A barrier-removing bomb based on a plastic base framework and a mixture of gradient metal powder and paraffin and a preparation method thereof

Abstract

This invention discloses a breaching projectile based on a plastic-based skeleton and a mixture of gradient metal powder and paraffin wax, and its preparation method, belonging to the field of anti-theft device breaching technology. The method includes: preparing a hollow plastic-based skeleton; melting solid paraffin wax into a liquid, then stirring it evenly with tungsten alloy powder to obtain a first mixture; melting solid paraffin wax into a liquid, then stirring it evenly with lead alloy powder to obtain a second mixture; melting solid paraffin wax into a liquid, then stirring it evenly with iron alloy powder to obtain a third mixture; placing the hollow plastic-based skeleton into a breaching projectile mold, then pouring in the first mixture and solidifying it to obtain a first layer; pouring the second mixture onto the first layer and solidifying it to obtain a second layer; pouring the third mixture onto the second layer and solidifying it to obtain a third layer; and finally, solidifying a top cover on the third layer. The breaching projectile of this invention can efficiently breach anti-theft wooden doors while ensuring the safety of the surrounding environment and personnel.

Description

Technical Field

[0001] This invention belongs to the field of anti-theft device obstacle-breaking technology, and particularly relates to an obstacle-breaking bullet based on a plastic matrix skeleton and a mixture of gradient metal powder and paraffin wax, and its preparation method. Background Technology

[0002] In everyday life, security devices (such as security wooden doors) are widely used in various buildings, playing a crucial role in protecting people's and property's safety. However, in special situations such as fire rescue and law enforcement operations, there is an urgent need for a quick and efficient method to break into security wooden doors to meet emergency rescue needs or successfully carry out missions.

[0003] Currently, existing methods for breaching security wooden doors include physical damage and explosive methods. Physical damage (such as using crowbars, hammers, and other manual tools) is time-consuming, inefficient, and requires a high level of physical strength from the operator. When facing structurally strong security wooden doors, it is difficult to achieve an effective breakthrough in a short time. Explosive methods (such as using 22mm rifle grenades) are ineffective at breaching metal security doors, and the shattered bullets are prone to ricocheting, easily injuring nearby people or hostages behind the door, posing a significant safety hazard. Summary of the Invention

[0004] One of the objectives of this invention is to provide a method for preparing a breaching projectile based on a plastic matrix skeleton and a mixture of gradient metal powder and paraffin wax. The breaching projectile prepared by this method can efficiently destroy anti-theft wooden doors while ensuring the safety of the surrounding environment and personnel, and is suitable for emergency breaching operations in special scenarios.

[0005] The second objective of this invention is to provide a barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax.

[0006] To achieve one of the above objectives, the present invention employs the following technical solution:

[0007] A method for preparing a barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax, the method comprising the following steps:

[0008] Step S1: Using the photopolymerization 3D printing method, the bright resin powder is exposed at 22-26℃ for 2-3 seconds to obtain a hollow plastic matrix skeleton.

[0009] Step S2: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add tungsten alloy powder and stir evenly to obtain the first mixture.

[0010] Step S3: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add lead alloy powder and stir evenly to obtain the second mixture.

[0011] Step S4: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add iron alloy powder and stir evenly to obtain the third mixture.

[0012] Step S5: After the hollowed-out plastic matrix skeleton is installed into the cylindrical inner cavity mold, the first mixture is poured into the cylindrical inner cavity mold and then solidified to obtain the plastic matrix skeleton and the first layer of the gradient metal powder and paraffin mixture.

[0013] Step S6: Pour the second mixture onto the first layer and then solidify it to obtain the second layer of plastic matrix skeleton and gradient metal powder and paraffin mixture;

[0014] Step S7: Pour the third mixture onto the second layer and then solidify it to obtain the third layer of plastic matrix skeleton and gradient metal powder and paraffin mixture;

[0015] Step S8: Perform top cover condensation and solidification on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0016] Furthermore, the porosity of the first mixture, the second mixture, and the third mixture is no greater than 0.05%, and the fracture strength is greater than or equal to 21 MPa.

[0017] Furthermore, the weight ratio of the first mixture, the second mixture, and the third mixture is 5-6:3.5:12-14.

[0018] Furthermore, in step S1, the particle size of the light-curing resin powder is less than or equal to 100 μm; the layer thickness of the photocurable 3D printing is 0.01 to 0.15 mm.

[0019] Furthermore, in step S1, each mesh-like meridian on the hollowed-out plastic base skeleton is arranged in a spiral at an equal angle to the center;

[0020] In step S1, the diameter of each mesh network on the hollowed-out plastic base skeleton is 1 to 1.5 mm;

[0021] In step S1, the hollowed-out plastic base skeleton is cylindrical in shape.

[0022] Further, in step S2, the weight ratio of the tungsten alloy powder to paraffin is 3-7:0.5;

[0023] In step S2, the particle size of the tungsten alloy powder is less than or equal to 50 μm.

[0024] Further, in step S3, the weight ratio of the lead alloy powder to paraffin is 1 to 5: 0.5;

[0025] In step S3, the particle size of the lead alloy powder is less than or equal to 50 μm.

[0026] Further, in step S4, the weight ratio of the ferroalloy powder to paraffin is 9.1–13.1:2.5;

[0027] In step S4, the particle size of the iron alloy powder is less than or equal to 50 μm.

[0028] Furthermore, in steps S5, S6, and S7, the condensation and solidification time is 1.5 to 2.5 hours.

[0029] In step S8, the time for the top cover to solidify is 1.5 to 2.5 hours.

[0030] To achieve the second objective mentioned above, the present invention employs the following technical solution:

[0031] A barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax, wherein the barrier-breaking projectile is prepared using the barrier-breaking projectile preparation method described above.

[0032] In summary, the solution proposed in this invention has the following technical effects:

[0033] This invention utilizes a hollowed-out plastic matrix skeleton as the supporting structure of the obstacle-clearing projectile, effectively improving its structural stiffness and strength, increasing its peak failure strength by two times or more compared to when it lacks a hollowed-out plastic matrix skeleton. This invention also prepares hybrids (including a first, second, and third hybrid) with different functional properties by mixing solid paraffin with tungsten alloy powder, lead alloy powder, and iron alloy powder, forming a "gradient" structure warhead. This improves the penetration performance of the obstacle-clearing projectile while maintaining a constant volume. The low-density characteristics of the third hybrid placed on top of the warhead achieve primary impact on the target. Furthermore, the higher density of the second and third hybrids... This hybrid system compensates for the insufficient armor-piercing capability of obstacle-clearing projectiles, enabling them to bluntly strike high-strength targets. It ensures that the projectile, powered by gunpowder, high-pressure gas, or other energy sources, will not automatically disintegrate even at a launch impact velocity of 400 m / s. Upon impact, it rapidly disintegrates into fine metal powder and fragments without the risk of ricocheting, and the flying metal powder and fragments will not cause fatal injuries to personnel. It quickly and efficiently destroys targets such as security door locks, improving the obstacle-clearing projectile's door-breaking and lock-picking capabilities. It is suitable for special forces, mobile units, and special police units to perform missions such as hostage rescue, decapitation strikes, and area clearing operations, meeting the requirements for breaching weak obstacle targets. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This embodiment provides a method for preparing a barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax. The method for preparing the barrier-breaking projectile includes the following steps:

[0036] Step S1: Using the photopolymerization 3D printing method, the light resin powder is exposed at 22-26℃ for 2-3 seconds to obtain a hollow plastic base skeleton.

[0037] In this embodiment, the hollow plastic base frame serves as the support structure for the breaching projectile. The hollow plastic base frame is obtained using Guangming resin powder with a particle size of less than or equal to 100μm and a photopolymerization 3D printing method. Each mesh-like meridian on the hollow plastic base frame is arranged in a spiral at an equal angle to the center. The diameter of each mesh-like meridian on the hollow plastic base frame is 1 to 1.5mm. The hollow plastic base frame is cylindrical in shape, which improves the structural rigidity and strength of the breaching projectile and achieves the purpose of destroying the anti-theft wooden door lock.

[0038] In this embodiment, the layer thickness of photopolymer 3D printing is controlled within 0.01 to 0.15 mm, which ensures the smoothness of the process of the obstacle-breaking projectile and avoids uneven fracture caused by the formation of a wavy surface or premature fracture due to initial defects.

[0039] Step S2: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into a liquid. Then add tungsten alloy powder and stir evenly to obtain the first mixture.

[0040] Step S3: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add lead alloy powder and stir evenly to obtain the second mixture.

[0041] The second hybrid in this embodiment serves as an intermediate layer, further compensating for the armor-piercing capability of the obstacle-penetrating projectile, and is low in cost.

[0042] Step S4: Cut the solid paraffin into granules and put them into a container. Heat the container to 83-87°C and melt it into a liquid. Then add the iron alloy powder and stir evenly to obtain the third mixture.

[0043] To improve the armor-piercing capability of the obstacle-clearing projectile and ensure that it can withstand a launch impact velocity of 400 m / s without automatically disintegrating, thereby achieving blunt impact damage to high-strength targets (such as the connection between the lock cylinder and the lock cylinder seat of a security wooden door), the weight ratio of tungsten alloy powder to paraffin wax in this embodiment is 3-7:0.5, the weight ratio of lead alloy powder to paraffin wax is 1-5:0.5, and the weight ratio of iron alloy powder to paraffin wax is 9.1-13.1:2.5.

[0044] In order to improve the degree of disintegration and fragmentation of the obstacle-clearing projectile after hitting the target and avoid the generation of large pieces that could cause injury, the particle size of the tungsten alloy powder, lead alloy powder and iron alloy powder in this embodiment is less than or equal to 50 μm.

[0045] Step S5: After the hollowed-out plastic matrix skeleton is inserted into the barrier-breaking projectile mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking projectile mold and then solidified to obtain the plastic matrix skeleton and the first layer of the gradient metal powder and paraffin mixture.

[0046] This embodiment utilizes the first composite material located in the first layer to efficiently blunt targets with high structural strength, such as lock cylinders. To improve the internal uniformity of the breaching projectile, the solidification time in this embodiment is set to 1.5–2.5 hours.

[0047] Step S6: Pour the second mixture onto the first layer and then solidify it to obtain the second layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0048] To improve the internal uniformity of the armor-piercing projectile, the solidification time in this embodiment is 1.5–2.5 hours. The second and first mixtures, due to their high density, form a gradient structure. With a constant volume, the gradient design offers superior penetration performance. The lead alloy powder, with a density between tungsten and iron alloy powders, primarily serves a supporting role. The second mixture, with its density equal to that of paraffin wax, compensates for the insufficient armor-piercing capability of the first mixture. The remaining energy of the second mixture is used for blunt impact against higher-strength targets such as the lock core.

[0049] Step S7: Pour the third mixture onto the second layer and then solidify it to obtain the third layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0050] To improve the internal uniformity of the obstacle-clearing projectile, the solidification time in this embodiment is 1.5–2.5 hours. The third layer (i.e., the third mixture) is located at the top of the warhead. Due to its low density, it is used for primary impact and penetration of high-strength targets such as sheet metal.

[0051] Step S8: Perform top cover condensation and solidification on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0052] To ensure that the third mixture is fully cooled and solidified within the hollowed-out plastic base frame, the cooling and solidification time of the top cover in this embodiment is 1.5 to 2.5 hours.

[0053] In this embodiment, the weight ratio of the first mixture, the second mixture, and the third mixture is 5-6:3.5:12-14.

[0054] To ensure uniform and rapid melting of paraffin wax during processing, thereby improving the molding precision and surface quality of the product, this embodiment cuts solid paraffin wax into particles of 1.5–2.5 mm × 1.5–2.5 mm × 1.5–2.5 mm. This embodiment utilizes the adhesive properties of paraffin wax to ensure the uniformity and consistency of the first mixture of tungsten alloy powder and paraffin wax in the first layer, the second mixture of lead alloy powder and paraffin wax in the second layer, and the third mixture of iron alloy powder and paraffin wax in the third layer. In this embodiment, the plastic matrix skeleton serves as a support, attached to the surfaces of the first, second, and third mixtures, forming a "gradient" structure projectile. This improves the penetration performance of the obstacle-clearing projectile while maintaining a constant volume.

[0055] To ensure the durability and impermeability of the first, second, and third mixtures and extend the service life of the structure, the porosity of the first, second, and third mixtures in this embodiment is no greater than 0.05%.

[0056] To ensure that the obstacle-clearing projectile breaks into small fragments upon impact with the target, thus preventing fatal injuries to nearby personnel, the fracture strength of the first, second, and third composite materials in this embodiment is greater than or equal to 21 MPa, preferably 22 to 24 MPa. This avoids the situation where large fragments result in high rebound mass and velocity, which could easily cause injury to nearby personnel.

[0057] This embodiment utilizes a hollowed-out plastic matrix skeleton as the support structure of the obstacle-clearing projectile, effectively improving its structural stiffness and strength (e.g., 20-22 MPa), resulting in a peak failure strength that is two times or more higher than that without the hollowed-out plastic matrix skeleton. This embodiment also prepares hybrids (including a first, second, and third hybrid) with different functional properties by mixing solid paraffin with tungsten alloy powder, lead alloy powder, and iron alloy powder, respectively, forming a "gradient" structure warhead. This improves the penetration performance of the obstacle-clearing projectile while maintaining a constant volume. The low-density characteristics of the third hybrid placed on top of the warhead achieve the initial impact on the target. The higher density of the third hybrid further enhances the impact. The two-component and the first-component hybrid system compensate for the insufficient armor-piercing capability of the obstacle-clearing projectile, enabling it to bluntly strike high-intensity targets. This ensures that the obstacle-clearing projectile of this embodiment, driven by power sources such as gunpowder and high-pressure gas, will not automatically disintegrate even when subjected to a launch impact velocity of 400 m / s. After impacting the target, it can quickly disintegrate into fine metal powder and fragments without the risk of rebound. Moreover, the splashed metal powder and fragments will not cause fatal injuries to personnel. It can quickly and efficiently destroy targets such as anti-theft wooden door locks, improving the obstacle-clearing projectile's door-breaking and lock-picking function. It is suitable for special forces, mobile forces, and special police forces to perform tasks such as hostage rescue, decapitation strikes, and area clearing operations, meeting the requirements for breaching weak obstacle targets.

[0058] Example 1:

[0059] Step S1: Using a photopolymerization 3D printing method with a layer thickness of 0.01 mm, 100 μm particle size Guangming resin powder is printed and exposed at 22°C for 2 seconds to obtain a cylindrical hollow plastic base skeleton in which each mesh meridian is spirally arranged at an equal angle to the center. The diameter of each mesh meridian on the hollow plastic base skeleton is 1 mm.

[0060] Step S2: Solid paraffin wax is cut into particles of 1.5mm × 1.5mm × 1.5mm and placed in a container. The mixture is heated to 83°C and melted into a liquid. Then, tungsten alloy powder with a particle size of 50μm is added and stirred until homogeneous, resulting in a first mixture with a porosity of 0.05% and a fracture strength of 21MPa. The weight ratio of tungsten alloy powder to paraffin wax is 3:0.5.

[0061] Step S3: After cutting solid paraffin into particles of 1.5mm × 1.5mm × 1.5mm, place them in a container and heat to 83℃ to melt them into a liquid. Then, add lead alloy powder with a particle size of 50μm and stir evenly to obtain a second mixture with a porosity of 0.05% and a fracture strength of 21MPa. The weight ratio of lead alloy powder to paraffin is 1:0.5.

[0062] Step S4: After cutting solid paraffin into particles of 1.5mm × 1.5mm × 1.5mm, place them in a container and heat to 83℃ to melt them into a liquid. Then, add ferroalloy powder with a particle size of 50μm and stir evenly to obtain a third mixture with a porosity of 0.05% and a fracture strength of 21MPa. The weight ratio of ferroalloy powder to paraffin is 9.1:2.5.

[0063] Step S5: After the hollowed-out plastic matrix skeleton is installed into the barrier-breaking projectile mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking projectile mold and solidified for 1.5 hours to obtain the first layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin wax.

[0064] Step S6: Pour the second mixture onto the first layer and then solidify it for 1.5 hours to obtain the second layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0065] Step S7: Pour the third mixture onto the second layer and solidify it for 1.5 hours to obtain the third layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0066] Step S8: Perform top cover condensation and curing on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture for 1.5 hours to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0067] In this embodiment, the weight ratio of the first mixture, the second mixture, and the third mixture is 5:3.5:12.

[0068] The breaching projectile of this embodiment is 37 mm long, 17.9 mm in diameter, has an elastic modulus of 780 MPa, and a yield strength of 20 MPa. Firing one breaching projectile of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinder of one security door; firing two breaching projectiles of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of two security doors without automatic disintegration. Furthermore, upon impact with the security door, the rapidly disintegrating metal powder and fragments do not rebound and do not cause fatal injuries to personnel.

[0069] Example 2:

[0070] Step S1: Using a photopolymerization 3D printing method with a layer thickness of 0.15 mm, 95 μm particle size Guangming resin powder is printed and exposed at 26℃ for 3 seconds to obtain a cylindrical hollow plastic base skeleton in which each mesh meridian is spirally arranged at an equal angle to the center. The diameter of each mesh meridian on the hollow plastic base skeleton is 1.5 mm.

[0071] Step S2: Solid paraffin wax is cut into particles of 2.5mm × 2.5mm × 2.5mm and placed in a container. The mixture is heated to 87℃ and melted into a liquid. Then, tungsten alloy powder with a particle size of 45μm is added and stirred until homogeneous, resulting in a first mixture with a porosity of 0.04% and a fracture strength of 24MPa. The weight ratio of tungsten alloy powder to paraffin wax is 7:0.5.

[0072] Step S3: After cutting solid paraffin into particles of 2.5mm × 2.5mm × 2.5mm, place them in a container and heat to 87℃ to melt them into a liquid. Then, add lead alloy powder with a particle size of 45μm and stir evenly to obtain a second mixture with a porosity of 0.04% and a fracture strength of 24MPa. The weight ratio of lead alloy powder to paraffin is 5:0.5.

[0073] Step S4: After cutting solid paraffin into particles of 2.5mm × 2.5mm × 2.5mm, place them in a container and heat to 87℃ to melt them into a liquid. Then, add ferroalloy powder with a particle size of 45μm and stir evenly to obtain a third mixture with a porosity of 0.04% and a fracture strength of 24MPa. The weight ratio of ferroalloy powder to paraffin is 13.1:2.5.

[0074] Step S5: After inserting the hollowed-out plastic matrix skeleton into the barrier-breaking projectile mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking projectile mold and solidified for 2.5 hours to obtain the first layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin wax.

[0075] Step S6: Pour the second mixture onto the first layer and then solidify it for 2.5 hours to obtain the second layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0076] Step S7: Pour the third mixture onto the second layer and then solidify it for 2.5 hours to obtain the third layer of plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0077] Step S8: Perform top cover condensation and curing on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture for 2.5 hours to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0078] In this embodiment, the weight ratio of the first mixture, the second mixture, and the third mixture is 6:3.5:14.

[0079] The breaching projectile of this embodiment is 37 mm long, 17.9 mm in diameter, has an elastic modulus of 780 MPa, and a yield strength of 22 MPa. Firing one breaching projectile of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of three security doors; firing two breaching projectiles of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of four security doors without automatic disintegration. Furthermore, upon impact with the security doors, the rapidly disintegrating metal powder and fragments do not rebound and do not cause fatal injuries to personnel.

[0080] Example 3:

[0081] Step S1: Using a photopolymerization 3D printing method with a layer thickness of 0.13 mm, 90 μm particle size Guangming resin powder is printed and exposed at 24℃ for 2.5 s to obtain a cylindrical hollow plastic base skeleton in which each mesh meridian is spirally arranged at an equal angle to the center. The diameter of each mesh meridian on the hollow plastic base skeleton is 1.3 mm.

[0082] Step S2: Solid paraffin wax is cut into particles of 2mm × 2mm × 2mm and placed in a container. The mixture is heated to 85℃ and melted into a liquid. Then, tungsten alloy powder with a particle size of 47μm is added and stirred until homogeneous, resulting in a first mixture with a porosity of 0.03% and a fracture strength of 23MPa. The weight ratio of tungsten alloy powder to paraffin wax is 5:0.5.

[0083] Step S3: After cutting solid paraffin into 2mm×2mm×2mm particles, place them in a container and heat to 84℃ to melt them into a liquid. Then, add lead alloy powder with a particle size of 46μm and stir evenly to obtain a second mixture with a porosity of 0.03% and a fracture strength of 23MPa. The weight ratio of lead alloy powder to paraffin is 3:0.5.

[0084] Step S4: After cutting solid paraffin into 2mm×2mm×2mm particles, place them in a container and heat to 84℃ to melt them into a liquid. Then, add ferroalloy powder with a particle size of 45μm and stir evenly to obtain a third mixture with a porosity of 0.03% and a fracture strength of 23MPa. The weight ratio of ferroalloy powder to paraffin is 11.1:2.5.

[0085] Step S5: After the hollowed-out plastic matrix skeleton is inserted into the barrier-breaking projectile mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking projectile mold and solidified for 2 hours to obtain the first layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0086] Step S6: Pour the second mixture onto the first layer and then solidify it for 2 hours to obtain the second layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0087] Step S7: Pour the third mixture onto the second layer and then solidify it for 2 hours to obtain the third layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0088] Step S8: Perform top cover condensation and curing on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture for 2 hours to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0089] In this embodiment, the weight ratio of the first mixture, the second mixture, and the third mixture is 5.5:3.5:13.

[0090] The breaching projectile of this embodiment is 37 mm long, 17.9 mm in diameter, has an elastic modulus of 798.38 MPa, and a yield strength of 21 MPa. Firing one breaching projectile of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of four security doors; firing two breaching projectiles of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of five security doors without automatic disintegration. Furthermore, upon impact with the security doors, the rapidly disintegrating metal powder and fragments do not rebound and do not cause fatal injuries to personnel.

[0091] Example 4:

[0092] Step S1: Using a photopolymerization 3D printing method with a layer thickness of 0.12 mm, 97 μm particle size Guangming resin powder is printed and exposed at 24℃ for 2.5 s to obtain a cylindrical hollow plastic base skeleton in which each mesh meridian is spirally arranged at an equal angle to the center. The diameter of each mesh meridian on the hollow plastic base skeleton is 1.4 mm.

[0093] Step S2: Solid paraffin wax is cut into particles of 2.2mm × 2.2mm × 2.2mm and placed in a container. The mixture is heated to 84℃ and melted into a liquid. Then, tungsten alloy powder with a particle size of 44μm is added and stirred until homogeneous, resulting in a first mixture with a porosity of 0.03% and a fracture strength of 22MPa. The weight ratio of tungsten alloy powder to paraffin wax is 4:0.5.

[0094] Step S3: After cutting solid paraffin into particles of 2.2mm × 2.2mm × 2.2mm, place them in a container and heat to 86℃ to melt them into a liquid. Then, add lead alloy powder with a particle size of 48μm and stir evenly to obtain a second mixture with a porosity of 0.03% and a fracture strength of 322MPa. The weight ratio of lead alloy powder to paraffin is 2:0.5.

[0095] Step S4: After cutting solid paraffin into particles of 2.2mm × 2.2mm × 2.2mm, place them in a container and heat to 85℃ to melt them into a liquid. Then, add ferroalloy powder with a particle size of 45μm and stir evenly to obtain a third mixture with a porosity of 0.03% and a fracture strength of 22MPa. The weight ratio of ferroalloy powder to paraffin is 12.1:2.5.

[0096] Step S5: After the hollowed-out plastic matrix skeleton is inserted into the barrier-breaking projectile mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking projectile mold and solidified for 2 hours to obtain the first layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0097] Step S6: Pour the second mixture onto the first layer and then solidify it for 2 hours to obtain the second layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0098] Step S7: Pour the third mixture onto the second layer and then solidify it for 2 hours to obtain the third layer of the plastic matrix skeleton and the mixture of gradient metal powder and paraffin.

[0099] Step S8: Perform top cover condensation and curing on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture for 2 hours to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

[0100] In this embodiment, the weight ratio of the first mixture, the second mixture, and the third mixture is 5.5:3.5:12.5.

[0101] The breaching projectile of this embodiment is 37 mm long, 17.9 mm in diameter, has an elastic modulus of 790 MPa, and a yield strength of 21.5 MPa. Firing one breaching projectile of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of two security doors; firing two breaching projectiles of this embodiment at a launch impact velocity of 400 m / s can destroy the lock cylinders of three security doors without automatic disintegration. Furthermore, upon impact with the security doors, the rapidly disintegrating metal powder and fragments do not rebound and do not cause fatal injuries to personnel.

[0102] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax, characterized in that, The method for preparing the obstacle-penetrating projectile includes the following steps: Step S1: Using the photopolymerization 3D printing method, the bright resin powder is exposed at 22-26℃ for 2-3 seconds to obtain a hollow plastic matrix skeleton. Step S2: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add tungsten alloy powder and stir evenly to obtain the first mixture. Step S3: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add lead alloy powder and stir evenly to obtain the second mixture. Step S4: After cutting solid paraffin into granules, put them into a container and heat them to 83-87°C to melt them into liquid. Then add iron alloy powder and stir evenly to obtain the third mixture. Step S5: After the hollow plastic matrix skeleton is installed into the barrier-breaking bullet mold with a cylindrical inner cavity, the first mixture is poured into the barrier-breaking bullet mold and then solidified to obtain the plastic matrix skeleton and the first layer of the gradient metal powder and paraffin mixture. Step S6: Pour the second mixture onto the first layer and then solidify it to obtain the second layer of plastic matrix skeleton and gradient metal powder and paraffin mixture; Step S7: Pour the third mixture onto the second layer and then solidify it to obtain the third layer of plastic matrix skeleton and gradient metal powder and paraffin mixture; Step S8: Perform top cover condensation and solidification on the third layer of the plastic matrix skeleton and gradient metal powder and paraffin mixture to obtain a barrier-breaking projectile based on the plastic matrix skeleton and gradient metal powder and paraffin mixture.

2. The method for preparing a barrier-breaking projectile according to claim 1, characterized in that, The porosity of the first mixture, the second mixture, and the third mixture is no greater than 0.05%, and the fracture strength is greater than or equal to 21 MPa.

3. The method for preparing a barrier-breaking projectile according to claim 2, characterized in that, The weight ratio of the first mixture, the second mixture, and the third mixture is 5-6:3.5:12-14.

4. The method for preparing a barrier-breaking projectile according to claim 3, characterized in that, In step S1, the particle size of the light-curing resin powder is less than or equal to 100 μm; the layer thickness of the photocurable 3D printing is 0.01 to 0.15 mm.

5. The method for preparing a barrier-breaking projectile according to claim 4, characterized in that, In step S1, each mesh-like meridian on the hollowed-out plastic base skeleton is arranged in a spiral at an equal angle to the center; In step S1, the diameter of each mesh network on the hollowed-out plastic base skeleton is 1 to 1.5 mm; In step S1, the hollowed-out plastic base skeleton is cylindrical in shape.

6. The method for preparing a barrier-breaking projectile according to claim 5, characterized in that, In step S2, the weight ratio of the tungsten alloy powder to paraffin wax is 3-7:0.5; In step S2, the particle size of the tungsten alloy powder is less than or equal to 50 μm.

7. The method for preparing a barrier-breaking projectile according to claim 6, characterized in that, In step S3, the weight ratio of the lead alloy powder to paraffin is 1-5:0.5; In step S3, the particle size of the lead alloy powder is less than or equal to 50 μm.

8. The method for preparing a barrier-breaking projectile according to claim 7, characterized in that, In step S4, the weight ratio of the ferroalloy powder to paraffin wax is 9.1–13.1:2.5; In step S4, the particle size of the iron alloy powder is less than or equal to 50 μm.

9. The method for preparing a barrier-breaking projectile according to claim 8, characterized in that, In steps S5, S6, and S7, the condensation and solidification time is 1.5 to 2.5 hours. In step S8, the time for the top cover to solidify is 1.5 to 2.5 hours.

10. A barrier-breaking projectile based on a plastic matrix framework and a mixture of gradient metal powder and paraffin wax, characterized in that, The obstacle-penetrating projectile is prepared using the obstacle-penetrating projectile preparation method described in any one of claims 1 to 9.