A method of additive manufacturing of a heat-protective material structure

Abstract

The application provides an additive manufacturing method of a heat absorption protective material structure piece, comprising the following steps: 1, preparing a heat absorption composite material; 2, designing a three-dimensional numerical model of the heat absorption protective composite material structure piece, and obtaining forming track data of the heat absorption protective material structure piece; 3, importing the three-dimensional numerical model into an additive manufacturing device, importing the heat absorption composite material into a low-temperature vacuum bin, controlling the outlet temperature of a heating nozzle and the extrusion speed, and forming a heat absorption protective material structure piece embryo by the nozzle according to the forming track; and 4, importing silicon dioxide into a powder bin, importing phenolic resin and foaming aids into a foam forming bin, and spraying and forming a heat insulation layer on the surface of the heat absorption protective material structure piece embryo in the X, Y and Z three-axis directions according to the forming track. The additive manufacturing method has the advantages of manufacturing special-shaped structure pieces, simple operation, high production efficiency, excellent performance of the heat absorption protective material structure piece and good heat absorption effect.

Description

Technical Field

[0001] This invention relates to the field of thermal protection technology, and specifically to an additive manufacturing method for a heat-absorbing protective material structural component. Background Technology

[0002] Currently, heat-absorbing protective material structural components are widely used in many fields such as aircraft, rail vehicles, and automobiles to ensure that the internal recording chips can completely download operational data in the event of a fire, thereby determining the cause of the accident. Generally, the main component of heat-absorbing protective materials is a phase change material. Because these structural components must meet high-temperature environmental performance requirements, they must not only exceed the test temperature of high-temperature testing projects to prevent phase transitions during testing, but also consider the maximum withstand temperature of the printed circuit board (PCB) of the recording chip to ensure that the high-temperature environment does not damage the PCB. Therefore, the heat-absorbing protective material must be lower than the maximum withstand temperature of the PCB to provide protection. However, irregularly shaped heat-absorbing protective material structural components with special requirements are difficult or impossible to process, affecting their application in related fields. Therefore, researching new molding processes for heat-absorbing protective materials is an extremely urgent need.

[0003] Fused Deposition Modeling (FDM), also known as fused deposition extrusion molding, involves extruding material through nozzles in FDM additive manufacturing equipment. The material is then shaped layer by layer according to the CAD model of the designed structural component, and through these layers, a three-dimensional solid is finally formed.

[0004] Phase change materials (PCMs) are substances that change their state of matter with temperature and can provide latent heat. The process of changing physical properties is called a phase change process, during which the PCM absorbs or releases a large amount of latent heat. In the phase change energy storage process, the PCM added to the heat-absorbing protective material maintains a near-constant temperature, effectively controlling the system temperature. The PCM used in the heat-absorbing protective material is a solid-solid PCM. Solid-solid PCMs do not produce liquid or gas during the phase change process and have advantages such as direct processing and shaping, small phase change volume change, stable performance, non-toxicity, non-corrosiveness, and no pollution.

[0005] Silica has an average pore size of 2-50 nm, a porosity of 80-99.8%, and a specific surface area as high as 800-1000 m². 2 With a density of over / g, it belongs to the typical mesoporous material category. Moreover, it can withstand temperatures up to 1000℃, and at room temperature, the thermal conductivity of silica aerogel is only 0.017W / m·K, exhibiting the characteristics of a super thermal insulation material.

[0006] Phenolic foam is made from phenolic resin, foaming agents, and other additives. It features low thermal conductivity, good thermal insulation, resistance to flame penetration, low water absorption, and strong resistance to vapor penetration. After thoroughly and uniformly mixing phenolic foam and silica, it is sprayed onto the surface of the heat-absorbing protective composite material structure blank. This provides a certain degree of thermal insulation, reducing the temperature conducted to the heat-absorbing protective composite material structure blank. The heat-absorbing protective composite material then absorbs heat, ensuring that the memory chip printed circuit board is not damaged.

[0007] Based on, but not limited to, the above-mentioned material properties, and combined with the advantages of new additive manufacturing technology, heat-absorbing and protective composite material structural parts with conventional or irregular structural features can be formed, with low production cost, high production efficiency, and good heat absorption effect. Summary of the Invention

[0008] In view of this, embodiments of this application provide an additive manufacturing method for heat-absorbing protective material structural components. This additive manufacturing method can be used to manufacture irregularly shaped structural components. It is simple to operate, has high production efficiency, and produces heat-absorbing protective material structural components with excellent performance and good heat absorption effect.

[0009] This application provides the following technical solution: an additive manufacturing method for a heat-absorbing and protective material structural component, comprising the following steps:

[0010] Step 1: Prepare the heat-absorbing composite material according to the components and proportions. Take phenolic resin, foaming agent, and silica with a diameter of 20-35μm for later use.

[0011] Step 2: Design a three-dimensional digital model of the heat-absorbing and protective composite material structure, and obtain the molding trajectory data of the heat-absorbing and protective material structure based on the three-dimensional digital model;

[0012] Step 3: Import the 3D digital model of the heat-absorbing protective material structure into the additive manufacturing equipment. Import the heat-absorbing composite material into the low-temperature vacuum hopper of the additive manufacturing equipment. Control the outlet temperature of the heating nozzle to 60-65℃ and the extrusion speed to 1-1.2m / min. The nozzle forms the heat-absorbing protective material structure blank layer by layer in the X, Y, and Z axes according to the forming trajectory in Step 2. The thickness of each layer is 0.5-1.5mm.

[0013] Step 4: Introduce silica into the powder hopper of the additive manufacturing equipment, and introduce phenolic resin and foaming agent into the foam molding hopper of the additive manufacturing equipment. According to the molding trajectory in Step 2, spray the heat insulation layer layer by layer on the surface of the heat-absorbing protective material structure blank in the X, Y and Z axes.

[0014] Further, by mass parts, the heat-absorbing composite material comprises: 5-10 parts of water-absorbing resin, 55-60 parts of phase change material, 5-10 parts of short fiber, and 10-20 parts of adhesive.

[0015] Furthermore, the absorbent resin is any one of acrylate, polyvinyl alcohol, or polyoxyalkylene hydrocarbon absorbent resins.

[0016] Furthermore, the phase change material is any one of pentaerythritol (PETP), magnesium nitrate dihydrate (Mg(NO3)·2H2O), aluminum ammonium sulfate hexahydrate (NH4AI(SO4)·6H2O), and tris(hydroxymethyl)aminomethane (TAM).

[0017] Furthermore, the short fibers have a length of 80-100 μm.

[0018] Furthermore, in step 3, the aspect ratio of the heating nozzle outlet can be automatically adjusted between 1:1.1 and 1.5 according to the molding trajectory of the phenolic foam layer, to obtain a heat-absorbing protective material structural blank with a thickness of 10-25mm.

[0019] Furthermore, step 4 also includes controlling the powder nozzle pressure to 1-3Kg and the powder nozzle diameter Φ to 0.5-2mm; controlling the foam nozzle pressure to 0.5-2Kg and the foam nozzle diameter Φ to 0.5-2mm, with the sprayed foam diameter being 40-50μm.

[0020] Furthermore, in step 4, the thickness of the molded heat insulation layer of the phenolic foam and silica mixture sprayed on the surface of the heat-absorbing protective material structural component blank is 2-30 mm.

[0021] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: the heat-absorbing composite material composition ratio obtained through experimental research in the embodiments of this invention has good heat absorption effect. Furthermore, by adjusting the extrusion temperature, pressure, speed, and nozzle diameter of the heating nozzle, powder nozzle, and foam nozzle during the additive manufacturing process, heat-absorbing protective material structural components are prepared. These components are simple to operate, have a short production cycle, and exhibit excellent heat absorption performance, making them suitable for application in thermal protection of aircraft. Detailed Implementation

[0022] The embodiments of this application are described in detail below.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be described in detail below with reference to the embodiments, providing a clear and complete description of the technical solutions of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] This invention provides an additive manufacturing method for a heat-absorbing protective material structural component, comprising the following steps:

[0025] Step 1: Mix the water-absorbing resin, phase change material, short fiber and adhesive evenly to prepare a heat-absorbing composite material; take phenolic resin, foaming agent and silica with a diameter of 20-35μm for later use.

[0026] The heat-absorbing composite material comprises, by weight parts: 5-10 parts of water-absorbing resin, 55-60 parts of phase change material, 5-10 parts of short fibers, and 10-20 parts of adhesive. The water-absorbing resin is any one of acrylate, polyvinyl alcohol, or polyoxyalkylene hydrocarbon resins. The phase change material is any one of pentaerythritol (PETP), magnesium nitrate dihydrate (Mg(NO3)·2H2O), aluminum ammonium sulfate hexahydrate (NH4Al(SO4)·6H2O), or tris(hydroxymethyl)aminomethane (TAM). The short fibers have a length of 80-100 μm.

[0027] Step 2: Design a three-dimensional digital model of the heat-absorbing and protective composite material structure, and obtain the molding trajectory data of the heat-absorbing and protective material structure based on the three-dimensional digital model;

[0028] In practice, CAD software is used to design the molding trajectory of the heat-absorbing protective composite material structure blank and the phenolic foam layer. At the same time, the extrusion temperature, extrusion pressure, extrusion speed and nozzle diameter of the heating nozzle, powder nozzle and foam nozzle are designed.

[0029] Step 3: When manufacturing heat-absorbing protective composite material structural parts using additive manufacturing equipment, the heat-absorbing composite material is first introduced into the low-temperature vacuum hopper of the equipment. The temperature of the heating pressure nozzle and the extrusion pressure are adjusted. The heat-absorbing composite material heated to a viscous state is extruded from the nozzle at a certain rate. According to the set forming trajectory, the heat-absorbing protective material structural part blank is formed layer by layer in the X, Y, and Z axes.

[0030] Specifically, the three-dimensional digital model of the heat-absorbing protective material structure is imported into the FDM additive manufacturing equipment, and the heat-absorbing composite material is imported into the low-temperature vacuum hopper of the additive manufacturing equipment. The outlet temperature of the heating nozzle is controlled at 60-65℃, and the extrusion speed is 1-1.2m / min. The nozzle forms the heat-absorbing protective material structure blank layer by layer in the X, Y, and Z axes according to the forming trajectory in step 2. The thickness of each layer is 0.5-1.5mm. The aspect ratio of the heating nozzle outlet can be automatically adjusted between 1:1.1-1.5 according to the forming trajectory of the phenolic foam layer to obtain a heat-absorbing protective material structure blank with a thickness of 10-25mm.

[0031] To achieve the best heat absorption effect, the heat-absorbing and protective composite material structural components need to be tightly bonded layer by layer and have a dense structure.

[0032] Step 4: After the heat-absorbing and protective composite material structural component preform is formed, a mixture of silica and phenolic foam is uniformly sprayed onto the surface of the preform to improve the heat absorption effect of the heat-absorbing and protective composite material structural component. The FDM additive manufacturing equipment in step (4) includes a heating and pressurizing nozzle, a powder nozzle, a foam nozzle, a low-temperature vacuum silo, a powder silo, a foam molding silo, a molding silo, a dust collection system, a temperature system, a pressure system, and a worktable.

[0033] Specifically, silica is introduced into the powder hopper of the additive manufacturing equipment, and phenolic resin and foaming agent are introduced into the foam forming hopper of the additive manufacturing equipment. The powder nozzle, foam nozzle pressure and nozzle diameter are adjusted to control the diameter of phenolic foam particles. After ensuring that silica and phenolic foam are fully mixed and uniform, the heat insulation layer is sprayed layer by layer onto the surface of the heat-absorbing protective material structure blank in the X, Y and Z axes according to the forming trajectory in step 2.

[0034] In step 4, the powder nozzle pressure is controlled at 1-3 kg, and the nozzle diameter Φ is 0.5-2 mm; the foam nozzle pressure is controlled at 0.5-2 kg, and the foam nozzle diameter Φ is 0.5-2 mm, resulting in a foam diameter of 40-50 μm. The powder and foam nozzles operate simultaneously and in the same direction, and can rotate in three axes to form a thorough and uniform mixture of phenolic foam and silica. The thickness of the molded heat-insulating layer, formed by spraying the phenolic foam and silica mixture onto the surface of the heat-absorbing protective material structural component blank, is 2-30 mm. Finally, once the phenolic foam and silica mixture reaches the designed thickness, the molding of the heat-absorbing protective material structural component is complete. After the structural component is molded and returned to room temperature, it can be removed for use.

[0035] The present invention will now be further described using specific embodiments.

[0036] Example 1

[0037] The components of the heat-absorbing composite material are as follows (by weight): 5 parts water-absorbing resin, 55 parts phase change material, 8 parts short fibers, and 15 parts adhesive. The short fibers have a length of 80-100 μm. The silica particles have a diameter of 20-35 μm.

[0038] Process parameters: The outlet temperature of the heating and pressurizing nozzle is 60℃, the extrusion speed is 1.1m / min, and the thickness of each layer is 1.1mm. The powder nozzle pressure is 2Kg, and the nozzle diameter is Φ1.1mm. The foam nozzle pressure is 0.8Kg, the nozzle diameter is Φ1.2mm, and the foam diameter is 40-50μm. The thickness of the prepared heat-absorbing protective material structural component blank is 10mm. The surface of the blank is coated with a 10mm thick mixture of phenolic foam and silica.

[0039] The heat-absorbing protective composite material structure obtained has a thermal conductivity of 0.112 W / m·K at 500℃.

[0040] Example 2

[0041] The components of the heat-absorbing composite material are as follows (by weight): 8 parts water-absorbing resin, 60 parts phase change material, 9 parts short fibers, and 17 parts adhesive. The short fibers have a length of 80-100 μm. The silica particles have a diameter of 20-35 μm.

[0042] Process parameters: The outlet temperature of the heating and pressurizing nozzle is 63℃, the extrusion speed is 1m / min, and the thickness of each layer is 0.6mm. The powder nozzle pressure is 1Kg, and the nozzle diameter is Φ0.5mm. The foam nozzle pressure is 1.2Kg, the nozzle diameter is Φ0.5mm, and the foam diameter is 40-50μm. The thickness of the prepared heat-absorbing protective material structural component blank is 20mm. The surface of the blank is coated with a phenolic foam and silica mixture to a thickness of 25mm.

[0043] The heat-absorbing protective composite material structure obtained has a thermal conductivity of 0.086 W / m·K at 500℃.

[0044] Example 3

[0045] The components of the heat-absorbing composite material are as follows (by weight): 7 parts water-absorbing resin, 57 parts phase change material, 10 parts short fibers, and 16 parts adhesive. The short fibers have a length of 80-100 μm. The silica particles have a diameter of 20-35 μm.

[0046] Process parameters: The outlet temperature of the heating and pressurizing nozzle is 62℃, the extrusion speed is 1.05m / min, and the thickness of each layer is 0.8mm. The powder nozzle pressure is 1.5Kg, and the nozzle diameter is Φ0.8mm. The foam nozzle pressure is 1.2Kg, the nozzle diameter is Φ0.8mm, and the foam diameter is 40-50μm. The thickness of the prepared heat-absorbing protective material structural component blank is 18mm. The surface of the blank is coated with a phenolic foam and silica mixture to a thickness of 22mm.

[0047] The heat-absorbing protective composite material structure obtained has a thermal conductivity of 0.098 W / m·K at 500℃.

[0048] This invention provides an additive manufacturing method for a heat-absorbing protective material structural component. By adjusting the extrusion temperature, pressure, speed, and nozzle diameter of the heating nozzle, powder nozzle, and foam nozzle, a heat-absorbing protective material structural component can be prepared. Moreover, the method is simple to operate, has a short production cycle, and exhibits excellent heat absorption performance.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An additive manufacturing method for a heat-absorbing protective material structural component, characterized in that, Includes the following steps: Step 1: Prepare the heat-absorbing composite material according to the components and proportions. Take phenolic resin, foaming agent, and silica with a diameter of 20-35μm for later use. Step 2: Design a three-dimensional digital model of the heat-absorbing and protective composite material structure, and obtain the molding trajectory data of the heat-absorbing and protective material structure based on the three-dimensional digital model; Step 3: Import the 3D digital model of the heat-absorbing protective material structure into the additive manufacturing equipment. Import the heat-absorbing composite material into the low-temperature vacuum hopper of the additive manufacturing equipment. Control the outlet temperature of the heating nozzle to 60-65℃ and the extrusion speed to 1-1.2m / min. The nozzle forms the heat-absorbing protective material structure blank layer by layer in the X, Y, and Z axes according to the forming trajectory in Step 2. The thickness of each layer is 0.5-1.5mm. Step 4: Introduce silica into the powder hopper of the additive manufacturing equipment, and introduce phenolic resin and foaming agent into the foam molding hopper of the additive manufacturing equipment. According to the molding trajectory in Step 2, spray the heat insulation layer layer by layer on the surface of the heat-absorbing protective material structure blank in the X, Y and Z axes.

2. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 1, characterized in that, The heat-absorbing composite material comprises, by weight, 5-10 parts of water-absorbing resin, 55-60 parts of phase change material, 5-10 parts of short fiber, and 10-20 parts of adhesive.

3. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 2, characterized in that, The absorbent resin is any one of acrylate, polyvinyl alcohol, or polyoxyalkylene hydrocarbon absorbent resins.

4. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 2, characterized in that, The phase change material is any one of pentaerythritol (PETP), magnesium nitrate dihydrate (Mg(NO3)·2H2O), aluminum ammonium sulfate hexahydrate (NH4AI(SO4)·6H2O), and tris(hydroxymethyl)aminomethane (TAM).

5. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 2, characterized in that, The short fibers have a length of 80-100 μm.

6. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 1, characterized in that, In step 3, the aspect ratio of the heating nozzle outlet can be automatically adjusted between 1:1.1 and 1.5 according to the molding trajectory of the phenolic foam layer, so as to obtain a heat-absorbing protective material structural blank with a thickness of 10-25mm.

7. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 1, characterized in that, Step 4 also includes controlling the powder nozzle pressure to 1-3Kg and the powder nozzle diameter Φ to 0.5-2mm; controlling the foam nozzle pressure to 0.5-2Kg and the foam nozzle diameter Φ to 0.5-2mm, with the sprayed foam diameter being 40-50μm.

8. The additive manufacturing method for the heat-absorbing protective material structural component according to claim 1, characterized in that, In step 4, the thickness of the molded heat insulation layer of the phenolic foam and silica mixture sprayed on the surface of the heat-absorbing protective material structural component blank is 2-30mm.