Composite holding base material for processing 3D printing honeycomb material and preparation method of composite holding base material

Abstract

The invention relates to the field of milling, in particular to a composite holding base material and a preparation method and application thereof. According to the invention, low-freezing-point agar and gelatin hydrogel with a mass ratio of 9: 1-1: 1 are used as a composite immobilization base material for the first time to be applied to the field of milling, so that stable immobilization and convenient disassembly of the honeycomb material are realized; the problems of high cutter cost, harsh parameters, unreasonable holding mode and poor process universality in the milling of the existing 3D printing honeycomb composite material are solved, the industrial pain points of difficult disassembly, easy workpiece damage and residual influence on performance in the traditional holding mode are solved, and powerful support is provided for diversified application of the 3D printing honeycomb composite material; and the method has wide industrial popularization value.

Description

Technical Field

[0001] This invention relates to the field of milling, and more specifically to composite retaining substrates, their preparation methods, and applications. Background Technology

[0002] 3D-printed honeycomb composite material is a thin-walled, porous, lightweight structural material with a porosity exceeding 90%. This material possesses characteristics such as light weight, high specific strength, impact resistance, corrosion resistance, high temperature resistance, and fatigue resistance. It also combines structural load-bearing capacity with electromagnetic stealth capabilities, making it widely used in the manufacture of high-performance energy-absorbing structural components in aerospace, automotive, and defense industries.

[0003] In the post-processing stage of 3D printed honeycomb composite materials, milling is a key process for achieving precise part forming. During milling, effective and stable holding of the workpiece is a prerequisite for ensuring machining quality. Currently, the mainstream approach for milling honeycomb materials in industrial production and research is to use a combination of disc milling cutters, combined with mechanical clamping or single adhesive holding. However, traditional disc milling cutters have large diameters, resulting in high tool manufacturing and maintenance costs. Furthermore, these tools are specialized, typically suitable only for milling one type of honeycomb material, and cannot be compatible with conventional tools used for machining other alloys and composites in industrial production, increasing tool inventory and replacement / adjustment costs for enterprises. Existing mechanical clamping or single adhesive holding methods also have significant drawbacks: with mechanical clamping, the thin walls of the honeycomb material are prone to deformation, and the small contact area leads to insufficient holding force, causing workpiece displacement and vibration during machining, resulting in defects such as burrs and tears; while using a single AB adhesive for holding offers high bonding strength, the workpiece is difficult to remove after machining, easily causing damage to the honeycomb wall, and adhesive residue can affect workpiece performance.

[0004] Furthermore, for common honeycomb materials such as Nomex and Peak honeycomb, to avoid processing damage and ensure processing quality, the industry currently commonly uses a combination of high speed, high feed, and shallow depth of cut. While this can reduce processing damage to some extent, the shallow depth of cut leads to an increase in the number of machining operations and a significant reduction in cutting efficiency. At the same time, high speed and high feed increase machine tool energy consumption and generate a large amount of cutting heat, which can easily cause thermoplastic deformation of the honeycomb material and affect the dimensional stability of the parts.

[0005] Furthermore, most existing empirical models for milling honeycomb materials are only applicable to a single honeycomb material selected for the cutting experiment. When machining honeycomb composite materials of different materials, types, and lattice structures, the original empirical models are no longer applicable, requiring repeated large-scale cutting experiments to explore parameters, which makes the technology difficult to promote.

[0006] As the aerospace industry continues to demand higher dimensional and assembly precision for honeycomb structural components, the limitations of conventional milling methods are becoming increasingly apparent. In particular, existing methods struggle to balance the requirements for strong holding force with easy disassembly. The industry urgently needs a milling process for honeycomb materials that is compatible with general-purpose industrial cutting tools and provides reliable holding. Summary of the Invention

[0007] To address the problems of high tool costs, stringent parameters, unreasonable holding methods, and poor process versatility in existing 3D printed honeycomb composite material milling processes, this invention provides a precision milling method based on a low-powdering agar + gelatin hydrogel composite holding method. By optimizing the holding process and milling parameters, the contact area between the honeycomb material and the machine tool table is increased, enhancing the holding force. Simultaneously, convenient and non-destructive workpiece disassembly is achieved. Combined with zoned machining to determine optimal machining parameters, this method meets the precision machining requirements of high-performance 3D printed honeycomb structures in aerospace and other fields.

[0008] Specifically as follows: A composite retaining substrate for 3D printing honeycomb materials, the composite retaining substrate containing a low-growth agar:gelatin hydrogel in a mass ratio of 9:1 to 1:1; the low-growth agar has a melting temperature of 60℃–65℃ and a solidification temperature of about 26℃–30℃; the gelatin hydrogel has a melting temperature of 28℃–34℃.

[0009] Furthermore, the composite retaining substrate contains a low-gluconate agar:gelatin hydrogel with a mass ratio of 9:1 to 4:1.

[0010] This invention does not limit the types of low-gluconate agar and gelatin hydrogel. It mainly utilizes the different components and melting temperatures of agar and gelatin to adjust the melting temperature of the composite holding substrate by adjusting the ratio of the two components, thereby controlling the melting temperature between 50℃ and 100℃.

[0011] The "low-melting-point agar" described in this invention, also known as "low-melting-point agarose" or "LMP agarose," refers to a chemically modified (e.g., hydroxyethylated) agarose derivative. Its core characteristics are low gelation and melting temperatures, making it suitable for handling heat-sensitive samples and widely used in biocompatibility testing related to molecular biology and materials processing. Its typical melting temperature is 60–65℃ (1.5% gel concentration, ≤65℃), significantly lower than conventional agarose (above 90℃). Its solidification temperature is approximately 26℃–30℃, exhibiting a significant thermal hysteresis effect. The "low-melting-point agar" described in this invention can be modified independently or purchased directly from commercially available products, such as synthetic agarose (BA8452 series, Shanghai Bohr Chemical Reagent Co., Ltd.); Biskanten™ low-melting-point agarose (LMP) (BSHT405, Bishui Hantian Biotechnology Co., Ltd.); Agarose II (LowMelt) (17856, Thermo Fisher Scientific), Agarose II Low Melt (95057, G-Biosciences), etc. As long as the melting and solidification temperatures are lower than those of ordinary agarose, with a melting temperature of around 65℃ (60℃-68℃) and a solidification temperature of around 30℃ (28℃-34℃), it is acceptable.

[0012] The "gelatin hydrogel" described in this invention refers to a gelatin hydrogel whose core chemical components consist of gelatin polypeptide molecules and water molecules. The added cross-linking agents / auxiliaries are functional chemical components. Pure physical gelatin hydrogels without these additives contain only gelatin polypeptides and water, and are naturally composed primarily of nitrogen-containing organic macromolecules. The gelatin hydrogel described in this invention can be modified independently or commercially available products such as EFL-GM-30, EFL-GM-60, and EFL-GM-90 can be purchased directly, provided the melting temperature is controlled between 28℃ and 34℃.

[0013] On the other hand, the present invention discloses a method for preparing the composite retaining substrate, comprising: (3) Weigh out the low-gluing agar and gelatin hydrogel in a mass ratio of 9:1 to 1:1. (4) Heat and melt the mixture in a constant temperature environment of 50-100℃ and stir until homogeneous.

[0014] Furthermore, the preparation method of the composite retaining substrate includes: weighing low-gluconate agar and gelatin hydrogel at a mass ratio of 9:1 to 4:1. (5) Heat and melt the mixture in a constant temperature environment of 75℃-85℃ and stir until homogeneous.

[0015] The stirring can be done manually with a glass rod or by using a stirrer, as long as the mixture is uniform. This invention does not limit the stirring method. After uniform stirring, it becomes the composite retaining substrate.

[0016] Furthermore, the constant temperature environment is selected from a water bath or a metal bath.

[0017] On the other hand, the present invention discloses the application of the composite holding substrate in the field of milling.

[0018] On the other hand, the present invention also discloses a pre-fixing structure, wherein the pre-fixing structure contains the composite fixing substrate.

[0019] Furthermore, the pre-fixed structure also contains a honeycomb material, preferably selected from aramid paper honeycomb, glass fiber honeycomb, polyaryletherketone microwave absorbing honeycomb composite material or fiber reinforced composite honeycomb.

[0020] The "honeycomb material" described in this invention, also known as a "honeycomb structure," is a composite material used in 3D printing. It is a sandwich structure composite material formed by bonding a honeycomb-shaped porous core layer with two thin upper and lower panels using an adhesive / composite process. The core layer has a regular honeycomb lattice (mainly hexagonal), forming a continuous three-dimensional load-bearing skeleton. The panels bear in-plane loads, while the core layer bears shear and compressive loads. It is a typical lightweight, high-strength, and high-specific-stiffness structural material, with core characteristics of "low density, high specific strength, and high specific modulus." This invention does not limit the honeycomb material and can be adapted to the processing of various honeycomb materials. Only the thickness of the composite holding substrate needs to be adjusted to adapt to different honeycomb materials. Because the paste-like substrate made of low-density agar and gelatin hydrogel can fully fill the pore structure at the bottom of the honeycomb material, the point contact and line contact of traditional mechanical clamping are transformed into full adhesion, which greatly increases the contact area and realizes the preparation of the pre-fixed structure for subsequent processing.

[0021] Furthermore, the thickness of the composite retaining substrate is 3 mm to 10 mm.

[0022] On the other hand, the present invention also discloses a pre-holding method, comprising: (3) Place the honeycomb material smoothly on the composite retaining substrate and press gently to ensure complete adhesion. (4) Allow to stand at room temperature to cure.

[0023] Furthermore, the settling time is 30 min - 60 min.

[0024] Further, step (1) involves uniformly pouring a layer of the composite material with a thickness of 3 mm to 10 mm into a container, placing the honeycomb material stably on the substrate, and gently pressing to ensure that the bottom of the honeycomb is completely adhered to the substrate.

[0025] On the other hand, the present invention also discloses a milling method for honeycomb materials based on the composite holding substrate, comprising: (5) Place the honeycomb material stably on the composite retaining substrate, press it gently to make it fully adhered, and let it stand at room temperature to prepare a pre-retaining structure; (6) Apply AB glue evenly to the surface of the machine tool worktable to form an adhesive underlayer; (7) Place the pre-fixed structure stably on the adhesive base layer, press gently to ensure that the bottom of the pre-fixed structure is completely attached to the adhesive base layer, and let it stand at room temperature to cure, forming the processed structure; (8) Perform milling on the machining structure described in step (3).

[0026] Furthermore, the AB adhesive coating thickness is 0.1 mm - 0.2 mm. The settling time is 10 min - 60 min, preferably 30 min.

[0027] Furthermore, the milling parameters are: spindle speed 5000-15000 rpm, feed rate 600-1400 mm / min, and depth of cut 3 mm-5 mm. Furthermore, the milling parameters are: spindle speed 7000 rpm, feed rate 600 mm / min, and depth of cut 5 mm.

[0028] Furthermore, the milling cutter is a 6 mm end mill.

[0029] This invention employs a "low-powder agar + gelatin hydrogel" composite holding substrate, achieving surface-to-surface contact holding between the honeycomb material and the machine tool table, completely overcoming the drawbacks of traditional holding methods. The paste-like substrate, made from a mixture of low-powder agar and gelatin hydrogel, fully fills the pores at the bottom of the honeycomb material, transforming the point and line contact of traditional mechanical clamping into a complete fit, significantly increasing the contact area. The bottom layer of AB adhesive provides stable bonding force, ensuring a firm bond between the holding substrate and the worktable, forming a dual holding system of "substrate support + adhesive layer bonding." During milling, this system effectively counteracts the impact and vibration forces from the cutting force, preventing workpiece displacement and vibration, and fundamentally reducing processing defects such as burrs, interlayer tearing, hole wall damage, and hole wall delamination caused by improper holding, ensuring the stability and consistency of the processing.

[0030] This invention utilizes a 6 mm end mill, commonly used in industrial machining of alloys and composite materials, to replace the traditional disc end mills required for machining honeycomb materials, significantly reducing the costs of tool procurement, maintenance, and equipment modification. Traditional disc end mills are specialized tools, characterized by long customization cycles, high manufacturing costs, and complex maintenance processes. They also require dedicated machine tools or modifications to existing equipment, increasing equipment investment for enterprises. In contrast, the 6 mm end mill is a universal, standardized tool with ample market inventory and low procurement costs. It can be directly adapted to conventional CNC milling machines without additional machine tool modifications. Furthermore, the tool changing and debugging process for universal tools is simple, reducing equipment downtime and improving overall production efficiency. From tool selection to equipment adaptation, this invention comprehensively reduces the process costs of milling honeycomb materials.

[0031] On the other hand, the present invention also discloses a method for disassembling the honeycomb material after milling, comprising: (3) Place the processed structure in hot water at 50℃-100℃ for more than 2 minutes to soften the composite retaining substrate and remove the pre-retaining structure; (4) Place the pre-fixed structure in boiling water at 100°C to remove the composite retaining substrate.

[0032] Furthermore, the processing structure is immersed in hot water at 70°C for 2-5 minutes.

[0033] The layered design of the composite holding method perfectly balances the need for high holding force during processing with convenient disassembly after processing. After processing, simply immerse the workbench and workpiece in hot water above the melting point of the composite holding substrate for at least 2 minutes. The low-pour-point agar + gelatin hydrogel will gradually soften and lose its supporting and securing function, allowing the honeycomb workpiece to be easily removed. The entire disassembly process requires no external prying force, avoiding damage to the honeycomb thin-walled structure. Simultaneously, the softened low-pour-point agar + gelatin hydrogel substrate leaves minimal residue and is easy to clean; it can be completely removed by immersing in boiling water at 100℃ for 5-10 minutes, unlike the adhesive residue problems associated with single AB glue holding. This characteristic effectively protects the original performance of the honeycomb material, preventing residue from affecting its core functions such as electromagnetic stealth, wave absorption, and mechanical load-bearing capacity. This solves the industry pain points of traditional holding methods, such as difficult disassembly, easy damage to the workpiece, and residue affecting performance.

[0034] Beneficial effects: (1) Composite holding method realizes surface contact holding of honeycomb material and machine tool table, realizing high holding force and convenient disassembly after processing.

[0035] (2) In this invention, there is no direct contact between the AB glue and the honeycomb material, so there is no problem of the honeycomb material performance being affected by the residue of the AB glue. In addition, after the composite holding substrate softens, it is easy to remove without damaging the honeycomb material.

[0036] (3) This invention breaks through the stringent parameter limitations of "high speed, high feed and small depth of cut" in the traditional milling of honeycomb materials. Through parameter synergistic optimization, the surface roughness of the part Sa≤3.026μm is effectively controlled, and the machining accuracy is stable in the high precision range of ≤±0.04mm (up to ≤±0.01mm). This achieves a dual improvement in machining efficiency and forming quality, and fully meets the precision assembly requirements of high-performance honeycomb structural parts in the aerospace and defense fields.

[0037] (4) The process is highly versatile and adaptable to a variety of honeycomb materials. The composite holding method does not depend on the surface characteristics of specific honeycomb materials. Whether it is a complex honeycomb structure or a simple straight hole honeycomb, whether it is a high-temperature resistant polyaryletherketone microwave absorbing honeycomb composite material or other metal or non-metal honeycomb systems, stable holding can be achieved by adjusting the thickness of the holding substrate. This feature greatly reduces the enterprise's technology research and development cycle and experimental costs, significantly improves the application flexibility of the technology, provides strong support for the diversified application of 3D printed honeycomb composite materials, and has broad industry promotion value.

[0038] (5) Reduce tooling costs and improve process economy. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 is a schematic diagram of a honeycomb material composite holding structure; Figure 2 shows a physical diagram of the processing area division for honeycomb materials; Figure 3 shows the relationship between processing parameters and surface roughness. Figure 4 shows the honeycomb material after machining. Detailed Implementation

[0041] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and similar modifications can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0043] Materials or reagents not specifically mentioned in this invention are all commercially available products or obtained through conventional technical means in the field.

[0044] In all embodiments, the processing equipment and auxiliary materials used are as follows: Processing equipment: CNC machining center; Cutting tool: 6mm industrial-grade end mill; Auxiliary materials: Low-growth agar (melting temperature 60℃–65℃, solidification temperature approximately 26℃–30℃); gelatin hydrogel (melting temperature 28℃–34℃); AB glue.

[0045] The steps for compound holding operation are as follows: ① Weigh low-density agar and gelatin hydrogel at a mass ratio of 9:1 to 1:1, heat and melt them in a constant temperature water bath at 50-100℃, and stir evenly to make a composite retention substrate. ② Pour a layer of the composite holding substrate with a thickness of 3 mm-10 mm evenly into the container, place the 3D printed black complex structure honeycomb material stably on the substrate, press gently to ensure that the bottom of the honeycomb is completely attached to the substrate and keep the bottom flat, let it stand at room temperature for 30 min-60 min to complete the curing, so that the honeycomb and the composite holding substrate are tightly bonded to form a stable pre-holding structure. ③ Apply a layer of AB glue with a thickness of 0.1 mm-0.2 mm evenly to the surface of the machine tool worktable to form an adhesive underlayer; ④ Place the cured pre-fixed structure stably on the AB glue, press gently to ensure that the bottom of the honeycomb is completely adhered to the glue, and let it stand at room temperature for more than 30 minutes to complete the curing.

[0046] Milling process: Start the CNC machining center and mill each area of ​​the honeycomb material according to the preset parameters. During the machining process, observe whether there is obvious vibration or whether the workpiece is displaced.

[0047] Disassembly process: After processing, the workbench and the workpiece are immersed in 70℃ hot water for 2 minutes. After the low-pour-point agar + gelatin hydrogel softens, the honeycomb workpiece can be easily removed. Placing the workpiece in boiling water at 100℃ can completely remove the substrate fixed by the low-pour-point agar + gelatin hydrogel without secondary damage.

[0048] Example 1: Study on Milling Parameters of 3D Cellular Materials (1) Experimental materials In this embodiment, a 3D printed black complex structure honeycomb material is selected. The basic dimensions are 60mm×60mm×50mm, and the material is a high-temperature resistant polyaryletherketone microwave absorbing honeycomb composite material.

[0049] (2) Processing equipment and auxiliary materials Processing equipment: CNC machining center; Cutting tool: 6mm industrial-grade end mill; Auxiliary materials: Low-gluing agar (C 12 +mH 18 +4mO9+m)n (melting temperature approximately 65℃, solidification temperature approximately 30℃), gelatin hydrogel ((C4H 11 NO3)n⋅mH2O (melting temperature approximately 30℃), AB glue.

[0050] (3) Composite holding operation steps ① Weigh low-density agar and gelatin hydrogel at a mass ratio of 9:1, heat and melt them in an 80℃ constant temperature water bath, and stir evenly to make a composite retention substrate; ② Pour a layer of the composite holding substrate with a thickness of 3 mm-5 mm evenly into the container, place the 3D printed black complex structure honeycomb material stably on the substrate, press gently to ensure that the bottom of the honeycomb is completely attached to the substrate and keep the bottom flat, let it stand at room temperature for 30-60 minutes to complete the curing, so that the honeycomb and the composite holding substrate are tightly bonded to form a stable pre-holding structure. ③ Apply a layer of AB glue with a thickness of 0.1 mm-0.2 mm evenly to the surface of the machine tool worktable to form an adhesive underlayer; ④ Place the cured pre-fixed structure stably on the AB glue, press gently to ensure that the bottom of the honeycomb is completely adhered to the glue, and let it stand at room temperature for 30 minutes to complete the curing.

[0051] like Figure 1As described above, after the curing of step ④, the structure from top to bottom consists of honeycomb material, composite retaining substrate (i.e., low-density agar + gelatin hydrogel), AB glue, and the cutting tool and worktable of the processing equipment are respectively placed on the upper side of the honeycomb material and the lower side of the AB glue. The honeycomb material and the composite retaining substrate constitute the pre-retaining structure. The pre-retaining structure is tightly fixed to the worktable by the AB glue. The composite retaining substrate increases the contact area with the honeycomb material. Due to the paste-like texture of the melted composite retaining substrate, it can fully fill the pore structure at the bottom of the honeycomb material, achieving surface contact and increasing stability. On the other hand, after the composite retaining substrate and the honeycomb material form the pre-retaining structure, the composite retaining substrate solidifies, and the contact area between its lower surface and the AB glue is also larger than that of mechanical structure fixation or AB glue directly fixed to the honeycomb structure, which can more stably achieve fixation.

[0052] (4) Milling ① Start the CNC machining center and perform milling on each area in sequence according to the preset parameters. There is no obvious vibration or workpiece displacement during the machining process.

[0053] The preset parameters: Three honeycomb materials were selected and divided into three equal-width processing areas along the y-direction, resulting in a total of nine sub-regions. The processing parameters for each region are shown in Table 1, and the actual images of each region are shown in Figure 2. Table 1 Milling machining parameter settings ; The results are shown in Table 2 and Figure 3-4 As shown: Table 2 Performance Test Results ; From Table 2 and Figure 3-4 It can be seen that: ① The composite holding method effectively improves the processing stability. The processing accuracy of all areas is ≤ ±0.04mm, and most areas reach ±0.01mm. There are no processing defects caused by workpiece displacement or vibration.

[0054] ② Spindle speed has a significant impact on surface roughness: At the same feed rate and depth of cut, when the spindle speed is increased from 3000 rpm to 7000 rpm, the surface roughness Sa is significantly reduced, and Sa is as low as 3.026 μm under the optimal parameter combination.

[0055] In practice, a Sa value below 5 μm is considered very good. Therefore, it can be seen that the machining effects of 2-2, 3-2, and 3-3 are all excellent. Furthermore, this embodiment determined the optimal combination of machining parameters: spindle speed 7000 rpm, feed rate 600 mm / min, and depth of cut 5 mm. This method, primarily using a large depth of cut in a single pass, reduces the number of cuts, significantly shortens machining time, and improves machining efficiency. Simultaneously, the reasonable matching of spindle speed and feed rate reduces heat output during the cutting process, preventing material deformation due to overheating, and is further enhanced by the stable support provided by the composite holding method.

[0056] (5) Disassembly process After processing, the workbench and the workpiece are immersed in 70℃ hot water for 2 minutes. After the low-pour-point agar + gelatin hydrogel softens, the honeycomb workpiece can be easily removed. Placing the workpiece in boiling water at 100℃ can completely remove the substrate fixed by the low-pour-point agar + gelatin hydrogel without secondary damage.

[0057] The hot water immersion disassembly method is convenient and non-destructive, and the removed honeycomb workpieces have no wall damage. The residual substrate is thoroughly cleaned without affecting the original properties of the material.

[0058] Example 2: Study on Composite Holding Substrates The experimental materials, processing equipment and auxiliary materials, composite holding operation, milling, and disassembly process in this embodiment are the same as in Embodiment 1. The milling parameters are selected as follows: spindle speed 7000 rpm, feed rate 600 mm / min, and depth of cut 5 mm.

[0059] This study focuses solely on the formulation of the composite holding substrate during the composite holding process. The specific proportions are shown in Table 3, where the proportions are by mass.

[0060] Table 3 Composition ratio of composite retainer substrate ; The results show Table 4 Performance Test Results ; Therefore, the ratio of the composite retaining substrate can be selected in the range of 9:1 to 1:1, with the optimal range being 9:1 to 4:1.

[0061] Example 3: Investigation of Different Cellular Materials The experimental materials, processing equipment and auxiliary materials, composite holding operation, milling, and disassembly process in this embodiment are the same as in Embodiment 1. The milling parameters are selected as follows: spindle speed 7000 rpm, feed rate 600 mm / min, and depth of cut 5 mm.

[0062] To compare the effect with that in Example 1, everything was the same except for the honeycomb material.

[0063] To better hold different honeycomb materials in place, composite holding substrates of different thicknesses can be used for different honeycomb materials, ranging from 3 mm to 10 mm, depending on the specific requirements.

[0064] Table 4 Selection of Different Cellular Materials ; The results show that the processing accuracy is within ±0.01, with the average surface roughness Sa of materials 1-4 being 4.139 μm, 3.535 μm, 3.026 μm, and 3.105 μm, respectively. This demonstrates that high-precision processing can be achieved for different honeycomb materials under the conditions of this invention.

[0065] In summary, the above embodiments are only for illustrating the relevant principles and implementation methods, and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention without departing from the principles of the present invention should be included within the protection scope of the present invention.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, 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 the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A composite holding substrate for 3D printing honeycomb materials, characterized in that, The composite retaining substrate contains a low-growth agar and gelatin hydrogel in a mass ratio of 9:1 to 1:1; the low-growth agar has a melting temperature of 60℃–65℃ and a solidification temperature of approximately 26℃–30℃; the gelatin hydrogel has a melting temperature of 28℃–34℃.

2. The composite retaining substrate according to claim 1, characterized in that, The composite retaining substrate contains a low-gluconate agar:gelatin hydrogel with a mass ratio of 9:1 to 4:

1.

3. The method for preparing the composite retaining substrate according to claim 1 or 2, characterized in that... include: (1) Weigh out the low-gluing agar and gelatin hydrogel in a mass ratio of 9:1 to 1:

1. (2) Heat in a constant temperature environment of 50-100℃ until melted, and stir evenly; Preferably, the temperature in step (2) is 70-80℃.

4. A pre-fixed structure, characterized in that, The pre-fixing structure contains the composite fixing substrate as described in claim 1.

5. The pre-fixed structure according to claim 4, characterized in that, The pre-fixed structure further includes a honeycomb material; more preferably, the honeycomb material is selected from aramid paper honeycomb, glass fiber honeycomb, polyaryletherketone microwave absorbing honeycomb composite material or fiber reinforced composite honeycomb.

6. The pre-fixing structure according to claim 4 or 5, characterized in that, The thickness of the composite retaining substrate in the pre-retaining structure is 3 mm - 10 mm.

7. A pre-fixing method, characterized in that, include: (1) Place the honeycomb material as described in claim 5 smoothly on the composite retaining substrate as described in claim 1, and gently press it to make it fully adhered. (2) Curing is completed by standing at room temperature; Preferably, the settling time in step (2) is 30 min - 60 min.

8. A method for milling honeycomb materials based on the composite retaining substrate as described in claim 1 or 2, comprising: (1) Place the honeycomb material described in claim 5 on the composite retaining substrate described in claim 1, press it lightly to make it fully adhered, and let it stand at room temperature to prepare a pre-retaining structure; (2) Apply AB glue evenly to the surface of the machine tool worktable to form an adhesive underlayer; (3) Place the pre-fixed structure stably on the adhesive base layer, press gently to ensure that the bottom of the pre-fixed structure is completely attached to the adhesive base layer, and let it stand at room temperature to cure, forming the processed structure; (4) Perform milling on the machining structure described in step (3); Preferably, the AB adhesive coating thickness is 0.1 mm - 0.2 mm, and the settling time is 10 min - 60 min.

9. The processing method according to claim 8, characterized in that, The milling parameters include: spindle speed of 5000-15000 rpm, feed rate of 600-1400 mm / min, and depth of cut of 3 mm-5 mm; preferably, the milling parameters are spindle speed of 7000 rpm, feed rate of 600 mm / min, and depth of cut of 5 mm; more preferably, the milling tool is a 6 mm end mill.

10. A method for disassembling honeycomb material after milling according to claim 8 or 9, characterized in that, include: (1) Immerse the processing structure in hot water at 50℃-100℃ for more than 2 minutes to soften the composite holding substrate and remove the pre-holding structure; (2) Place the pre-fixed structure in boiling water at 100°C to remove the composite fixing substrate; Preferably, the processing structure is immersed in hot water at 70°C for 2-5 minutes.

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