Method for preparing internal laser induced carbonization layer of aramid fiber resin matrix composite

Abstract

Disclosed in the present invention is a preparation method for a laser-induced carbonization layer in an aramid fiber reinforced polymer. The preparation method comprises: wiping the surface of an ara

Description

A method for preparing a laser-induced carbonized layer inside an aramid fiber resin-based composite material Technical Field

[0001] The invention relates to the technical field of laser processing, in particular to a laser modification method of an aramid fiber reinforced composite material. Background Art

[0002] Aramid fiber reinforced polymer (AFRP) is an advanced composite material composed of high-strength aramid fibers as reinforcement and a cured resin matrix. It boasts high specific strength and stiffness, excellent fatigue resistance, and strong designability. With advances in the design and manufacturing of aramid fiber reinforced polymers, they are gradually replacing components in certain key structural areas and are widely used as lightweight materials in the aerospace industry.

[0003] In the aerospace sector, aramid fiber-reinforced resin-based composites are primarily used in aerospace equipment housings and skins. Spacecraft require various sensors to be embedded or affixed to the surface of the structure to fulfill some of their functions. This involves the distribution of circuits. The traditional approach involves routing numerous wires within the space, but this approach consumes the already limited internal space. For spacecraft, which have extremely high internal space requirements, the space occupied by wires is a waste of internal space and has a certain impact on the overall design.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a laser-induced carbonization layer inside an aramid fiber resin-based composite material. Based on the different laser energy absorption rates of aramid fiber and resin, an infrared picosecond laser is used to scan the aramid fiber resin-based composite material to achieve high-temperature carbonization of the aramid fiber layer below the surface resin, thereby realizing the conductive function.

[0006] The technical solution adopted by the present invention is a method for preparing a laser-induced carbonized layer inside an aramid fiber resin-based composite material, which is specifically implemented according to the following steps.

[0007] Step 1: Wipe the surface of the aramid fiber resin-based composite material sample to ensure that there is no stain on the surface;

[0008] Step 2: Place the aramid fiber resin-based composite material sample on the laser sample platform, with the laser focus and the upper surface of the sample having a negative defocus, so that the laser focus is located on the horizontal plane inside the material;

[0009] Step 3: Use a low-power, high-speed infrared picosecond laser to scan the aramid fiber resin-based composite material sample multiple times. Set a specific scanning path and processing path to carbonize the aramid fiber layer below the surface resin under high temperature and oxygen deficiency, forming a specific carbonization path.

[0010] In the above solution, the thickness of the resin layer on the surface of the aramid fiber resin-based composite material in step 1 is 0.1 mm to 0.3 mm.

[0011] In the above solution, the defocusing amount between the laser focus and the upper surface of the sample in step 2 is -1mm to -10mm.

[0012] In the above scheme, the wavelength of the infrared picosecond laser in step three is 1064 nm.

[0013] In the above solution, the laser power used in step three is 4W to 15W, and the scanning speed is 500mm / s to 2000mm / s.

[0014] In the above solution, the number of scans of the aramid fiber resin-based composite material sample in step 3 is 6 to 12 times, and the time interval between each scan is 1 second to 2 seconds.

[0015] Beneficial effects of the present invention:

[0016] 1) The present invention uses an infrared picosecond laser to prepare a carbonized layer inside an aramid fiber resin-based composite material. The carbonized layer inside the aramid fiber resin-based composite material is prepared without damaging the surface resin, achieving innovation and breakthroughs in the experiment and process of preparing the carbonized layer inside the aramid fiber resin-based composite material using a picosecond laser.

[0017] 2) The present invention features a simple, low-cost, and highly efficient preparation process. The carbonized layer within the aramid fiber resin-based composite material produced by the present invention, due to its excellent electrical conductivity, can be widely used in various aerospace applications, promoting lightweight design and saving significant internal space in spacecraft. It also has potential application value in electromagnetic stealth for aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a transmission spectrum of a 1 mm thick epoxy resin plate in a method for preparing a carbonized layer inside an aramid fiber resin-based composite material using an infrared picosecond laser;

[0019] FIG2 is a schematic diagram of laser scanning in the method for preparing a carbonized layer inside an aramid fiber resin-based composite material using an infrared picosecond laser according to the present invention;

[0020] FIG3 is a scanning electron microscope image of the aramid fiber resin-based composite material in the method for preparing a carbonized layer inside the aramid fiber resin-based composite material using an infrared picosecond laser according to the present invention;

[0021] FIG4 is a schematic diagram of a laser scanning carbonization bending circuit in a method for preparing a carbonized layer inside an aramid fiber resin-based composite material using an infrared picosecond laser according to the present invention;

[0022] FIG5 is a schematic diagram of a laser scanning carbonized microstructure in a method for preparing a carbonized layer inside an aramid fiber resin-based composite material using an infrared picosecond laser according to the present invention.

[0023] The reference numerals are as follows:

[0024] 1-Laser scanning head; 2-Laser beam; 3-Carbonized layer circuit inside aramid fiber resin-based composite material; 4-Aramid fiber resin-based composite material; 5-Carbonized layer inside aramid fiber resin-based composite material; 6-Laser scanning carbonized curved circuit; 7-Laser scanning carbonized microstructure. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Taking advantage of the different laser energy absorption rates between the resin matrix and fibers in composite materials, laser carbonization of the composite's internal fibers imparts electrical conductivity, replacing traditional conductive wires. This contributes to the lightweight design of spacecraft and saves significant internal space. Furthermore, carbonization of the composite's internal fibers creates microstructures within the material that absorb incident electromagnetic waves, potentially enabling applications in electromagnetic stealth for aircraft.

[0027] Example 1.

[0028] The picosecond solid-state laser used in the present invention has a wavelength of 1064 nm, a pulse width of 15 ps, and a repetition rate of 50 kHz. In Example 1, the laser power used was 4.5 W, and the scanning speed was 1000 mm / s. The aramid fiber resin-based composite material of the present invention was prepared using a prepreg lamination process. It is composed of Kevlar-29 fiber fabric and epoxy resin, with a thickness of 1 mm. The epoxy resin accounts for 42% by volume, and the fiber accounts for 58% by volume.

[0029] The method for preparing a carbonized layer inside an aramid fiber resin-based composite material using an infrared picosecond laser comprises the following steps:

[0030] Step 1: Wipe the surface of the aramid fiber resin-based composite material sample to ensure that there is no stain on the surface;

[0031] Step 2: Place the aramid fiber resin-based composite material sample on the laser sample platform, with the defocus between the laser focus and the upper surface of the sample being -3 mm, so that the laser focus is located on the horizontal plane inside the material;

[0032] As shown in Figure 1, when the infrared laser acts on the aramid fiber resin-based composite material, the 1mm thick epoxy resin plate absorbs less than 15% of the laser energy. Therefore, when the laser acts on the aramid fiber resin-based composite material, most of the laser energy passes through the epoxy resin layer and directly acts on the internal aramid fiber. The laser carbonizes the internal aramid fiber without damaging the surface resin, forming a carbonization line along the laser scanning path, as shown in Figure 2.

[0033] Step 3: Scan the aramid fiber resin matrix composite material sample of 100mm×50mm with an infrared picosecond laser of 4.5W power and 1000mm / s scanning speed for 8 times. A carbonized line with a length of 50mm and a width of 0.1mm is obtained inside the material. The resistivity of the carbonized line is measured to be 4.6×10 -5 Ω·m.

[0034] Because the surface epoxy resin has low laser absorption, the laser beam passes through the resin and directly heats the aramid fiber. Using low power allows the aramid fiber to be ablated without damaging the surface resin. The aramid fibers within the aramid fiber-resin-based composite sample are exposed to an oxygen-deficient environment, so the aramid fiber layer beneath the surface resin carbonizes under the high-temperature, oxygen-deficient conditions, as shown in Figure 3. This carbonized layer is a highly conductive material, thus fulfilling the conductive function of the aramid fiber-resin-based composite.

[0035] Example 2

[0036] The laser parameters and materials used are the same as those in Example 1.

[0037] Step 1: Wipe the surface of the aramid fiber resin-based composite material sample to ensure that there is no stain on the surface.

[0038] Step 2: Place the aramid fiber resin-based composite material sample on the laser sample platform, with the defocus between the laser focus and the upper surface of the sample being -2 mm, so that the laser focus is located on the horizontal plane inside the material.

[0039] Step 3: Scan the aramid fiber resin matrix composite material sample of 100mm×50mm 10 times with an infrared picosecond laser of 10W power and 1000mm / s scanning speed. A carbonized line with a length of 50mm and a width of 0.2mm is obtained inside the material. The resistivity of the carbonized line is 4.1×10 -5 Ω·m.

[0040] Example 3

[0041] The laser parameters and materials used are the same as those in Example 1.

[0042] Steps 1 and 2 are the same as in Example 2.

[0043] Step 3: Scan the aramid fiber resin matrix composite material sample (100 mm x 50 mm) 12 times using an infrared picosecond laser with a power of 15W and a scanning speed of 1000 mm / s. A carbonized curved circuit with a length of 150 mm and a width of 0.2 mm is obtained inside the material, as shown in the schematic diagram in Figure 4. The resistivity of the carbonized circuit is measured to be 3.6×10 -5 Ω·m.

[0044] Example 4

[0045] The laser parameters and materials used are the same as those in Example 1.

[0046] Steps 1 and 2 are the same as in Example 2.

[0047] Step 3: Using an infrared picosecond laser with a power of 15W and a scanning speed of 1000mm / s, a 100mm x 50mm aramid fiber resin-based composite material sample was scanned 12 times. Several "mouth"-shaped microstructures with an outer edge length of 200µm and a line width of 30µm were formed within the material, as shown in Figure 4. Measurements showed that this sample absorbed terahertz waves.

[0048] 2 , it can be seen that the laser scanning head 1 emits a laser beam 2 to scan the inner fiber layer of the aramid fiber resin-based composite material 4 to obtain the inner carbonized layer circuit 3 of the aramid fiber resin-based composite material.

[0049] 3 is a scanning electron microscope image, which shows the carbonized layer obtained by the method of the present invention. This carbonized layer is a good conductive material, thereby realizing the conductive function of the aramid fiber resin-based composite material.

[0050] 4 , the laser-scanned carbonized curved circuit 6 scanned on the aramid fiber resin-based composite material 4 can achieve the conductive function in complex environments.

[0051] 5 , the laser scanning carbonized microstructure 7 obtained by the method of the present invention has an absorption effect on terahertz waves.

[0052] In the present invention, the surface of the aramid fiber resin-based composite material sample is wiped to ensure that there is no stain on the surface; this is because when the laser is irradiated on the surface of the aramid fiber resin-based composite material sample, the stains on the surface of the aramid fiber resin-based composite material will absorb part of the laser energy, resulting in a decrease in the laser energy absorbed by the interior of the aramid fiber resin-based composite material sample. In addition, when the laser acts on the surface stains, the high temperature generated will burn the surface resin.

[0053] The defocus amount between the laser focus and the upper surface of the aramid fiber resin-based composite material sample is -1 mm to -10 mm, so that the laser focus is located on the inner horizontal plane of the aramid fiber resin-based composite material sample.

[0054] The infrared picosecond laser with a laser power of 4W to 15W and a scanning speed of 500mm / s to 2000mm / s is used to scan the aramid fiber resin-based composite material sample 6 to 12 times.

[0055] A low-power, high-speed infrared picosecond laser is used to scan the aramid fiber resin-based composite material sample multiple times; since the surface epoxy resin has low laser absorption, the laser beam passes through the resin and directly heats the aramid fiber; using lower power can ablate the aramid fiber without damaging the surface resin. The aramid fiber inside the aramid fiber resin-based composite material sample is in an oxygen-deficient environment, so the aramid fiber layer under the surface resin is carbonized under high temperature and oxygen-deficient conditions. This carbonized layer is a good conductive material, thereby realizing the conductive function of the aramid fiber resin-based composite material and has potential application value in the electromagnetic wave shadowing of aircraft.

[0056] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0057] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for preparing a laser-induced carbonized layer inside an aramid fiber resin-based composite material, characterized in that: The steps include: Step 1: Wipe the surface of the aramid fiber resin-based composite material sample to ensure that there is no stain on the surface of the aramid fiber resin-based composite material sample; Step 2: Place the aramid fiber resin-based composite material sample on the laser sample platform, with the laser focus and the upper surface of the aramid fiber resin-based composite material sample having a negative defocus, so that the laser focus is located on the horizontal plane inside the aramid fiber resin-based composite material sample; Step 3: Use a low-power, high-speed infrared picosecond laser to scan the aramid fiber resin-based composite material sample multiple times; set a specific scanning processing path to carbonize the aramid fiber layer under the resin of the aramid fiber resin-based composite material sample under high temperature and oxygen deficiency, forming a specific carbonization path.

2. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: The defocus between the laser focus and the upper surface of the aramid fiber resin-based composite material sample is -1mm to -10mm.

3. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: In step three, the laser power is 4W to 15W, the scanning speed is 500mm / s to 2000mm / s, and the infrared picosecond laser wavelength is 1064nm.

4. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: In step three, the infrared picosecond laser scans the aramid fiber resin-based composite material sample 6 to 12 times, with the time interval between each scan being 1 second to 2 seconds.

5. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: The thickness of the resin layer in the aramid fiber resin-based composite material is 0.1 mm to 0.3 mm.

6. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: The thickness of the aramid fiber resin-based composite material is 1 mm, the volume fraction of the epoxy resin is 42%, and the volume fraction of the fiber is 58%.

7. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 3, characterized in that: The aramid fiber resin-based composite material sample was scanned using an infrared picosecond laser with a laser power of 4.5W and a scanning speed of 1000mm / s.

8. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 3, characterized in that: The aramid fiber resin-based composite material sample was scanned using an infrared picosecond laser with a laser power of 10W and a scanning speed of 1000mm / s.

9. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 3, characterized in that: The aramid fiber resin-based composite material sample was scanned using an infrared picosecond laser with a laser power of 15W and a scanning speed of 1000mm / s.

10. The method for preparing the internal laser-induced carbonization layer of the aramid fiber resin-based composite material according to claim 1, characterized in that: The size of the aramid fiber resin-based composite material sample is 100 mm × 50 mm.

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