Method for one-step near net shape forming of multi-profile composite armor and forming device thereof

Abstract

This invention provides a method and apparatus for one-time near-net-shape forming of composite armor with multiple profiles. The forming apparatus utilizes two longitudinal frames and N sets of transverse frames to form N-1 sequentially arranged limiting frames. The remaining layers of each composite armor plate are placed sequentially onto the crack-resistant layer within the corresponding limiting frame. A release film is then laid, and a contoured metal plate is placed on the release film corresponding to each composite armor plate. The length and width of the space within each limiting frame are adjusted and locked to ensure that the four sides of the limiting frame abut against the four edges of the remaining layers of the composite armor plate within the frame. Under the fixed clamping of the front and rear transverse frames, the crack-resistant layer within the limiting frame supports the bottom surface of the remaining layers of the composite armor plate and naturally conforms to the shape of the bottom surface. Ventilation holes on the lower and upper components of the transverse frames of the longitudinal and transverse frames connect the space inside the frame to the outside of the frame.

Description

Technical Field

[0001] This invention belongs to the field of composite bulletproof armor plate forming technology, and in particular relates to a method and device for forming near-net-shape composite armor with multiple profiles in one step. Background Technology

[0002] Existing methods for manufacturing composite bulletproof armor (especially integral ceramic composite armor) typically involve multiple processes, including molding of the composite material backing layer, forming of the transition layer, cutting and trimming of the backing and transition layer, bonding of the ceramic panel layer / composite material backing layer, and cutting and trimming of the composite armor. These processes result in long production cycles and low efficiency. Furthermore, during product lamination, multiple layers of panels need to be stacked and fixed with tape. During vacuuming and curing of the fixed multi-layered panels, the melting and flow of the adhesive film or liquid under high temperature and pressure can easily cause slippage and misalignment defects in each layer. Therefore, when performing final surface polyurea spraying or fabric encapsulation, it is necessary to cut, grind, and trim the periphery of the composite armor, or to wrap the sides of the composite armor with foam / rubber, etc., to ensure the smoothness and flatness of the product after fabric wrapping or polyurea spraying.

[0003] Patent CN113513945A discloses a method for forming composite armor plates, which uses a panel as a mold to directly lay fiber prepreg on the panel, and then seals and vacuums it before curing it in an autoclave. Although the above-mentioned preparation method can optimize the process path and shorten the production cycle based on the existing technology, it is also prone to slippage and misalignment defects between materials during the preparation process, and it is not easy to achieve mass production. Patent CN115127398A also discloses a method for preparing composite armor by integral molding in an autoclave. It lays carbon fiber fabric prepreg, ceramic fragmentation layer, ultra-high molecular weight polyethylene fiber fabric prepreg, and carbon fiber fabric prepreg in sequence on a rigid single-sided mold, inserts an adhesive film layer between each layer, and then seals the laid material system in a sealing device and transfers it as a whole to an autoclave for curing, thus obtaining a lightweight bulletproof and explosion-proof multiphase composite armor material based on a high-toughness heterogeneous interface layer. However, while laying ceramic molding on a rigid single-sided mold can ensure that the layers of composite armor are positioned without slippage, when the ceramic surface is curved, the high hardness of the ceramic and the error between its curvature and that of the rigid mold make it very easy for the ceramic panel layer to crack under high temperature and pressure, thus rendering the product unusable. In addition, when prepreg is used directly for composite armor molding, the lack of rigid support on the surface can cause wavy or prismatic protrusions and wrinkles to appear under high temperature and pressure molding, thus affecting the usability of the composite armor. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides the following technical solution:

[0005] A method for forming near-net-shape composite armor in one step, characterized in that the forming device consists of two longitudinal frame edges and N sets of transverse frame edges, each set of transverse frame edges consisting of a lower transverse frame edge component and an upper transverse frame edge component paired together.

[0006] First, vacuum bags, breathable felt, and a release film are laid out sequentially on the mobile trolley inside the autoclave. Then, on the release film, N-1 limiting frames are arranged sequentially using the two vertical frames and N sets of horizontal frames of the forming device. Each limiting frame uses the two vertical frames as its left and right side frames, and each limiting frame uses two adjacent sets of horizontal frames as its front and rear side frames. Adjacent limiting frames share the same set of horizontal frames.

[0007] The lower component of each horizontal frame is fastened to the upper component of the horizontal frame to achieve self-fastening of each horizontal frame and simultaneously clamping and locking the crack-stopping layer. Each horizontal frame is fastened to two vertical frames to lock the distance between the two vertical frames and the distance between adjacent horizontal frames. The length of the crack-stopping layer between two adjacent horizontal frames is greater than the distance between the two adjacent horizontal frames.

[0008] The remaining layers of plates that make up each composite armor plate are placed sequentially on the crack-resistant layer in the corresponding limiting frame, and then a release film is laid. This release film covers the top layer of each composite armor plate, and a contoured metal plate is laid on the release film corresponding to each composite armor plate, thereby sandwiching this shared release film between the top layer of each composite armor plate and the corresponding contoured metal plate.

[0009] The adjustment and locking of the length and width dimensions of the space inside each limiting frame should satisfy that the four side frames of the limiting frame respectively abut against the four side edges of the other layers of composite armor plate inside the frame, and the crack-stopping layer inside the limiting frame, under the fixed clamping of the front and rear side horizontal frames, supports the bottom surface of the other layers of composite armor plate and naturally conforms to the shape of the bottom surface.

[0010] The ventilation holes on the lower and upper components of the horizontal frame of the vertical frame and each group of horizontal frames respectively connect the space inside the frame with the outside of the frame.

[0011] Next, lay a release film, a breathable felt, a silicone sheet, and a vacuum bag in sequence. Seal the vacuum bag with high-temperature tape, and place the vacuum valve into the vacuum bag before it is completely sealed. The silicone sheet allows the breathable felt to conform to the shape of the product during vacuuming, thereby ensuring that the surface of each layer is subjected to uniform force and can be compacted.

[0012] Evacuate the autoclave by connecting the evacuation valve to the vacuum valve and evacuating to -1MPa. Maintain this for 10 minutes to ensure there are no leaks, then close the autoclave.

[0013] For curing and molding, the autoclave molding process is set at a temperature of 70℃-140℃, a pressure of 0.5MPa-5MPa, and a time of 20min-180min.

[0014] After curing and shaping, the composite armor plate is removed, the crack-resistant layer is cut, and the final N-1 composite armor plates are obtained.

[0015] The remaining layers of the composite armor plate are, in order, a ceramic layer, a transition layer, an energy-absorbing layer, and a back-protrusion reduction layer, wherein the back-protrusion reduction layer is the topmost layer of the remaining layers of the composite armor plate.

[0016] The crack-arresting layer is one or a combination of thermoplastic prepreg and thermosetting prepreg; the crack-arresting layer prepreg resin is any one of polyurethane, EVA, polyester, epoxy resin, and phenolic resin; the crack-arresting layer prepreg reinforcing fiber is any one of aramid fiber, PBO fiber, nylon fiber, etc.; and the crack-arresting layer prepreg fiber reinforcement structure is any one of woven fabric, knitted fabric, or braided fabric.

[0017] The ceramic layer is one or a combination of two of the following: homogeneous ceramics and ceramic-based fiber composite materials.

[0018] The hardness and strength of the transition layer are between those of the ceramic layer and the energy-absorbing layer. The transition layer is one or a combination of two of the following: alloy material and thermosetting resin-based composite material.

[0019] The contact surface between the transition layer and the ceramic layer is hardened and strengthened. The hardening and strengthening treatment method adopts any one or a combination of two or more of the following: carburizing, nitriding, hard anodizing, chromium plating, surface quenching, and metal infiltration.

[0020] The energy-absorbing layer is one or a combination of two of the following: multilayer prepreg and fiber composite material board;

[0021] The back-reducing layer has higher hardness and strength than the energy-absorbing layer, and the back-reducing layer is any one or a combination of two or more of thermosetting resin-based composite materials, steel, and alloy materials.

[0022] The forming device is applicable to the near-net-shape forming method of various composite armor with different profiles as described above. It consists of two longitudinal frame pieces and N sets of transverse frame pieces. Each set of transverse frame pieces is composed of a lower transverse frame piece and an upper transverse frame piece paired together. Each longitudinal frame piece has a long fastening through hole along its length direction. The fastening through hole penetrates the upper and lower surfaces of the longitudinal frame piece. The longitudinal frame piece also has multiple vent holes that penetrate the left and right surfaces of the longitudinal frame piece and the fastening through hole, respectively.

[0023] Each horizontal frame lower component has a long strip-shaped adjustment through hole that runs through its front and rear surfaces for the two vertical frames to pass through. The length of the adjustment through hole is sufficient to maintain a sufficient and adjustable gap between the two vertical frames. The horizontal frame lower component also has a fastening through hole that runs through the upper and lower walls of its adjustment through hole and the adjustment through hole. The upper and lower walls of the adjustment through hole are respectively provided with multiple vent holes that run through the front and rear surfaces of the horizontal frame lower component and the fastening through hole.

[0024] Each horizontal frame component has a fastening through hole corresponding to the fastening through hole of the paired horizontal frame lower component. The fastening through hole penetrates the upper and lower surfaces of the horizontal frame component. The horizontal frame component also has multiple vent holes that penetrate its front and rear surfaces and the fastening through hole respectively.

[0025] All edges on the vertical frame, the lower component of the horizontal frame, and the upper component of the horizontal frame are rounded to prevent damage to the vacuum bag during the vacuuming process, which could lead to air leakage.

[0026] This invention enables near-net-shape molding of composite armor with various surface profiles in a single step, directly skipping multiple processes such as composite material backplate molding, transition layer molding, backplate and transition layer cutting and trimming, and composite armor cutting and trimming. This invention directly uses a flexible crack-resistant layer as the support layer for each layer of the composite armor, and the different sizes and surface profiles of the composite armor are defined by the fixing of the molding device's limiting frame. It eliminates the need for precision contouring molds to position each layer of the composite armor, avoiding ceramic damage and eliminating post-processing after composite molding. The molding device and method of this invention result in a short production cycle, low cost, and ease of engineering, and the final product has high quality and good performance, exhibiting excellent ballistic protection and minimal back-convex deformation after ballistic impact. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a 3D diagram of the vertical border;

[0029] Figure 2 This is a 3D schematic diagram of the components below the horizontal border;

[0030] Figure 3 This is a 3D schematic diagram of the components on the horizontal border;

[0031] Figure 4 This is a schematic diagram showing the connection relationship between the two vertical frames of the molding device and the components under each horizontal frame;

[0032] Figure 5 A schematic diagram showing a continuous crack-resistant layer laid between two longitudinal frames and overlapping the components under each transverse frame.

[0033] Figure 6 A schematic diagram showing how the crack arresting layer is clamped and fixed to each group of horizontal frames using the lower and upper components of the horizontal frame;

[0034] Figure 7 A schematic diagram showing the layering sequence of the multi-layered composite armor plates in each limiting frame of the forming device.

[0035] Figure 8 This is a schematic diagram showing the state of the composite armor plates after they have been laid out in each limiting frame of the molding device.

[0036] The reference numerals in the diagram are: 1. Vertical frame; 2. Lower component of horizontal frame; 3. Upper component of horizontal frame; 4. Bolt fastening component; 5. Limiting frame; 6. Crack arresting layer;

[0037] 7. Ceramic layer; 8. Transition layer; 9. Energy-absorbing layer; 10. Back protrusion reduction layer; 11. Contour-like metal plate

[0038] Fastening through hole 101; Venting hole 102; Adjusting through hole 200; Fastening through hole 201; Venting hole 202; Fastening through hole 301; Venting hole 302. Detailed Implementation

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] As shown in the figure, the molding device of the present invention consists of two vertical frame edges 1 and multiple sets of horizontal frame edges. Each set of horizontal frame edges is composed of a lower horizontal frame component 2 and an upper horizontal frame component 3 paired together.

[0042] like Figure 1 As shown, each longitudinal frame 1 has a long fastening through hole 101 along its length direction. The fastening through hole 101 penetrates the upper and lower surfaces of the longitudinal frame 1. The longitudinal frame 1 also has multiple vent holes 102 that penetrate the left and right surfaces of the longitudinal frame 1 and the fastening through hole 101 respectively.

[0043] like Figure 2As shown, each horizontal frame lower component 2 has an elongated adjustment through hole 200 extending through its front and rear surfaces. The adjustment through hole 200 allows two vertical frame components 1 to pass through it, and the length of the adjustment through hole 200 is sufficient to maintain a sufficient and adjustable interval between the two vertical frame components 1. The horizontal frame lower component 2 also has a fastening through hole 201 extending through the upper and lower walls of its adjustment through hole 200 and the adjustment through hole 200. The upper and lower walls of the adjustment through hole 200 are respectively provided with a plurality of vent holes 202 extending through the front and rear surfaces of the horizontal frame lower component 2 and the fastening through hole 201.

[0044] like Figure 3 As shown, each horizontal frame component 3 has a fastening through hole 301 corresponding to the fastening through hole 201 of the paired horizontal frame lower component 2. The fastening through hole 301 penetrates the upper and lower surfaces of the horizontal frame component 3. The horizontal frame component 3 also has multiple vent holes 302 that penetrate its front and rear surfaces and the fastening through hole 301 respectively.

[0045] The assembly process of the molding device of the present invention is organically combined with and complements the layup process of composite armor, specifically:

[0046] First, a vacuum bag, a breathable felt, and a release film (not shown in the figure) are laid out sequentially on the mobile trolley inside the autoclave. For ease of distinction, this release film is defined as the bottom release film. Then, on the bottom release film, the two vertical frame 1 and N sets of horizontal frame 1 of the forming device are used. The figure shows six sets of horizontal frame 1, which, together with the two vertical frame 1, can form N-1 sets of five limiting frames arranged in sequence. Each limiting frame 1 uses the two vertical frame 1 as the left and right side frame 1, and each limiting frame 1 uses the two adjacent sets of horizontal frame 1 as the front and rear side frame 1, and two adjacent limiting frames 1 share the same set of horizontal frame 1.

[0047] In this embodiment, each set of two longitudinal frame 1 passes through the adjustment through hole 200 of the lower component 2 of the horizontal frame of each set of horizontal frame. The integral continuous anti-crack layer 6 shared by each composite armor is laid between the two longitudinal frame 1, and the anti-crack layer 6 is clamped and locked by each set of horizontal frame in sequence. In this embodiment, the bolt fastening component 4 passes through the corresponding fastening through hole 101, 201, 301 and is locked and fixed, so that the lower component of the horizontal frame is fastened to the upper component of the horizontal frame, thereby achieving the self-fastening of each set of horizontal frame and simultaneously clamping and locking the anti-crack layer. Each set of horizontal frame is fastened to the two longitudinal frame respectively, thereby locking the distance between the two longitudinal frame and the distance between adjacent sets of horizontal frame. That is, the length and width of the frame space inside each limiting frame are locked. At the same time, the effective length of the anti-crack layer inside the frame space of each limiting frame is greater than the width of the frame space, that is, the length of the anti-crack layer between two adjacent sets of horizontal frame is greater than the distance between the two adjacent sets of horizontal frame, so as to leave room for the conformal support of the other layers of composite armor.

[0048] The remaining layers of material that make up each composite armor plate (such as...) Figure 7 The ceramic layer 7, transition layer 8, energy-absorbing layer 9, and back-convexity reduction layer 10 shown are sequentially placed on the crack-stopping layer 6 within the corresponding limiting frame. Then, an upper release film is laid. This upper release film covers the topmost plate of each of the remaining plates of the composite armor (i.e., the back-convexity reduction layer 10 in this embodiment). A contoured metal plate 11 is laid on the upper release film corresponding to each composite armor plate, thereby sandwiching this shared upper release film between the back-convexity reduction layer 10 and the corresponding contoured metal plate 11 of each composite armor plate. A contoured metal plate 11 is also laid on the topmost plate of the composite armor (back-convexity reduction layer 10) to improve the appearance of the back surface of the composite armor plate and avoid wrinkles or wavy surface morphology of the fiber composite material layer under high temperature and high pressure conditions.

[0049] The adjustment and locking of the length and width dimensions of the space inside each limiting frame should satisfy that the four side frames of the limiting frame respectively abut against the four side edges of the other layers of composite armor plate inside the frame, and the crack-stopping layer 61 inside the limiting frame, under the fixed clamping of the front and rear side horizontal frames, supports the bottom surface of the other layers of composite armor plate and naturally conforms to the shape of the bottom surface.

[0050] The vents on the lower and upper components of the longitudinal frame 1 and each set of transverse frames connect the interior space to the exterior. These vents help to ensure the uniform removal of gas during the vacuuming process and the uniform suction force on various parts of the composite armor plate.

[0051] Then, lay a release film, a breathable felt, a silicone sheet, and a vacuum bag in sequence. Seal the vacuum bag with high-temperature tape, and put the vacuum valve into the vacuum bag before it is completely sealed. The silicone sheet can make the breathable felt conform to the shape of the product when vacuuming, so as to ensure that the surface of each layer is subjected to uniform force and can be compacted.

[0052] Evacuate the autoclave by connecting the evacuation valve to the vacuum valve and evacuating to -1MPa. Maintain this for 10 minutes to ensure there are no leaks, then close the autoclave.

[0053] The curing process is carried out in an autoclave with a temperature of 70℃-140℃, a pressure of 0.5MPa-5MPa, and a time of 20min-180min. After curing, the vacuum bag, breathable felt, etc. are removed and taken out of the molding device. The crack-resistant layer is then cut to obtain the final five composite armor products.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for one-time near-net-shape molding of multi-faceted composite armor, characterized in that, The molding device used consists of two vertical frame edges and N sets of horizontal frame edges. Each set of horizontal frame edges is composed of a lower component and an upper component of the horizontal frame edge. First, vacuum bags, breathable felt, and a release film are laid out sequentially on the mobile trolley inside the autoclave. Then, on the release film, N-1 limiting frames are arranged sequentially using the two vertical frames and N sets of horizontal frames of the forming device. Each limiting frame uses the two vertical frames as its left and right side frames, and each limiting frame uses two adjacent sets of horizontal frames as its front and rear side frames. Adjacent limiting frames share the same set of horizontal frames. The lower component of each horizontal frame is fastened to the upper component of the horizontal frame to achieve self-fastening of each horizontal frame and simultaneously clamping and locking the crack-stopping layer. Each horizontal frame is fastened to two vertical frames to lock the distance between the two vertical frames and the distance between adjacent horizontal frames. The length of the crack-stopping layer between two adjacent horizontal frames is greater than the distance between the two adjacent horizontal frames. The remaining layers of plates that make up each composite armor plate are placed sequentially on the crack-resistant layer in the corresponding limiting frame, and then a release film is laid. This release film covers the top layer of each composite armor plate, and a contoured metal plate is laid on the release film corresponding to each composite armor plate, thereby sandwiching this shared release film between the top layer of each composite armor plate and the corresponding contoured metal plate. The adjustment and locking of the length and width dimensions of the space inside each limiting frame should satisfy that the four side frames of the limiting frame respectively abut against the four side edges of the other layers of composite armor plate inside the frame, and the crack-stopping layer inside the limiting frame, under the fixed clamping of the front and rear side horizontal frames, supports the bottom surface of the other layers of composite armor plate and naturally conforms to the shape of the bottom surface. The ventilation holes on the lower and upper components of the horizontal frame of the vertical frame and each group of horizontal frames respectively connect the space inside the frame with the outside of the frame. Next, lay a release film, a breathable felt, a silicone sheet, and a vacuum bag in sequence. Seal the vacuum bag with high-temperature tape, and place the vacuum valve into the vacuum bag before it is completely sealed. The silicone sheet allows the breathable felt to conform to the shape of the product during vacuuming, thereby ensuring that the surface of each layer is subjected to uniform force and can be compacted. Evacuate the autoclave by connecting the evacuation valve to the vacuum valve and evacuating to -1MPa. Maintain this for 10 minutes to ensure there are no leaks, then close the autoclave. For curing and molding, the autoclave molding process is set at a temperature of 70℃-140℃, a pressure of 0.5MPa-5MPa, and a time of 20min-180min. After curing and shaping, the composite armor plate is removed, the crack-resistant layer is cut, and the final N-1 composite armor plates are obtained.

2. The method of one near net shape forming of multiple profiled armor according to claim 1, characterized in that, The remaining layers of the composite armor plate are, in order, a ceramic layer, a transition layer, an energy-absorbing layer, and a back-protrusion reduction layer, wherein the back-protrusion reduction layer is the topmost layer of the remaining layers of the composite armor plate.

3. The method of one near net shape forming of multiple profiled armor according to claim 2, wherein, The crack-arresting layer is one or a combination of two of thermoplastic prepreg and thermosetting prepreg; the prepreg resin of the crack-arresting layer is any one of polyurethane, EVA, polyester, epoxy resin, and phenolic resin; the reinforcing fiber of the prepreg of the crack-arresting layer is any one of aramid fiber, PBO fiber, and nylon fiber; and the fiber reinforcement structure of the prepreg of the crack-arresting layer is any one of woven fabric, knitted fabric, or braided fabric.

4. The method for one-time near-net-shape forming of multi-surface composite armor according to claim 2, characterized in that, The ceramic layer is one or a combination of two of the following: homogeneous ceramics and ceramic-based fiber composite materials.

5. The method of one near net shape forming of multiple profiled armor of claim 2, wherein, The hardness and strength of the transition layer are between those of the ceramic layer and the energy-absorbing layer. The transition layer is one or a combination of two of the following: alloy material and thermosetting resin-based composite material.

6. The method of one near net shape forming of multiple profiled armor of claim 2, wherein, The contact surface between the transition layer and the ceramic layer is hardened and strengthened. The hardening and strengthening treatment method adopts any one or a combination of two or more of the following: carburizing, nitriding, hard anodizing, chromium plating, surface quenching, and metal infiltration.

7. The method of one near net shape forming of multiple profiled armor of claim 2, wherein, The energy-absorbing layer is one or a combination of two of the following: multilayer prepreg and fiber composite material board.

8. The method of one near net shape forming of multiple profiled armor of claim 2, wherein, The back-reducing layer has higher hardness and strength than the energy-absorbing layer, and the back-reducing layer is any one or a combination of two or more of thermosetting resin-based composite materials, steel, and alloy materials.

9. A forming device suitable for use in a near net shape forming process of a plurality of faceted armor layers according to claim 1, wherein, It consists of two vertical frame sections and N sets of horizontal frame sections. Each set of horizontal frame sections is composed of a lower horizontal frame component and an upper horizontal frame component paired together. Each vertical frame section has a long fastening through hole along its length direction. The fastening through hole penetrates the upper and lower surfaces of the vertical frame section. The vertical frame section also has multiple vent holes that penetrate the left and right surfaces of the vertical frame section and the fastening through hole respectively. Each horizontal frame lower component has a long strip-shaped adjustment through hole that runs through its front and rear surfaces for the two vertical frames to pass through. The length of the adjustment through hole is sufficient to maintain a sufficient and adjustable gap between the two vertical frames. The horizontal frame lower component also has a fastening through hole that runs through the upper and lower walls of its adjustment through hole and the adjustment through hole. The upper and lower walls of the adjustment through hole are respectively provided with multiple vent holes that run through the front and rear surfaces of the horizontal frame lower component and the fastening through hole. Each horizontal frame component has a fastening through hole corresponding to the fastening through hole of the paired horizontal frame lower component. The fastening through hole penetrates the upper and lower surfaces of the horizontal frame component. The horizontal frame component also has multiple vent holes that penetrate its front and rear surfaces and the fastening through hole respectively.

10. The forming device of claim 9, wherein, All edges on the vertical frame, the lower component of the horizontal frame, and the upper component of the horizontal frame are rounded to prevent damage to the vacuum bag during the vacuuming process, which could lead to air leakage.

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