CN116810157A

CN116810157A - Laser texturing method and laser texturing equipment

Info

Publication number: CN116810157A
Application number: CN202310866997.8A
Authority: CN
Inventors: 姜代旬; 王睿; 杨洋; 张晓成; 孙禹; 何晓龙
Original assignee: CRRC Qingdao Sifang Co Ltd
Current assignee: CRRC Qingdao Sifang Co Ltd
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2023-09-29

Abstract

The invention firstly provides a roughening activating method, laser emitted by a laser irradiates to the surface of a workpiece after passing through a galvanometer system, and a control system controls the scanning speed of an X galvanometer according to the laser frequency, so as to control laser pulses to continuously perform pulse impact for a plurality of times at the same position of the workpiece and/or control the overlap ratio between adjacent impact positions, and realize roughening morphology formation on the surface of the workpiece in the X direction. The invention further provides laser texturing equipment. According to the laser texturing method and the laser texturing equipment, the movement of the galvanometer is controlled by adjusting the laser galvanometer system, so that the action position of laser pulses is controlled, and the same-point continuous multi-pulse laser texturing is realized.

Description

Laser texturing method and laser texturing equipment

Technical Field

The invention relates to the technical field of surface treatment, in particular to a laser texturing method and a pie texturing device.

Background

In order to improve the adhesive force between a paint layer and a plate, roughening treatment is generally carried out on the surface of a workpiece before paint spraying, and the traditional roughening treatment is generally carried out by adopting a sand blasting process, but a large amount of dust is generated in the sand blasting process, so that the paint has great noise pollution, poor working environment, occupational health and environmental protection hidden dangers, and meanwhile, the problem that a large thin-wall member is easy to deform during sand blasting treatment is solved, and the surface roughness after sand blasting roughening is uneven. In recent years, more surface treatment is carried out on a workpiece by adopting a laser texturing method, so that the texturing effect can be effectively realized, and the method has the advantages of high efficiency, environmental protection, good controllability, uniform roughness and the like.

The laser roughening technology is to focus and irradiate the laser beam with high energy density to the surface of the material based on the fast fusing principle, to melt the irradiated material to produce molten pool, to cool the material at high cooling speed and to form dense roughened spots on the surface of the material to increase the surface roughness and the adhesion of paint layer or adhesive layer.

Two important indexes are mainly involved in ensuring the quality of efficient laser texturing: the size of the texturing spots and the distribution of the texturing spots. Parameters affecting the size of the texturing spot mainly include laser power and pulse width, and parameters affecting the distribution of the texturing spot mainly include laser frequency, scanning speed and line spacing. As the laser power and the pulse width are increased, the pulse energy value of a single texturing point is increased, the molten pool of the texturing point is enlarged, and the size of the texturing point is increased; as the laser frequency increases, the arrangement of texturing spots becomes denser along the scanning direction, and as the scanning speed and line spacing decrease, the arrangement of texturing spots becomes denser along the processing direction. Therefore, by selecting proper laser processing parameters, a texturing dot matrix with reasonable size and arrangement distribution can be obtained, and higher texturing quality can be realized.

However, in general pulse laser equipment, for protecting a laser transmission system, a maximum monopulse energy value is limited, so that the size of a roughened spot is greatly dependent on the monopulse energy value, the size of the obtained roughened spot is limited to a certain extent due to the limitation of the maximum monopulse energy in a single scanning process, the depth size of the obtained roughened spot is only about 10 microns, the diameter is about 100 microns, the depth-to-width ratio is only about 0.1, the obtained roughened spot after roughening and the corresponding rotation speed V and pulse signals are as shown in fig. 1, the obtained roughened spot has a shallow depth size, a small depth-to-width ratio, the depth-to-width ratio is small, the paint locking effect of the roughened spot cannot be greatly improved, the surface area increasing range is limited, the contact area between a paint film and a substrate cannot be increased, the binding force of the paint film cannot be well improved, and the application of laser roughening on the paint layer is limited.

In order to obtain a texturing shape with large depth dimension and depth-to-width ratio by applying a plurality of pulse energies at the same position, a mode of scanning for multiple times is mainly adopted at the present stage, and the surface of a workpiece to be textured is textured for multiple times, but due to the influence of factors which are difficult to control, such as variable actual working conditions, jitter of a laser head and the like, the scanning process of each time is difficult to ensure to be completely at the same position, the coincidence ratio of laser pulses of each time cannot be ensured, and although the depth and the width of a texturing point can be increased to a certain extent, the improvement effect is not obvious as a whole.

Therefore, a roughening method needs to be found to realize the same-point continuous multi-pulse laser roughening.

Disclosure of Invention

The invention mainly aims to solve the problems and the defects, and firstly provides a laser texturing method which controls the action position of laser pulses by adjusting the motion of a laser galvanometer system to realize the same-point continuous multi-pulse laser texturing.

Another object of the present invention is to provide an apparatus for applying the laser texturing method, and as such, can achieve co-point continuous multi-pulse laser texturing of a workpiece surface.

In order to achieve the aim of the invention, the invention firstly provides a laser texturing method, which adopts the technical scheme that:

a laser texturing method includes such steps as laser emitting laser to the surface of workpiece, and controlling the scanning speed of X-vibration mirror by control system.

Further, when the same texturing morphology is obtained, the laser frequency is increased, and the control system controls the rotation speed of the X-vibration mirror to be reduced.

Further, the control system adjusts and controls the rotation speed of the Y vibrating mirror, the diameter and the arrangement of Gaussian light spots, so that the overlap ratio of the light spots on the Y direction of the workpiece is (-0.3 to-0.05).

Further, the scanning speed of the X-vibration mirror comprises an initial speed V1 and a moving speed V2, V1 is more than or equal to 0 and less than V2, and the control system controls the X-vibration mirror to rotate alternately in sequence at the initial speed V1 and the moving speed V2.

Further, after the X-vibration mirror continuously rotates for N pulses at the initial speed V1, the X-vibration mirror is controlled to continuously rotate for M pulses at the moving speed V2, and the X-vibration mirror is alternately controlled, wherein N is more than 1, and M is more than or equal to 1.

Further, the overlap ratio between adjacent impact positions=1- (n×v-sweep)/(V1×n+d×f), where d is the shift diameter and f is the laser frequency.

Further, when the initial velocity v1=0, V-sweep=v2/N.

Further, when the initial velocity V1 > 0, V sweep=v1+ (V2/N).

Further, the method comprises the following steps:

s1, fixing a workpiece to be roughened on a roughening platform, moving a laser roughening integrated machine and an executing mechanism to a working position, and checking the states of ventilation equipment and water cooling equipment;

s2, adjusting the position of the laser cleaning texturing head to ensure the stable length of the focal length;

s3, setting laser process parameters including, but not limited to, average power of laser, adjustable pulse width, repetition frequency, spot diameter and pulse energy according to workpiece materials, paint layer materials and paint spraying requirements;

s4, setting an initial speed V1, a moving speed V2, repeated pulse numbers N and M and a rotating speed of the Y vibrating mirror in the texturing process according to the adhesive force requirement of the paint layer, and controlling the line spacing so as to ensure that a saw-tooth texturing shape can be formed in the X direction of the surface of the workpiece;

s5, starting the ventilation equipment 9, the water cooling equipment and the galvanometer system, starting a laser, starting the laser roughening operation on the surface of the workpiece, and controlling the system to complete X-direction scanning according to the parameters set in the step S4 and then realizing line feed scanning by controlling the rotation of the Y galvanometer;

and S6, repeating the step S5 until the laser texturing is finished in a set area, turning off the laser, stopping the laser texturing head galvanometer system, turning off the ventilation equipment 9, and turning off the water cooling equipment, so that the laser texturing operation is stopped.

The invention further provides laser texturing equipment, which adopts the following technical scheme:

a laser texturing device comprises a control system, a laser, an isolator and a galvanometer system, wherein the control system is respectively in communication connection or electric connection with the laser and the galvanometer system to execute the laser texturing method.

In summary, the laser texturing method and the laser texturing device provided by the invention have the following technical advantages compared with the prior art:

the invention provides a method capable of improving the depth-to-width ratio range of texturing points, which can more stably control the arrangement mode and the size of the texturing points by adjusting the motion form of a galvanometer system, obtain the depth-to-width ratio range of the texturing points in a larger range and expand the practical application range of laser texturing;

the roughening effect is good, and a plurality of continuous pulses can act on the same position through the action position of the pulse energy regulated and controlled by the motion of the galvanometer system, so that the size of a deeper roughening point is obtained;

the action position of the pulse energy is regulated and controlled through the movement of the vibrating mirror system in the X direction, so that a plurality of continuous pulses can be distributed together at a large overlap ratio to obtain a saw-tooth roughened surface morphology;

the pulse energy can be arranged at will according to the requirement, and various texturing morphologies can be obtained;

compared with a method of scanning a certain area for multiple times, the method has the advantages that the effect of the same-point continuous multi-pulse laser texturing output is more stable, and the method is more suitable for complex working conditions;

the invention obtains the aspect ratio texturing morphology in a larger range and various optionally controllable texturing morphologies, and increases the application field of laser texturing;

the laser texturing method has good controllability, and compared with other texturing methods, the laser texturing method can realize the shape and size of texturing points, and the distribution is adjustable and controllable.

Description of the drawings:

fig. 1: in the prior art, continuously scanning single-pulse laser texturing pulse, vibrating mirror rotation speed and texturing effect schematic diagrams;

fig. 2: the invention relates to a composition schematic diagram of laser texturing equipment;

fig. 3: the invention relates to a flow diagram in a laser texturing method;

fig. 4: the invention relates to a laser texturing method, which is characterized in that the rotation speed and texturing effect of a laser pulse and a vibrating mirror are shown in a schematic diagram during the same-point continuous multi-pulse laser texturing;

fig. 5: the invention relates to a laser texturing method, which is characterized in that laser pulse, vibrating mirror rotation speed and texturing effect are schematic when a saw-tooth texturing morphology is formed;

fig. 6: the invention relates to an influence rule diagram of pulse interval number N on texturing size and depth-to-width ratio in a laser texturing method;

fig. 7: the invention relates to ventilation equipment, a schematic diagram of the incidence angle between a light beam and the surface of a workpiece in a laser texturing method;

fig. 8: the invention discloses a hairing method schematic diagram in a laser roughening method.

In the figure: control system 1, laser 2, isolator 3, homomorphism ware 4, galvanometer system 5, X galvanometer 51, Y galvanometer 52, lens 6, light beam 7, work piece 8, ventilation equipment 9.

Detailed Description

The invention is described in further detail below with reference to the drawings and the detailed description.

The invention provides laser texturing equipment, which is shown in fig. 2, and comprises a control system 1, a laser 2 and a galvanometer system 5, wherein:

the control system 1 is respectively connected with the laser 2 and the galvanometer system 5 through a communication system, is internally provided with a laser texturing method and respectively controls the working states of the laser 2 and the galvanometer system 5 according to a preset control method; the communication system comprises an optical fiber transmission system and a control signal transmission system, and realizes communication connection in a signal connection or electric connection mode;

the laser 2 receives a control signal of the control system 1 to realize automatic on-off and emits laser with preset parameters according to a control instruction; in this embodiment, the laser 2 is a pulsed fiber laser; the laser 2 provided by the invention further comprises a texturing executing mechanism such as a texturing head, which is a conventional technology and is not described in detail;

the galvanometer system 5 comprises an X galvanometer 51 and a Y galvanometer 52, and the control system 1 controls the rotation and the rotation speed of the X galvanometer 51 and the Y galvanometer 52 respectively, wherein the rotation of the X galvanometer 51 is controlled to realize the scanning (texturing) of laser in the X direction of the workpiece 8, and the rotation of the Y galvanometer 52 is controlled to realize the transposition in the Y direction on the workpiece 8.

In this embodiment, an isolator 3 and a homogenizer 4 are disposed between the laser 2 and the galvanometer system 5, a lens 6 is disposed between the galvanometer system 5 and the workpiece 8, the lens 6 may be an F-theta lens, the control system 1 controls the laser 2 to start and emit laser light meeting requirements, the control system 1 integrates the isolator 3 and the homogenizer 4, so that the laser light emitted from the laser 2 becomes a spot light through the isolator 3 and the homogenizer 4, the diameter of the spot light is adjusted through the isolator 3 and the homogenizer 4 to control the diameter of an impact point on the workpiece 8, then the laser light becomes a two-dimensional plane light beam 7 after passing through the X-galvanometer 51 and the Y-galvanometer 52, the light beam 7 reaches the surface of the workpiece 8 after passing through the F-theta lens to become a line light spot, and laser texturing is performed on the surface of the workpiece 8.

The galvanometer system 5 further comprises a first motor and a second motor, the first motor receives a control instruction of the control system 1 to control the X galvanometer 51 to rotate, laser scanning in the X direction on the workpiece 8 is achieved, texturing processing is conducted, the second motor receives a control instruction of the control system 1 to control the Y galvanometer 52 to rotate, line feed scanning in the Y direction is achieved, and multiple texturing paths in the X direction are formed on the workpiece 8. In the conventional technology, the first motor controls the X-vibrating mirror 51 to rotate at a constant speed V, and a uniform texturing process of scanning in the X-direction is reflected on the workpiece 8 in cooperation with a pulse period of laser, so that a plurality of spaced texturing points are formed on the surface of the workpiece 8, for example, laser processing parameters are set as follows: the laser frequency f=80 kHz, the scanning speed v sweep=10000 mm/s, at this time, only one pulse energy acts on each impact point (acting position), and a texturing point array with a diameter size of 56 μm, a depth of 10 μm and a scanning direction interval of 125 μm as shown in fig. 1 is obtained, and the texturing point has a small depth size, a small depth-to-width ratio (ratio of impact depth to texturing point diameter), a weak texturing effect and poor paint locking capability. Therefore, the invention provides a laser roughening method capable of enhancing roughening effect and improving paint locking capability, wherein the laser roughening method is preset in a control system 1, and the control system controls a laser 2 and a galvanometer system 5 to perform corresponding work according to the method requirement and the preset method requirement so as to realize corresponding roughening effect, and as shown in fig. 3, the laser roughening method comprises the following steps:

s1, in the preparation process, the workpiece 8 to be roughened is fixed on a roughening platform, and the laser roughening equipment is moved to a working position to wait for roughening work. The workpiece 8 may be a newly produced workpiece, or may be a painted workpiece, and the workpiece is required to be painted secondarily after paint removal, so that certain dust and impurities are generated in the texturing process, and the laser texturing device further comprises ventilation and water cooling equipment, or the ventilation and water cooling equipment is required to be equipped in the laser texturing process, before the texturing process is performed, the ventilation equipment 9 (a smoke absorbing device, a smoke purifier and the like, and the like) is also required to be checked, the water cooling equipment and the like are normal, and the working positions of the ventilation equipment 9 and the water cooling equipment are adjusted, so that dust generated in the texturing process is collected in time in the texturing process, and effective water cooling and temperature reduction treatment is performed on the surface of the workpiece 8 at any time, and high temperature generated when laser pulses impact the surface of the workpiece 8 is quickly condensed to form texturing points. The ventilation equipment 9 matched with the laser texturing equipment comprises a dust collector and a smoke purifier, cleaning residues and dust can be effectively removed, purified air is discharged after filtration, and therefore the laser cleaning texturing machine is harmless to human bodies and environment during and after use, and is environment-friendly.

S2, adjusting the laser 2, determining a laser emission focal length according to the texturing requirement after finishing the early-stage equipment inspection, adjusting the position of a laser texturing head, and ensuring the stable length of the focal length.

S3, setting process parameters involved in the roughening process according to the material and paint spraying requirements of the workpiece 8, wherein the reference requirements of the workpiece 8 include, but are not limited to, workpiece materials, smoothness of the surface to be sprayed, and workpiece 8 surface treatment requirements (whether the surface of the workpiece 8 has a paint layer and needs cleaning or other attachments need to be removed, such as lubricating oil, dust and the like), the paint spraying requirements include, but are not limited to, paint types, viscosity, adhesion capability, paint spraying tools, paint spraying speed, paint spraying pressure and the like, respectively combining the paint spraying and the material to determine the process parameters in the roughening process, forming a process database corresponding to the workpiece materials in a production field according to the paint spraying parameters corresponding to the workpiece materials commonly seen in the production field, determining a corresponding table of the matching relation of the parameters between the different workpiece materials and the paint layer thickness according to experience and experimental determination results, and setting the laser roughening control parameters corresponding to the different materials and setting the paint spraying requirements into the control system 1, so that the roughening process is more specific, improving the setting efficiency of the process parameters in the conventional production process, selecting the corresponding parameters in the corresponding table according to the paint spraying requirements of the workpiece 8, and transmitting control signals to the laser control system 2 through the control system 2 to emit laser treatment signals to the laser treatment system 2.

In this embodiment, considering that there may be a certain unevenness and a microstructure on the surface of the workpiece 8, in this embodiment, the long focal depth technology is adopted, by adjusting the technological parameters of the laser, as shown in fig. 7, the angle delta between the ventilation device 9 and the normal direction of the cleaning and texturing point of the workpiece is adjusted, and can be set to be 0 degree delta to 15 degrees, as shown in fig. 8, the angle theta of the light beam 7 is made incident, and can be set to be 5 degrees to 20 degrees, so that the laser beam 7 is allowed to have a certain height difference, such as 1cm, when the surface of the workpiece 8 is cleaned and/or textured, different heights of the same end face or different end faces can be cleaned simultaneously, and simultaneously, the incident angle between the light beam 7 and the surface of the workpiece 8 is adjusted, so that better surface cleaning and subsequent texturing effects can be obtained.

When the existing paint layer is required to be cleaned on the surface of the workpiece 8, the pulse laser beam 7 is utilized to enable the paint layer on the surface of the workpiece 8 to absorb laser energy to be sublimated or vaporized and evaporated instantly, the cleaning efficiency is higher, ventilation equipment 9 and water cooling equipment are matched, and meanwhile pollution of paint layer gasified matters to the vibrating mirror system 5 and harm to the health of staff are reduced. The average power of the laser emitted by the laser 2 is respectively set to be 30W-500W, the adjustable pulse width is 100-300 ns, the laser repetition frequency is 10-1000 kHz, the laser spot diameter is 0.03 mm-0.1 mm, and the pulse energy is 0.5-100 mJ.

When the workpiece 8 has no other attachments such as paint layer and lubricating oil, corresponding parameters can be directly selected according to the corresponding table, and the next step is carried out, when the workpiece 8 has other attachments on the surface and needs to be cleaned and then roughened, the step further comprises a laser cleaning process, so that the synchronous processing of laser cleaning and roughening on the surface of the workpiece 8 is realized, the process parameters in the cleaning and roughening process need to be further set, the corresponding table of the parameter matching relation among the material of the workpiece 8, the paint layer type and thickness and the laser cleaning roughening control parameters corresponding to the paint spraying requirement of a new paint layer is set according to the experience values of the existing paint layer thickness and the paint layer adhesion force of the workpiece and the experience accumulation and the experimental result, and is set in the control system 1, and in the actual work, the corresponding process parameters are selected in the corresponding table, for example, the cleaning and roughening operation can be completed, the laser average power is set to be 30W-1000W, the adjustable laser repetition frequency is 10-1000 kHz, the laser spot diameter is 0.03 mm-0.1 mm, and the pulse energy is 0.5-100 mJ.

S4, the control system 1 sends a control signal to control the scanning speed (hereinafter referred to as the rotating speed) of the X-vibration mirror 51, so that laser pulses are controlled to continuously perform pulse impact for multiple times at the same position of the workpiece 8, the depth dimension of a texturing point is increased, meanwhile, the continuous pulse impact for multiple times can deepen the depth dimension of the texturing point, the surface of the workpiece 8 can continuously obtain energy, the diameter of a molten pool of the punching point can be increased, namely, the diameter of the texturing point can be increased during continuous impact, the texturing morphology with larger depth-to-width ratio as shown in FIG. 4 is obtained, and the adhesive force of a paint layer is improved.

As described above, when the control system controls the X-vibration mirror to rotate at a uniform speed, uniformly distributed texturing points with smaller depth dimensions as shown in fig. 1 are generated, and the requirement of texturing at the present stage cannot be met, so that the control system 1 needs to control the X-vibration mirror 51 to rotate in an intermittent or variable speed manner, so as to realize continuous pulse impact at the same position for multiple times, ensure that the shock point cannot deviate, during the impact process, the control system 1 controls the X-vibration mirror 51 not to rotate, and the duration T1 is kept for the time T1, so that the pulse impact is continuously performed to the same shock point, after the time T1 is finished, the control system 1 controls the X-vibration mirror 51 to rotate again for the duration T2, so that the laser pulse is focused to the next impact position, and after the duration T2 is finished, the control system 1 controls the X-vibration mirror 51 to stop rotating again, and the time of stopping rotating is kept for the duration T1, so repeatedly, and the intermittent rotation of the X-vibration mirror 51 is controlled, so that the texturing operation in the X direction is realized.

Further, the time T1 is N pulse intervals, N is more than 1, N is more than or equal to 4, in the time T1, the X vibrating mirror 51 stops rotating, N pulse impacts are continuously carried out on the same point, the impact point does not deviate and acts on the same position, so that the depth of the impact point is increased, and meanwhile, the melting range is enlarged by utilizing the high temperature generated by laser so as to increase the diameter of the roughening point; the time T2 is M pulse intervals, m=1 is recommended, in the process of focusing the X-vibration mirror 51 to the next impact point, in the process of rotating, no laser pulse is emitted to the workpiece 8, after the M pulse intervals are finished, the control system 1 controls the X-vibration mirror 51 to stop rotating again, the time interval for stopping rotating is also N pulse intervals, and the like, and the X-vibration mirror is alternately reciprocated to form a texturing morphology as shown in fig. 4; when M > 1, the X vibrating mirror 51 rotates according to the instruction of the controller, during the rotation, the laser 2 emits laser pulses to the surface of the workpiece 8 to form M-1 relatively shallow impact points (the sizes of texturing points of relatively multiple impacts), after the M pulse intervals are over, the control system 1 controls the X vibrating mirror 51 to stop rotating for N pulse intervals again, N pulse impacts are continuously carried out on the same texturing point, and thus the laser alternately reciprocates, and M-1 relatively shallow texturing points are arranged between every two adjacent texturing points of N continuous impacts.

Further, in the present embodiment, the control system 1 controls the X-rotating mirror 51 to rotate at an initial speed V1 and a moving speed V2, and V1 is less than or equal to 0 and less than V2, and the control process of controlling the rotation of the X-vibrating mirror 51 may be that the initial speed V1 and the moving speed V2 are alternately performed, and the control system 1 controls the X-vibrating mirror 51 to rotate at the initial speed V1 for a duration T1, then controls the X-vibrating mirror 51 to move at the moving speed V2 for a duration T2, so as to gather the laser to the next impact position, and then re-controls the X-vibrating mirror 51 to rotate again at the initial speed V1 to perform the continuous pulse action of the next position, so repeatedly, and the control system 1 controls the X-vibrating mirror 51 to rotate at the initial speed V1 and the moving speed V2 for different time intervals and alternately.

When v1=0, as described above, a roughened shape as shown in fig. 4 or a roughened shape of M-1 relatively shallow roughened points spaced between two adjacent N-time-impacted roughened points can be formed.

When V1 > 0, the control system 1 controls the X-rotating mirror 51 to rotate at an initial speed V1, the duration T1 is N pulse intervals, the control system 1 controls the X-rotating mirror 51 to rotate at a moving speed V2, the duration T2 is M pulse intervals, and controls the X-rotating mirror 51 to recover the initial speed V1 and keep the initial speed V1N pulse intervals, so repeatedly, alternately controls the X-rotating mirror 51 to alternately rotate at the initial speed V1 and the moving speed V2, and by controlling the value of the initial speed V1, the X-rotating mirror 51 rotates at a very small (approaching zero) speed, the continuous N laser pulses act on similar positions, and the N impact points are connected with each other at a very large overlap ratio, and in the time T1, the molten pools generated by the impacts affect each other, act repeatedly to deepen the depth of the texturing points, increase the aspect ratio, and affect the texturing morphology; after N pulses, the X-turn mirror 51 is controlled to rotate at a moving speed V2 and continues to focus on the next impact position for M pulses, the moving speed V2 influences the distance between adjacent impact points (texturing points), and when the overlap ratio between adjacent texturing points is large, a saw-tooth-like texturing morphology as shown in fig. 5 is formed.

As described above, the N pulses (T1 time) are controlled to impinge on the workpiece 8 at similar positions by controlling the initial velocity V1, and the overlap ratio between adjacent impingement points is controlled by controlling the moving velocity V2, so as to achieve the saw-tooth-like roughened morphology on the workpiece 8 as shown in fig. 5. In this embodiment, V1 is greater than or equal to 0 and less than V2, M is greater than or equal to 1 and less than N, fig. 6 is a graph of the influence of the number of repeated pulses N on the texturing size and the aspect ratio, as shown in fig. 6, the texturing point diameter is increased to a certain extent and then remains stable as the repetition number N increases, the texturing point depth and the aspect ratio linearly increase, the depth size increases, the aspect ratio increases, and the depth-to-width ratio increases can reach 1.25 or more, so that the requirement of the texturing point on a larger range of the aspect ratio can be met. According to the material and paint spraying requirements of the workpiece 8, a proper pulse repetition number N is selected from the rule diagram of FIG. 6 according to the roughening morphology, the depth-to-width ratio and the diameter to be obtained. After the single-line scanning in the X direction is completed, the control system 1 controls the Y galvanometer 52 to rotate at a set speed, the line feed scanning is performed, the texturing operation of the other line is performed, and meanwhile, the texturing point distance in the Y direction is realized by controlling the rotation speed, the duration and the lap ratio of the Y galvanometer 52, so that the overall texturing shape of the surface of the workpiece 8 is controlled.

By selecting proper laser processing parameters, a texturing lattice with reasonable size and arrangement distribution can achieve higher texturing quality, and two important indexes are mainly involved in ensuring high-efficiency laser texturing quality: the size of the texturing points and the distribution of the texturing points, the parameters influencing the texturing size mainly comprise laser power and pulse width, the parameters influencing the distribution of the texturing points mainly comprise laser frequency, scanning speed and line spacing, the pulse energy value of a single texturing point is increased along with the increase of the laser power and the pulse width, a molten pool of the texturing points is increased, and the size of the texturing points is increased; as the laser frequency increases, the arrangement of the texturing points becomes denser along the scanning direction, as the scanning speed and the line spacing decrease, the arrangement of the texturing points becomes denser along the processing direction, and under the same texturing shape, the rotation speed of the X-vibrating mirror 51 needs to be controlled to decrease when the laser frequency increases, and correspondingly, in the embodiment, under the same texturing shape, when the laser frequency increases, the value of the transfer speed V2 can be reduced. In the texturing method provided in this embodiment, the X-rotating mirror 51 rotates alternately at the initial speed V1 and the moving speed V2, respectively, instead of the control system 1 controlling the X-rotating mirror 51 to perform variable speed motion from the initial speed V1 to the moving speed V2, the moving speed V2 is adjusted to control the distance between adjacent texturing points. Overlap ratio between adjacent impact positions = 1- (N x V sweep)/(V1 x n+d x f), where d is the spot diameter and f is the laser frequency.

In the X direction, since the scanning speed includes the initial speed V1 and the moving speed V2 as described above, when v1=0, V sweep=v2/N, the laser frequency f, the number of pulses N, and the speeds V1, V2 are set, and the distance d= (N/f) ×n1+ (1/f) ×n2 between two texturing points in the scanning direction can be obtained. As shown in fig. 3, when the laser frequency f=80 kHz, the pulse numbers n=13, v1=0 and v2=10000 mm/s, a roughened dot array having a diameter size of 90 μm, a depth of 95 μm and a scanning direction pitch of 125 μm is obtained; when V1 > 0, V sweep=v1+ (V2/N), and the laser frequency f, the number of pulses N, and the speeds V1, V2 are set, the distance d= (N/f) ×v1+ (1/f) ×v2 between two texturing points in the scanning direction can be obtained. As shown in fig. 4, the laser frequency f=80 kHz, the number of pulses n=7, v1=300 mm/s and v2=4000 mm/s, and a roughened dot array having a serration length of 125 μm, a serration depth of 40 μm and a scanning direction pitch of 160 μm was obtained. In the Y direction, the line spacing can be controlled by controlling the rotating speed of the Y vibrating mirror 52, so that the overlapping rate between two texturing lines in the adjacent X direction is controlled, and further, the control system 1 adjusts and controls the rotating speed of the Y vibrating mirror 52 and the Gaussian spot diameter and arrangement, so that the spot overlapping rate of the workpiece 8 in the Y direction is in a (-0.3 to-0.05) interval, and preferentially, the spot overlapping rate of the workpiece 8 in the Y direction is in a (-0.2 to-0.1) interval. Specifically, in practical application, according to the size of the roughened spot to be obtained, the corresponding laser parameters may be selected in the following table:

laser parameter and texturing spot size comparison table

It should be noted that, the texturing process described in this embodiment may be a single texturing process, or may be a cleaning-hair-body integrated process including a cleaning process, in which the rotational speed (the scanning speed, including the initial speed V1 and the moving speed V2) of the X-vibrating mirror 51 is controlled, and multiple pulse impacts are continuously performed on the same surface of the workpiece 8, or multiple pulse impacts are continuously performed at similar positions on the surface of the workpiece 8, and further, when V1 > 0, by controlling the laser frequency, the initial speed V1 and the moving speed V2, overlapping rates of different X-directions and Y-directions are obtained and controlled, so that a discontinuous saw-tooth-like textured appearance or a continuous saw-tooth-like textured appearance is formed on the surface of the workpiece 8. As described above, the rotational speeds of the X-galvanometer 51 and the Y-galvanometer 52 can be adjusted according to the laser frequency. Still further, the control system 1 further comprises a disorder control module 1, and by controlling the parameter changes such as the laser frequency, the scanning speed of the X vibrating mirror 51 and the Y vibrating mirror 52, the value of N and the like, the disorder arrangement of texturing points is realized, the roughness of the surface of the workpiece 8 is improved, and the texturing effect is improved; or two groups of random signals are adopted to regulate and control each frequency of energy during laser texturing, compared with the prior art, the unordered texturing improves the surface anisotropy, and an isotropic surface is obtained, and the freshness after painting is better.

As the thicknesses of the paint layers on the surface of the aluminum alloy car body for different applications are different, the thickness of the paint layer of the car body is generally between 60 and 300 mu m, different laser processing parameters and the times of repeated processing are set according to different thicknesses in the laser cleaning process, and according to the difference of the thickness of the paint layer on a workpiece, better cleaning effect is obtained by selecting different process parameters, the cleaning efficiency is improved, and the method is as follows:

when the thickness of the paint layer is 60-100 mu m, the laser power is 100-300W, the pulse width is 100-500 ns, the laser pulse frequency is 10-1000 kHz, and the cleaning speed is 0.1-0.2 m/s. The laser frequency and the cleaning speed at this time have a certain adaptation degree to the line spacing to ensure that a certain overlap ratio is satisfied. The size of a general laser spot is greatly influenced by the type of a selected field lens, the standard diameter of the spot is D under the field lens of the selected type, and the laser frequency f, the scanning speed V and the line interval D selected at the moment have the following corresponding relation for ensuring the proper overlap ratio:

column overlap ratio: 1-v/(f.times.d) ∈ (0.1, 0.3)

Row overlap ratio: 1-D/D E (0.1, 0.3)

When the paint layer thickness is 100-200 mu m, the laser power is 300-400W, the pulse width is 100-500 ns, the laser pulse frequency is 10-1000 kHz, and the cleaning speed is 0.05-0.1 m/s. The laser frequency and the cleaning speed at this time have a certain adaptation degree to the line spacing to ensure that a certain overlap ratio is satisfied. The size of a general laser spot is greatly influenced by the type of a selected field lens, the standard diameter of the spot under the field lens of the selected type is set as D, and the laser frequency f, the scanning speed v and the line spacing D selected at the moment have the following corresponding relation for ensuring the proper overlap ratio:

column overlap ratio: 1-v/(f.times.d) ∈ (0.3, 0.5)

Row overlap ratio: 1-D/D E (0.3, 0.5)

When the paint layer thickness is above 200 mu m, the laser power is 400-1000W, the pulse width is 100-500 ns, the laser pulse frequency is 10-1000 kHz, and the cleaning speed is 0.03-0.05 m/s. The laser frequency and the cleaning speed at this time have a certain adaptation degree to the line spacing to ensure that a certain overlap ratio is satisfied. The size of a general laser spot is greatly influenced by the type of a selected field lens, the standard diameter of the spot under the field lens of the selected type is set as D, and the laser frequency f, the scanning speed v and the line spacing D selected at the moment have the following corresponding relation for ensuring the proper overlap ratio:

column overlap ratio: 1-v/(f.times.d) ε (0.5,0.6);

row overlap ratio: 1-D/d.epsilon. 0.5,0.6.

Providing laser roughening process parameters when roughening an aluminum alloy workpiece: the laser power is selected to be 200-500W, the pulse width is 100-500 ns, the laser frequency is selected to be 10-1000 kHz, and the laser texturing scanning speed is 1-5 mm/s. When the two groups of random signals act, the laser power is randomly changed at 50% -100% of the set parameters, and the laser frequency is randomly changed at 80% -120% of the set frequency parameters. The laser frequency and the cleaning speed at this time have a certain adaptation degree to the line spacing to ensure that a certain overlap ratio is satisfied. The size of a general laser spot is greatly influenced by the type of a selected field lens, the standard diameter of the spot under the field lens of the selected type is set as D, and the laser frequency f, the scanning speed v and the line spacing D selected at the moment have the following corresponding relation for ensuring the proper overlap ratio:

column overlap ratio: 1-v/(f.d) ∈ (-0.1, 0.2);

row overlap ratio: 1-D/d.epsilon.0.1, 0.2.

S5, starting the ventilation equipment 9, water cooling equipment, starting the laser texturing head and the galvanometer system 5 to work, starting the laser 2, starting the laser texturing operation on the surface of the workpiece 8, collecting dust, impurities and workpiece scraps generated in the texturing process by the ventilation equipment 9, and effectively cooling the laser impact molten pool on the surface of the workpiece in time by the water cooling equipment to obtain a clean texturing appearance.

S6, after the laser texturing is finished in the set area, the laser 2 is turned off, the galvanometer system 5 stops working, the ventilation equipment 9 is turned off, the water cooling equipment is turned off, and the laser texturing operation is stopped. The roughening device may further include a DCC camera, which is connected to the control system 1 to observe the roughening effect at any time, and sends photographing data at any time to determine whether the roughening result meets a set requirement, if the roughening effect does not reach the standard, returning to step S3, resetting the process parameters of the laser roughening process, and re-roughening the surface of the workpiece 8, where in the secondary roughening process, the process parameters such as the N value, the scanning speed, etc. may be reduced correspondingly by means of the primary roughening effect.

And S7, repeating the steps S1 to S6 to finish the surface roughening of the next workpiece.

In summary, the laser texturing method and the device provided by the invention have the following technical advantages compared with the prior art:

the invention provides a method capable of improving the depth-to-width ratio range of texturing points, which can more stably control the arrangement mode of the texturing points by adjusting the motion form of a galvanometer system, obtain the depth-to-width ratio range of the texturing points in a larger range and expand the practical application range of laser texturing;

the roughening effect is good, and a plurality of continuous pulses can act on the same position through the action position of the pulse energy regulated and controlled by the movement of the vibrating mirror, so that the size of a deeper roughening point is obtained;

the action position of pulse energy is regulated and controlled through the movement of the vibrating mirror, so that a plurality of continuous pulses can be distributed together at a large overlap ratio to obtain a saw-tooth roughened surface morphology;

As mentioned above, similar technical solutions can be derived in combination with the presented solution content. However, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A laser texturing method, which is characterized in that: the laser emitted by the laser irradiates the surface of the workpiece after passing through the galvanometer system, and the control system controls the scanning speed of the X galvanometer according to the laser frequency, thereby controlling the laser pulse to continuously perform pulse impact for a plurality of times at the same position of the workpiece and/or controlling the overlap ratio between adjacent impact positions, and texturing the surface of the workpiece in the X direction.

2. A laser texturing method as claimed in claim 1, wherein: when the same texturing morphology is obtained, the laser frequency is increased, and the control system controls the rotation speed of the X-vibration mirror to be reduced.

3. A laser texturing method as claimed in claim 1, wherein: the control system adjusts and controls the rotation speed of the Y vibrating mirror and the Gaussian spot diameter and arrangement, so that the overlap ratio of the spots on the workpiece Y is within the range of (-0.3) to (-0.05).

4. A laser texturing method according to any one of claims 1 to 3, wherein: the scanning speed of the X vibrating mirror comprises an initial speed V1 and a moving speed V2, V1 is more than or equal to 0 and less than V2, and the control system controls the X vibrating mirror to rotate alternately in sequence at the initial speed V1 and the moving speed V2.

5. A method of laser texturing as recited in claim 4 wherein: after the X vibrating mirror continuously rotates for N pulses at the initial speed V1, the X vibrating mirror is controlled to continuously rotate for M pulses at the moving speed V2, and the X vibrating mirror is alternately controlled, wherein N is more than 1, and M is more than or equal to 1.

6. A laser texturing method according to claim 5, wherein: overlap ratio between adjacent impact positions = 1- (N x V sweep)/(V1 x n+d x f), where d is the spot diameter and f is the laser frequency.

7. A method of laser texturing as recited in claim 6 wherein: when the initial velocity v1=0, vbass=v2/N.

8. A method of laser texturing as recited in claim 6 wherein: when the initial velocity V1 > 0, V sweep = v1+ (V2/N).

9. A laser texturing method according to any one of claims 1 to 8, wherein: comprises the following steps of the method,

s5, starting the ventilation equipment, the water cooling equipment and the galvanometer system, starting a laser, starting the laser roughening operation on the surface of the workpiece, and controlling the system to complete X-direction scanning according to the parameters set in the step S4 and then realizing line feed scanning by controlling the rotation of the Y galvanometer;

and S6, repeating the step S5 until the laser texturing is finished in a set area, closing the laser, stopping the laser texturing head galvanometer system, closing the ventilation equipment, and water-cooling equipment, and stopping the laser texturing operation.

10. The utility model provides a laser texturing equipment, includes control system, laser instrument, isolator, galvanometer system, wherein, control system respectively with laser instrument and galvanometer system communication connection or electricity are connected, its characterized in that: a laser texturing method according to any one of claims 1 to 9.