Low-density composite material shaped charge liner based on fused deposition 3D printing technology and preparation method thereof

Abstract

The invention provides a low-density composite material shaped charge liner based on a fused deposition 3D printing technology and a preparation method of the low-density composite material shaped charge liner. The method comprises the steps that (1) a three-dimensional model structure of the low-density composite material shaped charge liner is designed; (2) setting various 3D printing parameters of the low-density composite material shaped charge liner; (3) the three-dimensional model of the low-density composite material shaped charge liner is decomposed into two-dimensional slice models, the two-dimensional slice models are imported into a 3D printer, and fused deposition 3D printing work is conducted through a PLA-Cu composite material; then, the 3D printed low-density composite material shaped charge liner is taken out, and edge polishing is conducted; and (4) a multi-stage series warhead preceding-stage small-caliber charging structure is designed, and the 3D-printed low-density composite material shaped charge liner and the charging structure are adjusted and installed. According to the preparation method of the low-density composite material shaped charge liner, the model size is accurate and controllable, the preparation time is short, the process is simple, the cost is low, the shaped charge liner material is a degradable material and is environmentally friendly, and the prepared shaped charge liner has the effect that an explosive reactive armor can be penetrated without explosion.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing and shaped-charge warheads, and specifically relates to a low-density composite material liner based on fused deposition 3D printing technology and a preparation method thereof. Background Art

[0002] Because of its light weight and excellent protective performance, "explosive reactive armor" is often mounted on tanks to deal with anti-tank ammunition. It is usually made of two parallel steel plates with a layer of explosives sandwiched between them. The explosives in the sandwich are often inert and have certain detonation conditions. When the armor-piercing projectile penetrates the explosive reactive armor box, the fuze of the projectile detonates the shaped charge warhead, forming a shaped armor-piercing jet to detonate the inert explosives in the middle layer. Under the detonation of the sandwich explosives, the front and rear flying plates of the explosive reactive armor begin to move at high speed along the normal direction of their respective plate surfaces, and periodically cut the shaped armor-piercing jet, causing the jet to lose continuity and stability after passing through the explosive reactive armor. At the same time, the jet will be severely distorted and broken under the lateral resistance of metal fragments and the detonation products ejected at high speed toward the penetration entrance, thereby weakening the penetration and penetration ability of the jet main armor.

[0003] The emergence of explosive reactive armor has also promoted the development of anti-armor weapons. The anti-explosive reactive armor weapons that are widely used at present mainly use tandem warhead technology. For example, the tandem warhead with shaped charge in both the front and rear stages generally uses a metal charge cap, and uses the generated metal jet to impact and detonate the sandwich explosive of the explosive reactive armor. After a certain delay time, the rear charge detonates to form a main jet to damage the target armor. Although this technology avoids the main jet directly facing the explosive reactive armor, it will still be affected by the detonation field generated by the explosion of the sandwich explosive of the explosive reactive armor, reducing the penetration power of the main jet. In order to avoid this situation, people have proposed a technology of "penetrating but not exploding" for the explosive reactive armor, the purpose of which is to allow the jet to pass through the explosive reactive armor without detonating the sandwich explosive in the middle, so as to open up a penetration channel for the rear main jet of the tandem warhead.

[0004] At present, research has found that if the front-stage shaped jet of the tandem warhead uses low-density materials such as non-metallic and metal-non-metallic composite materials, the low-density shaped jet produced can achieve the technology of penetrating explosive reactive armor without exploding. Therefore, low-density composite liner is one of the powerful weapons and equipment used to deal with "explosive reactive armor". The existing preparation methods of low-density composite liner include: traditional turning, cold pressing sintering, compression molding, hot pressing and other processing technologies. The above preparation processes have the disadvantages of low precision, large material waste, and long time consumption. Summary of the invention

[0005] In view of this, the present invention aims at the defects of low precision, large material waste, and long time consumption in the traditional preparation process of low-density composite drug caps, and proposes a new preparation method of low-density composite drug caps based on fused deposition 3D printing technology. The technology adopts digital modeling and parameterized technical methods to effectively control the printing accuracy while reducing the cumbersome processing steps of the traditional processing technology, and can meet the requirements of rapid prototyping drug caps, which is suitable for the preparation of low-density composite drug caps. At the same time, the present invention proposes for the first time to use PLA-Cu composite materials for fused deposition 3D printing of drug caps. By using additive manufacturing, compared with subtractive manufacturing, the waste of raw materials can be reduced from the source. Therefore, the preparation of 3D printed low-density composite drug caps has important research significance. Using this method and new materials, the preparation of low-density composite drug caps can be completed with the characteristics of high and controllable precision, fast printing speed, and less waste of raw materials.

[0006] The technical purpose of the present invention is achieved through the following technical solutions.

[0007] On the one hand, the present invention provides a method for preparing a low-density composite material liner based on fused deposition 3D printing technology, characterized in that it comprises the following steps:

[0008] 1) Designing the three-dimensional model structure of the low-density composite material liner using three-dimensional modeling software according to the size of the front-stage small-caliber armor-piercing warhead in the multi-stage tandem warhead;

[0009] 2) Setting the layer height, nozzle diameter, nozzle temperature, routing direction, and printing speed of the 3D printing of the low-density composite drug liner;

[0010] 3) In combination with the slicing software of the 3D printer, the three-dimensional model of the low-density composite liner is decomposed into a two-dimensional slicing model, and the model is imported into the 3D printer for fused deposition 3D printing using the PLA-Cu composite material; then the 3D printed low-density composite liner is taken out and edge polishing is performed;

[0011] 4) Design a small-caliber charge structure for the front stage of a multi-stage tandem warhead, and use adhesive to install and debug the 3D-printed low-density composite material liner and the charge structure.

[0012] Furthermore, in step 2), the ratio of the nozzle diameter to the wall thickness of the low-density composite material liner is not greater than 30%.

[0013] Furthermore, in step 2), the nozzle temperature is 10%-20% higher than the melting temperature of the PLA-Cu composite material.

[0014] Furthermore, in step 2), the routing direction is guided by the internal density of the low-density composite material liner, and the density is not less than 99%.

[0015] Furthermore, in step 2), the printing speed is not higher than 45 mm / min.

[0016] Furthermore, in step 3), the slicing software is an open source slicing software for a fused deposition type 3D printer.

[0017] Furthermore, in step 4), the caliber of the small-caliber charge at the front stage of the multi-stage tandem warhead is between 15-45 mm, and the length-to-diameter ratio of the charge is between 0.8-1.3.

[0018] Furthermore, in step 4), the charge density of the charge structure is not less than 1.65 g / cm 3 .

[0019] Furthermore, in step 4), the adhesive is a shellac paint material.

[0020] On the other hand, the present invention also provides a low-density composite material liner prepared by the above preparation method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The present invention proposes a new method for preparing a medicine cap using a 3D printing process. This technology adopts digital modeling and parameterized technical methods, which can effectively control the printing accuracy while reducing the cumbersome processing steps of the traditional processing technology, and can meet the requirements of rapid prototyping medicine caps. It is suitable for the preparation of low-density composite material medicine caps.

[0023] 2) The present invention creatively proposes to use PLA-Cu composite materials for melt deposition 3D printing of charge liners. Charge liners have special requirements for material properties. Polylactic acid copper is usually not considered as a 3D printing material for charge liners. First, in terms of mechanical properties, the charge liner needs to withstand extremely high pressure and rapid deformation under the explosion of explosives. The good ductility of traditional materials such as copper is more advantageous in this case. Second, in terms of energy transfer and penetration capability, traditional high-energy density materials such as tantalum-tungsten alloys perform outstandingly in this regard. Third, in terms of stability, the working environment of the charge liner is an extreme environment of high temperature and high pressure generated by the explosion. The high-temperature stability of materials such as pure nickel has been recognized for use in some special environments. Therefore, technicians tend to use these existing mature materials.

[0024] 3) 3D printing technology uses additive manufacturing, which can reduce the waste of raw materials from the source compared to subtractive manufacturing. Therefore, the preparation of 3D printed low-density composite liner has important research significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a preparation flow chart of the 3D printed PLA-Cu composite drug liner of the present invention.

[0026] Figure 2 It is a three-dimensional model diagram of the low-density composite material medicine liner provided in an embodiment of the present invention.

[0027] Figure 3 It is a 3D printed two-dimensional slice diagram of the low-density composite material medicine liner provided in an embodiment of the present invention.

[0028] Figure 4 It is a diagram of the charge structure dimensions provided in an embodiment of the present invention.

[0029] Figure 5 It is a diagram of the charge structure and charge liner assembly model provided in an embodiment of the present invention.

[0030] Figure 6 This is a physical picture of the 3D printed low-density PLA-Cu composite material liner provided in an embodiment of the present invention.

[0031] Figure 7 It is an assembly diagram of a charge structure and a charge liner provided in an embodiment of the present invention.

[0032] Figure 8 This is the result of the impact detonation test of the low-density PLA-Cu composite material liner provided in the embodiment of the present invention on the explosive reactive armor. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. The specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0034] The present invention provides a low-density composite material liner based on fused deposition 3D printing technology and a preparation method thereof. The preparation method comprises the following steps:

[0035] 1) According to the size of the front-stage small-caliber armor-piercing warhead in the multi-stage tandem warhead, use the 3D modeling software to design the 3D model structure of the low-density composite material liner, and select the 3D printing material of the low-density composite material liner. The 3D printing material should have the characteristics of low viscosity, low melting temperature, good mechanical properties, good adhesion, low shrinkage, etc. It is a non-metal and metal-non-metal composite material suitable for fused deposition 3D printing technology. Preferably, the density of the composite material is not more than 5g / cm 3 In the present invention, it is proposed for the first time to use PLA-Cu composite materials for 3D printing of medicine liner.

[0036] 2) According to the structural dimensions of the low-density composite liner model, set the layer height, nozzle diameter, nozzle temperature, routing direction, and printing speed of the 3D printing of the low-density composite liner. The layer height of the 3D printing must meet the accuracy and density requirements described in the liner design drawings, and the error between the liner density and the wire density is not more than 1%. The nozzle diameter must be determined in a timely manner according to the particle size of the printing material, and the ratio of the nozzle diameter to the liner wall thickness is not more than 30%. If a metal-non-metal composite material is used, the nozzle diameter should be 100-1000 times the metal particle size. Since the 3D printing material will undergo a "solid-molten state-solid" transformation process, in order to meet the filamentation requirements of the material, the nozzle temperature should be 10%-20% higher than the melting temperature of the selected 3D printing material. The routing direction should be guided by the density of the inside of the liner, which is perpendicular to the direction of the detonation wave, and the density is not less than 99%. The printing speed requirement should ensure that the fuse does not break during the printing process, and the printing speed is not higher than 45mm / min.

[0037] 3) In combination with the slicing software of the 3D printer, the three-dimensional model of the low-density composite drug liner is decomposed into a two-dimensional slicing model, and the two-dimensional slicing model information is imported into the 3D printer, and the PLA-Cu composite material is used for fused deposition 3D printing, and then the 3D printed low-density composite drug liner is taken out and the edge is polished; the two-dimensional slicing model design should meet the parameter standards set in step 2. Support materials include but are not limited to water-soluble PVA materials. The two-dimensional slicing software used is an open source slicing software suitable for fused deposition 3D printers.

[0038] 4) Design a small-caliber charge structure for the front stage of a multi-stage tandem warhead, and use adhesives to install and debug the 3D-printed low-density composite charge liner and the charge structure. The caliber of the small-caliber charge for the front stage of the multi-stage tandem warhead is between 15-45mm, and the charge aspect ratio is between 0.8-1.3. The charge density should be no less than 1.65g / cm 3 The invention relates to installing and debugging a structure between a 3D printed low-density composite material liner and a charge column, wherein the installation and adjustment adhesive used includes a shellac paint material.

[0039] Example 1

[0040] The 3D printer used in the present invention is an Ultimaker S5 3D printer from Ultimaker of the Netherlands, and its sample molding method is a fused deposition method. The maximum printing size of the supported specimen can reach 330mm*240mm*300mm.

[0041] like Figure 1 and 2As shown in the figure, according to the size of the front small-caliber armor-piercing warhead in the multi-stage tandem warhead, a PLA-Cu charge cover solid model is established in the 3D modeling software according to the designed model style and size. Then it is saved and exported as an STL file, and then the STL file is imported into Cura, an open source slicing software suitable for Ultimaker S5 3D printer, for 2D slicing processing, as shown in the figure. Figure 3 The low-density composite drug liner material used in the present invention is a copper powder filled modified polylactic acid material (PLA-Cu). Preferably, the density of the PLA-Cu material is 1.46 g / cm 3 The PLA-Cu material has a copper powder content of 2.85% and a copper powder particle size of 20-50 μm.

[0042] The caliber of the three-dimensional model of the low-density composite material liner is between 15-45 mm, and the length-to-diameter ratio of the liner is between 0.8-1.3. Preferably, the caliber of the three-dimensional model of the low-density composite material liner is 37 mm, and the length-to-diameter ratio of the liner is 1.24. Figure 4 As shown. The three-dimensional modeling software suitable for 3D printers is computer design-aided CAD software. Preferably, the three-dimensional modeling software for the low-density composite material liner is Solid Works. Select a 3D printer suitable for fused deposition 3D printing technology. Preferably, the 3D printing machine is an Ultimaker S5 model, and the open source slicing software is Cura. Select a material suitable for fused deposition 3D printing technology. Preferably, the 3D printing material is copper powder-filled modified polylactic acid (PLA-Cu).

[0043] In the two-dimensional slicing software Cura, the printing layer height of the low-density PLA-Cu composite drug liner solid model was set to 0.1mm, the nozzle diameter was 0.2mm, the nozzle temperature was 230℃, the routing direction was selected as concentric circles, the printing speed was 20mm / min, and the filling density was 100%. Finally, the sliced ​​two-dimensional slice model was sent to the Ultimaker S5 3D printer to complete the preparation of the low-density composite drug liner.

[0044] Before starting printing, enter the printing parameters in the 3D printer. In the present invention, the filling density is 100% to minimize the internal voids of the low-density composite drug liner. Because the melting temperature of the PLA-Cu material is 190°C, the nozzle temperature is set to 230°C. At the same time, the temperature of the printing platform is set to 60°C, and the 3D printer is kept warm during the entire printing process to ensure that the edge of the low-density composite drug liner will not warp or deform due to excessive temperature differences during the printing process. Different caliber printing nozzle diameters are selected for different materials. Preferably, the printing nozzle diameter of the PLA-Cu composite material is 0.4mm.

[0045] Wait for the model to cool down, then take out the low-density PLA-Cu composite liner printed by fused deposition modeling from the support platform of the 3D printer, and use sandpaper to polish the edges. The results are as follows: Figure 5 As shown. Figure 4 Design and process the front-stage small-caliber charge column mold of the multi-stage tandem warhead, according to 1.71g / cm 3 The required mass of 8701 explosive is calculated according to the requirements, the 8701 explosive is poured into the mold, and the preparation of the charge is completed on a uniaxial press. Finally, the low-density PLA-Cu composite charge liner is bonded to the charge using 90% shellac, such as Figure 6 and Figure 7 shown.

[0046] The measured wall thickness of the PLA-Cu liner is 0.311, with a relative error of 3.7% from the set wall thickness. The height is 26.055, with a relative error of 0.06% from the set height. The cone angle of the liner is 59.9°, with a relative error of 0.17% from the set cone angle.

[0047] Performance Testing

[0048] The 3D printed low-density PLA-Cu composite liner obtained in Example 1 was subjected to a test of shaped jet impact detonation of explosive reactive armor. The impact detonation results of the explosive reactive armor are shown in Figure 1. Figure 8 As shown in the figure, it can be seen that the PLA-Cu composite charge liner not only achieves the "penetration without explosion" of the explosive reactive armor, but also causes a large-scale failure of the explosive layer in the explosive reactive armor, thus achieving the effect of interfering with the penetration of the subsequent main jet into the explosive reactive armor.

[0049] In summary, we can conclude that:

[0050] First, the present invention proposes a low-density composite material liner based on fused deposition 3D printing technology and a preparation method thereof. The low-density PLA-Cu composite material liner prepared by the present invention has high precision and a small relative error with the design model on the drawing, thereby improving the preparation accuracy of the low-density composite material liner.

[0051] Second, the present invention proposes a new idea of ​​using PLA-Cu composite materials to prepare low-density composite liner. The material has the ability to degrade and is very friendly to the ecological environment without affecting the penetration performance of the low-density composite liner. Compared with the existing low-density composite liner materials, it has stronger applicability.

[0052] In particular, the low-density PLA-Cu composite charge liner prepared by the present invention can penetrate the explosive reactive armor without exploding, has a larger opening for the explosive reactive armor, and causes a large-scale failure of the explosive layer of the explosive reactive armor, thereby perfectly achieving the effect of opening a penetration channel for the subsequent main jet.

[0053] It should be noted that the above-described embodiments are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, the present invention may be modified, improved and replaced with equivalents, and these modifications, improvements and equivalent replacements are also considered to fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a low-density composite material liner based on fused deposition 3D printing technology, characterized in that: The steps include: 1) Designing the three-dimensional model structure of the low-density composite material liner using three-dimensional modeling software according to the size of the front-stage small-caliber armor-piercing warhead in the multi-stage tandem warhead; 2) Setting the layer height, nozzle diameter, nozzle temperature, routing direction, and printing speed of the 3D printing of the low-density composite drug liner; 3) In combination with the slicing software of the 3D printer, the three-dimensional model of the low-density composite liner is decomposed into a two-dimensional slicing model, and the model is imported into the 3D printer for fused deposition 3D printing using the PLA-Cu composite material; then the 3D printed low-density composite liner is taken out and edge polishing is performed; 4) Design a small-caliber charge structure for the front stage of a multi-stage tandem warhead, and use adhesive to install and debug the 3D-printed low-density composite material liner and the charge structure.

2. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 2), the ratio of the nozzle diameter to the wall thickness of the low-density composite material liner is not greater than 30%.

3. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 2), the nozzle temperature is 10%-20% higher than the melting temperature of the PLA-Cu composite material.

4. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 2), the routing direction is guided by the internal density of the low-density composite material liner, and the density is not less than 99%.

5. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 2), the printing speed is no higher than 45 mm / min.

6. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 3), the slicing software is an open source slicing software for a fused deposition type 3D printer.

7. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 4), the caliber of the small-caliber charge at the front stage of the multi-stage tandem warhead is between 15-45 mm, and the length-to-diameter ratio of the charge is between 0.8-1.

3.

8. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 4), the charge density of the charge structure is not less than 1.65 g / cm 3 .

9. The method for preparing a low-density composite material liner based on fused deposition 3D printing technology according to claim 1, characterized in that: In step 4), the adhesive is a shellac paint material.

10. A low-density composite material liner prepared by the preparation method according to any one of claims 1 to 9.

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