Surface microstructure for improving stress tolerance of coating and processing method thereof

Abstract

The invention belongs to the technical field of laser etching, and particularly relates to a surface microstructure for improving stress tolerance of a coating and a processing method of the surface microstructure. According to the technical scheme, according to the surface microstructure for improving the stress tolerance of the coating, a plurality of first direction grooves which are evenly distributed in parallel and a plurality of second direction grooves which are evenly distributed in parallel are machined in the surface of the coating through a laser etching machine, and the included angle between each first direction groove and the corresponding second direction groove is 60 degrees; a surface microstructure distributed in a net shape is formed; and the cross sections of the first direction grooves and the second direction grooves are inverted isosceles triangles. According to the surface microstructure for improving the stress tolerance of the coating and the machining method of the surface microstructure, the stress tolerance capacity of the coating is greatly improved, the problems of cracking and falling of the coating in a thermal cycle environment are solved, the service time of the coating is prolonged, and the repair cost of parts with the coating is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of laser etching, and in particular relates to a surface microstructure for improving the stress tolerance of a coating and a processing method thereof. Background Art

[0002] Aviation engine coating is an important technical means used to improve engine performance and reliability. There are many types of coatings, including thermal barrier coatings, wear-resistant coatings, antioxidant coatings, etc. The application of these coatings helps to improve the efficiency, durability and safety of the engine.

[0003] At present, there is no post-processing process after coating preparation. Under the action of thermal expansion and contraction, due to the different expansion coefficients of the coating and the substrate, the stress changes caused by thermal cycles will cause the coating to crack or even fall off, which is a major problem that plagues the demand for long-term use of the coating. In the face of coating shedding on parts, the only way is to replace the parts during engine repair, which consumes a lot of repair costs and affects repair efficiency.

[0004] Laser etching is a method of finely processing materials using laser beams, which can accurately form specific patterns and structures on materials. Laser etching has the advantages of high precision, high controllability, and non-contact, and is widely used in the field of precision machining. Summary of the invention

[0005] The present invention provides a surface microstructure for improving the stress tolerance of a coating and a processing method thereof, which greatly improves the stress tolerance of the coating, solves the problems of cracking and shedding of the coating in a thermal cycle environment, prolongs the service life of the coating, and saves the repair cost of coated parts.

[0006] The technical solution of the present invention is as follows:

[0007] A surface microstructure for improving the stress tolerance of a coating, wherein a plurality of parallel and evenly distributed first-direction grooves and a plurality of parallel and evenly distributed second-direction grooves are processed on the coating surface by a laser etching machine, wherein the angle between the first-direction grooves and the second-direction grooves is 60°, forming a surface microstructure with a network distribution; the cross-sectional shapes of the first-direction grooves and the second-direction grooves are both inverted isosceles triangles.

[0008] Furthermore, in the surface microstructure for improving the stress tolerance of the coating, the spacing between adjacent first-direction grooves is 5 mm, and the spacing between adjacent second-direction grooves is 5 mm.

[0009] Furthermore, in the surface microstructure for improving the stress tolerance of the coating, the base length of the isosceles triangle is 100 μm and the height is 500 μm.

[0010] Furthermore, in the surface microstructure for improving the stress tolerance of the coating, the height of the isosceles triangle is less than half of the thickness of the coating.

[0011] The above-mentioned surface microstructure processing method for improving the stress tolerance of the coating comprises the following steps:

[0012] 1) Fix the part to be processed on the chuck of the laser etcher;

[0013] 2) Modeling is done by imaging after the parts are scanned;

[0014] 3) Import the etching pattern and generate the processing program by block division;

[0015] 4) Setting the process parameters of the laser etcher; the process parameters include power, pulse width, repetition frequency, spot diameter and scanning speed;

[0016] 5) Laser etching: etching in blocks until the entire coating is processed;

[0017] 6) Parts cleaning: Use compressed air to clean the coating surface of the parts and remove particles attached to the coating surface.

[0018] Furthermore, in the processing method, the process parameters of the laser etcher are: power 18W, pulse width 100ns, repetition frequency 60KHz, spot diameter 0.03mm, and scanning speed 500mm / s.

[0019] Furthermore, in the processing method, the laser etching machine adopts green light band laser.

[0020] The beneficial effects of the present invention are:

[0021] The present invention provides a surface microstructure for improving the stress tolerance of the coating and a processing method thereof. The surface microstructure can release the generated stress under the action of thermal expansion and contraction, greatly improving the stress tolerance of the coating, solving the cracking and shedding problems of the coating in a thermal cycle environment, extending the service life of the coating, and saving the repair cost of coated parts. During processing, the laser etching machine uses a green light band laser, which significantly improves the processing quality compared to the commonly used infrared band laser, and the groove size and groove surface accuracy are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of surface microstructure to improve the stress tolerance of coating;

[0023] Figure 2 Front view of the surface microstructure to improve the stress tolerance of the coating. DETAILED DESCRIPTION

[0024] like Figure 1 ,2 As shown, a surface microstructure for improving the stress tolerance of a coating is formed by processing a plurality of parallel and evenly distributed first direction grooves 2 and a plurality of parallel and evenly distributed second direction grooves 3 on the surface of a coating 1 by a laser etching machine. The spacing between adjacent first direction grooves 2 is 5 mm, the spacing between adjacent second direction grooves 3 is 5 mm, and the angle between the first direction grooves 2 and the second direction grooves 3 is 60°, forming a network-like surface microstructure; the cross-sectional shapes of the first direction grooves 2 and the second direction grooves 3 are both inverted isosceles triangles; the base length of the isosceles triangle is 100 μm and the height is 500 μm; the height of the isosceles triangle is less than half the thickness of the coating 1.

[0025] The above-mentioned surface microstructure processing method for improving the stress tolerance of the coating comprises the following steps:

[0026] 1) Fix the part to be processed on the chuck of the laser etcher;

[0027] 2) Modeling is done by imaging after the parts are scanned;

[0028] 3) Import the etching pattern and generate the processing program by block division;

[0029] 4) Set the process parameters of the laser etcher: use green light band laser, power 18W, pulse width 100ns, repetition frequency 60KHz, spot diameter 0.03mm, scanning speed 500mm / s;

[0030] 5) Laser etching: etching in blocks until the entire coating is processed;

[0031] 6) Parts cleaning: Use compressed air to clean the coating surface of the parts and remove particles attached to the coating surface.

Claims

1. A surface microstructure for improving the stress tolerance of a coating, characterized in that: A laser etcher is used to process multiple parallel and evenly distributed first-direction grooves and multiple parallel and evenly distributed second-direction grooves on the coating surface. The angle between the first-direction grooves and the second-direction grooves is 60°, forming a network-distributed surface microstructure. The cross-sectional shapes of the first-direction grooves and the second-direction grooves are both inverted isosceles triangles.

2. The surface microstructure for improving the stress tolerance of the coating according to claim 1, characterized in that: The spacing between adjacent first-direction grooves is 5 mm, and the spacing between adjacent second-direction grooves is 5 mm.

3. The surface microstructure for improving the stress tolerance of the coating according to claim 1, characterized in that: The isosceles triangle has a base length of 100 μm and a height of 500 μm.

4. The surface microstructure for improving the stress tolerance of the coating according to claim 3, characterized in that: The height of the isosceles triangle is less than half the thickness of the coating.

5. The method for processing a surface microstructure for improving the stress tolerance of a coating according to claim 1, characterized in that: The steps include: 1) Fix the part to be processed on the chuck of the laser etcher; 2) Modeling is done by imaging after the parts are scanned; 3) Import the etching pattern and generate the processing program by block division; 4) Setting the process parameters of the laser etcher; the process parameters include power, pulse width, repetition frequency, spot diameter and scanning speed; 5) Laser etching; Etching is performed in blocks until the entire coating is processed; 6) Parts cleaning: Use compressed air to clean the coating surface of the parts and remove particles attached to the coating surface.

6. The processing method according to claim 5, characterized in that: The process parameters of the laser etcher are: power 18W, pulse width 100ns, repetition frequency 60KHz, spot diameter 0.03mm, scanning speed 500mm / s.

7. The processing method according to claim 5, characterized in that: The laser etching machine uses green light band laser.

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