Process for optimizing service life of water-jet guided laser processing nozzle

Abstract

The invention discloses a process for optimizing the service life of a water-guided laser processing nozzle, which effectively prolongs the service life of the nozzle by optimizing a nozzle material, processing parameters and processing steps, thereby remarkably improving the economical efficiency and sustainability of water-guided laser processing, and providing important support for popularization and application of water-guided laser in wider fields. The service life of the nozzle is prolonged, the number of waste nozzles is reduced, the environmental burden of industrial production is reduced, and the concept of green manufacturing is met. And for equipment manufacturers, the comprehensive performance of the equipment can be remarkably improved through the durable nozzle design and the efficient process scheme, and the market competitiveness is enhanced. And for users, the use cost can be reduced, and the economical efficiency is improved, so that the popularization and development of the water-jet guided laser technology are further promoted.

Description

Technical Field

[0001] The invention relates to the technical field of water-conducting laser processing, in particular to a process for optimizing the life of a water-conducting laser processing nozzle. Background Art

[0002] As a green and efficient precision machining technology, water-conducting laser machining is gradually becoming the mainstream choice in the field of precision machining due to its environmentally friendly machining process, excellent surface quality and non-tapered hole shape accuracy. Water-conducting laser machining equipment couples nanosecond pulsed lasers with fine high-speed water jets. The flushing of the water jet can cool the workpiece in real time during the machining process, reduce the heat-affected zone, improve machining accuracy and quality, and reduce machining time and waste. However, for difficult-to-machine materials such as diamond and silicon carbide ceramics, the existing water-conducting laser machining technology still faces great challenges. These materials usually require higher single pulse energy to meet the requirements of deep processing and high precision. Under high energy conditions, the key consumables of water-conducting laser machining, the nozzle, are often significantly shortened in service life due to the combined effect of strong energy impact and water flow pressure. This not only increases the processing cost, but also limits the upper limit of the application of water-conducting lasers in the field of difficult materials.

[0003] For example, Chinese patent CN 118926681 A discloses a coupling component and a water-guided laser processing device containing the component. An hourglass-shaped homogenization chamber is opened inside the main body of the coupling component, and an air inlet is opened on the side wall of the main body. The air inlet passes gas into the thin waist section of the homogenization chamber from both sides. After the gas is blocked by the water jet and the cavity wall, two spindle-shaped vortices with opposite flows are formed, thereby weakening the interference of the airflow on the water jet. The upper vortex flows upward close to the water jet, inhibiting the downward transmission of the surface wave of the water jet; the lower vortex moves downward along the water jet and then swirls upward, enhancing the suppression effect on the recoil water, and can extend the stable length while improving the stability of the water jet. In the water-guided laser processing device containing the above-mentioned coupling component, the different effects generated by the two airflows are superimposed at the same time, so that the coupling component can greatly improve the processing quality and efficiency under the condition of unchanged energy consumption, so as to meet the processing requirements of workpieces with a large depth-to-diameter ratio. However, the nozzles involved in this technical solution will significantly increase material costs and maintenance costs due to their high frequency of replacement, and have a short service life. Nozzle wear or damage will cause water column instability and uneven energy distribution, thereby affecting processing accuracy and surface quality and reducing production efficiency.

[0004] Another example is Chinese patent CN 118744278 A which discloses an electric field deflected water beam water-guided laser device and processing method, which relates to water-guided laser processing technology, including a lens bracket, a coupling cavity and a nozzle bracket; a hydraulic cavity is formed between the lens bracket, the coupling cavity and the nozzle bracket, an elastic gasket is arranged in the lens bracket, a focusing lens is arranged in the elastic gasket, and a water-light coupling laser upper conduit is arranged in the nozzle bracket. The laser passes through the focusing lens in sequence and is focused in the water-light coupling laser upper conduit to form a water-light coupling laser with the liquid entering through the liquid input end nut. This technical solution uses a focusing lens to focus the laser into a vertically downward water beam, and emits a water-light coupled laser from a nozzle. Under the action of the non-uniform electric field, the water beam is deflected by the electrophoretic force. The gear rotating platform is adjusted by a stepper motor to adjust the rotation angle of the vertical axis of the electric field. The voltage controller is used to adjust the voltage between the electrode rod and the electrode plate to control the size of the water beam deflection angle. However, in actual operation, this technical solution requires frequent replacement of nozzles, which will cause equipment shutdown and affect production efficiency. It is impossible to ensure that the water column remains stable during processing, thereby ensuring the consistency and reliability of processing. Summary of the invention

[0005] Purpose of the invention: In order to solve the shortcomings of the existing technology, the present invention provides a process for optimizing the life of the water-conducting laser processing nozzle. The process extends the life of the nozzle, thereby reducing the consumption of spare parts and reducing the processing cost. Extending the life of the nozzle can significantly reduce downtime and improve the utilization rate of the equipment. The increase in the life of the nozzle can ensure that the water column remains stable during the processing, ensuring the consistency and reliability of the processing.

[0006] Technical solution: In order to achieve the above purpose, the present invention provides a process for optimizing the life of a water-guided laser processing nozzle, which includes the following specific steps:

[0007] Step 1

[0008] The nozzle is installed on the water-conducting laser processing equipment. The water-conducting laser processing equipment uses a small power below the ablation threshold to open the light 3h to 4h in advance to realize the heat treatment process. Because heat is also generated during the processing, this part of heat is used to change the crystal structure.

[0009] Step 2

[0010] The nozzle after heat treatment is placed in anhydrous ethanol for ultrasonic cleaning, and then the nozzle after ultrasonic cleaning is cleaned again with distilled water to make the surface clean;

[0011] Step 3

[0012] Place the nozzle in a drying oven and dry it until the nozzle surface is clean and dust-free;

[0013] Step 4

[0014] After the nozzle is installed on the water-guided laser processing head, the parameters set on the water-guided laser equipment are adjusted to obtain different single pulse energies, thereby calculating the ablation threshold of the nozzle. The single pulse energy calculation formula is as follows:

[0015] E=P / f

[0016] Where E is the single pulse energy, P is the average power in the water beam, and f is the laser repetition frequency;

[0017] Step 5

[0018] The water-guided laser processing head is set with a limited water pressure. The water-guided laser processing equipment is a device that integrates the optical path, water path, and gas path. The water pressure can be set on the processing equipment. It will not affect the total reflection of light during the processing due to low water pressure, nor will it affect the stability of the water jet during the processing due to excessive water pressure. Among them, the stability of the water jet length on the water-guided laser processing head depends on the water pressure and the micropore diameter, and the relevant water jet length directly depends on the water speed:

[0019]

[0020] Where v is the water velocity in m / s and p is the water pressure in bar;

[0021] Step 6

[0022] The single pulse energy is opened with 10% lower than the nozzle ablation threshold. The nozzle surface is laser heated and water jet cooled, which prompts the nozzle crystal structure to change to an amorphous structure. This change is achieved by heating and rapid cooling. The purpose of laser heating and water jet rapid cooling, which is lower than 10% of the ablation threshold, is to maximize the degree of nozzle crystal structure transformation, and then start processing parts.

[0023] Step 7

[0024] After the parts processing is completed, the nozzle is taken out from the processing head, and finally ultrasonically cleaned in anhydrous ethanol, and then cleaned again with clean water to clean the surface and facilitate the statistics of the nozzle surface quality;

[0025] Step 8

[0026] The nozzle after part cutting is placed under an optical microscope, and the ablation of the nozzle during the processing is counted to adjust the processing parameters.

[0027] As a further preferred embodiment of the present invention, the nozzle surface temperature is 1800° C., and the nozzle surface is cooled by a water spray device with a power of 30W to 40W installed on the water-conducting laser processing equipment, because the water jet will flow through the nozzle surface.

[0028] As a further preferred embodiment of the present invention, in step 1, the power in water is 30-40w, the temperature is about 1800 degrees, and the cooling method is water jet cooling with ultrapure water provided by the water-guided laser equipment;

[0029] As a further preferred embodiment of the present invention, the ablation threshold of the nozzle in step one is that the nozzle is damaged after working continuously for one week.

[0030] As a further preferred embodiment of the present invention, in step 2, the ultrasonic cleaning for re-cleaning is to use ultrapure water to clean the nozzle for 5 minutes to 8 minutes.

[0031] As a further preferred embodiment of the present invention, in step 4, the parameters set on the water-guided laser equipment are: power of 40w-50w, frequency of 8-12kHz, and water pressure of 250-350bar.

[0032] As a further preferred embodiment of the present invention, in step five, the limited water pressure set on the water-conducting laser processing head is 250 bar to 350 bar.

[0033] As a further preferred embodiment of the present invention, in step seven, the nozzle is ultrasonically cleaned and then cleaned with ultrapure water for 5 minutes to 6 minutes.

[0034] Beneficial effects: Compared with the prior art, the process for optimizing the life of a water-guided laser processing nozzle described in the present invention has a simple operation process and is easy to operate, and can enable the nozzle to withstand high-load work for a longer period of time under high-power conditions, thereby significantly increasing the service life. This method can not only ensure processing efficiency, but also reduce long-term operating costs; under high-energy conditions, the use of the processing technology of the present invention can increase the life of the nozzle by more than 10 times, thereby significantly improving the economy and sustainability of water-guided laser processing, providing important support for the promotion and application of water-guided laser in a wider range of fields, providing a new breakthrough for the development of water-guided laser technology, optimizing economic benefits, and providing reliable support for the processing of difficult materials, while complying with the development trend of green manufacturing and precision processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 1 As shown, the process for optimizing the life of a water-guided laser machining nozzle according to the present invention is specifically implemented in the following steps:

[0039] 1. Install the nozzle on the water-conducting laser processing equipment. The water-conducting laser processing equipment uses a low power lower than the ablation threshold to open the light for 3 hours in advance to achieve the heat treatment process. Because heat is also generated during the processing, this part of the heat is used to change the crystal structure. The ablation threshold of the nozzle is that the nozzle is damaged after working continuously for one week. The surface temperature of the nozzle is as high as 1800℃. The nozzle surface is cooled by a 30w water spray device installed on the water-conducting laser processing equipment. Because the water jet will flow through the nozzle surface, the nozzle temperature can be reduced during the heat treatment process.

[0040] 2. Place the heat-treated nozzle in anhydrous ethanol for ultrasonic cleaning, and then use distilled water to clean the ultrasonic cleaning thickness nozzle again to make the surface clean. The second ultrasonic cleaning is to use ultrapure water to clean the nozzle for 5 minutes;

[0041] 3. Place the nozzle in a drying oven and dry it until the nozzle surface is clean and dust-free;

[0042] 4. After installing the nozzle on the water-guided laser processing head, adjust the parameters set on the water-guided laser equipment, such as power of 40w, frequency of 8kHz, and water pressure of 250bar, to obtain different single pulse energies, so as to calculate the ablation threshold of the nozzle. The single pulse energy calculation formula is as follows:

[0043] E=P / f

[0044] Where E is the single pulse energy, P is the average power in the water beam, and f is the laser repetition frequency;

[0045] 5. The water pressure of 250 bar is set on the water-guided laser processing head. The water-guided laser processing equipment integrates the optical path, water path and gas path. The water pressure can be set on the processing equipment. It will not affect the total reflection of light during the processing due to low water pressure, nor will it affect the stability of the water jet during the processing due to excessive water pressure. Among them, the stability of the water jet length on the water-guided laser processing head depends on the water pressure and the micropore diameter, and the relevant water jet length directly depends on the water speed:

[0046]

[0047] Where v is the water velocity in m / s and p is the water pressure in bar;

[0048] 6. Use a single pulse energy of 10% below the nozzle ablation threshold to open the laser. The nozzle surface is heated by laser and cooled by water jet, which prompts the nozzle crystal structure to change to an amorphous structure. This change is achieved by heating and rapid cooling. The purpose of laser heating and water jet rapid cooling below 10% of the ablation threshold is to maximize the degree of nozzle crystal structure transformation, and then start processing parts;

[0049] 7. After the parts processing is completed, take the nozzle out of the processing head, and finally ultrasonically clean it in anhydrous ethanol. Then, use ultrapure water to clean the nozzle for 5 minutes after ultrasonic cleaning. The purpose is to clean the surface and facilitate the statistics of the surface quality of the nozzle.

[0050] 8. Place the nozzle after part cutting under an optical microscope and count the ablation of the nozzle during the processing to adjust the processing parameters.

[0051] Example 2

[0052] The process for optimizing the life of a water-guided laser machining nozzle described in the present invention is specifically implemented in the following steps:

[0053] 1. Install the nozzle on the water-conducting laser processing equipment. The water-conducting laser processing equipment uses a low power lower than the ablation threshold to open the light in advance for 3.5 hours to realize the heat treatment process. Because heat is also generated during the processing, this part of heat is used to change the crystal structure. The ablation threshold of the nozzle is that the nozzle is damaged after working continuously for one week. The surface temperature of the nozzle is as high as 1800℃. The nozzle surface is cooled by a 35W water spray device installed on the water-conducting laser processing equipment. Because the water jet will flow through the nozzle surface, the nozzle temperature can be reduced during the heat treatment process.

[0054] 2. Place the heat-treated nozzle in anhydrous ethanol for ultrasonic cleaning, and then use distilled water to clean the ultrasonic cleaning thickness nozzle again to make the surface clean. The second ultrasonic cleaning is to use ultrapure water to clean the nozzle for 6 minutes;

[0055] 3. Place the nozzle in a drying oven and dry it until the nozzle surface is clean and dust-free;

[0056] 4. After installing the nozzle on the water-guided laser processing head, adjust the parameters set on the water-guided laser equipment, such as power of 45W, frequency of 10kHz, and water pressure of 300bar, to obtain different single pulse energies, so as to calculate the ablation threshold of the nozzle. The single pulse energy calculation formula is as follows:

[0057] E=P / f

[0058] Where E is the single pulse energy, P is the average power in the water beam, and f is the laser repetition frequency;

[0059] 5. The water pressure of 300 bar is set on the water-guided laser processing head. The water-guided laser processing equipment is a device that integrates the optical path, water path and gas path. The water pressure can be set on the processing equipment. It will not affect the total reflection of light during the processing due to low water pressure, nor will it affect the stability of the water jet during the processing due to excessive water pressure. Among them, the stability of the water jet length on the water-guided laser processing head depends on the water pressure and the micropore diameter, and the relevant water jet length directly depends on the water speed:

[0060]

[0061] Where v is the water velocity in m / s and p is the water pressure in bar;

[0062] 6. Use a single pulse energy of 10% lower than the nozzle ablation threshold to open the laser. The nozzle surface is laser heated and water jet cooled, which prompts the nozzle crystal structure to change to an amorphous structure. This change is achieved by heating and rapid cooling. The purpose of laser heating and water jet rapid cooling, which is lower than 10% of the ablation threshold, is to maximize the degree of nozzle crystal structure transformation, and then start processing parts.

[0063] 7. After the parts processing is completed, take the nozzle out of the processing head, and finally ultrasonically clean it in anhydrous ethanol. Then, use ultrapure water to clean the nozzle for 5 minutes to 6 minutes after ultrasonic cleaning. The purpose is to clean the surface and facilitate the statistics of the surface quality of the nozzle.

[0064] 8. Place the nozzle after part cutting under an optical microscope and count the ablation of the nozzle during the processing to adjust the processing parameters.

[0065] Example 3

[0066] The process for optimizing the life of a water-guided laser machining nozzle described in the present invention is specifically implemented in the following steps:

[0067] 1. Install the nozzle on the water-conducting laser processing equipment to implement the heat treatment process. The water-conducting laser processing equipment is opened 4 hours in advance with a low power lower than the ablation threshold, because heat is also generated during the processing, and this part of the heat is used to change the crystal structure. The ablation threshold of the nozzle is that the nozzle is damaged after working continuously for one week. The surface temperature of the nozzle is as high as 1800℃. The nozzle surface is cooled by a 40W water spray device installed on the water-conducting laser processing equipment, because the water jet will flow through the nozzle surface to achieve the cooling of the nozzle during the heat treatment process;

[0068] 2. Place the heat-treated nozzle in anhydrous ethanol for ultrasonic cleaning, and then use distilled water to clean the ultrasonic cleaning thickness nozzle again to make the surface clean. The second ultrasonic cleaning is to use ultrapure water to clean the nozzle for 8 minutes;

[0069] 3. Place the nozzle in a drying oven and dry it until the nozzle surface is clean and dust-free;

[0070] 4. After installing the nozzle on the water-conducting laser processing head, adjust the parameters set on the water-conducting laser equipment, such as power of 450w, frequency of 12kHz, and water pressure of 350bar, to obtain different single pulse energies, so as to calculate the ablation threshold of the nozzle. The single pulse energy calculation formula is as follows:

[0071] E=P / f

[0072] Where E is the single pulse energy, P is the average power in the water beam, and f is the laser repetition frequency;

[0073] 5. The water pressure of 350 bar is set on the water-guided laser processing head. The water-guided laser processing equipment is a device that integrates the optical path, water path and gas path. The water pressure can be set on the processing equipment. It will not affect the total reflection of light during the processing due to low water pressure, nor will it affect the stability of the water jet during the processing due to excessive water pressure. Among them, the stability of the water jet length on the water-guided laser processing head depends on the water pressure and the micropore diameter, and the relevant water jet length directly depends on the water speed:

[0074]

[0075] Where v is the water velocity in m / s and p is the water pressure in bar;

[0076] 6. Use a single pulse energy of 10% lower than the nozzle ablation threshold to open the laser. The nozzle surface is laser heated and water jet cooled, which prompts the nozzle crystal structure to change to an amorphous structure. This change is achieved by heating and rapid cooling. The purpose of laser heating and water jet rapid cooling, which is lower than 10% of the ablation threshold, is to maximize the degree of nozzle crystal structure transformation, and then start processing parts.

[0077] 7. After the parts processing is completed, take the nozzle out of the processing head, and finally ultrasonically clean it in anhydrous ethanol. Then, use ultrapure water to clean the nozzle for 5 minutes to 6 minutes after ultrasonic cleaning. The purpose is to clean the surface and facilitate the statistics of the surface quality of the nozzle.

[0078] 8. Place the nozzle after part cutting under an optical microscope and count the ablation of the nozzle during the processing to adjust the processing parameters.

[0079] Under high-power processing conditions, the increased nozzle life can better adapt to materials that are difficult to process, such as diamond and silicon carbide ceramics, and expand the application range of water-guided lasers. More durable nozzles can withstand high temperatures, high pressures, and strong impact environments, further improving the equipment's ability to adapt to complex processing scenarios.

[0080] Experiments show that by setting the underwater power to 28W, the nozzle of the water-guided laser processing head equipment can continue to work in a high temperature environment after running for 3h to 4h.

[0081] Under high-energy conditions, this process can increase the life of the nozzle by more than 10 times, thereby significantly improving the economy and sustainability of water-guided laser processing, and providing important support for the promotion and application of water-guided laser in a wider range of fields. The extended life of the nozzle reduces the number of discarded nozzles, helps reduce the environmental burden of industrial production, and conforms to the concept of green manufacturing. For equipment manufacturers, durable nozzle design and efficient process solutions can significantly improve the overall performance of the equipment and enhance market competitiveness. For users, it can also reduce the cost of use and improve economy, thereby further promoting the popularization and development of water-guided laser technology.

[0082] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for optimizing the life of a water-guided laser machining nozzle, characterized in that: It includes the following steps: Step 1 The nozzle is installed on the water-conducting laser processing equipment, and the water-conducting laser processing equipment is opened 3h to 4h in advance with a low power below the ablation threshold to realize the heat treatment process; Step 2 The nozzle after heat treatment is placed in anhydrous ethanol for ultrasonic cleaning, and then the nozzle after ultrasonic cleaning is cleaned again with distilled water to make the surface clean; Step 3 Place the nozzle in a drying oven and dry it until the nozzle surface is clean and dust-free; Step 4 After the nozzle is installed on the water-guided laser processing head, the parameters set on the water-guided laser equipment are adjusted to obtain different single pulse energies, thereby calculating the ablation threshold of the nozzle. The single pulse energy calculation formula is as follows: E=P / f Where E is the single pulse energy, P is the average power in the water beam, and f is the laser repetition frequency; Step 5 A defined water pressure is set on the water-guided laser machining head, wherein the stability of the water jet length on the water-guided laser machining head depends on the water pressure and the micropore diameter, wherein the relevant water jet length directly depends on the water velocity: Where v is the water velocity in m / s and p is the water pressure in bar; Step 6 Using a single pulse energy of 10% below the nozzle ablation threshold, the nozzle surface is heated by laser and cooled by water jet before processing the part; Step 7 After the parts processing is completed, the nozzle is removed from the processing head, and finally ultrasonically cleaned in anhydrous ethanol, and then cleaned again with clean water; Step 8 The nozzle after part cutting is placed under an optical microscope, and the ablation of the nozzle during the processing is counted to adjust the processing parameters.

2. A process for optimizing the life of a water-guided laser machining nozzle according to claim 1, characterized in that: In step 1, the nozzle surface temperature is 1800°C, and the nozzle surface is cooled by a water spray device with a power of 30W to 40W installed on the water-guided laser processing equipment, because the water jet flows through the nozzle surface.

3. A process for optimizing the life of a water-guided laser machining nozzle according to claim 1, characterized in that: The ablation threshold of the nozzle described in step 1 is the ablation threshold when the nozzle is damaged after working continuously for one week.

4. A process for optimizing the life of a water-conducting laser machining nozzle according to claim 1, characterized in that: In step 2, the ultrasonic cleaning of the second cleaning is to use ultrapure water to clean the nozzle for 5 minutes to 8 minutes.

5. A process for optimizing the life of a water-guided laser machining nozzle according to claim 1, characterized in that: In step 4, the parameters set on the water-guided laser equipment are: power 40w-50w, frequency 8-12kHz, and water pressure 250-350bar.

6. A process for optimizing the life of a water-guided laser machining nozzle according to claim 1, characterized in that: In step 5, the limited water pressure set on the water-conducting laser processing head is 250 bar to 350 bar.

7. A process for optimizing the life of a water-guided laser machining nozzle according to claim 1, characterized in that: In step seven, the nozzle is ultrasonically cleaned and then cleaned with ultrapure water for 5 to 6 minutes.

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