CN113634902B - A gas-assisted laser processing method for removing stealth coatings on aircraft surfaces - Google Patents

Abstract

The invention discloses a gas-assisted laser processing method for removing a stealth coating on the surface of an aircraft. One side of the coating is aligned with the laser cleaning head; 2) The gas-assisted protection device includes a main device and a tail device, and an inert gas is introduced from the protective gas inlet to form an inert gas protective layer on the surface area of the stealth coating; 3) Using Pulse laser to remove the stealth coating; 4) Turn off the laser and gas-assisted protection device, clean the residual waste on the surface of the sample, and take out the sample; 5) If the stealth coating is not completely removed, repeat the above steps 1) to 4 ). The technology of the invention has the advantages of high precision, fast efficiency, no damage to the substrate, and can be used for large-area removal; the gas-assisted protection device ensures the safety of the laser removal process and effectively improves the removal quality of the stealth coating on the surface of the aircraft.

Description

A gas-assisted laser processing method for removing stealth coating on aircraft surface

technical field

The invention relates to the technical field of advanced laser manufacturing on aircraft surfaces, in particular to a gas-assisted laser processing method for removing stealth coatings on aircraft surfaces.

Background technique

Stealth technology is the latest achievement of contemporary advanced science and technology, which is of great military significance. By applying stealth coating on the surface of weapons and equipment, it can reduce radar, infrared, audio frequency and other optical, electrical, magnetic and other characteristic signals, making weapons and equipment difficult to find, track, identify and attack, which can effectively improve the penetration performance of weapons and equipment and survivability. However, after a long period of service, the stealth coating will gradually deteriorate, crack or even fall off and become invalid. Therefore, after a certain period of service, the stealth coating on the surface of the weapon must be quickly removed and then re-coated.

Compared with traditional mechanical grinding technology and chemical treatment technology, laser removal technology has the advantages of non-contact, high precision, good removal effect, no damage to the substrate, and suitable for large area removal. However, for the laser removal of stealth coatings, due to the material's absorbing function requirements, the coating is generally thicker, reaching the mm level, and a large number of sparks caused by excessive ablation often occur during the removal process, which is more polluting to the environment. It is fatal to bring a fire safety hazard.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a gas-assisted laser processing method for removing stealth coating on the surface of an aircraft.

To achieve the above purpose, the present invention adopts the following technical solutions:

A gas-assisted method for improving the quality of laser removal of stealth coatings, comprising the following steps:

1) Fix the surface sample of the aircraft to be treated with the stealth coating on the surface, and fix it on the working platform, and align the coated side with the laser cleaning head;

2) The gas auxiliary protection device includes a main device and a tail device, the main device is a vent pipe structure, the tail device is an auxiliary vent pipe, the main device is provided with a main protective gas inlet, and the tail device is A tail shielding gas inlet is provided, and inert gas is introduced from the main shielding gas inlet and the tail shielding gas inlet to form an inert gas protective layer on the surface area of the stealth coating;

3) Use pulsed laser to remove stealth coating;

4) Turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample;

5) If the stealth coating is not completely removed, repeat steps 1) to 4) above until the stealth coating is completely removed.

Preferably, the inert gas in the step 2) is any one or a combination of helium, neon and argon.

Preferably, in the step 3), the laser wavelength ranges from 200 nm to 10.6 μm, and the output power ranges from 10% to 100%.

Preferably, the pulsed laser in the step 3) is a CO ₂ laser, a Nd:YAG laser or a fiber laser, etc., and the power of the pulsed laser ranges from 100W to 500W.

Preferably, in the step 3), a circular laser spot or a square laser spot is used for laser processing.

Further preferably, the diameter of the circular laser spot in the step 3) is 1 mm˜20 mm, and the side length of the square laser spot is 1 mm˜25 mm.

Preferably, the pulse width in the step 3) ranges from 2 ns to 400 ns, and the pulse frequency ranges from 10 Hz to 5000 kHz.

Preferably, the scanning speed in the step 3) ranges from 1000 mm/s to 9000 mm/s, and the line spacing ranges from 0.01 mm to 5 mm.

Preferably, the average laser power density in the step 3) ranges from 50W/cm ² to 500W/cm ² .

Further, the aircraft surface samples in the step 1) are metal materials such as aluminum alloys and titanium alloys.

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

(1) The present invention uses a laser method to remove the stealth coating on the surface of the aircraft. The laser beam acts on the coating to cause lattice vibration inside the coating to be peeled off from the surface of the sample. Compared with traditional mechanical polishing or chemical methods, This technology has the advantages of high precision, fast efficiency, no damage to the substrate, and can be used for large area removal.

(2) The present invention uses a gas-assisted protection device to form an inert gas protective layer on the surface of the coating, so that the laser action area is effectively isolated from oxygen, which significantly suppresses the generation of sparks during the ablation process, and not only ensures the safety of the laser removal process. , and effectively improve the removal quality of the stealth coating on the surface of the aircraft. To further achieve the goal of green, environmentally friendly, safe and reliable processing, and at the same time, it can effectively improve the removal quality of the surface coating, thereby ensuring the comprehensive mechanical properties of the aircraft surface.

(3) The present invention can also be applied to the fields of aircraft skin paint layer removal, metal welding, etc., and is of great significance for ensuring processing safety and improving processing quality.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

Fig. 1 is the principle diagram of the gas-assisted laser processing method of the present invention;

In the figure, 1- aircraft surface sample, 2- stealth coating, 3- laser cleaning head, 4- inert gas protective layer, 5- gas auxiliary protection main device, 6- main protective gas inlet, 7- gas auxiliary Protect the tail device, 8-tail protective gas inlet.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example 1

The gas-assisted laser processing method for removing the stealth coating on the surface of the aircraft of the present invention is as follows:

The first step is to cut the 12024 aluminum alloy wire of the aircraft surface sample to be treated with the stealth coating 2 on the surface to a suitable size, fix it on the working platform by a clamp, and align the coated side with the laser cleaning head 3;

The second step is to turn on the switch of the gas auxiliary protection device, and pass helium gas from the main protective gas inlet and the tail protective gas inlet to form a uniform gas protective layer on the surface area of the stealth coating;

In the third step, a 100W CO ₂ laser was used to remove the stealth coating. The high-speed motion of the X and Y galvanometers applied the laser energy to the coating surface in a two-dimensional arrangement. A 5mm circular laser spot is selected for laser processing, the laser wavelength is 10.6 μm, and the output power is 50%. The pulse width is set to 100ns, and the pulse frequency is set to 100kHz. The stealth coating is removed by point-by-point, line-by-line, and surface-by-surface laser scanning. The scanning speed of the laser spot is set to 2000mm/s, the line spacing is set to 0.05mm, and the average laser power density is 100W/cm ² ;

The fourth step, turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample;

Step 5: If the stealth coating is not completely removed, repeat steps 1 to 4 above until the stealth coating is completely removed.

As shown in FIG. 1, it is a schematic diagram of the gas-assisted laser processing method of the present invention. The gas-assisted protection device includes a main device 5 and a tail device 7. The main device is a ventilation pipe structure, and the tail device is an auxiliary ventilation pipe. In order to ensure that the inert gas environment is sufficient, the main device 5 is provided with a main protective gas inlet 6, and the tail device 7 is provided with a tail protective gas inlet 8, from the main protective gas inlet 6 and the tail protection. The inert gas is introduced into the gas inlet 8 to form the inert gas protective layer 4 on the surface area of the stealth coating.

Example 2

The first step is to cut the 7075 aluminum alloy wire coated with stealth coating to a suitable size, fix it on the working platform by a clamp, and align the coated side with the laser cleaning head;

In the second step, turn on the switch of the gas auxiliary protection device, and introduce neon gas from the main protective gas inlet and the tail protective gas inlet to form a uniform gas protective layer on the surface area of the stealth coating;

In the third step, a 300W Nd:YAG laser was used to remove the stealth coating. The high-speed motion of the X and Y galvanometers applied the laser energy to the coating surface in a two-dimensional arrangement. A 10mm circular laser spot is selected for laser processing, the laser wavelength is 1064nm, and the output power is 80%. The pulse width is set to 6ns, and the pulse frequency is set to 30Hz. The stealth coating is removed by point-by-point, line-by-line, and surface-by-surface laser scanning. The scanning speed of the laser spot is set to 4000mm/s, the line spacing is set to 0.5mm, and the average laser power density is 200W/cm ² ;

The fourth step, turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample;

Step 5: If the stealth coating is not completely removed, repeat steps 1 to 4 above until the stealth coating is completely removed.

Example 3

The first step is to cut the TC4 titanium alloy wire coated with stealth coating to a suitable size, fix it on the working platform by a clamp, and align the coated side with the laser cleaning head;

The second step is to turn on the switch of the gas auxiliary protection device, and pass argon gas from the main shielding gas inlet and the tail shielding gas inlet to form a uniform gas shielding layer on the surface area of the stealth coating;

In the third step, a 500W fiber laser is used to remove the stealth coating. The high-speed motion of the X and Y galvanometers acts on the surface of the coating in a two-dimensional arrangement. A 2mm circular laser spot is selected for laser processing, the laser wavelength is 1030nm, and the output power is 30%. The pulse width is set to 200ns, and the pulse frequency is set to 200kHz. The stealth coating is removed by point-by-point, line-by-line, and surface-by-surface laser scanning. The scanning speed of the laser spot is set to 6000mm/s, the line spacing is set to 0.02mm, and the average laser power density is 50W/cm ² ;

The fourth step, turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample;

Step 5: If the stealth coating is not completely removed, repeat steps 1 to 4 above until the stealth coating is completely removed.

Example 4

The gas-assisted laser processing method for removing the stealth coating on the surface of the aircraft of the present invention is as follows:

The first step is to cut the TC6 titanium alloy wire coated with stealth coating to a suitable size, fix it on the working platform by a clamp, and align the coated side with the laser cleaning head;

The second step is to turn on the switch of the gas auxiliary protection device, and respectively introduce helium and argon from the main protective gas inlet and the tail protective gas inlet to form a uniform gas protective layer on the surface area of the stealth coating;

In the third step, a 100W fiber laser was used to remove the stealth coating. The high-speed motion of the X and Y galvanometers applied the laser energy to the coating surface in a two-dimensional arrangement. A 20mm square laser spot is selected for laser processing, the laser wavelength is 200nm, and the output power is 60%. The pulse width is set to 400ns, and the pulse frequency is set to 4000kHz. The stealth coating is removed by point-by-point, line-by-line and surface-by-surface laser scanning. The scanning speed of the laser spot is set to 3000mm/s, the line spacing is set to 5mm, and the average laser power density is 500W/cm ² ;

The fourth step, turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample;

Step 5: If the stealth coating is not completely removed, repeat steps 1 to 4 above until the stealth coating is completely removed.

The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various variations or modifications within the scope of the claims, which do not affect the essential content of the present invention.

Claims (9)

1. a gas-assisted method for improving stealth coating laser removal quality, is characterized in that, comprises the following steps: 1) Fix the surface sample of the aircraft to be treated with the stealth coating on the surface, and fix it on the working platform, and align the coated side with the laser cleaning head; 2) The gas auxiliary protection device includes a main device and a tail device, the main device is a vent pipe structure, the tail device is an auxiliary vent pipe, the main device is provided with a main protective gas inlet, and the tail device is A tail shielding gas inlet is provided, and inert gas is introduced from the main shielding gas inlet and the tail shielding gas inlet to form an inert gas protective layer on the surface area of the stealth coating; 3) Use pulsed laser to remove stealth coating; 4) Turn off the laser and gas-assisted protection device, clean up the residual waste on the surface of the sample, and take out the sample; 5) If the stealth coating is not completely removed, repeat the above steps 1) to 4) until the stealth coating is completely removed; The pulse width in the step 3) ranges from 2ns to 400ns, and the pulse frequency ranges from 10Hz to 5000kHz. 2. the method for improving stealth coating laser removal quality with gas assistance according to claim 1, is characterized in that, the inert gas in described step 2) is any one or more in helium, neon and argon The combination. 3 . The method of claim 1 , wherein in the step 3), the laser wavelength ranges from 200 nm to 10.6 μm, and the output power ranges from 10% to 100%. 4 . 4. the method for improving stealth coating laser removal quality with gas assistance according to claim 1, is characterized in that, the pulsed laser in described step 3) is _CO laser, Nd: YAG laser or fiber laser, described pulsed laser The power range is 100W ~ 500W. 5 . The method for improving the laser removal quality of stealth coating by gas assistance according to claim 1 , wherein, in the step 3), a circular laser spot or a square laser spot is selected for laser processing. 6 . 6. The method according to claim 5, wherein the diameter of the circular laser spot in the step 3) is 1mm～20mm, and the side length of the square laser spot is 1mm ~25mm. 7 . The method of claim 1 , wherein the scanning speed range in step 3) is 1000mm/s～9000mm/s, and the line spacing range is 0.01mm～ 5mm. 8 . The method of claim 1 , wherein the average laser power density in the step 3) ranges from 50W/cm ² to 500W/cm ² . 9 . 9 . The method for improving the laser removal quality of stealth coatings by gas assistance according to claim 1 , wherein the aircraft surface samples in the step 1) are aluminum alloys and titanium alloys. 10 .

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