A laser processing process of self-cleaning high-temperature alloy maintaining original mechanical properties

Abstract

The application provides a laser processing technology of self-cleaning high-temperature alloy with original mechanical properties, and belongs to the technical field of laser precision machining. First, the K424 high-temperature alloy sheet cleaned and dried by ultrasonic waves is placed on a nanosecond laser processing system, and processing is carried out according to set tracks and processing parameters, wherein the laser beam line spacing is less than the width of the laser affected area but not less than the laser processing spot diameter, and the total height of the laser processing area is greater than 10 microns; after the processing is completed, the high-temperature alloy sheet is immersed in a fluorosilane ethanol solution with a mass fraction of 1% for 30 minutes; finally, superhydrophobicity is obtained on the premise of maintaining the original mechanical properties of the high-temperature alloy, and excellent self-cleaning effect on high-temperature carbon deposition is exhibited. The self-cleaning high-temperature alloy obtained by the application has a tensile strength, elongation and width shrinkage rate close to those of the untreated sample; the self-cleaning high-temperature alloy obtained has good superhydrophobicity; and the self-cleaning high-temperature alloy obtained has good carbon deposition self-cleaning property.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser precision machining, and relates to a laser processing technology of high-temperature alloy, which can obtain excellent self-cleaning performance on the premise of maintaining original mechanical properties. BACKGROUND

[0002] High-temperature alloy is often used to manufacture turbine, blade and engine nozzle and other components due to its low density, high high-temperature strength, plasticity and good processability. However, under the actual working state of the engine, the carbon particles generated by the high-temperature combustion of fuel are usually deposited on the surface of the engine and gradually accumulate and thicken with the service time of the engine. The thick carbon layer reduces the power performance of the engine, reduces the service life of the engine, and even causes serious use safety problems. Considering that the super-hydrophobic surface has excellent self-cleaning performance, if the carbon on the surface of the component can be easily and efficiently washed away by water droplets in daily maintenance work, thereby timely restoring the performance of the engine, it is beneficial to prolong the service time of the engine and ensure use safety.

[0003] Laser processing technology is a fast and efficient method for preparing super-hydrophobic surface. By the thermal effect of high-energy laser beam, a micro-nano composite rough structure is etched on the metal substrate, and then a super-hydrophobic surface with good performance is obtained by modification with a low surface energy material. With the help of precise control of computer software, laser processing technology can accurately adjust each processing parameter, thereby preparing super-hydrophobic surface with high precision and repeatability.

[0004] However, the current method of using laser processing technology to construct micro-nano structure on metal surface to prepare super-hydrophobic surface has the problem of excessive processing, that is, repeated processing or too many scanning times on the same area. Excessive processing will thin the thickness of the metal substrate and produce a brittle recast layer, which seriously reduces the mechanical properties of the component. In addition, there is no research on laser processing technology of self-cleaning high-temperature alloy at present. SUMMARY

[0005] In view of the problems existing in the current laser processing technology, the application provides a laser processing technology of self-cleaning high-temperature alloy which maintains the original mechanical properties.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is:

[0007] The application discloses a laser processing technology of self-cleaning high-temperature alloy with original mechanical properties, and the processing technology is realized based on a traditional nanosecond laser processing system, a laser beam is scanned on an arbitrary area of the high-temperature alloy only once, a line spacing of the laser beam is less than a width of a laser affected area but not less than a laser processing spot diameter, and a total height of a laser processing area is greater than 10 microns. The laser beam is a nanosecond laser with a wavelength of 1064 nm and a pulse width of 100 ns; the line spacing of the laser beam refers to a distance between centers of adjacent tracks; the width of the laser affected area refers to a total width of etching and sputtering areas after the laser beam is scanned; and the total height of the laser processing area refers to a distance between a top of a protrusion and a bottom of a depression in a processing affected area.

[0008] Specifically, the application comprises the following steps:

[0009] Firstly, the high-temperature alloy sheet is subjected to ultrasonic cleaning and drying, and then is placed on the nanosecond laser processing system. Secondly, parameters of the nanosecond laser processing system are set, a processing route is set, and processing is performed, wherein the parameters include power, scanning speed, line spacing of the laser beam and laser repetition frequency. Finally, the surface of the processed high-temperature alloy sheet is subjected to fluorination treatment, and high-temperature drying and cooling are performed.

[0010] Further, the parameters of the nanosecond laser processing system are as follows: the laser power is not greater than 30 W; the scanning speed is not greater than 2000 mm / s, and is preferably 100-500 mm / s; the line spacing of the laser beam is 50-120 mm; and the laser repetition frequency is 20 kHz.

[0011] Further, the fluorination treatment method is that the high-temperature alloy sheet is immersed in a fluorosilane ethanol solution with a mass fraction of 1% for 30 minutes.

[0012] Compared with the existing laser processing super-hydrophobic surface technology, the application has the following beneficial effects:

[0013] (1) The self-cleaning high-temperature alloy obtained by the application has a tensile strength, elongation and width shrinkage rate close to those of an untreated sample.

[0014] (2) The self-cleaning high-temperature alloy obtained by the application has good super-hydrophobicity.

[0015] (3) The self-cleaning high-temperature alloy obtained by the application has good carbon deposition self-cleaning property. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1 is a schematic diagram of a laser line spacing and a laser affected area width in the application;

[0017] Figure 2 Fig. 2 is a schematic diagram of a total height and a width of a laser processing area in the application.

[0018] Figure 3 This is the tensile stress-strain curve in Example 1 of this invention; Figure 3 (a) is the tensile stress-strain curve of the unlaser-scanned specimen in Example 1 of the present invention; Figure 3 (b) is the tensile stress-strain curve of the sample obtained by one laser scan in Example 1 of the present invention.

[0019] Figure 4 These are optical photographs of the water droplet contact angle in five embodiments of the present invention; Figure 4 (a) is an optical photograph of the water droplet contact angle in Example 1 of the present invention; Figure 4 (b) is an optical photograph of the water droplet contact angle in Example 2 of this invention; Figure 4 (c) is an optical photograph of the water droplet contact angle in Example 3 of the present invention; Figure 4 (d) is an optical photograph of the water droplet contact angle in Example 4 of this invention; Figure 4 (e) is an optical photograph of the water droplet contact angle in Example 5 of this invention; Figure 4 (f) is an optical photograph of the water droplet contact angle in Example 6 of this invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] A laser processing technology for self-cleaning high-temperature alloys that maintains their original mechanical properties is disclosed. This technology is based on a traditional nanosecond laser processing system, and a specific implementation example is provided below.

[0022] Example 1

[0023] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1 The laser trajectory was processed at 15W power, 500mm / s scanning speed, 50mm laser beam spacing, and 20kHz frequency (the laser-affected zone width under these parameters is 91mm). After processing, the sample was immersed in a 1% (w / w) fluorosilane ethanol solution for 30 minutes, ultimately achieving superhydrophobicity with a contact angle of 165.5°, a roll-off angle of 2.2° in the groove direction, and a roll-off angle perpendicular to the groove direction of 3.5°. This results in good self-cleaning properties for high-temperature deposited carbon. The tensile stress-strain curve of the prepared superhydrophobic K424 high-temperature alloy sheet is close to that of the unprocessed K424 high-temperature alloy sheet, maintaining its original good mechanical properties.

[0024] Example 2

[0025] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1 The trajectory was processed at 30W power, 500mm / s scanning speed, 100mm laser beam spacing, and 20kHz frequency (the width of the laser-affected area under these parameters is 105mm). After completion, it was immersed in a 1% fluorosilane ethanol solution for 30min. Finally, a superhydrophobic property was obtained with a contact angle of 160.2°, a roll-off angle of 5.2° in the groove direction, and a roll-off angle of 7.9° perpendicular to the groove direction. It has good self-cleaning properties for high-temperature deposited carbon deposits.

[0026] Example 3

[0027] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1 The trajectory was processed at 30W power, 100mm / s scanning speed, 115mm laser beam spacing, and 20kHz frequency (the width of the laser-affected area under these parameters is 116mm). After completion, it was immersed in a 1% fluorosilane ethanol solution for 30min. Finally, a superhydrophobic property was obtained with a contact angle of 151.4°, a roll-off angle of 10.4° in the groove direction, and a roll-off angle of 16.9° perpendicular to the groove direction. It has good self-cleaning properties for high-temperature deposited carbon deposits.

[0028] Example 4

[0029] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1 The trajectory was processed at 15W power, 500mm / s scanning speed, 90mm laser beam spacing, and 20kHz frequency (the width of the laser-affected area under these parameters is 91mm). After completion, it was immersed in a 1% fluorosilane ethanol solution for 30min. Finally, a superhydrophobic property was obtained with a contact angle of 164.5°, a roll-off angle of 4.4° in the groove direction, and a roll-off angle of 4.4° perpendicular to the groove direction. It has good self-cleaning properties for high-temperature deposited carbon deposits.

[0030] Example 5

[0031] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1The trajectory was processed at 15W power, 100mm / s scanning speed, 95mm laser beam spacing, and 20kHz frequency (the width of the laser-affected area under these parameters is 98mm). After completion, it was immersed in a 1% fluorosilane ethanol solution for 30 minutes, and finally obtained a superhydrophobic property with a contact angle of 161.9°, a roll-off angle of 4.8° in the groove direction, and a roll-off angle of 5.8° perpendicular to the groove direction. It has good self-cleaning properties for carbon deposited at high temperature.

[0032] Example 6

[0033] After ultrasonic cleaning and drying, the K424 high-temperature alloy sheet was placed on the nanosecond laser processing system. The parameters of the nanosecond laser processing system were set, and then... Figure 1 The trajectory was processed at a power of 1.5W, a scanning speed of 100mm / s, a laser beam spacing of 50mm, and a frequency of 20kHz (the width of the laser-affected area under these parameters is 51mm). After completion, it was immersed in a 1% fluorosilane ethanol solution for 30min. Finally, a superhydrophobic property was obtained with a contact angle of 157.1°, a roll-off angle of 15.0° in the groove direction, and a roll-off angle of 16.6° perpendicular to the groove direction. It has good self-cleaning properties for carbon deposited at high temperatures.

[0034] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. 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 modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A laser processing method of self-cleaning high-temperature alloy that maintains original mechanical properties, the processing method being implemented based on a conventional nanosecond laser processing system, characterized in that, In the processing, the laser beam scans any area of the high-temperature alloy only once, the laser beam line spacing is less than the width of the laser affected area but not less than the laser processing spot diameter, and the total height of the laser processing area is greater than 10 μm, wherein the laser beam refers to a nanosecond laser with a wavelength of 1064 nm and a pulse width of 100 ns; the laser beam line spacing refers to the distance between the centers of adjacent tracks; The width of the laser affected area refers to the total width of the etching and sputtering area after the laser beam scans; The total height of the laser processing area refers to the distance between the top of the raised area and the bottom of the recessed area in the processing affected area; The parameters are: the laser power is not greater than 30 W; the scanning speed is 100-500 mm / s, the laser beam line spacing is 50-120 mm; and the laser repetition frequency is 20 kHz.

Images