adjust the pressure inside the reduction equipment; S44, copper-clad tungsten composite powder is reduced by heating with a reduction device to remove residual chelating agent; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

[0025] Example 5 This embodiment discloses a method for preparing a perforated ammunition cover. As a preferred embodiment of the present invention, it includes the following steps: S1, preparing iron-coated tungsten powder using iron pentacarbonyl and tungsten powder, specifically includes the following steps: S11. Prepare tungsten powder (CTP tungsten powder) and load it into a rotary reactor; wherein the particle size of the tungsten powder is 20μm~100μm; S12, After assembling the sealing cover of the rotary reactor, the rotary reactor is evacuated; S13, tungsten powder is heated by a rotary reactor to a temperature of 100℃~200℃ and kept at that temperature for 1~3 hours to ensure that the tungsten powder is fully heated; S14, preheating iron pentacarbonyl at a temperature of 80℃~120℃; S15, start the rotary reactor to rotate, and add preheated iron pentacarbonyl to the rotary reactor. Using the rotary reactor, iron-coated tungsten powder is prepared based on iron pentacarbonyl and tungsten powder. Specifically, iron pentacarbonyl is fully pyrolyzed and coated to prepare core-shell structured iron-coated tungsten powder. The obtained iron-coated tungsten powder needs to be stored under vacuum.

[0026] S2, Prepare the copper salt reaction solution by adding iron-coated tungsten powder to the copper salt reaction solution; wherein, preparing the copper salt reaction solution includes the following steps: S21, copper salt is placed into a reaction vessel containing water to obtain a reaction solution; S22, add 20g / 100ml to 80g / ml chelating agent to the reaction solution, wherein the chelating agent is one or more of EDTA, HEDP and sodium citrate; S23. Add sodium hydroxide to the reaction solution to adjust the pH value, stir well and let it stand for more than 10 minutes.

[0027] S3, Obtaining copper-coated tungsten composite powder from a copper salt reaction solution containing iron-coated tungsten powder, specifically includes the following steps: S31, add iron-coated tungsten powder to the reaction solution, stir evenly and let stand, wait for iron and copper to fully replace each other to generate copper-coated tungsten; S32, after filtering the excess aqueous solution in the reaction vessel, add carbon tetrachloride to the remaining aqueous solution to separate the copper-coated tungsten from the aqueous solution using carbon tetrachloride. S34, based on the stratification of carbon tetrachloride and aqueous solution, the aqueous solution is extracted, leaving carbon tetrachloride containing copper-coated tungsten; S35 involves vacuum-treating carbon tetrachloride containing copper-coated tungsten and filtering out the carbon tetrachloride to initially obtain copper-coated tungsten composite powder.

[0028] S4, the reduction of copper-clad tungsten composite powder is carried out, specifically including the following steps: S41, vacuum dry the copper-clad tungsten composite powder after filtration; S42, the dried copper-clad tungsten composite powder is placed into a reduction device (continuous reduction furnace, bell furnace or carbon tube furnace); S43. A reducing gas (decomposed ammonia, hydrogen, or coal gas) is introduced into the reduction equipment to adjust the internal pressure. The pressure inside the reduction equipment (i.e., inside the furnace chamber, where the reduction reaction takes place) is ΔP higher than outside the furnace. If ΔP is too low, it will affect product quality and may even cause an explosion due to air entering the furnace, posing a safety risk. If ΔP is too high, it will affect the reaction effect and increase the gas consumption. Therefore, ΔP = 25~90 Pa can ensure a good and safe reaction effect inside the furnace, and an appropriate gas consumption. S44. The copper-clad tungsten composite powder is reduced by heating with a reduction device to remove residual chelating agent. The process includes the following two stages: the first stage is reduction at 300℃~400℃ for 4~5h, and the second stage is reduction at 700℃ for 0.5~1.5h. The final copper-clad tungsten composite powder has a W content of 90~92wt% and the balance is Cu.

[0029] S5, take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material.

[0030] S6. The mixed material is spun and pressed to obtain a shaped charge liner. A liner pressing machine (SLCZ150 type) can be used for the spun pressing process. Spinning ensures uniform distribution of the mixed material, improving the strength of the shaped charge liner's ends. Assembling and pressing this shaped charge liner with the explosive yields a high-performance perforated projectile. Figure 2 It can be seen that the jet stream from the perforation hole is continuous and straight, and quite long.

Claims

1. A method for preparing a perforated ammunition cover, characterized in that, Includes the following steps: S1, preparing iron-coated tungsten powder using iron pentacarbonyl and tungsten powder, specifically includes the following steps: S11, Prepare tungsten powder and load it into the rotary reactor; S12, After assembling the sealing cover of the rotary reactor, the rotary reactor is evacuated; S13, heating tungsten powder using a rotary reactor; S14, preheating pentacarbonyl iron; S15, start the rotary reactor to rotate, put the preheated iron pentacarbonyl into the rotary reactor, and use the rotary reactor to prepare iron-coated tungsten powder based on iron pentacarbonyl and tungsten powder; S2, prepare the copper salt reaction solution, and add the iron-coated tungsten powder into the copper salt reaction solution; S3, copper-coated tungsten composite powder is obtained from a copper salt reaction solution containing iron-coated tungsten powder; S4, to reduce copper-clad tungsten composite powder; S5, Take the reduced copper-clad tungsten composite powder and mix it with graphite and machine oil to obtain a mixed material; S6. Take the mixed material and spin press it to obtain the shaped charge.

2. The method for preparing a perforated ammunition cover as described in claim 1, characterized in that: In step S11, the particle size of the tungsten powder is 20μm to 100μm.

3. The method for preparing a perforated ammunition cover as described in claim 1, characterized in that: In step S13, the tungsten powder is heated to 100℃~200℃ and kept at that temperature for 1~3 hours.

4. The method for preparing a perforated ammunition cover as described in claim 1, characterized in that, In step S2, preparing the copper salt reaction solution includes the following steps: S21, copper salt is placed into a reaction vessel containing water to obtain a reaction solution; S22, a chelating agent is added to the reaction solution; S23, add sodium hydroxide to the reaction solution to adjust the pH value, stir well and let stand.

5. The method for preparing a perforated ammunition cover as described in claim 4, characterized in that, In step S22, the chelating agent is one or more of EDTA, HEDP, and sodium citrate.

6. The method for preparing a perforated ammunition cover as described in claim 5, characterized in that, In step S21, the copper salt is one or more of copper chloride, copper sulfate, and copper nitrate.

7. The method for preparing a perforated ammunition cover as described in claim 1, characterized in that, In step S3, obtaining the copper-clad tungsten composite powder includes the following steps: S31, add iron-coated tungsten powder to the reaction solution, stir evenly and let stand, wait for iron and copper to fully replace each other to generate copper-coated tungsten; S32, after filtering the excess aqueous solution in the reaction vessel, add carbon tetrachloride to the remaining aqueous solution to separate the copper-coated tungsten from the aqueous solution using carbon tetrachloride. S33, based on the stratification of carbon tetrachloride and aqueous solution, the aqueous solution is extracted, leaving carbon tetrachloride containing copper-coated tungsten; S34. The carbon tetrachloride containing copper-coated tungsten is vacuum-treated and the carbon tetrachloride is filtered out to initially obtain copper-coated tungsten composite powder.

8. The method for preparing a perforated ammunition cover as described in claim 1, characterized in that, In step S4, the reduction of the copper-clad tungsten composite powder includes the following steps: S41, vacuum dry the copper-clad tungsten composite powder after filtration; S42, put the dried copper-clad tungsten composite powder into the reduction equipment; S43, introduce reducing gas into the reduction equipment and adjust the pressure inside the reduction equipment; S44, copper-clad tungsten composite powder is reduced by heating with a reduction device to remove residual chelating agent.

9. The method for preparing a perforated ammunition cover as described in claim 8, characterized in that, In step S44, the reduction of copper-clad tungsten composite powder includes two stages: the first stage is reduction at 300℃~400℃ for 4~5h, and the second stage is reduction at 700℃ for 0.5~1.5h.

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