CN109813805A - A kind of laser cleaning process monitoring method based on acoustic emission - Google Patents
A kind of laser cleaning process monitoring method based on acoustic emission Download PDFInfo
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Abstract
The laser cleaning process monitoring method based on acoustic emission that the invention discloses a kind of, the monitoring system is made of near-infrared nanosecond optical-fiber laser system of processing, data collecting card, preamplifier, signal cable and acoustic emission sensor, and principle is that the laser cleaning process based on acoustic emission monitors cleaning effect real non-destructive；Mutual mathematical relationship, the setting of real-time control laser processing parameter are obtained in cleaning effect (workpiece surface remnants corrode object amount) and sound emission signal amplitude, to realize to the online non-destructive monitoring of laser cleaning；In addition, acoustic emission sensor is directly arranged at workpiece corrosion layer surface, reduces other signal interferences, improve the reliability of the acoustic emission signal of acquisition.The structure of monitoring system and method provided by the present invention and using very simple, rationally, precision height and performance are stablized, and solve the problems, such as that existing laser cleaning technique does not have real-time detection and improves cleaning quality and efficiency.
Description
Technical field
The present invention relates to the monitoring technical field of laser cleaning process more particularly to laser cleaning process monitoring technologies.
Background technique
Laser cleaning technique is the pulsed laser radiation workpiece surface using high-peak power, makes pollutant, the rust on surface
It loses object or the coat of paint absorbs a series of variations such as moment removing or evaporation after laser energy, be finally efficiently removed from substrate.
Laser cleaning is mainly shown as that on-mechanical contact process will not to workpiece there are apparent advantage compared with conventional cleaning process
Cause mechanical damage, laser direction is good to be accurately positioned and can adapt to have in complex-curved to can realize cleaning area
The advantages that no flying dust pollution, energy conservation and environmental protection.
However laser cleaning mechanism is complicated, so far none complete mathematical model can description quantitatively it so that
Laser cleaning technique more relies on personal experience and lacks real-time analysis instrument detection process.To avoid pulsed laser irradiation
Overlong time and cause matrix surface damage or it is too short and cause residual contaminants cleaning not exclusively, to clean the surface carry out
Real-time monitoring seems still be important.It is related to the practical application of laser cleaning technique for example traditional spectral analysis technique and CCD light
The monitoring technology such as imaging technique are learned, equipment is expensive, anti-interference ability is poor, signal processing is cumbersome.Skill is monitored with sound emission (AE)
Art carries out systematic research sex work to laser cleaning field not yet, and the acoustic emission signal that laser cleaning process generates includes
Cleaning information abundant can be used for real-time monitoring and adjust laser parameter and improve cleaning effect.
Therefore, the prior art requires further improvement and perfect.
Summary of the invention
It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of structure and use simple, reasonable, precision
The high and stable laser cleaning process monitoring method based on acoustic emission of performance.
The purpose of the invention is achieved by the following technical solution:
A kind of laser cleaning process monitoring method based on acoustic emission, the monitoring method mainly include following specific
Step:
Step S1: carbon steel exemplar is placed and is located on nanosecond near infrared optical-fiber laser X/Y/Z workbench, laser pair
Coke makes light spot focus be located at carbon steel corrosion layer surface.
Step S2: and then the placement of sensor is carried out, width is carried out according to the attenuation characteristic of workpiece corrosion layer acoustic emission signal
Curved measurement test is spent, determining that sensor is coated vaseline and is arranged in apart from acoustic emission source (derusting region) length is 8mm's
On position.
Step S3: carrying out building for acoustic emission detection system, is connected sensor and preamplifier using signal cable
It connects, the output end of preamplifier is linked into PCI-2 data collecting card, and corresponding channel parameters are arranged.Finally by sound emission
Instrument is connect with display, and the display and analysis for acquiring signal are handled.
Step S4: change nanosecond near infrared laser system laser energy density, cover it is low, in, it is higher, high
(15.76J/cm2, 42.7J/cm2, 53J/cm2, 72.1J/cm2) four kinds of typical energies, other parameters remain unchanged.To identical
The corrosion layer of thickness carries out square region lasing area scanning machining three times.Sound emission using acoustic emission system to synchronous acquisition
Range signal is handled, according to amplitude versus time scatter diagram with scanning times variation determine laser cleaning effect with
Quality, every kind of energy density carry out the laser cleaning process of Surface scan three times and observe effect after cleaning.
In addition, high, normal, basic three kinds of exemplary energy density (15.76J/cm2, 42.7J/cm2, 53J/cm2, 72.1J/cm2),
Specifically 4 kinds of different energy densities, wherein 53J/cm2, be laser carry out second of square region cleaning process incited somebody to action
The corrosion layer on carbon steel surface removes substantially, and third time square region cleaning process laser starts to act on rustless steel substrate surface,
So can find out the third time sound emission range signal signal band similar with comparison diagram 2, this energy density is both to clean
The end that can be used as laser cleaning process when the range signal feature that experimental result comparison or the inside occur judges in advance.
Step S5: the cleaning process low for energy density observes the remaining a large amount of rust of workpiece surface.Work as energy
When metric density reaches medium, cleaning effect is obvious, and black splotch, which thoroughly removes, is presented substrate original color.When energy density reaches
To it is higher when, corrosion layer completely remove and substrate color occur it is faint yellow, removal efficiency is more preferable.All removal swashs Surface Rust
Light starts to act on steel substrate surface.Thermal damage, surface are presented dark yellow and lose original base by substrate surface under high-energy density
The color of body.
Step S6: the generation of sound emission amplitude scatterplot signal is reacted from laser and Surface Rust.According to step S4's
Surface corrosion layer residual volume and substrate surface pattern are it is found that when low laser energy, and corrosion layer removal ability is lower, signal characteristic
The distribution of inactive and scatterplot has no apparent variation.
Step S7: the increase of laser energy shows that corrosion layer removal efficiency improves, and amplitude scatterplot divergent trend more shifts to an earlier date.
Scatterplot distributed number is fewer simultaneously, along with the reduction of rust residual volume, the reaction severity of laser and corrosion layer compared with
It is low.Amplitude is constantly decreased near 45dB.
Step S8: being 53J/cm in energy density2When, workpiece surface rusty scale is all gone after cleaning by second
It removes.In the range signal appearance one of third time scanning process and laser action in rustless substrate surface, and it is parallel to X-axis
Scatterplot signal band illustrates that laser starts to act on steel substrate surface.The appearance of this range signal feature can be used as laser cleaning mistake
Judgement before the end of journey.
Step S9: in highest energy density 72.1J/cm2When, signal scatterplot numerical value is larger, and the degree of diverging is further
It improves and starts to present in square region cleaning process of laser alignment, illustrate that removal effect is best.In second and third time
Cleaning process observes that the distribution of signal amplitude scatterplot can be merged into the signal band that aggregation rises by diverging, observes steel at this time
There is color transition under high-temperature oxydation in material surface, and the color that dark yellow loses original matrix is presented in surface.Signal band is as steel
Material surface laser overclean and cause serious thermal damage.
Step S10: passed through according to the relationship of step S4 and step S5 in conjunction with three kinds of amplitude scatterplot signal characteristics of appearance
Relationship, signal scatterplot distributional pattern and the cleaning effect of sound emission range signal and scanning times are analyzed, including is cleaned not complete
Entirely, rust removes substantially and overclean causes ablation, and is combined into the surface shape after cleaning under different-energy density
Looks are used to monitor the anticipation of laser cleaning process for acoustic emission.
As a preferred solution of the present invention, it is contemplated that laser cleaning process influences the most important ginseng of rust removal mechanisms at work
Number is laser energy, selects different laser energy density, the effect for the condition control cleaning process that other parameters remain unchanged,
Simultaneously for convenience of detecting, rectangular area size is set as 12mm*12mm in step S4 of the present invention.
As a preferred solution of the present invention, channel parameters are set as in the step S3: signal gain 40dB, data sampler
Sample rate 5MHz；According to the material property of carbon steel work-piece: when peak value defines time 300 μ s, Hit (impact event) definition
Between 600 μ s and Hit blocking time, 1000 μ s, while sound emission acquisition threshold be set as 30dB.
As a preferred solution of the present invention, the other parameters in the step S4 are as follows: repetition rate 10khz, pulse width
200ns, scanning speed 240mm/s, laser beam overlap ratio 40%.
As a preferred solution of the present invention, in the step S6 numerical values recited of scatterplot signal between 30~80dB.
The invention also discloses a kind of laser cleaning process monitoring system based on acoustic emission, monitoring system master
Will include near-infrared nanosecond optical-fiber laser system of processing, data collecting card, two preamplifiers, two acoustic emission sensors,
And computer.The near-infrared nanosecond optical-fiber laser system of processing includes scanning galvanometer, nanosecoud pulse laser, for controlling
The control system of nanosecoud pulse laser processed and the optical path component for being used for transmission laser.The data collecting card is mounted on meter
On calculation machine.
Specifically, the acoustic emission sensor is mounted in the rust of workpiece, output channel and preamplifier
Input channel connection；The output channel of the preamplifier is by having the signal cable for inhibiting electromagnetic noise to be connected to number
According to the input channel of capture card；It cleans collected acoustic emission signal and data collecting card is entered by the above device, be equipped with
The display of AEwin software based on PCI-2 system carries out signal processing and analyzing.
Compared with prior art, it also have the advantage that
(1) acoustic emission sensor of the laser cleaning process monitoring method provided by the present invention based on acoustic emission
It is directly arranged at workpiece corrosion layer surface, other signal interferences is reduced, improves the reliability of the acoustic emission signal of acquisition.
(2) the laser cleaning process monitoring method provided by the present invention based on acoustic emission can be studied in difference
Under laser energy or other technological parameters, the otherness and its Precursor Law of the sound emission signal characteristic of different cleaning effects.
(3) the laser cleaning process monitoring method provided by the present invention based on acoustic emission, structure is simple, existing
Lay with it is easy to operate, and use scope extensively, can accurately and effectively detect different types of laser cleaning process, most
After can also be evaluated for cleaning effect.
(4) object that the laser cleaning process monitoring method provided by the present invention based on acoustic emission is monitored is not
Be limited only to carbon steel rusty scale, can also monitor other laser cleaning techniques (include derusting, paint removal, oxide film dissolving, except micro-
Grain pollutant degreases).
(5) sound emission range signal provided by the present invention derives from the effect of laser and pollutant, has visualization
Height, signal are easily understood, and are easy to the advantage judged, detect laser cleaning mistake with traditional utilization machine vision or image recognition
Journey is compared to more conducively real-time monitoring cleaning effect and makes anticipation step, and equipment is relatively inexpensive, and signal processing is succinct.
Detailed description of the invention
Fig. 1 is the schematic illustration of the laser cleaning process monitoring method provided by the present invention based on acoustic emission.
Fig. 2 is 53J/cm2The sound emission range signal schematic diagram of laser action under energy density in rustless steel substrate.
Fig. 3 is that the attenuation characteristic of workpiece corrosion layer acoustic emission signal carries out amplitude curve measurement result figure.
Fig. 4 is range signal-time diagram of different-energy density laser cleaning process three times.
Fig. 5 is the steel surface shape appearance figure after different-energy density laser cleans three times.
The meaning of above-mentioned attached drawing Chinese and English illustrates:
Amp AE/Amplitude: signal amplitude；Distance: acoustic emission source between sensor at a distance from；
Preamplifier: preamplifier；Digital acquisition card: Data Acquisition Card；Signal cable: signal
Cable；Scanning galvanometer: scanning galvanometer；Pulsed laser: nanosecoud pulse laser；controlled
System: laser processing parameter control system.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention clearer and more explicit, as follows in conjunction with drawings and embodiments
The invention will be further described.
Embodiment 1:
As shown in Figures 1 to 5, present embodiment discloses a kind of laser cleaning process monitoring side based on acoustic emission
Method, the monitoring method mainly comprise the following specific steps that:
Step S1: carbon steel exemplar is placed and is located on nanosecond near infrared optical-fiber laser X/Y/Z workbench, laser pair
Coke makes light spot focus be located at carbon steel corrosion layer surface.
Step S2: and then the placement of sensor is carried out, width is carried out according to the attenuation characteristic of workpiece corrosion layer acoustic emission signal
Curved measurement test is spent, determining that sensor is coated vaseline and is arranged in apart from acoustic emission source (derusting region) length is 8mm's
On position.
Step S3: carrying out building for acoustic emission detection system, is connected sensor and preamplifier using signal cable
It connects, the output end of preamplifier is linked into PCI-2 data collecting card, and corresponding channel parameters are arranged.Finally by sound emission
Instrument is connect with display, and the display and analysis for acquiring signal are handled.
Step S4: change nanosecond near infrared laser system laser energy density, cover it is low, in, it is higher, high
(15.76J/cm2, 42.7J/cm2, 53J/cm2, 72.1J/cm2) four kinds of typical energies, other parameters remain unchanged.To identical
The corrosion layer of thickness carries out square region lasing area scanning machining three times.Sound emission using acoustic emission system to synchronous acquisition
Range signal is handled, according to amplitude versus time scatter diagram with scanning times variation determine laser cleaning effect with
Quality, every kind of energy density carry out the laser cleaning process of Surface scan three times and observe effect after cleaning.
In addition, high, normal, basic three kinds of exemplary energy density (15.76J/cm2, 42.7J/cm2, 53J/cm2, 72.1J/cm2),
Specifically 4 kinds of different energy densities, wherein 53J/cm2, it is that laser is carrying out second of square region cleaning process by carbon
The corrosion layer of steel surface removes substantially, and third time square region cleaning process laser starts to act on rustless steel substrate surface, institute
Can find out the third time sound emission range signal signal band similar with comparison diagram 2, this energy density is both to clean reality
The end that can be used as laser cleaning process when testing the range signal feature that Comparative result or the inside occur judges in advance.
Step S5: the cleaning process low for energy density observes the remaining a large amount of rust of workpiece surface.Work as energy
When metric density reaches medium, cleaning effect is obvious, and black splotch, which thoroughly removes, is presented substrate original color.When energy density reaches
To it is higher when, corrosion layer completely remove and substrate color occur it is faint yellow, removal efficiency is more preferable.All removal swashs Surface Rust
Light starts to act on steel substrate surface.Thermal damage, surface are presented dark yellow and lose original base by substrate surface under high-energy density
The color of body.
Step S6: the generation of sound emission amplitude scatterplot signal is reacted from laser and Surface Rust.According to step S4's
Surface corrosion layer residual volume and substrate surface pattern are it is found that when low laser energy, and corrosion layer removal ability is lower, signal characteristic
The distribution of inactive and scatterplot has no apparent variation.
Step S7: the increase of laser energy shows that corrosion layer removal efficiency improves, and amplitude scatterplot divergent trend more shifts to an earlier date.
Scatterplot distributed number is fewer simultaneously, along with the reduction of rust residual volume, the reaction severity of laser and corrosion layer compared with
It is low.Amplitude is constantly decreased near 45dB.
Step S8: being 53J/cm in energy density2When, workpiece surface rusty scale is all gone after cleaning by second
It removes.In the range signal appearance one of third time scanning process and laser action in rustless substrate surface, and it is parallel to X-axis
Scatterplot signal band illustrates that laser starts to act on steel substrate surface.The appearance of this range signal feature can be used as laser cleaning mistake
Judgement before the end of journey.
Step S9: in highest energy density 72.1J/cm2When, signal scatterplot numerical value is larger, and the degree of diverging is further
It improves and starts to present in square region cleaning process of laser alignment, illustrate that removal effect is best.In second and third time
Cleaning process observes that the distribution of signal amplitude scatterplot can be merged into the signal band that aggregation rises by diverging, observes steel at this time
There is color transition under high-temperature oxydation in material surface, and the color that dark yellow loses original matrix is presented in surface.Signal band is as steel
Material surface laser overclean and cause serious thermal damage.
Step S10: passed through according to the relationship of step S4 and step S5 in conjunction with three kinds of amplitude scatterplot signal characteristics of appearance
Relationship, signal scatterplot distributional pattern and the cleaning effect of sound emission range signal and scanning times are analyzed, including is cleaned not complete
Entirely, rust removes substantially and overclean causes ablation, and is combined into the surface shape after cleaning under different-energy density
Looks are used to monitor the anticipation of laser cleaning process for acoustic emission.
As a preferred solution of the present invention, it is contemplated that laser cleaning process influences the most important ginseng of rust removal mechanisms at work
Number is laser energy, selects different laser energy density, the effect for the condition control cleaning process that other parameters remain unchanged,
Simultaneously for convenience of detecting, rectangular area size is set as 12mm*12mm in step S4 of the present invention.
As a preferred solution of the present invention, channel parameters are set as in the step S3: signal gain 40dB, data sampler
Sample rate 5MHz；According to the material property of carbon steel work-piece: when peak value defines time 300 μ s, Hit (impact event) definition
Between 600 μ s and Hit blocking time, 1000 μ s, while sound emission acquisition threshold be set as 30dB.
As a preferred solution of the present invention, the other parameters in the step S4 are as follows: repetition rate 10khz, pulse width
200ns, scanning speed 240mm/s, laser beam overlap ratio 40%.
As a preferred solution of the present invention, in the step S6 numerical values recited of scatterplot signal between 30~80dB.
The invention also discloses a kind of laser cleaning process monitoring system based on acoustic emission, monitoring system master
Will include near-infrared nanosecond optical-fiber laser system of processing, data collecting card, two preamplifiers, two acoustic emission sensors,
And computer.The near-infrared nanosecond optical-fiber laser system of processing includes scanning galvanometer, nanosecoud pulse laser, for controlling
The control system of nanosecoud pulse laser processed and the optical path component for being used for transmission laser.The data collecting card is mounted on meter
On calculation machine.
Specifically, the acoustic emission sensor is mounted in the rust of workpiece, output channel and preamplifier
Input channel connection；The output channel of the preamplifier is by having the signal cable for inhibiting electromagnetic noise to be connected to number
According to the input channel of capture card；It cleans collected acoustic emission signal and data collecting card is entered by the above device, be equipped with
The display of AEwin software based on PCI-2 system carries out signal processing and analyzing.
Embodiment 2:
As shown in Fig. 1 to 5, present embodiment discloses a kind of structure and using simply, rationally, precision height and performance are stablized
A kind of pulse laser cleaning process in acoustic emission monitor(ing) method, do not have real-time inspection to solve existing laser cleaning technique
Survey and improve the problem of cleaning quality and efficiency.
To achieve the above object, the present invention adopts the following technical scheme that:
(1) the pulse laser cleaning process real-time monitoring system based on acoustic emission, is shown in Fig. 1, it is characterised in that: packet
Include near-infrared nanosecond optical-fiber laser system of processing, PCI-2 data collecting card, two preamplifiers, two sound emission nano-
30 resonant transducers；Acoustic emission sensor is mounted in the rust of workpiece, the output channel and preamplifier of sensor
Input channel connection, the output channel of preamplifier passes through the signal cable with inhibition electromagnetic noise and is connected to data
The input channel of capture card.It cleans collected acoustic emission signal and data collecting card is entered by the above device, be equipped with base
Signal processing and analyzing is carried out in the display of the AEwin software of PCI-2 system；
(2) in terms of test material, for the Q235 steel board of use with a thickness of 1mm, material surface is thick by drawing light processing surface
Rugosity Ra value is 0.3 μm, and exemplar is set and is soaked in tap water, guarantees that moist outdoor environment places a month rear surface shape
At corrosion, about 45 μm of corrosion layer thickness, it is B grades that rusting grade, which occurs, for surface；
(3) in terms of laser technical parameters, it is contemplated that it is most important that laser cleaning process influences rust removal mechanisms at work
Parameter is laser energy, selects different laser energy density, the effect for the condition control cleaning process that other parameters remain unchanged
Fruit.For convenience of detection, the fixed region of the corrosion layer to workpiece carries out the rectangular area scanning of 12mm*12mm three times；
The characterization and analysis aspect of acoustic emission signal, rise form judgement according to signal amplitude and time relationship and scatterplot
Cleaning effect under different laser energy density.As surface corrosion object is removed by series reaction, corresponding sound hair
Penetrating signal intensity, there are three obvious characteristics: (1) variation of signal scatterplot quantity: by up to few (rusty scale on carbon steel surface is reduced)
(2) numerical value and slope of signal scatterplot overall distribution: (reduction of rust causes swashing for laser action carbon steel to the trend of attenuating
Strong degree reduces) Divergent Phenomenon of (3) scatterplot (increases laser energy density away rust by laser effect to be more obvious, believe in a certain range
The phenomenon that number scatterplot diverging, more shifts to an earlier date).
Specifically comprise the following steps:
(1) firstly, the surface corrosion layer prepared is placed with a thickness of 45 μm of carbon steel exemplar and to be located in nanosecond closely red
On infrared optical fiber laser X/Y/Z workbench, laser focusing makes light spot focus be located at carbon steel corrosion layer surface；
(2) placement for then carrying out sensor, is surveyed according to the attenuation characteristic amplitude curve of workpiece corrosion layer acoustic emission signal
Amount test, measurement result are shown in Fig. 3, determine that sensor is coated vaseline and is arranged in apart from acoustic emission source (derusting region) length
For the position of 8mm；
(3) it carries out acoustic emission detection system according to Fig. 1 building, using signal cable by sensor and preamplifier
Connection, the output end of preamplifier is linked into PCI-2 data collecting card, and corresponding channel parameters: signal gain are arranged
40dB, data sampler sample rate 5MHz；According to the material property of carbon steel work-piece: peak value defines time 300 μ s, Hit and defines the time
600 μ s and Hit blocking time, 1000 μ s, while sound emission acquisition threshold is set as 30dB；Finally by Acoustic radiating instrument and display
Connection, display and analysis for acquiring signal are handled；
(4) laser energy density for changing nanosecond near infrared laser system, covers low middle height (15.76J/cm2, 42.7J/
cm2, 53J/cm2, 72.1J/cm2) three kinds of typical energies, other parameters remain unchanged (repetition rate 10khz, pulse width
200ns, scanning speed 240mm/s, laser beam overlap ratio 40%).12mm*12mm three times is carried out to 45 μm of same thickness of corrosion layers
Square region lasing area scanning machining.It is handled using sound emission range signal of the acoustic emission system to synchronous acquisition, according to
Amplitude-time scatter diagram with scanning times variation determine laser cleaning effect (every kind of energy density is equal with quality
It carries out the laser cleaning process of Surface scan three times and observes effect after cleaning)；
(5) for energy density (15.76J/cm2) low cleaning process, observe the remaining a large amount of corrosion of workpiece surface
Object；As energy density (42.7J/cm2) when reaching medium, cleaning effect is obvious, and black splotch thoroughly removes that substrate is presented is original
Color；Slightly increase energy (53J/cm2) when, corrosion layer completely removes and substrate color appearance is faint yellow, and removal efficiency is more
It is good.All removal laser starts to act on steel substrate surface Surface Rust；High-energy density (72.1J/cm2) under substrate surface
By thermal damage, the color that dark yellow loses original matrix is presented in surface；See Fig. 5；
(6) generation of sound emission amplitude scatterplot signal reacting from laser and Surface Rust.See Fig. 4 (in figure,
Gradual decrease of rust layer indicates that corrosion layer gradually subtracts；Appearance of steel substrate
Indicate that steel substrate surface starts to appear)；According to the surface corrosion layer residual volume of step (5) and substrate surface pattern it is found that laser
(15.76J/cm when energy is lower2) corrosion layer removal ability is lower, signal characteristic is inactive and scatterplot distribution have no it is apparent
Variation, between 30~80dB；
(7) increase (42.7J/cm of laser energy2) show that corrosion layer removal efficiency improves, amplitude scatterplot divergent trend
More shift to an earlier date；Scatterplot distributed number is fewer simultaneously, and along with the reduction of rust residual volume, laser and reacting for corrosion layer are fierce
Degree is lower；Amplitude is constantly decreased near 45dB；
It (8) is 53J/cm in energy density2When, workpiece surface rusty scale all removes after cleaning by second.?
It is similar in rustless substrate surface with laser action that the range signal of third time scanning process occurs one, and is parallel to dissipating for X-axis
Point signal band, is shown in Fig. 2, illustrates that laser starts to act on steel substrate surface.It is clear that the appearance of this range signal feature can be used as laser
Judgement before washing the end of journey；
(9) according to the relationship of step (5) and step (6), in conjunction with three kinds of amplitude scatterplot signal characteristics of appearance, by dividing
Relationship, signal scatterplot distributional pattern and the cleaning effect of analysis sound emission range signal and scanning times, including cleaning be not complete,
Rust removes substantially and overclean causes ablation, in conjunction with the surface being illustrated in figure 5 after cleaning under different-energy density
Pattern can be used for acoustic emission for monitoring the anticipation of laser cleaning process.
The above embodiment is a preferred embodiment of the present invention, but embodiments of the present invention are not by above-described embodiment
Limitation, it is other it is any without departing from the spirit and principles of the present invention made by change, modification, substitution, combination, letter
Change, should be equivalent substitute mode, be included within the scope of the present invention.
Claims (5)
1. a kind of laser cleaning process monitoring method based on acoustic emission, which comprises the steps of:
Step S1: carbon steel exemplar is placed and is located on nanosecond near infrared optical-fiber laser X/Y/Z workbench, and laser focusing makes light
Spot focus is located at carbon steel corrosion layer surface；
Step S2: and then the placement of sensor is carried out, it is bent to carry out amplitude according to the attenuation characteristic of workpiece corrosion layer acoustic emission signal
Line measurement test determines that sensor is coated vaseline and is arranged in apart from the position that acoustic emission source (derusting region) length is 8mm
On；
Step S3: carrying out building for acoustic emission detection system, is connect sensor with preamplifier using signal cable, preposition
The output end of amplifier is linked into PCI-2 data collecting card, and corresponding channel parameters are arranged；Finally by Acoustic radiating instrument and display
Device connection, display and analysis for acquiring signal are handled；
Step S4: changing the laser energy density of nanosecond near infrared laser system, cover it is low, in, higher, high (15.76J/cm2,
42.7J/cm2, 53J/cm2, 72.1J/cm2) four kinds of Typical laser energy, other parameters remain unchanged；Corrosion to same thickness
Layer carries out square region lasing area scanning machining three times；It is carried out using acoustic emission signal amplitude of the acoustic emission system to synchronous acquisition
Processing, determines the effect and quality of laser cleaning according to amplitude versus time scatter diagram with the signal intensity of scanning times, every kind
Energy density carries out the laser cleaning process of Surface scan three times and observes effect after cleaning；
Step S5: the cleaning process low for energy density observes the remaining a large amount of rust of workpiece surface；Work as energy density
When reaching medium, cleaning effect is obvious, and black splotch, which thoroughly removes, is presented substrate original color；When energy density reaches higher
When, corrosion layer completely removes and substrate color appearance is faint yellow, and removal efficiency is more preferable；All removal laser starts to make Surface Rust
For steel substrate surface；The color that dark yellow loses original matrix is presented in thermal damage, surface by substrate surface under high-energy density；
Step S6: the generation of sound emission amplitude scatterplot signal is reacted from laser and Surface Rust；According to the surface of step S4
Corrosion layer residual volume and substrate surface pattern are it is found that when low laser energy, and corrosion layer removal ability is lower, and signal characteristic is inactive
And scatterplot distribution has no apparent variation；
Step S7: the increase of laser energy shows that corrosion layer removal efficiency improves, and amplitude scatterplot divergent trend more shifts to an earlier date；It dissipates simultaneously
Point distributed number is fewer, and along with the reduction of rust residual volume, the reaction severity of laser and corrosion layer is lower；Amplitude is not
It is disconnected to be decreased near 45dB；
Step S8: being 53J/cm in energy density2When, workpiece surface rusty scale all removes after cleaning by second；?
The range signal appearance one of scanning process and laser action are in rustless substrate surface three times, and are parallel to the scatterplot signal of X-axis
Band illustrates that laser starts to act on steel substrate surface；The appearance of this range signal feature can be used as the end of laser cleaning process
Preceding judgement；
Step S9: in highest energy density 72.1J/cm2When, signal scatterplot numerical value is larger, the degree of diverging further increase and
Start to present in square region cleaning process of laser alignment, illustrates that removal effect is best；It was cleaned in second and third time
Journey observes that the distribution of signal amplitude scatterplot can be merged into the signal band that aggregation rises by diverging, observes that steel surface exists at this time
Occurs color transition under high-temperature oxydation, the color that dark yellow loses original matrix is presented in surface；Signal band swashs as steel surface
Light overclean and cause serious thermal damage；
Step S10: analysis is passed through in conjunction with three kinds of amplitude scatterplot signal characteristics of appearance according to the relationship of step S4 and step S5
The relationship of sound emission range signal and scanning times, signal scatterplot distributional pattern and cleaning effect, including cleaning be not complete, corrosion
Object removes substantially and overclean causes ablation, and is combined into the surface topography after cleaning under different-energy density, is used for sound
Lift-off technology is used to monitor the anticipation of laser cleaning process.
2. the laser cleaning process monitoring method according to claim 1 based on acoustic emission, which is characterized in that described
Rectangular area size is set as 12mm*12mm in step S4.
3. the laser cleaning process monitoring method according to claim 1 based on acoustic emission, which is characterized in that described
Channel parameters are set as in step S3: signal gain 40dB, data sampler sample rate 5MHz；According to the material property of carbon steel work-piece:
Peak value defines time 300 μ s, Hit (impact event) and defines 600 μ s and Hit blocking time of time, 1000 μ s, while sound
Transmitting acquisition threshold is set as 30dB.
4. the laser cleaning process monitoring method according to claim 1 based on acoustic emission, which is characterized in that described
Other parameters in step S4 are as follows: repetition rate 10khz, pulse width 200ns, scanning speed 240mm/s, laser beam overlap ratio
40%.
5. the laser cleaning process monitoring method according to claim 1 based on acoustic emission, which is characterized in that described
The numerical values recited of scatterplot signal is between 30~80dB in step S6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910082208.5A CN109813805B (en) | 2019-01-28 | 2019-01-28 | Laser cleaning process monitoring method based on acoustic emission technology |
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| CN110653223A (en) * | 2019-09-26 | 2020-01-07 | 厦门理工学院 | Laser cleaning monitoring device and monitoring method thereof and laser cleaning machine |
| CN111495883A (en) * | 2020-04-24 | 2020-08-07 | 武汉大学 | Device and method for carrying out deoxidation treatment on Be window of radiation detector |
| CN112255191A (en) * | 2020-09-25 | 2021-01-22 | 广东工业大学 | Laser-induced breakdown spectroscopy and acoustic reflection combined online monitoring system and method |
| CN113649361A (en) * | 2021-08-18 | 2021-11-16 | 沈阳工业大学 | Laser cleaning quality online detection system and method based on heat flux |
| CN113758939A (en) * | 2020-06-04 | 2021-12-07 | 中国科学院大连化学物理研究所 | Method for representing metal surface cleanliness by using metal surface reflection and scattering spectrum |
| CN114345840A (en) * | 2021-12-29 | 2022-04-15 | 北京航空航天大学合肥创新研究院(北京航空航天大学合肥研究生院) | Online optimization method for energy density in process of cleaning high-temperature oxide layer on surface of stainless steel by pulse laser |
| CN114608660A (en) * | 2022-03-28 | 2022-06-10 | 上海建冶科技股份有限公司 | Real-time monitoring system for laser rust removal process |
| CN114689564A (en) * | 2022-03-29 | 2022-07-01 | 上海建冶科技股份有限公司 | Laser derusting state detection method |
| CN115055846A (en) * | 2022-07-22 | 2022-09-16 | 广东工业大学 | Laser-stripped crystal ingot real-time monitoring system and method |
| TWI820397B (en) * | 2021-02-25 | 2023-11-01 | 宏惠光電股份有限公司 | Dry laser cleaning equipment and procedures |
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| CN110653223A (en) * | 2019-09-26 | 2020-01-07 | 厦门理工学院 | Laser cleaning monitoring device and monitoring method thereof and laser cleaning machine |
| CN111495883A (en) * | 2020-04-24 | 2020-08-07 | 武汉大学 | Device and method for carrying out deoxidation treatment on Be window of radiation detector |
| CN111495883B (en) * | 2020-04-24 | 2021-06-15 | 武汉大学 | Device and method for carrying out deoxidation treatment on Be window of radiation detector |
| CN113758939B (en) * | 2020-06-04 | 2022-10-18 | 中国科学院大连化学物理研究所 | Method for representing metal surface cleanliness by using metal surface reflection and scattering spectrum |
| CN113758939A (en) * | 2020-06-04 | 2021-12-07 | 中国科学院大连化学物理研究所 | Method for representing metal surface cleanliness by using metal surface reflection and scattering spectrum |
| CN112255191A (en) * | 2020-09-25 | 2021-01-22 | 广东工业大学 | Laser-induced breakdown spectroscopy and acoustic reflection combined online monitoring system and method |
| TWI820397B (en) * | 2021-02-25 | 2023-11-01 | 宏惠光電股份有限公司 | Dry laser cleaning equipment and procedures |
| CN113649361A (en) * | 2021-08-18 | 2021-11-16 | 沈阳工业大学 | Laser cleaning quality online detection system and method based on heat flux |
| CN114345840A (en) * | 2021-12-29 | 2022-04-15 | 北京航空航天大学合肥创新研究院(北京航空航天大学合肥研究生院) | Online optimization method for energy density in process of cleaning high-temperature oxide layer on surface of stainless steel by pulse laser |
| CN114608660A (en) * | 2022-03-28 | 2022-06-10 | 上海建冶科技股份有限公司 | Real-time monitoring system for laser rust removal process |
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| CN115055846A (en) * | 2022-07-22 | 2022-09-16 | 广东工业大学 | Laser-stripped crystal ingot real-time monitoring system and method |
| CN115055846B (en) * | 2022-07-22 | 2024-06-11 | 广东工业大学 | Real-time monitoring system and method for laser stripped ingot |
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